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Calculation of reaction apparatus for the production of explosives. Calculation of the consequences of an explosion inside technological equipment

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RESOLUTION of the Gosgortekhnadzor of the Russian Federation dated 05-05-2003 29 ON APPROVAL OF THE GENERAL RULES OF EXPLOSION SAFETY FOR EXPLOSIVE AND FIRE HAZARDOUS ... Relevant in 2018

4.6. Chemical reaction processes

4.6.1. Technological systems that combine several processes (hydrodynamic, heat and mass transfer, reaction) are equipped with devices for monitoring regulated parameters. The means of control, regulation and emergency protection must ensure the stability and explosion safety of the process.

4.6.2. Technological equipment for reaction processes for blocks of any explosion hazard categories is equipped with automatic control, regulation and protective interlocks for one or a group of parameters that determine the explosiveness of the process (the amount and ratio of incoming starting substances, the content of components in material flows, the concentration of which in the reaction equipment can reach critical values, pressure and temperature of the medium, quantity, flow rate and parameters of the coolant, etc.). At the same time, the process equipment, which is part of the plant with process units of explosion category I, is equipped with at least two sensors for each dangerous parameter (for dependent parameters, one sensor for each), control and emergency automatic protection, and, if necessary, redundant systems management and protection.

4.6.3. The operation of automatic emergency protection systems should be carried out according to specified programs (algorithms).

4.6.4. In reaction process control systems in process units with QB<= 10, допускается использование средств ручного регулирования при условии автоматического контроля опасных параметров и сигнализации, срабатывающей при выходе их за допустимые значения.

4.6.5. In reaction processes proceeding with the possible formation of intermediate peroxide compounds, by-products of explosive resinification and compaction (polymerization, polycondensation) and other unstable substances with their possible deposition in equipment and pipelines, the following are provided:

monitoring the content of impurities in the incoming raw materials that contribute to the formation of explosive substances, as well as the presence of unstable compounds in intermediate products and ensuring the specified mode;

introduction of inhibitors that exclude the formation of dangerous concentrations of unstable substances in the equipment; fulfillment of special requirements for the quality of the structural materials used and the cleanliness of the surface treatment of apparatuses, pipelines, fittings, sensors of devices in contact with the products circulating in the process;

continuous circulation of products, raw materials in capacitive equipment to prevent or reduce the possibility of deposition of solid explosive unstable products;

withdrawal of the reaction mass enriched with dangerous components from the equipment;

ensuring the established modes and time of storage of products that can polymerize or resin, including the timing of their transportation.

The choice of necessary and sufficient conditions for the organization of the process is determined by the developer of the process.

The methods and frequency of monitoring the content of impurities in raw materials, unstable compounds in the reaction mass of intermediate and final products, the procedure for withdrawing the reaction mass containing hazardous by-products, the modes and time of storage of products are established by the process developer, are reflected in the design documentation and production procedures.

4.6.6. If there is a possibility of deposits of solid products on the internal surfaces of equipment and pipelines, their clogging, including emergency drain devices from process systems, control over the presence of these deposits and measures for their safe removal, and, if necessary, backup equipment are provided.

4.6.7. When using catalysts, including organometallic ones, which, when interacting with atmospheric oxygen and (or) water, can ignite spontaneously and (or) explode, it is necessary to provide measures that exclude the possibility of supplying raw materials, materials and inert gas containing oxygen and (or) moisture in quantities exceeding the maximum allowable values. Permissible concentrations of oxygen and moisture, methods and frequency of control over their content in the initial products are determined taking into account the physicochemical properties of the catalysts used, the explosion hazard category of the technological unit and are regulated.

4.6.8. The dosage of components in reaction processes should be predominantly automatic and carried out in a sequence that excludes the possibility of the formation of explosive mixtures inside the equipment or an uncontrolled course of reactions, which is determined by the developer of the process.

4.6.9. To exclude the possibility of overheating of the substances involved in the process, their self-ignition or thermal decomposition with the formation of explosive and flammable products as a result of contact with heated elements of the equipment, temperature conditions, optimal product movement rates, and the maximum allowable time for their stay in the high temperature zone are determined and regulated.

4.6.10. To eliminate the danger of uncontrolled development of the process, measures should be taken to stabilize it, emergency localization or release of devices.

4.6.11. The use of the residual pressure of the medium in the batch reactor for transferring the reaction mass into another apparatus is allowed in separate, justified cases.

4.6.12. The equipment of liquid-phase processes is equipped with systems for monitoring and regulating the liquid level in it and (or) means for automatically shutting off the supply of this liquid to the equipment when a predetermined level is exceeded or other means that exclude the possibility of overflow.

4.6.13. Reaction apparatus for explosive technological processes with agitators, as a rule, are equipped with means of automatic control over the reliable operation and tightness of the agitator shaft seals, as well as interlocks that prevent the possibility of loading products into the equipment when the agitators are not working, in cases where this is required by the conditions of the process and security.

4.6.14. Reaction equipment, in which the removal of excess reaction heat during heat transfer through the wall is carried out due to the evaporation of the cooling liquid (refrigerant), is equipped with means of automatic control, regulation and signaling of the refrigerant level in the heat exchange elements.

4.6.15. In systems for cooling reaction equipment with liquefied gases:

the temperature of the refrigerant (boiling point of liquefied gas) is ensured by maintaining an equilibrium pressure, the value of which must be automatically adjusted;

measures are provided that automatically ensure the release (drain) of the refrigerant from the heat exchange elements of the reaction apparatus, as well as measures that exclude the possibility of increasing the pressure above the permissible level in the cooling systems in the event of its sudden shutdown.

4.6.16. Development and implementation of reaction processes in the production or use of products characterized by high explosiveness (acetylene, ethylene at high parameters, peroxide, organometallic compounds, etc.), prone to thermal decomposition or spontaneous spontaneous polymerization, self-heating, and also capable of self-ignition or explosion upon interaction with water and air, should be carried out taking into account these properties and provide for additional special security measures.

CALCULATION OF THE CONSEQUENCES OF THE EXPLOSION

INSIDE THE PROCESS EQUIPMENT

The development of the chemical industry is accompanied by an increase in the scale of production, the capacity of installations and apparatuses, and the complication of technological processes and production control modes. Due to the complexity and increase in production, the resulting accidents have increasingly serious consequences. Of particular danger are chemical, explosive industries, nuclear power plants, warehouses of explosive and flammable substances, ammunition, as well as vessels and tanks intended for the storage and transportation of petroleum products and liquefied gases.

Currently, the world is increasingly paying attention to the issues of ensuring a high level of environmental protection, life safety and labor protection. One of the possible ways to reduce the risk of emergencies at industrial facilities is the analysis of accidents that have occurred. On their basis, measures are developed to prevent the occurrence of accidents and prevent dangerous consequences.

One of the types of accidents at industrial facilities are explosions of process equipment. The explosion of equipment carries a potential danger of injury to people and has a destructive ability.

An explosion (explosive transformation) is a process of rapid physical or chemical transformation of a substance, accompanied by the transition of the potential energy of this substance into mechanical energy of motion or destruction. Depending on the type of energy carrier and the conditions of energy release during an explosion, chemical and physical sources of energy are distinguished.

A physical explosion can be caused by the sudden destruction of a vessel with a compressed gas or superheated liquid, mixing of superheated solids (melt) with cold liquids, etc.

The source of a chemical explosion is fast self-accelerating exothermic reactions of the interaction of combustible substances with oxidizers or thermal decomposition of unstable compounds.

Physical explosions in equipment

Physical explosions are usually associated with explosions of vessels from the pressure of gases or vapors.

In chemical technology, it is often necessary to deliberately compress both inert and combustible gases, while expending electrical, thermal or other forms of energy. At the same time, compressed gas (steam) is located in sealed apparatuses of various geometric shapes and volumes. However, in some cases, the compression of gases (vapors) in technological systems occurs by chance due to the excess of the regulated rate of heating of the liquid by the external coolant.

When pressure vessels explode, strong shock waves can be generated, a large number of fragments are formed, which leads to serious damage and injuries. In this case, the total energy of the explosion is converted mainly into the energy of the shock wave and the kinetic energy of the fragments.

Many liquids are stored or used under conditions where their vapor pressure is much higher than atmospheric pressure. The energy of liquid overheating can be a source of purely physical explosions, for example, during intensive mixing of liquids with different temperatures, during contact of a liquid with metal melts and heated solids. In this case, chemical transformations do not occur, and the overheating energy is spent on vaporization, which can proceed at such a speed that a shock wave arises. The mass of vapors formed and the rate of vaporization are determined by the material and heat balances of two possible models of emergency situations: 1) heat release with vaporization occurs at a constant volume; 2) heat release while maintaining volume is followed by expansion while maintaining thermal equilibrium.

When mixing two liquids with significantly different temperatures, physical detonation phenomena are possible with the formation of a cloud of liquid droplets of one of the components.

At industrial enterprises, neutral (non-combustible) compressed gases - nitrogen, carbon dioxide, freons, air - are found in large volumes mainly in high-pressure spherical gas holders.

On July 9, 1988, there was an explosion of a spherical compressed air gas holder with a volume of 600 m3 (sphere radius 5.25 m), made of steel with a wall thickness of 16 mm and designed to operate at a pressure of 0.8 MPa. The explosion of the gas tank (occurred at a pressure of 2.3 MPa) was preceded by a slow increase in pressure to the yield strength of the steel from which it was made.

The spherical gas holder was a part of the technological unit for the production of urea, put into operation in April 1988. Air was supplied to the gas holder from a common factory process line through a check valve and fittings. The gas holder was not equipped with means of pressure relief, since the maximum possible air pressure (0.8 MPa) in it was ensured by its stabilization in the process system and the characteristics of air compressors of the VP-50-8 type. Pressure control was carried out by locally indicating and registering pressure gauges on the control panel.

