RU2553850C1 - Plant to drain liquefied hydrocarbon gases (lhg) from tank car, method of lhg draining from tank car with application of said plant, plant for degassing of said tank car with its application as well as method of lhg draining and tank gas degassing with application of these plants - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to operation of tank cars used for transportation of LHG. Plant for draining of LHG from tank car (1) is equipped with angular fill-discharge valves (6 and 7), angular valve for LHG (8) vapour bleed and feed, fill-discharge pipes (4) and a pipe for LHG (5) vapour bleed and feed. It includes tank car (12) to intake said LHG. Tank car (12) incorporates fill-discharge valves (34 and 35), angular valve for LHG bleed and feed valves (36) and bleed and feed pipes (37). Besides, it comprises tank car (13) for displacing fluid with its equalizing pipeline inlet (40) connected to valve (8) of tank car (1) and outlet coupled with valve (82) of tank car (12). Bypass pipeline (38) is connected by its inlet to valve (7) of tank car (1) and by its outlet with valve (36) of tank car (12). Pressure pipeline (15) is connected by its inlet to valve (13) of tank car (1) and by its outlet with valve (6) of tank car (1). Pipeline (15) is provided with LHG check valve (22) and valves (21) and (17) fitted at the section between valve (22) and tank car (13). Displacing fluid pump (20) can develop pressure of at least 2.5 MPa. Pump inlet is connected to suction line (39) provided with check valve (16) and inlet located nearby tank car bottom (13) and outlet connected to pipeline (15) at the section between valves (21) and (17) via valve (30).

EFFECT: emptying of emergent tank cars, gassing at emergency sites, stationary operating conditions without application of expensive compressors and liquid nitrogen.

33 cl, 2 ex, 3 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the operation of rail tank cars (VC) used for transporting liquefied petroleum gases (LPG) and is aimed at the safe emptying and degassing of emergency CC from LPG in the field. The invention can also be used in stationary conditions, for example, in the conditions of a car repair depot, for safe emptying and degassing from LHG of emergency CCs and CCs that require repair.

BACKGROUND

During rail transportation, on the route, emergency situations may occur with the CC containing LPG as a result of accidents, train wrecks and train gatherings. These accidents, and especially accidents with rollover and collisions of the CC, are accompanied by damage to the wagon trolleys, the wagon frame, the tank boiler and other wagon structures. Possible disruption of the boiler tank from the frame, damage to the shut-off and safety valves of the boiler, violation of the integrity of the shells and bottoms of the boiler with the formation of leakage of LPG. In case of accidents with a CC containing LPG, emergency situations can develop according to the following scenarios: fire of the strait, fire of a tank car, formation of a fireball, explosion of a gas-air cloud, explosion of a tank car. The distance to the safety zone for people and buildings with a fireball and an explosion of a tank car containing propane is 190 meters and 1281 meters, respectively, under normal conditions (see Questions on warning, warning, localization, mitigation and liquidation of emergency situations and their consequences during transportation dangerous goods on the railways of Ukraine // Collection of materials of the scientific and practical conference September 12-13, 2013 Odessa, TzOV “Vidavnichy Dim Ukrpol”, 304 pages). In case of accidents of a CC with LPG, there is a danger of fires and explosions on the railway and residential zone, a threat to the life of the population is created, and the normal functioning of railway transport is disrupted.

In the event of a CC accident with LPG, in the presence of a van tank wagon and overturning, and LPG leakage, it is necessary to eliminate product leakage and organize LPG pumping out of the CC on the spot, in the field conditions of the railway, and then carry out its degassing. This will allow you to safely transport the emergency CC and send it, for example, to a car repair depot for inspection and repair work.

However, to date, effective mobile plants have not been developed for pumping LPG from the CC and degassing. This is due to the lack of facilities for the emptying and degassing of HCs from LPG that are acceptable in mass and size characteristics, which could be applied in the field. At the same time, each of the more than 300 fire trains of Russian Railways (see the publication "The company increased the number of fire trains" // Electronic resource http://www.01.ru/?id=37266) have pumping units and empty tank cars for emptying emergency oil tank cars from oil and pumping oil into empty tank cars.

