RU2635303C2 - Reservoir for process operations with oil or oil products with self-extinguishing in reservoir - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: in the upper part of the reservoir wall, grill cassettes with a packed granular extinguishing material, for example foam glass, are fixed around the perimeter, and the packages are made of low-melting oil-and-petrol resistant material, for example polyethylene, with melting point less than 200°C. With occurrence of flame inside the reservoir and reaching the melting point of the packages, the granular extinguishing material is deposited on the surface of the oil product to extinguish the fire source by spraying.

EFFECT: providing self-extinguishing of the reservoir by preventing the development of oil product combustion power, and increasing the fire fighting efficiency, as a result of which temperature radiation is reduced to the surrounding medium.

2 dwg

Description

The invention relates to tanks for technological operations with oil and oil products. Known tanks with external fire extinguishing systems: foam, sublayer or gas.

According to the requirements of GOST 31385-2008, paragraphs V9 and SP21-104-98 “Code of practice for the design of fire protection systems for tank farms of the Goskomrezerv of Russia,” the tanks are equipped with stationary foam suppression systems (SPT) and systems from mobile vehicles (SPT).

The disadvantage of fire extinguishing systems from mobile vehicles is a long time from the moment of ignition to the moment of foam supply, the fire is gaining full power and complicates approaches to the tank.

The closest technical solution to the proposed invention is SSPT. SSPTs consist of a pumping station, water tanks and a foaming agent, a foam generator for producing foam of appropriate multiplicity, valves with remote control, metering equipment, pipelines for supplying solution from the pumping station to the foam generators installed on the tank, and automation equipment.

The disadvantage is poor reliability and complexity of the systems, in case of failure of any of the components of the system, foam extinguishing does not work, in addition, at low ambient temperatures, freezing of the liquid (foaming agent solution, water) in the foam pipes or fittings and blockage of the pipeline is possible. SSPTs are inertial, the time from the moment of ignition to the supply of foam to the burning liquid in the tank is also long, it takes time for the actuators to operate, turn on the pumps, open the valves on the foam pipes. During this period, the flame manages to gain more power, which makes foam suppression difficult.

The purpose of the invention is self-extinguishing by a fire tank, preventing the development of powerful combustion of the oil product and increasing the efficiency of fire fighting.

This goal is achieved by the fact that

- for self-extinguishing a fire in the tank around the perimeter of the stiffening ring or in the upper part of the tank wall in lattice cassettes, packaged granular extinguishing material, for example foam glass, is placed, and the sealed bags are made of fusible oil and petrol resistant material, for example polyethylene;

- in order to prevent the development of powerful combustion of the oil product in the tank, the melting temperature of the package material does not exceed 200 ° C, the quenching material from the packages is dumped onto the burning surface of the oil product in the initial period of ignition at relatively low temperatures;

- fire extinguishing efficiency is achieved by more than ten-fold reduction in temperature radiation around the burning tank, which reduces the risk of fire or explosion on adjacent tanks, creates more favorable conditions for the operational personnel of mobile fire extinguishing systems to complete the fire.

In FIG. Figure 1 shows a cross-sectional general view of the tank with lattice cassettes located along the perimeter in the upper part of the tank wall with packaged extinguishing material, for example, granulated foam glass, at the time of melting of the packages and the extinguishing material spilling onto the burning surface of the oil product.

In FIG. Figure 2 shows the closed surface of the burning oil product with the extinguishing material spreading over the surface and possible individual small points with incomplete extinguishing of the oil product.

In FIG. 1 shows schematically located along the perimeter and fixed on the stiffening ring 2 lattice cartridges 4 with packaged extinguishing material 3 and spilled extinguishing material 5 after melting and depressurization of the packages, the outline of the flame 6 inside the walls 1 in the tank.

In FIG. 2 shows cassettes 3 after the packages were melted and the extinguishing material spilled onto the surface of the oil product, the extinguishing material spreading out on the surface of the oil product 9 and the possible remaining small windows that were not covered by the extinguishing material on the surface of the oil product with small flame tongues 7.

The tank with self-extinguishing fires works as follows.

In the normal operating position, lattice cartridges with packaged granular extinguishing material, for example, foam glass, are fixed along the perimeter in the upper part of the tank. The volume of the extinguishing material is calculated based on the complete coverage of the surface of the oil product with a layer sufficient to extinguish the flame. The experimental data confirmed the sufficiency of the layer, for example, granulated foam glass of 30-50 mm.

Sealed oil and petrol resistant bags are made of material with a melting point less than 200 ° C, for example polyethylene film thickness (0.5-1.00 mm).

With the occurrence of a flame on the surface of the oil product and reaching a temperature in the upper part of the tank of about 200 ° C, the packages melt and the extinguishing material wakes up on the surface of the oil product, spreading over the surface, the granules of the extinguishing material extinguish the flame, preventing powerful combustion from developing. The flame power is more than ten times reduced in comparison with a flame without the use of self-extinguishing.

The amount of extinguishing material, the number of lattice cassettes and the amount of extinguishing material in the cassette are calculated by the formulas

V _tm = (πd ² : 4) × T _tm ;

_to n = πd: l;

V _tmk = V _tm : n _to

where V _tm - the amount of extinguishing material;

d is the diameter of the tank;

T _tm - the necessary layer of extinguishing material;

l is the width of the cassettes, in practice it is 1-2 m;

V _tmk - the amount of extinguishing material in the cartridge;

n _to - the number of cassettes.

Even in cases of incomplete fire extinguishing and the presence of individual small combustion points, due to a sharp decrease in temperature radiation to the environment, safe conditions are created for the operational personnel of mobile fire extinguishing equipment. If necessary, the completion of the extinguishing carried out by the inclusion of automatic fire extinguishing systems or mobile means with the supply of foam in the tanks. The service life of the material of the perimeter cartridges, packaged extinguishing material is not less than the service life of the tank.

Claims (1)

The tank for technological operations with oil and oil products with self-extinguishing fires in the tank, containing sealed vertical steel cylindrical walls, a roof and a bottom, is characterized in that the tank for self-extinguishing fires in the tank is equipped with perimeter lattice cassettes with packaged granular extinguishing material, for example, granular foam glass, fixed in the upper part of the tank wall, for example, to the stiffening ring, and the packages are made of fusible oil and petrol resistant mat series.

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