From the gas tank, air was supplied through a pipeline system for technological needs, including the separation of CO2 from combustible impurities. In this compartment, air from the gas tank was discharged through a pipeline with a diameter of 150 mm to the discharge line of the CO2 turbocompressor of the Babet type, operating at a pressure of 2.3 MPa and simultaneously being the intake line of a piston compressor booster up to 10.0 MPa (4DVK-210-10); The supplied air was intended for purge of the compression system and through it the technological line from CO2 before repair.

At the end of the repair of the process unit, the CO2 turbocompressor was turned on and after 10 minutes, with a pressure in the discharge line of 2.3 MPa, the piston compressor was turned on with adjustment to a mode pressure of 10.0 MPa. After starting the centrifugal CO2 compressor, the pressure in the air gas tank began to increase; at the same time, the pressure gauge with a scale of 0.8 MPa on the control panel went off scale. Dioxide through a loosely closed valve from the discharge pipeline, the operating centrifugal compressor through the air line entered the air gas tank. The gas pressure in the gas holder increased for 4 hours, which led to the destruction of the gas holder from excess pressure.

The flow of CO2 into the air gasholder is confirmed by the decrease in air temperature to 0°C due to the throttling of CO2 with the discharge pressure of the centrifugal compressor to the pressure in the gasholder.

In areas of low pressure, the shock wave destroyed up to 100% of the glazing in six industrial buildings located at a distance of m from the installation site of the exploded gas tank; minor damage to the glazing (up to 10%) was noted in the houses of residential areas located 2500 m from the explosion site.

The flying fragments of the gas tank shell posed a great danger.

Chemical explosions in equipment

Exothermic chemical reactions are carried out in technological systems (reactors) balanced in terms of thermal conditions. The heat released during the reaction is removed by an external refrigerant through the walls of heat exchange elements with heated reaction products or with excess raw materials due to its evaporation, etc. The stable flow of the reaction process is ensured by the equality of heat release and heat removal rates. The rate of the reaction and, accordingly, the influx of heat increases according to a power law with an increase in the concentration of reactants and increases rapidly with increasing temperature.

When a chemical reaction gets out of control, the following explosion mechanisms are possible.

1. If the reaction mass is a condensed explosive, when the critical temperature is reached, the detonation of the product is possible; in this case, the explosion will occur according to the mechanism of explosion of a point explosive charge in the shell. The energy of the explosion will be determined by the TNT equivalents of the entire mass of explosives in the system.

2. Under the conditions of gas-phase processes, thermal decomposition of gases or explosive combustion of a gas mixture is possible; they should be considered as explosions of gases in closed volumes, taking into account real energy potentials and TNT equivalents.

3. In liquid-phase processes, a variant of emergency explosive energy release is possible: overheating of the liquid and an increase in the vapor pressure above it to a critical value.

The total energy of the explosion of the cloud will be equal to the sum of the equivalents of the heats of combustion of the vapors present in the system and additionally formed during the evaporation of the liquid.

The reasons for getting out of control of an exothermic chemical reaction are often a decrease in heat gain in liquid-phase periodic processes with large masses and reactants and limited possibilities for heat removal by conventional methods. Such processes include, in particular, monomer bulk polymerization, in which the reaction rate is controlled by conventional methods, as well as by the dosage of initiating substances. In case the process goes out of control, it is additionally provided that substances are introduced into the reaction mass that reduce the rate or suppress the exothermic reaction.

Some substances can polymerize more or less spontaneously, and conventional polymerization reactions will be exothermic. If the monomer is volatile, as is often the case, a stage is reached at which a dangerous increase in pressure can occur. Sometimes polymerization can only proceed at elevated temperatures, but for some substances, such as ethylene oxide, polymerization can begin at room temperature, especially when the starting compounds are contaminated with polymerization accelerators.

Similar accidents have occurred in the polymerization of vinyl chloride and other monomers, in chloroprene storage facilities, and in railroad tank cars with liquid chlorine, hydrocarbons and other active compounds, when they were mistakenly injected with substances that interact with the products they contain. With a significant excess of heat release compared to heat removal during such accidents, the process system is completely opened, at which the pressure decreases sharply, the rate of the chemical reaction decreases, or it stops altogether. In this case, the total energy potential is the sum of the equivalents of the combustion energies of vapors (gases) located above the liquid and formed as a result of evaporation under the action of the heat of superheating the liquid to a temperature corresponding to the critical conditions for the destruction of the system.

Also, the simplest case of an explosion is a decomposition process that gives gaseous products. One example is hydrogen peroxide, which decomposes with a significant heat of reaction to give water vapor and oxygen:

2H2O2 -> 2H2O + O2 - 23.44 kcal / mol

As a household product, hydrogen peroxide is sold as a 3% aqueous solution and poses a minor hazard. The situation is different with “high grade” hydrogen peroxide, which is 90% or more in concentration. The decomposition of such H2O2 is accelerated by a number of substances that are used as jet fuel or in a gas turbine to pump fuel to the main engines.

One example is redox reactions and condensations:

one). Redox reactions in which air or oxygen reacts with a reducing agent are very common and form the basis of all combustion reactions. In cases where the reducing agent is a non-dispersed solid or liquid, combustion reactions do not proceed rapidly enough to become explosive. If solid finely divided or the liquid is in the form of droplets, a rapid increase in pressure is possible. This can lead, under conditions of a closed volume, to an increase in overpressure up to 0.8 MPa.

2). Condensation reactions are very common. They are particularly widely used in the paint, varnish and resin industries, where they form the basis of processes in continuous reactors with heating or cooling coils. Many examples of uncontrolled reactions have been recorded, due to the fact that the rate of heat transfer in such vessels is linear function the temperature difference between the reaction mass and the coolant, while the reaction rate is an exponential function of the reactant temperature. However, due to the fact that the rate of heat release, as a function of the concentration of the reactants, decreases during the course of the reaction, the undesirable effect is to some extent compensated.

Thus, the energy of an explosion caused by an out-of-control exothermic chemical reaction depends on the nature of the technological process and its energy potential. Such processes, as a rule, are equipped with appropriate controls and emergency protection, which reduces the possibility of an accident. However, chemical reactions are often a source of uncontrolled release of energy in equipment that does not provide for organized heat removal. Under these conditions, self-accelerating chemical reactions that have begun inevitably lead to the destruction of technological systems.

Accident statistics

Table 1 presents data on accidents associated with explosions inside process equipment.

Table 1 - List of occurred accidents

date and place accidents	Type of accident	Description of the accident and main reasons	The scale of the development of the accident, the maximum zones of action of damaging factors	Number of victims	The source of information

Jonava	Storage tank explosion	As a result of the polymerization of vinyl acetate, heat was released, sufficient to create a destructive pressure.	Destruction of the reservoir.
	Destruction of the oxidation apparatus	When the exothermic reaction of isopropylbenzene oxidation with air got out of control, the apparatus was destroyed due to a sharp rise in pressure.	Destruction of the device.
warehouse of Sumgayit PO	Explosion of a spherical tank	As a result of the beginning of the process of polymerization of butadiene, the reservoir was destroyed.	The rupture of the tank led to the explosion of the tank. Shrapnel damaged neighboring tanks and the building.

Table 1 continued


	Gas tank explosion	The explosion of the gas tank was preceded by a slow increase in pressure to the yield strength of steel.	At a distance of m from the gas tank, the glazing is 100% destroyed, 2500 m - 10%.
02.1990 Novokuibyshev Refinery	vessel explosion	The vessel collapsed as a result of excess vapor pressure of the propane-butane fraction in the separator.	Destruction of the container along the solid metal of the shell.
	Reactor explosion	As a result of the exothermic chemical reaction of the decomposition of nitromass and excess pressure, the reactor exploded.	The building where the reactor was located was destroyed.
07.1978 San Carlos	Tanker shell rupture		The fragments scattered at a distance of 250 m, 300 m, 50 m. The tractor was at a distance of 100 m.
07.1943 Ludwigsgafen,	Tank car explosion	Due to excess hydraulic pressure	Shell destruction.

Table 1 continued


Germany		collapsed tank containing butane-butylene mixture.
07.1948 Ludwigsgafen, Germany	Dimethyl ether tank explosion	Due to excess hydraulic pressure, the tank collapsed.	Shell destruction.
02/10/1973 New York, USA	Explosion in the tank	During the repair of the tank, natural gas vapors exploded from a spark.	Destruction of the reservoir.	40 people died, 2 were injured.
10/24/1973 Sheffield, England	Underground tank explosion	Explosion of material residues from equipment for cutting materials with a flame.	The radius of destruction was about half a kilometer.	3 people died, 29 were injured
December 19, 1982 Caracas, Venezuela	tank explosion	A tank with 40,000 tons of fuel exploded at an oil storage warehouse	Burning oil poured into the city and into the sea. A tanker caught fire in the bay and another tank on the shore exploded.	140 people died, more than 500 were injured.
06/20/2001 Catalonia, Spain	tank explosion	An explosion of a tank with technical alcohol occurred at a chemical plant.		2 people died

Method of calculation

When equipment explodes, the main damaging factor is the air shock wave.

When assessing the parameters of an emergency explosion of a container with an inert gas (mixture of gases), it is assumed that the shell has spherical shape. Then the stress in the wall of the spherical shell is determined by the formula:

σ = ∆P r/(2d), (1)

where σ is the stress in the wall of the spherical shell, Pa;

ΔP—pressure difference, Pa;

r is the radius of the shell wall, m;

d is the shell wall thickness, m.