It should also be noted that the frequency of scheduled repairs of the CC for LPG is strictly regulated. In railway tanks, a part of the product (propane-butane gases and mixtures) always remains in both the gaseous and liquid state after the discharge of the main volume. To safely carry out repair and hot work during scheduled repairs of the CC, it is also necessary not only to remove the LPG in the liquid state (empty the CC from the LPG in the liquid phase), but also to degass the tank. Degassing of a CC consists in the removal of LPG vapor from a CC to its safe concentration in the air of the CC, or in another gas mixture located in the CC.

Consider the features of the design and operation of the CC for LPG, as well as fire safety rules and the procedure for handling emergency CC with LPG.

LPG are stored and transported to the CC under elevated overpressure (up to 2.0 MPa), therefore the action of the “Rules for the Construction and Safe Operation of Pressure Vessels” of the Gosgortekhnadzor of Russia applies to tank boilers (see Rules for the Construction and Safe Operation of Vessels Operating under pressure // Gosgortekhnadzor of Russia. Moscow, PIO OBT, 1996).

LPG are dangerous goods, therefore, the organization of transport, maintenance of tanks in technically sound condition, repair and maintenance of tanks is subject to the "Safety Rules for the Transport of Dangerous Goods by Rail" (Rules for the Transport of Dangerous Goods by Rail, Ministry of Railways of the Russian Federation. // Moscow, Transport , 1997).

Particular attention when working with a CC containing LPG is given to meeting the requirements of the Fire Safety Rules in the Russian Federation PPB 01-03 (Fire Safety Rules in the Russian Federation. PPB 01-03 // Moscow, 2003, 91 pp. See electronic resource http : //www.rubin01.ru/zakonodatelstvo/pravila-pozharnoj-bezopasnosti-ppb-20171/pravila-pozharnoj-bezopasnosti-ppb/ppb-01-03-pravila-pozharnoj).

It is also necessary to observe the safety rules and the emergency response procedure for CCs with LPG when transporting them by rail (see Safety Rules and the emergency response procedure for dangerous goods when transporting them by rail, Ministry of Railways of the Russian Federation // Moscow, 1997).

At the same time, the parameters of the main structural element of the tank — the boiler in the form of a vessel operating under pressure — and the technical condition of the discharge and loading valves are extremely important for ensuring the safety of transportation.

Below, as an example, the characteristics of the tank car 15-9872 for the transportation of liquefied hydrocarbons are given (Tank car 15-9872 for the transportation of liquefied hydrocarbons // Electronic resource http://www.nvc-vagon.ru/services/new/service4_10 .html).

Tank car 15-9872 is designed for transportation of 1520 mm gauge hydrocarbon gases by rail with a saturated vapor pressure at a temperature of 50 ° C of not more than 1.928 MPa (19.28 bar) and their mixtures, as well as liquids with a density of not more than 0.731 t / m ³ .

A wide range of LPG, including propane, butane, and other gases, as well as their mixtures, differing in their chemical and physical properties, is transported in Exhibition Center 15-9872. Common to all these products is that at low temperatures (up to -40 ° C) and a pressure of not more than 2.0 MPa, they pass into the liquid phase. According to the degree of danger, all of them belong to class 2.3 - flammable (combustible) gases.

The tank boiler is designed for an operating pressure of 2.0 MPa, has a wall thickness of the cylindrical part of 20 mm and bottoms of 22 mm. A hatch with a diameter of 528 mm is located in the middle of the boiler.

Drainage, control and measuring valves and safety valve are located on the manhole cover and are closed with a protective cap. Drain and bulk fittings include three valves (two liquid and one gas). Instrumentation includes two valves for monitoring the preliminary and maximum filling levels, a drain control valve, and a valve for cleaning product residues. Technical characteristics of the tank car model 15-9872 are shown in table 1.

Table 1 Technical characteristics of the tank car model 15-9872 Carrying capacity, t 52 Tare Weight, t 38 The volume of the boiler, m ³ 83.9 The diameter of the boiler is internal, mm 3200 Boiler length, mm 11000 Operating pressure in the boiler, MPa 2.00 ± 0.01 Design pressure in the boiler, MPa 2.11 ± 0.01 Trial pressure in the boiler during a hydraulic test, MPa 2.76 ± 0.01

Rules for working with emergency CC containing LPG. The fire safety rules PPB 01-03 provide the following safety measures when working with CC containing LPG, described below.

A tank with a detected malfunction, due to which it cannot follow its intended purpose, must be disconnected from the train and taken to a separate path to a safe place.

