CS238873B1 - Ways to protect taclmolojic equipment from potential explosions - Google Patents

Abstract

The invention provides a method of protecting technological equipment spaces from a potential explosion of a mixture of flammable substances with air by inerting. Fly ash containing flammable substances is removed from the technological equipment space, combusted with air and gaseous and/or liquid and/or solid fuel, and the gaseous atmosphere of the protected space is inerted with the combustion gas thus obtained in an amount controllable according to the residual oxygen content in the gaseous atmosphere.

Description

(54) Means of protecting the spaces of taclolo- gical installations from potential explosions

The invention solves a method of protecting the premises of technological equipment against the potential explosion of a mixture of flammable substances with air by inertization. Flyn containing flammable materials is discharged from the process plant space, combusted with air and with gaseous and / or liquid and / or solid fuel, and the combustion gas thus obtained in an amount controlled by the residual oxygen content of the gaseous atmosphere is inerted.

The invention relates to a method of protecting the premises of technological equipment against the potential explosion of a mixture of flammable substances with air and their simultaneous disposal.

A number of process equipment releases flammable gases, vapors, and dispersion mixtures that can form explosive mixtures with air under appropriate conditions during the manufacturing or processing process. Most often, such technological processes are associated with heating substances for drying, evaporation of solvents, heat treatment of plastics, respectively. creating suitable reaction conditions. In such cases, the potential risk of explosion is further exacerbated by the presence of initiating sources or heat carriers, which, depending on the conditions and type of substances, may be an initiating source of the explosive process. In particular, drying devices as well as reactively deposited dusts, which can ignite spontaneously and subsequently cause an explosion or fire, pose a great risk of possible initiation.

The knowledge regarding explosion protection of technological equipment spaces is insufficient. The current state of explosion protection consists of protective measures which are generally imposed by state standards.

One form of explosion protection is to prevent the formation of explosive concentrations of flammable substances in the air, which is mainly provided by intensive ventilation of the hazardous area so that the concentration of the explosive in the atmosphere does not reach half the concentration of the lower explosive limit. The disadvantage of this method is the high consumption of heat (if the environment must be heated), the air containing flammable substances pollutes the production environment and does not use the heat capacity of the dissipated substances hidden in their combustion heat.

The premises of the technological equipment can be protected from the potential explosion by inertization of the gaseous environment of the technological equipment. This inertization is carried out in turn by adding inert gases - carbon dioxide, nitrogen, water vapor, halogenated hydrocarbons to the atmosphere of the production plant according to technological possibilities. The disadvantage of this method is the relatively high cost of the inerting means, the heat that can be obtained from the combustion of combustible substances is not used and, as in the previous process, the removal of the substances away from the plant pollutes the production environment.

The third basic means of protection is the technical equipment of the device, which prevents the possible initiation of formed explosive mixtures. This is done by eliminating possible initiation sources from the environment where there is a potential for the formation of explosive mixtures or by using explosion-proof equipment (electrical equipment).

In practice, double safety measures are usually used to enhance occupational safety by combining these as necessary, but with increased costs. Pollution of the environment and energy losses resulting from the unused energy potential of released flammable substances are the same as in the previous methods of protection.

The above mentioned methods of protection, especially Inertisation of the endangered area, are used mainly for the protection of the free space of tanks of flammable liquids, tankers, aircraft tanks, coal mills. However, the current use of the energy potential of hazardous substances and the disposal of these substances as exhalates are not addressed in the current known procedures.

The aforementioned disadvantages are eliminated by the method of protecting the premises of technological equipment against the potential explosion of a mixture of flammable substances with air by inerting with combustion gases, which is done so; The method according to claim 1, characterized in that the gas containing flammable substances is discharged from the process plant space, is burnt with air and with gaseous and / or liquid and / or solid fuel, and then the combustion gas obtained in an amount controlled according to residual oxygen content in the gas atmosphere is inerted.

Advantages of said method include the fact that the inert gas is combustion gases, i. j. waste product of combustion of the heating installation, whereby the generated heat can be used for technological or hygienic needs of workers. Another advantage is the fact that the combustible substances leaving the vapor from the technological process are economically used for heat recovery. The disposal is also an advantage! harmful pollutants endangering work and the environment.