Transformation of formula (1) makes it possible to calculate the breaking pressure (destruction condition - σ ≥ σв):

ΔP = 2d σw/ r, (2)

where σv is the temporary resistance to the destruction of the material, Pa.

The pressure of the gas-vapor mixture in the tank:

Р = ΔP + Р0, (3)

where P0 is atmospheric pressure, 0.1 106 Pa.

Isentropic equation:

Р/Р0 = (ρ/ρ0)γ, (4)

where γ is the gas adiabatic index;

ρ0 – gas density at atmospheric pressure, kg/m3,

ρ is the density of the gas at pressure in the vessel, kg/m3.

The density of the gas at pressure in the container is determined after the transformation of the isentropic equation (4):

ρ = ρ0 (Р/Р0)1/γ, (5)

Gross mass of gas:

С = ρ V, (6)

where V is the volume of the gas-vapor mixture, m3.

When a tank explodes under internal pressure P of an inert gas (mixture of gases), the specific energy Q of the gas:

Q= ΔP/[ρ (γ - 1)] (7)

For compressed explosive gas:

Q = Qv + ΔP/[ ρ (γ - 1)], (8)

where Qv is the specific energy of the gas mixture explosion, J/kg.

The TNT equivalent of an explosion of a gas container will be:

qtnt = Q С/ Qtnt, (9)

where Qthn is the specific explosion energy of TNT, equal to 4.24 106 J/kg.

The shock wave equivalent is estimated with a factor of 0.6:

qu. v. = 0.6 qtnt (10)

q = 2 qy. v. (eleven)

The excess pressure at the shock wave front (ΔРfr, MPa) at a distance R is determined by the formula for a spherical air-blast in free space:

where , R is the distance from the epicenter of the explosion to the recipient, m.

Table 2 presents the values of the maximum allowable overpressure of the shock wave during the combustion of gas, steam or dusty mixtures in a room or open space, for which distances are selected to determine the affected areas.

Table 2 - Maximum allowable excess pressure during the combustion of gas, steam or dusty air mixtures in a room or open space

Degree of damage	Overpressure, kPa
Complete destruction of buildings (fatal human injury)
50% destruction of buildings
Medium building damage
Moderate damage to buildings (damage to internal partitions, frames, doors, etc.)
Lower threshold of human wave damage pressure
Minor damage (broken glass)

Pressure wave impulse, kPa s:

Formulas (12.13) are valid under the condition ≥0.25.

The conditional probability of injury by overpressure, developed during the explosion of vapor-gas-air mixtures, to a person located at a certain distance from the epicenter of the accident, is determined using the "probit-function" Pr, which is calculated by the formula:

Pr = 5 – 0.26 ln(V) , (14)

where

The connection between the function Рr and the probability Р of one or another degree of damage is found in Table 3.

Table 3 - Relationship between the probability of defeat and the "pierced" function

The main purpose of calculations using this method is to determine the radii of zones of varying degrees of air-blast damage to buildings, structures and people and to determine the probability of damage to people located at a certain distance from the epicenter of the explosion.

Calculation examples

physical explosions

Example #1

The explosion of a spherical compressed air gas tank with a volume of V = 600 m3 occurred due to the excess of the regulated pressure. The apparatus is designed to operate under pressure P = 0.8 MPa. The explosion occurred at a pressure P = 2.3 MPa. Gas density at normal pressure ρ = 1.22 kg/m3, adiabatic index γ = 1.4. Assess the consequences of an explosion of compressed air in a spherical gas tank (determine the radii of zones of varying degrees of air-blast damage to buildings, structures and people) and determine the probability of human damage at a distance R = 50 m.

Solution:

The pressure drop is determined by converting formula (3):

ΔР = 2.3 - 0.1 = 2.2 MPa

The gas density is calculated according to equation (5):

ρ = 1.22 (2.3/0.1)1/1.4 = 11.46 kg/m3

Gross mass of gas:

C \u003d 11.46 600 \u003d 6873 kg

Q = 2.2 / = 0.48 MJ/kg

qtnt \u003d 0.48 6873 / 4.24 \u003d 778 kg

Shock wave equivalent:

qu. v. = 0.6 778 = 467 kg

With regard to a ground explosion, the following value is taken:

q = 2 467 = 934 kg

The calculation results are shown below (table 4).

Table 4 - Radii of air-blast impact zones

ΔРfr, kPa

To determine the probability of hitting a person at a given distance, using formulas (12.13), the excess pressure in the wave front and the specific impulse for a distance of 50 m are calculated:

50/(9341/3) = 5,12

ΔРfr = 0.084/5.12 + 0.27/5.122 + 0.7/5.123 = 31.9 kPa.

I = 0.4 9342/3/50 = 0.76 kPa s

The conditional probability of an overpressure injury to a person located 50 m from the epicenter of the accident is determined using the probit function Pr, which is calculated by formula (14):

V = (17500/(31.9 103))8.4 + (290/(0.79 103))9.3 = 0.0065

Pr = 5 - 0.26 ln(0.0065) = 6.31

Using table 3, the probability is determined. A person located at a distance of 50 m can receive injuries of varying severity with a probability of 91%.

Example #2

The explosion of a spherical carbon dioxide gas holder with a volume of V = 500 m3 (sphere radius 4.95 m) occurred due to excess of the regulated pressure. The apparatus is made of steel 09G2S with a wall thickness of 16 mm and is designed to operate under pressure P = 0.8 MPa. The tensile strength of the destruction of the material σv = 470 MPa. Gas density at normal pressure ρ = 1.98 kg/m3, adiabatic index γ = 1.3. Assess the consequences of an explosion of compressed carbon dioxide in a spherical gas tank (determine the radii of zones of varying degrees of air-blast damage to buildings, structures and people) and determine the probability of human damage at a distance R = 120 m.

Solution:

The breaking pressure is determined by the formula (2):

ΔP = 2 0.016 470/4.95 = 3 MPa

The pressure of the gas-vapor mixture in the tank is determined by the formula (3):

P \u003d 3 + 0.1 \u003d 3.1 MPa

The gas density is calculated according to equation (5) at pressure Р:

ρ = 1.98 (3.1/0.1)1/1.3 = 28.05 kg/m3

Gross mass of gas:

C \u003d 28.05 550 \u003d 14026 kg

According to formula (7), the specific energy of the gas is calculated:

Q = 3 / = 0.36 MJ/kg

The TNT equivalent of a gas explosion will be:

qtnt \u003d 0.36 14026 / 4.24 \u003d 1194 kg

Shock wave equivalent:

qu. v. = 0.6 1194 = 717 kg

With regard to a ground explosion, the following value is taken:

q \u003d 2 717 \u003d 1433 kg

The method of selecting the distance from the epicenter of the explosion according to formulas (12.13) determines the radii of zones of varying degrees of air-blast damage to buildings, structures and people, indicated in Table 2.

The calculation results are shown below (table 5).

Table 5 - Radii of air-blast impact zones

ΔРfr, kPa

To determine the probability of hitting a person at a given distance, using the formulas (12.13), the excess pressure in the wave front and the specific impulse for a distance of 120 m are calculated:

120/(14333) = 10,64

ΔРfr = 0.084/10.64 + 0.27/10.642 + 0.7/10.643 = 10.9 kPa.

I = 0.4 14332/3/120 = 0.42 kPa s

The conditional probability of an overpressure injury to a person located 120 m from the epicenter of the accident is determined using the probit function Pr, which is calculated by formula (14):

V = (17500/(10.9*103))8.4 + (290/(0.42*103))9.3 = 0.029

Pr = 5 - 0.26 * ln(0.029) = 5.92

Using table 3, the probability is determined. A person located at a distance of 120 m can receive injuries of varying severity with a probability of 82%.

chemical explosions

Example #1

Toluene was drained from the storage facility with a volume of V = 1000 m3 for repairs. At the beginning of welding, an explosion of toluene vapor occurred. Vapor density in air at normal pressure ρ = 3.2, adiabatic index γ = 1.4, VKPV - 7.8% vol., gas explosion heat 41 MJ / kg. Assess the consequences of the explosion (determine the radii of zones of varying degrees of air-blast damage to buildings, structures and people) and determine the probability of human damage at a distance R = 100 m.

Solution:

Atmospheric pressure in the storage is P = 0.1 MPa.

Vapor Density:

ρ = 3.2 1.29 = 4.13 kg/m3

The volume of vapor is found through the VKV (it is assumed that the entire volume is filled with a mixture with a concentration of toluene vapor corresponding to the VKV):

V \u003d 1000 7.8 / 100 \u003d 78 m3

Gross mass of gas:

C \u003d 4.13 78 \u003d 322 kg

According to formula (8), the specific energy of the gas is calculated:

Q = 41 + 1/ = 41.06 MJ/kg

The TNT equivalent of an explosion will be:

qtnt \u003d 41.06 322 / 4.24 \u003d 3118 kg

Shock wave equivalent:

qu. v. = 0.6 3118 = 1871 kg

With regard to a ground explosion, the following value is taken:

q = 2 1871 = 3742 kg

The results of counting pressures and pulses are shown below (Table 6).

Table 6 - Radii of air-blast impact zones

ΔРfr, kPa

To determine the probability of hitting a person at a given distance, using formulas (12.13), the excess pressure in the wave front and the specific impulse for a distance of 100 m are calculated:

100/(37421/3) = 6,44

ΔРfr = 0.084/6.44 + 0.27/6.442 + 0.7/6.443 = 22.2 kPa.

I = 0.4 37422/3/100 = 0.96 kPa s

The conditional probability of an overpressure injury to a person located 100 m from the epicenter of the accident is determined using the probit function Pr, which is calculated by formula (14):

V = (17500/(22.2 103))8.4 + (290/(0.96 103))9.3 = 0.14

Pr = 5 - 0.26 ln(0.14) = 5.51

Using table 3, the probability is determined. A person who is at a distance of 100 m can receive injuries of varying severity with a probability of 69%.