If there are specialists, it is necessary to eliminate the leak, if this is not dangerous, pump the contents of the tank into a serviceable tank (tank) in accordance with safety precautions and if there are emergency fire fighting units at the emergency work site. Take the tank car with LPG to a safe place.

In case of intensive leakage, the gas should be allowed to completely exit the tank, while it is necessary to constantly monitor the formation of possible gas zones within a radius of 200 meters until the gas is scattered. Call the operational units of the GPS, the emergency group and the gas rescue service in the area at the accident site. Notify authorities of danger. Do not allow LPG to enter tunnels, basements, sewers.

Repair of the boiler of the tank, its elements, as well as its internal inspection is allowed to be carried out only after the boiler volume is degassed and the work manager has completed the appropriate permit order.

Before working inside the tank boiler, it is necessary to analyze the air in the boiler volume for the absence of a dangerous concentration of hydrocarbons and for the oxygen content. The oxygen content should be within 19 ÷ 20% (vol.). The concentration of combustible substances in the boiler volume should not exceed 20% of the value of the lower concentration limit of flame propagation (hereinafter - LEL) of LPG.

When performing repair work, it is prohibited:

- repair the boiler in the loaded state, as well as in the empty state before the degassing of its volume;

- make blows to the boiler;

- perform welding and firing work under the tank.

The same requirements for the safe operation of tanks are set out in the instructions for filling, draining and transporting liquefied petroleum gases in railway tank cars (Instructions for filling, draining and transporting liquefied hydrocarbon gases in railway tank cars // M .: Nedra, 1980, 32 from.). The specified instruction also includes the following items:

It is forbidden to fill tanks if the residual excess vapor pressure of the product is less than 0.5 kgf / cm ² (for liquefied gases, the vapor pressure of which in winter may be lower than 0.5 kgf / cm ^{2, the} residual excess pressure is set by local production instructions), except for tanks poured for the first time or after repair.

The safety valve should fully open at an overpressure of 23 kgf / cm ² .

Analogs and their shortcomings. Let us consider the methods for discharging LPG from a CC (or liberating a CC from a LPG) and the methods of degassing a CC that are used on the railway. First of all, we are interested in carrying out the indicated operations with emergency CCs at the scene of an emergency (emergency) in the field, as well as in stationary conditions as applied to emergency CCs and CCs that require repair.

In PPB 01-03 the following option is proposed for the liberation of the CC from LPG. In the event of an intensive leak, allow the gas to completely exit the CC, while constantly monitoring the formation of possible gas zones in a radius of 200 meters, until the gas is scattered. Call the operational units of the GPS, the emergency group and the gas rescue service in the area at the accident site. Notify authorities of danger. Do not allow LPG to enter tunnels, basements, sewers. This method is extremely undesirable, especially in residential and industrial areas, due to the explosion hazard of LPG and the stifling effect of hydrocarbon gases.

In the event of an emergency related to depressurization of the CC and ignition of the expiring LPG, the localization and liquidation manager can order the ignition of the expiring LPG, if this does not threaten the safety of people, will not lead to the destruction of other objects and the spontaneous development of fire. Ignition of the gas should be carried out remotely due to shelter with a rocket launcher, firecrackers, etc. Work on burning LPG should be carried out after the arrival of the necessary and estimated number of GPS units at the accident site (see Fire Safety Rules in the Russian Federation. PPB 01-03. Moscow, 2003, 91 pp. // Electronic resource http.//www.rubin01 .ru / zakonodatelstvo / pravila-pozharnoj-bezopasnosti-ppb-2017 / pravila-pozharnoj-bezopasnosti-ppb / ppb-01-03-pravila-pozharnoj).

The specified method is applied in practice. In case of LHG leakage from shut-off valves or damaged CC, the hydrocarbon gas is ignited, and the tank itself is cooled with water jets from fire hoses to prevent heating of the tank under the influence of thermal radiation (see electronic resource http://www.dailymail.co.uk/ news / article-2029891 / Burning-rail-car-holding-29-000-gallons-propane-explode-like-small-thermal-nuclear-bomb.html). If the LPG escaping from the CC is not burned, there is a risk of contamination of the area with asphyxiating and explosive hydrocarbon gas, which is heavier than air and spreads over the terrain, concentrating in the lowlands. The use of this method of removing LPG from a CC is also undesirable due to the loss of a large amount of expensive product, environmental pollution by combustion products, the need to cool the CC with water for a long time - up to a day or more.