The inertial rate is determined by the residual oxygen content in the environment, which is checked continuously by a suitable oxygen analyzer. The residual oxygen content in the gaseous atmosphere of the device must not be greater than 0.8 parts of the critical oxygen content needed to burn the respective combustible, for most substances it is about 8% by volume.

A certain amount of gases are continuously withdrawn from the protected area of the technological equipment, which represents the increase of flammable substances in the protected area and is led together with the air separately to the combustion plant, which is also supplied with energy fuel. In the combustion plant, combustible substances leaving the technological equipment are also burned with the fuel. Supply of inert gas of combustion gases. to the protected space is carried out from the combustion gas source, the chimney space through the system of protective devices.

Example 1

A certain amount of gases are continuously withdrawn from the gas space of the process equipment, which represents the increase of flammable substances in the protected space and is introduced into the air, which is led to the combustion plant, which is simultaneously supplied with energy fuel. In the combustion plant, combustible substances leaving the process equipment are also burned with the fuel. Combustion gases with an oxygen content of less than 2% by volume are fed into the explosion-proof device (oven) equipped with an oxygen analyzer according to the volume of the free space. so that in the gaseous protected space the amount of oxygen is below 8% vol. After inertization, the gaseous atmosphere of the process equipment has no greater oxygen content than 8% by volume. in areas where hydrocarbons are handled and 4% by volume when hydrogen is present.

Example 2

In the drying chamber with a free volume of 5 m ³ , the material with the applied coating material is fed, from which the solvents evaporate in an amount of about 5 kg / h. At the same time, approx. 5 m ^{3 of} air is sucked into the dryer through the openings and blows 5 m ^{3 of} inert gas with a residual content of 0.1 to 2% vol. oxygen.

The mixture of gases - solvent vapors, air and combustion gases is discharged from the dryer to the combustion plant, which simultaneously burns in 65 m ^{3 of} air and 1 m ^{3 of} natural gas also exhausted flammable solvent vapors withdrawn from the protected space. '

Of the resulting combustion gases, a portion is used to inertize the free space of the dryer and the remainder is discharged through the chimney into the atmosphere. The heat obtained is suitably used.

Example 3

The procedure is as in Example 2. Instead of a natural gas combustion plant, a solid or liquid fuel combustion plant is used.

Claims (3)

EXAMPLE 1 A number of gases are continuously withdrawn from the gaseous space of the process equipment, which represents the flammable substances in the protected space and is fed to the air which is fed through the after-burning device to which the energy fuel is simultaneously supplied. In the combustion plant, both combustible and combustible materials from the process equipment are burned with the fuel. According to the volume of free space, the explosion-proof device (an oven equipped with an oxygen analyzer is fed with combustion gases with an oxygen content below 2% by volume, so that an oxygen content of less than 8% by volume is present in the gas-protected space). The gaseous atmosphere of the process equipment does not have a higher oxygen content than 8% by volume in areas where carbon-hydrogen and 4% by volume are used when water is present. 2 A material with a applied coating material is added to the 5 m3 free volume dryer and the solvents are evaporated in an amount of about 5 kg / h. At the same time, about 5 m 3 of air is sucked into the dryer through the open holes and 5 m 3 of inerting combustion gas with a residual content of 0.1 to 2% by volume of oxygen is blown from the combustion device. The gas / vapor mixture of the solvent, air and combustion gases is discharged from the combustion apparatus dryer, in which the exhausted vapors of the solvent removed from the protected space are also burned in 65 m 3 of air and 1 m 3 of natural gas. From the resulting combustion gases, a portion is used to inertize the free space of the dryer and the remainder is discharged through the stack into the atmosphere. The heat obtained is useful. Example 3 The procedure of Example 2 is followed. A solid fuel or liquid fuel firing plant is used for the natural gas firing plant. E R E D E T E A method of protecting the premises of technological equipment from potentially explosive mixtures of combustible substances with combustion gases. characterized in that the gas containing the combustible substances is discharged from the technical equipment space, is combusted with air and gas, and / or liquid and / or solid fuel, and then with the thus obtained combustible gas in a controlled amount The amount of residual oxygen in the gas atmosphere is inerted by the gaseous atmosphere of the protected space.