Example #2

The explosion of a railway tank car with a volume of V = 60 m3, filled with 80% toluene, occurred as a result of a lightning strike. The gas density at normal pressure is ρ = 4.13 kg/m3, the adiabatic index is γ = 1.4, VKVV is 7.8% vol., and the heat of gas explosion is 41 MJ/kg. The pressure in the tank P = 0.1 MPa. Assess the consequences of the explosion (determine the radii of zones of varying degrees of air-blast damage to buildings, structures and people) and determine the probability of human damage at a distance R = 30 m.

Solution:

The gas volume is determined in terms of the fill factor and the WTF (it is assumed that the entire volume is filled with a mixture with a toluene vapor concentration corresponding to the WTF):

V = 60 0.2 0.078 = 0.936 m3

Gross mass of gas:

C \u003d 4.13 0.936 \u003d 3.9 kg

According to formula (7), the specific energy of the gas is calculated:

Q = 41 + 0.9/ = 41.1 MJ/kg

The TNT equivalent of an explosion will be:

qtnt \u003d 41.1 3.9 / 4.24 \u003d 37.4 kg

Shock wave equivalent:

qu. v. = 0.6 37.4 = 22.4 kg

With regard to a ground explosion, the following value is taken:

q \u003d 2 22.4 \u003d 44.8 kg

The results of counting pressures and pulses are shown below (Table 7).

Table 7 - Radii of air-blast impact zones

ΔРfr, kPa

To determine the probability of hitting a person at a distance R, using the formulas (12.13), the excess pressure in the wave front and the specific impulse are calculated for a distance of 30 m:

30/(44,81/3) = 8,4

ΔРfr = 0.084/8.4 + 0.27/8.42 + 0.7/8.43 = 14.9 kPa.

I = 0.4 44.82/3/30 = 0.17 kPa s

The conditional probability of an overpressure injury to a person located 70 m from the epicenter of the accident is determined using the probit function Pr, which is calculated by formula (14):

V = (17500/(14.9 103))8.4 + (290/(0.17 103))9.3 = 161

Pr \u003d 5 - 0.26 ln (161) \u003d 3.7

Using table 3, the probability is determined. A person located at a distance of 30 m can receive injuries of varying severity with a probability of 10%.

List of used literature

1. Chelyshev theory of explosion and combustion. Textbook - M .: Ministry of Defense of the USSR, 1981. - 212 p.

2. Explosive phenomena. Evaluation and consequences: In 2 books. Book 1. Per. from English / - M .: Mir, 1986. - 319 p.

3. Beschastnov explosions. Evaluation and warning - M .: Chemistry, 1991. - 432 p.

5.http://www. Press Center. en

6. Accidents and catastrophes. Prevention and liquidation of consequences. Tutorial. Book 2. and others - M .: Ed. DIA, 1996. - 384p.

7. GOST R 12.3.047-98 SSBT. Fire safety of technological processes. General requirements. Control methods.

8. RD Methodology for assessing the consequences of emergency explosions of fuel-air mixtures.

9. Fire and explosion hazard of substances and materials and their extinguishing agents /, etc. - M .: Chemistry, 1990. - 496 p.

10. Flammable and combustible liquids. Handbook / ed. -Agalakova - M .: Publishing house of min. communal economy, 1956. - 112 p.

11., Noskov and tasks in the course of processes and apparatuses of chemical technology. Textbook - L .: Chemistry, 1987. - 576 p.

12. Berezhkovsky and transportation of chemical products. - L.: Chemistry, 1982. - 253 p.

13., Kondratieff safe apparatus for chemical and petrochemical industries. - L .: Mechanical engineering. Leningrad. Department, 1988. - 303 p.

14. Handbook of a metal worker. In 5 volumes. T. 2. Ed. , - M .: Mashinostroenie, 1976. - 720 p.

Applications

Annex A

Table A1 - Properties of gases and certain liquids

Name	The density of matter kg/m3 (at 20 °C)	Density by air gas (steam)*	Adiabatic coefficient


Acetylene




nitrogen dioxide
Carbon dioxide
Oxygen



Propylene

Note: To determine the vapor density, the air density at 0 °C is used.

Annex B

Table B1 - Structural materials

Material	Tensile strength, σin MPa	Purpose
St3ps, St3sp (gr. A)		For parts of machines, machine tools, tanks.
		For storage of dilute nitric and sulfuric acid, ammonium nitrate solution and similar substances with a density of 1400 kg/m3.
		For storage of aggressive chemical products with a density of 1540 kg/m3.
		In the manufacture of pipelines and apparatus. Tanks for storage of liquefied gases, railway tanks.


		Pipelines, pressure up to 100 kgf/cm2.
		Northern version for machine parts.

Home > Law

production of explosives and containing their products 1. The equipment must be designed taking into account the physical, chemical and explosive properties of explosives and products intended for use: sensitivity to impact and friction, exposure to positive and negative temperatures, chemical activity and the ability to form new products, electrification, tendency to dusting, caking, stratification, suitability for pneumatic transport or pumping through pipes and other properties that directly or indirectly affect the safety of the explosive-equipment system. 2. The design of the equipment must ensure the safety of operating personnel, as well as technical characteristics and modes of operation that meet the requirements of regulatory and technical documentation for explosives and products intended for use, including: the possibility of free access for inspection and cleaning of nodes where explosives and explosives products are subjected to mechanical stress, as well as to places where the accumulation of residues of explosives, lubricants and other products is possible; limitation of mechanical loads on explosives and products to safe limits; protection of sleeves, grounding conductors of pipelines, rods, electrical wiring from abrasion during operation; compliance with the parameters of the specified thermal regime, incl. exclusion of overheating in units and parts in contact with explosives and products, and, if necessary, temperature control; dosage of explosive components; installed dust suppression; blocking from a dangerous violation of the sequence of operations; remote control of dangerous operations; reliable and timely control of ongoing technological processes; reliable light and (or) sound signaling of the occurrence or approach of dangerous (emergency) modes. 3. When choosing materials for the manufacture of vessels and apparatuses, the wall temperature (minimum negative and maximum calculated), chemical composition, nature of the medium (corrosive, explosive, flammable, etc.) and technological properties of substances are taken into account. Materials should not enter into interaction with the reaction mass, vapors or dust of the processed substances. 4. For the manufacture of individual parts, heat-resistant electrically conductive plastics of sufficient strength can be used. 5. Assemblies with rubbing and colliding parts that do not have direct contact with explosives and products, but are made of materials that produce sparks, must be reliably isolated from explosives and products or covered with plastic, or hermetically sealed with a casing made of materials that do not produce sparks . 6. In all cases, if this is not determined by specially regulated operating conditions of the units, the design of the equipment must exclude the ingress of explosives into the gaps between rubbing and colliding parts. The latter can be achieved by using appropriate seals, remote bearings, auger baffles, and similar solutions. 7. There should be no fasteners (bolts, studs, dowels, pins, cotter pins) in the explosive passage paths. 8. In threaded connections outside the path of passage of explosives, it is necessary to provide for a cotter pin or another method of fixing fasteners. 9. Equipment in which explosives are produced or processed that are capable of decomposing when they stay in a vessel or apparatus for a long time, should not have stagnant zones where substances can accumulate.10. The design of equipment units should exclude the possibility of lubricants getting into explosives. 11. During the operation of the equipment, the heating of the surfaces of assemblies and parts, on which explosive dust can settle, should not exceed 60 ° C. This must be ensured by selecting the appropriate operating modes and only in exceptional cases (pipelines and shirts with hot water , exhaust pipes of internal combustion engines, heaters, heat exchangers) by applying thermal insulation. 12. The outer surfaces of vessels and apparatus having a temperature of more than 45 ° C must be thermally insulated. Thermal insulation is fastened at the installation site, for which the design of vessels and apparatuses must be provided with devices for fastening thermal insulation. Thermal insulation materials must be non-combustible and not interact with the processed substances. Vessels and apparatus must have devices that prevent the penetration of explosives between the thermal insulation and their outer surface. 13. The lubricants used must be indicated in the passport (form) for the equipment and in the relevant operational documentation approved in the prescribed manner. 14. The design of vessels and apparatuses must exclude the possibility of the appearance in parts and assembly units of loads that can cause their destruction, which poses a danger to workers, in all intended modes of operation. 15. The design of vessels and apparatuses and their individual parts must exclude the possibility of their falling, overturning under all envisaged conditions of operation and installation (dismantling). 16. The design of clamping, gripping, lifting, loading, etc. devices or their drives must exclude the possibility of a hazard in the event of a complete or partial spontaneous interruption of the power supply, and also exclude a spontaneous change in the state of these devices when the power supply is restored. 17. Structural elements of vessels and apparatus should not have sharp corners, edges, burrs and other surfaces with irregularities that pose a risk of injury to workers, if their presence is not determined by the functional purpose of these elements. 18. Parts of the equipment, including pipelines of steam, hydraulic, pneumatic systems, safety valves, cables, etc., mechanical damage to which may cause a hazard, must be protected by guards or located so as to prevent accidental damage by workers or maintenance tools. 19. The design of vessels and apparatuses must exclude spontaneous loosening or separation of fastenings of assembly units and parts, and also exclude the movement of moving parts beyond the limits provided for by the design, if this may lead to the creation of a dangerous situation. 20. In the design of equipment, pneumatic, hydraulic, explosion-proof electrical and mechanical drives can be used. 21. Taking into account the purpose, the design of the equipment and the methods of work regulated in the operational documentation should exclude: the ingress of foreign objects and substances into explosives and products, as well as atmospheric precipitation; damage to electrical wires, detonating cords, waveguides and other means of initiation during the loading process. 22. Covers and nets made of steel, removed during operation, at the joints with the frame of the hatch of the bunker must be reinforced with a material that softens the blow and does not give sparks (rubber, elastic plastic), with the implementation of measures to protect against the accumulation of potentials of static electricity. 23. In order to prevent the ingress of foreign objects into the path of the explosives, grids should be installed on the loading hatches and openings of the containers. Mesh mesh sizes should not exceed 15x15 mm for grammonites, granulotol, alumotol, 10x10 mm for other explosives and ammonium nitrate, in cases of perforated (round) holes, respectively, diameters: 18 and 12 mm. In order to avoid the formation of plugs during pneumatic charging, it is necessary to observe the condition that the size of the sieve cells is no more than 1/2 of the nominal diameter of the charging pipeline. 24. The design of the equipment must exclude the hanging of materials in bunkers, chambers and other accumulation and bypass units. If it is impossible to fulfill this requirement, the equipment must be equipped with effective and safe means to eliminate or prevent freezing of explosives. 25. In screw conveyors, the possibility of pressing explosives or their components into the end parts of the screws, the ingress of products into the bearings and the friction of the screw screw against the inner walls of the casing should be excluded. In order to exclude the pressing of explosives in the end parts of the screw, the design of the screw-screw should provide for cutting off the flow of explosives by using baffle turns in the end of the screw. The length of the screws in all cases should be taken such that friction of its ribs against the casing is excluded, including due to deflection. 26. Vibratory feeders may be used only for explosives that do not delaminate in the process of exposure to vibration. 27. To move liquid components and pouring explosives along the equipment paths, it is allowed to use hose and screw pumps.28. Belt conveyors for supplying explosives and products must be protected against slipping and equipped with a system that provides duplicate shutdown at any point along the length. The width of the conveyor belt must correspond to the design of the conveyor and be no more than one and a half width of a bag with explosives (ammonium nitrate). When transporting granulated explosives in bulk, the width of the belt must be at least 3 times wider than the bulk of explosives on the belt. The design of belt conveyors should exclude the ingress of explosives on the tension drums and support rollers, as well as ensure the cleaning of the conveyor belt from adhering explosive particles by using special devices. Conveyors may only use belts made of flame-retardant materials that comply with current regulations. 29. In cases where the shaft drives the actuators of grinding, mixing, transporting or dosing devices located in chambers or cavities where explosives can be located, the shaft bearings must be remote. The visible gap between the bearings and the wall separating the explosive path must be at least 40 mm. The arrangement of outboard bearings located inside the explosive flow is not allowed. Seals must be placed at the place where the shaft passes through the wall separating the path of the explosive movement. 30. Remote bearings must be sealed by installing glands in the bearing caps. Reducers and bearing assemblies must be designed to reliably protect against oil leakage and exclude moisture, dirt and dust from entering them. 31. In all cases, gasket and stuffing (sealing) materials should not enter into a chemical reaction with explosives and their components. 32. Containers for flammable liquids on charging machines must have quenching partitions, air vents or safety valves in the form of membranes designed to squeeze out the contents at a pressure of 0.05 MPa above the maximum allowable or a fusible element that collapses at a temperature of 110 -–115 ° C. Safety valves should be located at the top of the tank. Care must be taken to protect the valves from any damage. 33. The degree of filling of containers for combustible flammable liquids and solutions of oxidizing agents should not exceed 90% of their capacity. 34. For maintenance of loading hatches located at a height of more than 1.5 m from the floor level (platforms), it is necessary to provide working platforms equipped with ladders for lifting, fences and handrails. 35. Before loading explosives and components into apparatuses, measures must be taken to exclude the possibility of foreign objects entering these apparatuses (filtration of liquid components, screening or magnetic separation of bulk materials). The need to combine these control operations is determined by the directive technological process. The mesh sizes of sieves for sifting components must be specified in the process schedule. 36. All devices, equipment, assemblies, parts, devices, tools and other items that have become unusable and have been in contact with explosives, subject to further use or destruction, must be pre-cleaned, washed and, if necessary, fired. 37. The equipment of points for the production and preparation of explosives and products used directly for the production and processing of explosives and products must comply with the requirements of the design documentation developed in accordance with this regulation and the requirements of the relevant standards. 38. Changes in the design of the equipment in operation are permitted only if the relevant design documentation is available, approved in the manner established by the organization and agreed with the developer of this equipment. 39. Passports (forms) outlining the basic requirements for their operation must be drawn up for all equipment put into operation. Imported equipment or equipment manufactured under foreign licenses must ensure the safety requirements provided for by this technical regulation. Article 22 Requirements for the means of mechanization of transport technological, transport, loading and unloading and storage operations