In case of serious damage to propane tanks and the impossibility of their safe transportation, it is proposed to burn propane in place using controlled explosions of small profiled explosive charges and pyrotechnic gas arson. At the first detonation, small holes form in the upper part of the tank (near the bottom of the tank) with the simultaneous ignition of gas (from the explosion itself or pyrotechnic means) emerging from the holes under high pressure. This controlled explosion in the upper part of the tank quickly reduces the pressure inside the tank, thereby reducing the likelihood of an explosion of the entire tank as a result of a fire. Shortly after the pressure in the tank decreases, small shaped charges are blown up at the bottom at the other end of the tank, and as a result of the charges blown up, a series of round holes are formed at the bottom of the tank. Through the indicated openings, LPG is poured in the form of a liquid into a previously prepared drainage trench diverted from the tank. In a long drainage trench, LPG is ignited and burned in a controlled manner without the risk of gas overheating in the tank (see The Last Resort: Vent and Burn // Electronic resource http://www.tc.gc.ca/eng/tdg/publications-menu- 1153.htm) The indicated “release and burn” method is recommended as a last resort.

In the field, when it becomes necessary to free the emergency CC from LPG, a mobile flare unit (FU) is also used. It is installed at a safe distance from the CC, for example, 100 meters, and gas is supplied through the flexible hose to the FC from the wagon, controlledly opening an angle valve to equalize the gas pressure. The gas leaving the FU is remotely set on fire, for example, using a rocket launcher.

There is also a more acceptable way to remove LPG from the CC by burning LPG in a stationary FU remote from the CC. It is used for cleaning contaminated surfaces of tank cars from under LPG. In this case, the technological process of processing from under the LPG is complicated by the fact that the residual gas under pressure up to 7 ÷ 15 kg / cm ² , consisting of liquid and vapor phases, can be in the boiler car submitted for processing. Therefore, before carrying out the boiler washing operation, this residual gas must be removed and disposed of. Today, the LHG removal operation is everywhere carried out by a long energy-intensive process, and the excess gas released during this technological process is utilized by burning at the FU, which, in turn, is irrational, because it can be used as an energy carrier, and on the other hand, it obliges to build such training points in close proximity to the existing educational institutions, i.e. near the refinery (see Smolyanov V.M. Ecological safety and resource-saving technologies for processing contaminated surfaces // Electronic resource http://ctg.su/sysfiles/File/Post/Post%2012.%20SYG.pdf).

The widely used method of liberating a HV from LPG by burning gas in a stationary FU remote from the HV is used in car repair depots with the subsequent degassing of the HV by blowing tanks first with gaseous nitrogen and then with steam. After depressurization of gaseous nitrogen, the tank is steamed with hot steam for 6 hours. Steam pressure 0.8 MPa, temperature 180 ° C (see Electronic resource http://rpp.nashaucheba.ru/docs/index-107829.html). Considering that the CC can contain 30 + 45 and more tons of LPG, gas burning in the FU is economically disadvantageous.

A known method of preparing gas tanks for repair and further technical examination, including the discharge of excess pressure from the tank to the flare pipe, where liquefied gases are burned. Overpressure from the tank is vented through a surge valve. Then the tank is inflated with gaseous nitrogen to a pressure of ~ 0.25 MPa and the liquid residue is removed. At the end of the discharge of the liquid residue, excess nitrogen pressure is released onto the candle. After depressurization of gaseous nitrogen, the tank is steamed with hot steam for 6 hours. Steam pressure 0.8 MPa, temperature 180 ° C. The main purpose of steaming is the final degassing and liquefaction of hydrocarbon deposits on the inner surface of the tank. Overpressure is vented through a surge valve connected to the relief manifold onto the candle. Excess steam passes through filters, where it is cleaned of suspended solids and enters sequentially into air-cooling units, in which it condenses and cools to a temperature of 50 ° С. From the air cooling apparatus, steam condensate enters the condensate receiving tank. At the end of the steaming, a sample of the vapor phase for hydrocarbon content is taken from the tank. After steaming and removing condensate, the tank is blown with air with a pressure of 0.8 MPa and a temperature of 20 ÷ 40 ° C.