1. The main special requirements for lifting and transport machines and auxiliary devices used in explosive and flammable rooms and outdoor installations for working with explosive and flammable goods, must be:

Elimination of the impact of electrical sparks and discharges, sparks from friction and impact, heated surfaces on the explosive environment surrounding the equipment and the transported cargo;

exclusion of places inaccessible for cleaning in order to prevent stagnation, accumulation, crusting and pinching of the product;

the use of materials for the manufacture of structural elements of machines, taking into account the nature of the aggressive effects of transported substances, the features of technological processes and safety requirements;

exclusion of the interaction of the transported product with lubricants, working fluids of hydraulic systems, if such interaction leads to fire or explosion.

2. To perform lifting and transport operations in industrial, warehouse, loading and unloading areas, in railway cars with explosive and flammable substances in packaging, cases, boxes, it is allowed to use mass-produced lifting and transport machines and auxiliary devices of a general destination subject to the requirements of Part 1 and the carrying capacity of which is greater than the nominal gross mass of the package of explosives and their products. 3. Load lifting mechanisms for lifting machines used to transport explosives, fire hazardous goods must be equipped with two brakes and have a load rope safety factor of at least six.4. explosive substances in liquid state or in the form of a suspension should be transported, as a rule, by the injection method, as well as using diaphragm, membrane and other pumps specially designed for this purpose. 5. When transferring flammable substances and products by continuous transport from one room (building) to another room (building) isolated from it, automatic devices must be installed to prevent the spread of combustion. 6. When transferring explosives from one building to another by continuous transport, the transfer of detonation along the transport chain between buildings, as well as the spread of flame in the event of a fire, must be excluded. The use of pneumovacuum transport for transporting explosives between storage facilities and technological buildings is not allowed. Conveyors transporting flammable and explosive substances must have locking devices that ensure a stop in case of slipping, breakage of the traction organs when the propeller is jammed. Conveyors with inclined and vertical sections of the route must have safety devices that prevent spontaneous movement of the traction body or the transported cargo. 7. Operators exercising local or remote control of the operation of hoisting and transport machines in explosive and fire hazardous premises must be provided with the possibility of evacuation. The control of the movement of lifting machines and mechanisms used to move explosive and flammable goods must be floor-mounted. Article 23 . Requirements for heat supply, water supply and sewers 1. Heat and water supply for the production of explosives and products must be carried out taking into account the provision of technological needs, trouble-free shutdown of processes in case of sudden restrictions on the supply of heat and water, and the needs for the elimination of emergency situations. 2. The supply of steam to technological consumers of the main industries should be carried out through two main pipelines with a design load for each 70% of the total total consumption. 3. Branches of heat pipelines from the mains must be carried out with two pipes to those buildings in which interruptions in the heat supply of process consumers are not allowed due to safety precautions or loss of product quality. 4. Entering heating networks into rooms with explosive and fire hazardous, as well as corrosive materials, is not allowed. Heat carrier inlets, heat points, water heating installations serving explosive and fire hazardous industries should be located in isolated rooms with independent entrances from the outside, from local cages or from safe corridors. It is allowed to place heating points and water-heating installations in the rooms of supply ventilation chambers. For heating industrial premises in which dust of explosives is emitted, air heating combined with supply ventilation, or water heating, or combined air-water heating with a temperature on the surface of heating heating devices not higher than 80 ° C should be used. 5. Water supply network of the building must provide the sum of the maximum costs for the automatic fire extinguishing system, fire hydrants and external fire extinguishing. 6. Estimated water consumption for external fire extinguishing of buildings of categories A, Al, B, C, G is assumed to be at least 25 l / s. 7. The capacity of the fire-fighting water supply in the tanks of the enterprise's water supply system is selected taking into account the operating time of automatic fire extinguishing systems according to Appendix 11. more than 200 m or from hydrants located on the ring water supply network. In this case, one fire is taken into account, regardless of the area of the territory, with a water flow of 20 l / s.

9. The capacitive structures of the water supply system (reservoirs, receiving chambers) must be equipped with devices for the intake of water by fire engines and have free hard-surfaced entrances.

10. In order to save fresh water, the water supply of enterprises should be designed with the installation of closed systems for cooling purposes, as well as systems for the reuse of waste uncontaminated water and treated decontaminated wastewater.

11. In addition to hydrants on the fire water pipeline network, it is also necessary to install hydrants on the chilled water pipeline networks of circulating systems passing near explosive and fire hazardous buildings.

12. Industrial wastewater containing products of production, as a rule, is discharged to local treatment facilities by an independent (industrial) sewerage system.

13. When discharging industrial wastewater together with domestic wastewater through the integrated sewerage system, subject to the possibility of their joint transportation and treatment, the content of contaminants in wastewater should not exceed the permissible concentrations for biological treatment facilities.

14. Wastewater containing nitroesters are diverted by an independent special network to the decomposition and neutralization unit. Neutralized wastewater is sent to the biological treatment facilities together with the utility water of the enterprise. 15. Waste water from the production of IVV, production containing substances of the first hazard class, must be completely captured and neutralized directly in the building, after which they can be released into the control well, and then into the sewer network. 16. The need for a storm sewer and storm water treatment is determined depending on the density of the territory, the nature of the road surface and the possible degree of pollution.

Article 24 Ventilation Requirements

1. Explosive production, where harmful vapors, gases, dust are released into the air, must be equipped with ventilation devices, while ventilation must be carried out according to a system that prevents the possibility of fire transmission from one room to another through air ducts and prevents the occurrence of fire in them.2 . At the stages of drying, screening and capping of explosives production, except for TNT, dinitronaphthalene and other insensitive to mechanical influences, exhaust ventilation should be carried out using ejectors. products with these substances, where, when gases and vapors are removed from the process equipment, condensate sensitive to mechanical influences can form, the ejecting air must be heated to a temperature that excludes condensation of vapors and gases. 3. The air removed by local exhausts, containing harmful explosive and flammable substances, before being released into the atmosphere, must be cleaned to an acceptable level of industrial site atmosphere pollution, as well as to the MPC in the air settlements. 4. Exhaust systems that remove explosive and flammable dust must be equipped with filters with irrigation with water or others that exclude the release of dust into the atmosphere. The operation of the exhaust fan must be interlocked with the filter irrigation system, and, if necessary, with process equipment. The filter must be installed upstream of the fan in the direction of the airflow. Filters can be installed both inside the process rooms and in the room of the exhaust ventilation chamber. 5. Explosion- and fire-hazardous industrial premises, interconnected by open unprotected technological or door openings, can be served by common ventilation systems. It is not allowed to release into one ventilation system vapors and gases, products, the interaction of which may create a risk of fire, explosion and equipment of harmful products. Explosive and fire hazardous premises that have independent external entrances that do not communicate with each other and are not connected by a single technological process must be served by independent ventilation systems for each room. 6. Separated explosion and fire hazardous industrial premises of the same technological process, located within the same floor, can be served by common supply ventilation systems of the collector type, subject to following conditions: the total area of the serviced premises should not exceed 1100 m 2; each isolated room must be served by independent supply air ducts coming from the collectors; on each branch from the collector within the ventilation chamber, a self-closing check valve must be installed; collectors should be placed within the premises intended for the installation of ventilation equipment (ventilation chambers), or outside the building. In some cases, it is allowed to place the collector in a safe room in a place accessible for servicing check valves; protection of transit air ducts laid through other premises should be provided with a standardized fire resistance limit of at least 0.5 h; the length of the air duct from the collector to the nearest air outlet must be at least 4 m; 7. The need for emergency ventilation and the amount of harmful substances for calculating the air exchange in each individual case are determined by the directive technological process. The emergency ventilation should be switched on automatically and duplicated by manual switching outside the serviced premises at the entrance to it. 8. Exhaust fans moving air with an admixture of explosive and flammable substances must be of a design that excludes the possibility of initiating a fire or explosion of the transported medium. 9. Supply fans serving industrial premises, where the flow of the technological process is associated with the release of vapors of solvents, dust of explosive substances and compositions, can be adopted in a normal version made of carbon steel, provided that a self-closing check valve is installed on the air ducts after the fan and heaters, preventing penetration into the fan, when it is stopped, and heaters of explosive and flammable substances from the premises. 10. Fans, as well as control devices installed on air ducts that remove air from industrial premises, in the absence of explosive vapors or dust emissions during the technological process, can be adopted in a normal version made of carbon steel. In exhaust systems with wet air cleaning, transporting dust of ammonium perchlorate, potassium chlorate and ammonium nitrate, fans are accepted in the normal version of acid-resistant steel, provided that the fans are installed after the filter. 11. If the production process in a bunded building is associated with the release of toxic gases, vapors and dust, the intake of outside air for supply systems should be carried out from the outside of the shaft. It is allowed to take direct intake of outside air from the space between the shaft and the building, if all exhaust units are provided with effective cleaning devices with a purification rate of at least 90%, while ventilation emissions must be made outside the circulation zone. 12. In technological supply units, fans that blow air into technological apparatuses in which explosive vapors or dust are emitted must be spark-proof. It is allowed to use fans with increased protection against sparking. In cases where plate or finned heaters without a bypass channel are installed between the fan and the process apparatus, fans can be used from carbon steel. In this case, a self-closing explosion-proof check valve must be installed after the heater along the air flow within the ventilation chamber. Regulatory and other elements within the production area must be explosion-proof. 13. When extracting the vapor-air mixture of solvents for recuperation in process rooms of category B, it is planned to install oil screen filters located upstream of the flame arrester along the path of the vapor-air mixture.14. Premises for equipment of exhaust systems must meet the explosion and fire safety requirements for the production premises they serve, depending on the category of the premises located in them. production processes. 15. Explosives warehouses are equipped with a natural exhaust ventilation system to prevent moisture condensation on the packaging surface.16. In workshops and at individual workplaces where dust formation is possible, the distribution of supply air must be carried out through air distributors with a rapid attenuation of speeds, which excludes the possibility of dust blowing.17. The inner surface of the pipelines of the ventilation system must be such that dust from the products does not linger on it, and that it can be easily cleaned or washed from contamination. Ventilation units must have hatches in the air ducts for flushing and cleaning the inner surface of the air ducts during general cleaning and before repair, as well as hatches for checking the actual performance and sampling the air for maintenance chemical substances. Article 25 power requirements and

Initial data for calculations. Tasks term paper: - systematization consolidation and expansion of theoretical and practical knowledge in these disciplines; - acquisition of practical skills and development of independence in solving engineering and technical problems; - preparing students for work on further coursework and graduation projects DEVICE OF THE APPARATUS AND SELECTION OF STRUCTURAL MATERIALS Description of the device and the principle of operation of the apparatus The reaction apparatus is called closed vessels intended for carrying out ...

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Introduction ...................................................................................................................................

Device device and...............................
1. …………………………
2. ……
3. Choice of construction materials………………………………………..

Purpose of calculations and initial data……………………………………………………
1. Purpose of calculations ……………………………………………………………………
2. Calculation scheme of the device……………………………………………………..
3. Initial data for calculations……………………………………………….
4. …………………………………………

Strength calculation of the main elements of the apparatus……………………………….
1. ………………………………………………
  1. Calculation of the wall thickness of the casing shell loaded with excess internal pressure……………………………………………………………..
  2. Calculation of the wall thickness of the casing shell loaded with external pressure
  3. Calculation of a jacket shell loaded with internal pressure
2. Bottom calculation ……………………………………………………………………..
  1. Calculation of the bottom of the hull loaded with excess internal pressure…………………………………………………………………………….
  2. Calculation of the wall thickness of the bottom of the housing loaded with external pressure…………………………………………………………………………….
  3. Calculation of the bottom of a shirt loaded with excess internal pressure…………………………………………………………………………….
3. ………………………………………………..
4. ………………………...
5. Selection and calculation of the support…………………………………………………………...

conclusions ………………………………………………………………………………………..

Bibliography.......................................................................................

INTRODUCTION

Modern chemical production with specific operating conditions of equipment, often characterized by high operating parameters (temperature and pressure) and, in general, high productivity, requires the creation of high quality apparatuses.

The high quality of the devices is characterized by: high efficiency; durability (service life of at least 15 years); economy; reliability; security; convenience and ease of maintenance, depending on both quality and workmanship.

Objectives of the course work:

Systematization, consolidation and expansion of theoretical and practical knowledge in these disciplines;

Acquisition of practical skills and development of independence in solving engineering and technical problems;

Preparing students for work on further course and diploma projects

DEVICE OF THE DEVICE AND SELECTION OF STRUCTURAL MATERIALS

Description of the device and the principle of operation of the device

The reaction apparatus is called closed vessels designed to carry out various physical and chemical processes. Reactor - an apparatus in which the main process of chemical technology takes place; it must work effectively, i.e. provide a certain depth and selectivity of the chemical transformation of substances. The reactor must meet the following requirements: have the required reaction volume; to ensure the specified productivity and hydrodynamic mode of movement of the reactants, to create the required phase contact surface, to maintain the necessary heat transfer, the level of catalyst activity, etc.

The design of the reaction apparatus is determined by a number of factors: temperature, pressure, the required intensity of heat transfer, the consistency of the processed materials, the state of aggregation of materials, etc.

On the cover and body of the apparatus there are two branch pipes for supplying and discharging products. With the help of a stirrer, the substances are mixed. To maintain a certain temperature inside the reactor, the apparatus is equipped with a jacket, on which there are two branch pipes for supplying a heating agent and draining condensate.

The choice of the design of the main elements of the apparatus

The elements to be selected and designed are: shell (body), bottom, cover, shirt, mixer, flange connections, supports.

The choice of the design of the main elements of the apparatus is made in accordance with the use.

For steel cylindrical shells, the shells of which are made of sheet metal, GOST 9617-76 is applied.

We choose the bottom of an elliptical shape with a flange on the cylinder (GOST 6533-78) [p. 112, fig. 7.1 (a), 1]. The dimensions of the bottom of the case are taken according to Table 7.2, page 116:

; ; .

Covers of devices can be both detachable and all-welded with the device. Such all-welded apparatus are usually equipped with hatches, which are standardized. Manhole design with a cover - we accept with a spherical cover, version 1 with a seal on the connecting ledge.

Jackets are designed for external heating or cooling of liquid products processed and stored in the apparatus. By design, shirts are one-piece and detachable. One-piece shirts are simpler and more reliable in work. Therefore, we accept a steel one-piece jacket for a steel vertical apparatus of type 1 with an elliptical bottom and a lower output page 164:

; ; ; .

Designation: Shirt 1-3000-3563-2-O OST 26-01-984-74.

Shirts with elliptical bottoms are used when and, which corresponds to the specified conditions in the shirt (,).

In devices for detachable connection of composite housings and individual parts, flange connections are used, mainly of a round shape. The design of the flange connection is used depending on the operating parameters of the apparatus. When and use flat welded flanges .

We accept the design of the mixer open turbine. Turbine mixers provide intensive mixing in the entire working volume of the mixer when mixing liquids with a viscosity of up to, as well as coarse suspensions.

Installation of devices on foundations or special supporting structures is carried out mostly with the help of supports. Vertical apparatuses are usually installed on suspension legs when the apparatus is placed between ceilings in a room or on special structures. We accept the design of supports - paws.

Choice of construction materials

When choosing construction materials, it is necessary to consider:

Operating conditions of the device, i.e. corrosion and erosion properties of the medium, temperature and pressure of the medium;

Technological properties of the material used: weldability, plasticity and others;

Feasibility considerations

For the body of the apparatus, we choose steel 12X18H10T GOST 5632-72. Steel 12X18H10T is a high-alloy austenitic corrosion steel. This steel is very common in the chemical industry and is not in short supply. Steel will not affect the liquid medium in the body of the apparatus.

According to the condition, the jacket contains a non-aggressive medium (water vapor). Given this, for the shirt we choose carbon steel of ordinary quality Vst3sp5 GOST 380-71.

The agitator and shaft, which are in contact with the working medium, are made of steels with corrosion resistance not lower than the steel from which the apparatus body is made. We also choose steel 12X18H10T GOST 5632-72.

Since the apparatus has a non-toxic and non-explosive environment, as well as the working pressure does not exceed the value, stuffing box seals are used.

The blank material or finished fasteners must be heat treated. Mating nuts and bolts (studs) must be made of materials of different hardness, while it is preferable to accept bolts (studs) as harder ones. According to the material of the fasteners, we select St 35 GOST 1050-74 HB=229 (bolts) and HB=187 (nuts).

We choose the material of the gaskets paronite GOST 480-80.

Rectilinear and circumferential butt welds of an apparatus made of sheet steel are performed by semi-automatic welding under a flux layer. We select welding materials used for semi-automatic welding:

for high-alloy steel 12X18H10T:

Wire grade 05X20N9FBS GOST 2246-70

for carbon steel Vst3sp5:

Wire grade SV-08A GOST 2246-70

Flux brand OSC-45 GOST 9087-69

for high-alloy steel 12X18H10T with carbon VSt3sp5:

Wire grade 07X25N12G2T GOST 2246-70

Flux grade AN-26S GOST 9087-69

In the manufacture and welding of the internal devices of the apparatus, supporting structures, manual arc welding is used. We select the following welding materials:

1) for fittings made of high-alloy steel 12X18H10T, with a body:

Electrode type E08Kh20N9G2B GOST 10052-75;

2) for fittings and supports made of VSt3sp5 carbon steel with a jacket:

Electrode type E50A GOST 9467-75.

PURPOSE OF CALCULATIONS AND INITIAL DATA
1. Purpose of calculations

The aim of the work is:

Determination of the thickness of the walls of the shells, the bottoms of the hull and jacket;

Determination of the main dimensions of the reinforcing elements of the holes;

Selection of a flange connection, determination of the diameter and number of bolts of a flange connection;

Selection and calculation of support

Calculation scheme of the device

The design of the mixer for liquid media with a stirrer is shown in Figure 1. In accordance with Figure 1, the main elements of the mixer are: a shell with a jacket, a cover, a drive with a stand, a rotating mixer mounted on a shaft, a stuffing box and a mechanical seal, a fitting for removing reaction products .

Rice. 1 Calculation scheme of the device.

Initial data for calculations

Initial data:

Apparatus volume

in the reactor
Wednesday	Temperature, C	Pressure, MPa
Glycerin, 30%
In a shirt
Wednesday	Temperature, C	Pressure, MPa
Steam		0,33

Diameter values

Drive weight

Place the supports on the wall of the shirt;

The drive in the drawing is shown conditionally. Take the height of the drive equal to the height of the reactor.

Determination of design parameters

The design temperature is determined on the basis of a thermal calculation or test results. If it is impossible to perform a thermal calculation, the design temperature is equal to the operating temperature, but not less than 20 0 C, therefore:

Operating Temperature: Enclosures

shirts

Design Temperature: Enclosures

shirts

The design pressure for the body of the apparatus is taken equal to:

(2.1)

Let's check the need to take into account the pressure of the hydrostatic column of liquid by checking the condition:

; (2.2)

; (2.3)

where is the density of the medium in the housing at operating temperature. The medium in the housing is a 30% glycerol solution. The density of the solution is determined by the formula:

; (2.4)

where W - humidity, accept W=90%;

T=275 - 295 0 K, accept T=290 0 K;

The height of the liquid level in the apparatus body;

The condition is met, therefore, the pressure of the hydrostatic liquid column in the apparatus must be taken into account. Then the design pressure is determined by the formula:

; (2.5)

We select the allowable stresses of the case material according to Table 1.4 at the design temperature

We select the allowable stresses of the shirt material according to Table 1.3 at the design temperature

Design pressure for jacket:

(2.6)

Let us check the need to take into account the hydrostatic column of liquid in the jacket. According to formula (2.3):

Then by formula (2.2) we obtain:

Since the condition is not met, the pressure of the hydrostatic liquid column in the apparatus is not taken into account. Hence.

Test pressure during hydraulic testing of the body is determined by the formula for:

; (2.7)

The test pressure during hydraulic testing of the jacket is determined by the formula for:

; (2.8)

Permissible stresses during hydraulic testing are determined by the formula:

; (2.9)

where is a correction factor that takes into account the type of workpiece. For steel sheet

Steel yield strength at 20 0 C. For steel 12X18H10T; for steel Vst3sp5;

For body material;

For shirt material.

Let's check the need to calculate the apparatus for the internal test pressure by checking the condition:

; (2.10)

where - hydrotest pressure is determined by the formula:

; (2.11)

where is the density of water at;

The height of the liquid column (water);

By formula (2.10) we obtain:

The condition is not met;

We check condition (2.10) for the shirt:

where is the height of the water level in the jacket during hydrotesting;

By formula (2.10) we obtain:

The condition is not met, therefore, the calculation of the strength of the jacket of the apparatus under hydrotesting conditions is required.

STRENGTH CALCULATION OF THE MAIN ELEMENTS OF APPARATUS

Calculation of cylindrical shells

Let's start with the calculation of the cylindrical shell of the body.

Two pressures act on the shell: excess internal (inside the reactor) and external pressure (pressure in the jacket), thus, when calculating the cylindrical casing shell, there will be two thickness options, from which you need to choose the maximum.

The volume occupied by the shell is determined as the difference between the volume of the apparatus and the volume of the bottom:

; (3.1)

Shell height:

; (3.2)

Estimated length of the cylindrical shell of the body:

; (3.3)

where is the length of the shell on which external pressure acts;

The height of the cylindrical part of the mating bottom, we take according to p.118;

The height of the elliptical part of the bottom;

3.1.1 Calculation of the wall thickness of the hull shell loaded with excess internal pressure

We determine the calculated thickness of the hull shell, the calculation is carried out according to and:

; (3.4)

where is the internal pressure;

Shell diameter;

Estimated shell thickness for hydraulic testing conditions:

; (3.5)

Checking the condition:

; (3.6)

The condition is not met, therefore, .

The effective wall thickness is determined by the formula:

; (3.7)

where from - the total value of the increase to the calculated wall thicknesses. Value With is determined by the formula:

; (3.8)

where from 1 – an increase to compensate for corrosion and erosion;

From 2 - an increase to compensate for the negative tolerance;

From 2 – technological increase;

Increase from 1 is determined by the formula:

; (3.9)

where is the corrosion rate of the body material - steel 12X18H10T

T = 20 years - the service life of the apparatus;

values c 2 , c 3 are equal to zero.

By formula (3.7) we obtain:

Choose the nearest larger standard value.

3.1.2 Calculation of the wall thickness of the casing shell loaded with external pressure

The approximate wall thickness is determined by the formula:

; (3.10)

where is the coefficient determined according to Fig. 6.3 depending on the values of the coefficients and:

; (3.11)

where - stability factor for working conditions, accepted according to p.105;

Stability factor for hydrotest conditions, accepted according to p.105;

Modulus of elasticity for steel 12X18H10T;

Modulus of elasticity for steel Vst3sp5;

Estimated external pressure, taken equal to the water pressure in the jacket;

for working conditions: ;

for hydrotesting: .

Estimated coefficient K 3 is determined by the formula:

; (3.12)

We define: for operating conditions

For hydrotesting conditions.

According to formula (3.10) for operating conditions:

For hydrotest conditions:

The design wall thickness of the casing shell loaded with internal and external pressure is taken from the maximum condition:

; (3.13)

; (3.14)

Axial compressive force F is determined by the formula:

for working conditions; (3.15)

for hydrotest conditions (3.16)

Let's check the stability of the body shell. The condition must be met:

for working conditions; (3.17)

for hydrotesting conditions; (3.18)

where and - pressure in operating conditions and hydrotesting, respectively;

And - permissible external pressure in working conditions and in conditions of hydrotesting;

And - allowable axial compressive force under operating conditions and under hydraulic testing conditions;

Permissible external pressure from the strength condition:

In working conditions; (3.19)

under hydrotesting conditions; (3.20)

In working conditions; (3.21)

where B 1 - is defined as follows:

; (3.22)

accept B 1 =1;

Under hydrotest conditions (3.23)

Permissible external pressure, taking into account strength and stability:

In working conditions; (3.24)

Under hydrotesting conditions; (3.25)

Let's check the shell strength condition:

In working conditions; (3.26)

Under hydrotesting conditions; (3.27)

The strength conditions are met.

Permissible axial compressive force from the strength condition:

For working conditions; (3.28)

for hydrotesting conditions; (3.29)

Permissible axial compressive force from the condition of stability within the limits of elasticity at; (3.30)

; (3.31)

For working conditions;

for hydrotesting conditions.

Permissible axial compressive force considering both conditions:

For working conditions; (3.32)

for hydrotesting conditions; (3.33)

We check condition (3.17):

We check condition (3.18):

Both stability conditions are satisfied.

3.1.3 Calculation of the jacket shell loaded with internal pressure

The design shell thickness of the jacket is determined by the formula:

; (3.34)

where is the pressure in the jacket;

shirt diameter;

Strength factor of the weld for butt welds of the jacket with double-sided continuous penetration, performed by automatic welding;

For hydrotest conditions:

; (3.35)

As design thickness

Executive wall thickness:

; (3.36)

where c is determined by the formula:

; (3.37)

where is the corrosion rate of the body material - steel Vst3sp5

We accept a larger standard value.

For working conditions; (3.38)

for hydrotesting conditions; (3.39)

Checking the strength condition

For working conditions; (3.40)

For hydrotesting conditions; (3.41)

Bottom calculation

We start the calculation from the bottom of the case. Two pressures act on it: external and internal excess.

3.2.1 Calculation of the bottom of the hull loaded with excess internal pressure

In working conditions; (3.42)

where is the internal pressure;

bottom diameter;

Permissible stresses for steel 12X18H10T at;

The strength factor of the weld in automatic arc electric welding, we accept according to;

under hydrotesting conditions; (3.43)

Of the two values, we choose the larger one, i.e. .

3.2.2 Calculation of the wall thickness of the bottom of the hull loaded with external pressure

The wall thickness of the elliptical bottom is calculated by the formula:

In working conditions; (3.44)

where K E is the reduction factor for the radius of curvature of the elliptical bottom. For preliminary calculation, we accept K E \u003d 0.9;

Under working conditions

or;

for hydrotesting conditions; (3.45)

or;

The calculated thickness of the wall of the bottom of the housing, loaded with excess internal and external pressure, is taken from the condition:

; (3.46)

8.5mm.

Executive wall thickness:

; (3.47)

We accept a larger standard value.

Permissible internal overpressure:

; (3.48)

Let's check the strength condition:

; (3.49)

Permissible external pressure is determined by the formula:

For working conditions; (3.50)

Permissible pressure from the strength condition:

; (3.51)

Permissible pressure from the stability condition:

; (3.52)

Coefficient K e determined by the formula:

; (3.53)

; (3.54)

For hydrotesting conditions; (3.55)

; (3.56)

Permissible pressure from the stability condition:

; (3.57)

Checking the strength condition

For working conditions; (3.58)

For hydrotesting conditions; (3.59)

Both strength conditions are met.

3.2.3 Calculation of the bottom of a jacket loaded with excess internal pressure

The design wall thickness of the elliptical bottom is determined by the formula:

In working conditions; (3.60)

where is the internal pressure;

shirt diameter;

Permissible stresses for steel Vst3sp5 at;

The strength factor of the weld in automatic arc electric welding, we accept according to;

under hydrotesting conditions; (3.61)

Of the two values, we choose the larger one, i.e. .

Executive wall thickness:

; (3.62)

We accept a larger standard value.

Permissible internal overpressure:

For working conditions; (3.63)

for hydrotesting conditions; (3.64)

Checking the strength condition

For working conditions; (3.65)

For hydrotesting conditions; (3.66)

Both strength conditions are met.

Calculation and strengthening of holes

Let's calculate the hole that does not require strengthening:

; (3.67)

where; (3.68)

; (3.69)

We check the condition: ; (3.70)

The condition is met, therefore, this hole should not be strengthened. This also applies to other holes.

Selection of flange connection and calculation of its bolts

Material of bolts, nuts - steel 35 GOST 1050-74;

Flange material - 20K;

Gasket material - paronite GOST 480-80;

Estimated pressure inside the apparatus - 0.136 MPa;

Design temperature -

Internal diameter of flange connection;

wall thickness;

The main parameters of the flange connection:

Flange inner diameter;

Flange outer diameter;

Bolt circle diameter;

Geometric dimensions of the sealing surface;

Flange thickness;

Bolt hole diameter;

Number of holes;

bolt diameter;

Main gasket parameters:

Outside diameter;

Inner diameter;

Laying width;

Load acting on the flange connection from excessive internal pressure:

; (3.71)

where is the average diameter of the gasket;

; (3.72)

Gasket reaction under operating conditions:

; (3.73)

where is the effective width of the gasket;

for flat gaskets; (3.74)

Coefficient, accepted by ;

The force arising from temperature deformations. For weld flanges of the same material:

; (3.75)

where is the number of bolts;

; (3.76)

where is the pitch of the bolts;

; (3.77)

Dimensionless coefficient. For connections with welded flanges:

; (3.78)

where; (3.79)

where is the linear compliance of the gasket;

(3.80)

where is the ultimate elasticity modulus of the gasket material, taken according to ;

Linear flexibility of bolts:

; (3.81)

where is the estimated length of the bolt:

; (3.82)

where is the length of the bolt between the bearing surfaces of the bolt head and the nut;

; (3.83)

- ;

Estimated cross-sectional area of the bolt on the inner diameter of the thread, ;

Longitudinal modulus of elasticity of the bolt material;

Flange Angular Compliance:

; (3.83)

where w is a dimensionless parameter;

Coefficient;

Dimensionless parameter;

Estimated flange thickness;

Longitudinal modulus of elasticity of the flange material;

; (3.84)

where is a dimensionless parameter;

; (3.85)

for flat welded flanges; ; (3.86)

We accept according to;

; (3.87)

where; (3.88)

Equivalent flange spigot thickness for flat weld flanges;

Smaller thickness of the conical flange bushing;

But; (3.89)

We accept according to;

Coefficient of thermal linear expansion of the flange material;

Coefficient of thermal linear expansion of the bolt material;

According to ;

; (3.90)

where is a parameter, we accept according to ;

Rigidity factor of the flange connection;

; (3.91)

where; (3.92)

for flat welded flanges.

We accept according to;

; (3.93)

Reduced bending moments in the diametrical direction of the flange section:

; (3.94)

; (3.95)

; (3.96)

Bolt strength conditions:

; (3.97)

; (3.98)

; ;

; .

The torque on the key when tightening the bolts (studs) is determined by.

Gasket strength condition:

; (3.99)

; .

The gasket strength condition is met.

s 1 flange:

; (3.100)

at - accept according to

Maximum stress in section s 0 flange:

; (3.101)

where - we accept according to;

Stress in the flange ring from the action of the moment M 0 :

; (3.102)

Stresses in the flange sleeve due to internal pressure:

; (3.103)

; (3.104)

Flange strength condition:

; (3.105)

at; (3.106)

Flange Angle:

; (3.107)

for flat flanges ;

. (3.108)

Selection and calculation of the support

The calculation is carried out according to .

We determine the calculated loads. The load on one support is determined by the formula:

; (3.109)

where, - coefficients depending on the number of supports;

P is the weight of the vessel under operating conditions and under hydrotesting conditions;

М – external bending moment;

D - shirt diameter;

e - the distance between the point of application of force and the backing sheet.

Since the external bending moment is zero, formula (3.109) takes the form:

; (3.110)

With the number of supports;

Vessel weight in working conditions;

Vessel weight under hydrotest conditions;

for working conditions;

for hydrotesting conditions;

Axial stress from internal pressure and bending moment:

; (3.111)

where is the wall thickness of the apparatus at the end of its service life;

; (3.112)

where s is the effective wall thickness of the apparatus;

C - increase to compensate for corrosion;

From 1 - additional increase;

for working conditions;

for hydrotesting conditions.

Circumferential stress from internal pressure:

; (3.113)

for working conditions;

for hydrotesting conditions.

Maximum membrane stress from main loads and support reaction:

; (3.114)

for working conditions;

for hydrotesting conditions.

The maximum membrane stress from the main loads and the support reaction is determined by the formula:

; (3.115)

[ 1, p.293, fig.14.8] ;

for working conditions;

for hydrotest conditions

Maximum bending stress from support reaction:

; (3.116)

where is a coefficient depending on the parameters and.[ 1, p.293, fig.14.9] ;

for working conditions;

for hydrotesting conditions.

The strength condition has the form:

; (3.117)

where - for operating conditions;

For hydrotesting conditions;

for working conditions;

for hydrotesting conditions;

The strength condition is met.

The thickness of the overlay sheet is determined by the formula:

where is the coefficient, we accept according to ;

for working conditions;

for hydrotesting conditions;

We finally accept.

CONCLUSIONS

The result of the course design is a detailed calculation of the apparatus and its elements based on the conditions of its operation. In particular, the thicknesses of the shell, jacket, bottom were calculated; flange connection calculation; hole strengthening calculation; support calculation. The selection of materials was also made taking into account technical and economic indicators. Most of the thicknesses of the elements of the device were taken with a margin based on strength calculations, which makes it possible to use the device under more severe conditions than the specified ones.

So, based on the calculation, we can conclude that the designed apparatus is suitable for operation under the given conditions.

BIBLIOGRAPHY

1. Lashinsky A.A. Design of Welded Chemical Apparatuses: A Handbook. - L .: Mechanical engineering. Leningrad. department, 1981. - 382 p., ill.

2. Mikhalev M.F. "Calculation and design of machines and devices for chemical production";

3. Lecture notes on CREO

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