At the end of the purge, a sample of air for the content of hydrocarbon and oxygen is taken from the tank. Further, if for the technical examination requires cleaning the inner surface of the tank, use rinsing with hot water.

Wash water is removed by a pump to a neutralization station for further treatment (Institute project енг Lengiproneftekhim ’, implemented at the Primorsky KBSG shopping center). This technical solution allows to reduce the amount of manual labor, but has a number of drawbacks, the main of which is the discharge of excess LPG pressure from the tank to the flare pipe, where liquefied gases are burned, as well as a large amount of condensate and wash water to be treated accordingly. The processing time is ~ 900 min (RF patent for the invention No. 2205709).

A known installation of degassing tanks for transportation of liquefied petroleum gases (LPG), including a tank for transporting LPG, a device for the production of a working fluid - nitrogen, a condensate collector, a gas analyzer, inlet and outlet pipelines, control and regulation valves, characterized in that as devices for receiving the working fluid, an adsorption nitrogen unit is used, connected by a supply pipe with a tank and a feed pipe - with a discharge pipe, on which updated: a pre-cooling heat exchanger, a refrigerating machine’s condenser heat exchanger, a filter separator and an LPG collector, the preliminary cooling heat exchanger being connected by a pipeline to the steam zone of the filter separator, and the liquid zone of the heat exchanger-condenser is connected to the pipeline for draining the liquid from the filter separator to the SUG collector, connected by a drain pipe to a tank (RF patent for utility model No. 126635). The known installation of degassing tanks is stationary and cannot be used in the field. The delivery of the most cumbersome part - the adsorption unit - to the emergency site can be very problematic, especially when the access roads to the emergency site of the railway are blocked by debris.

Known technologies for the discharge-loading and degassing of the CC from LPG (Electronic resource http://vipgaztech.ru/index.php/ct-menu-item-4/ct-menu-item-6), based on the use of unified gas technology modules ( UTMG). Technological complex - modular, block-container execution; operated in an open area at an ambient temperature of minus 40 ° C to 45 ° C. The preparation of tank cars is carried out in two stages:

Stage 1. A 100% discharge of the liquid phase of the LPG and complete selection (utilization) of the vapor phase of the LPG to atmospheric pressure are performed. Equipment - “Unified technological module gas type UTMG-03M”.

Stage 2. Degassing (neutralization) of the inner surface of the boiler of the tank car is carried out. Equipment - a modular installation for the production of nitrogen from the air using membrane technology with a purity of nitrogen gas up to 99.9%.

Both stages are combined at the hardware level into a single piping with an additional common control panel.

Degassing is performed as follows.

- tank wagons, which are being repaired or prepared for filling with the remnants of liquefied gases, are fed to the overpass for organizing a complete discharge of the liquid phase and selection of the vapor phase to atmospheric pressure through the use of a special compressor unit and a four-way valve. The number of processed cars - up to 5 ÷ 6 within 4.0 ÷ 5.0 hours.

Upon reaching atmospheric pressure in the boiler, the complex switches to switching on the capacities for degassing (neutralization) using nitrogen gas. The operating pressure of the nitrogen station is up to 1043 atm, the nitrogen capacity is at least 180 ÷ 200 m ³ / h. The processing time of one carriage with nitrogen by the “pressurization” method is not more than 1.5 hours. When processing cars according to the “from car to car” method, the technological time will be up to 1.0 hour. This degassing technology eliminates the need for flare construction.

The use of this technology allows, in particular:

- several times reduce the cost of owners of tank cars for paying tariffs to railway transport enterprises for the discharge and degassing of air handling units using standard methods;

- organize the degassing of tank boilers with the execution of an act in the form of VU-19 (VU-20).

For LHG discharge and CC degassing in the field, it is necessary to use several modules — a module with a special compressor unit, a separate autonomous generator, a cryogenic nitrogen gasifier. Given the scale of the Russian Federation, the search and delivery of all the equipment listed to the scene of the accident is associated with significant loss of time and can be a definite problem. It should be noted that mobile nitrogen gasification units do not belong to widespread types of industrial equipment and are not available in every region of the Russian Federation. In addition, for the deployment of the system, it is necessary to quickly find and deliver to the accident site trained personnel of engineering and working specialties and observers of the equipment-owner company. Thus, the estimated time from the moment of the accident to the beginning of the LPG pumping out can be 8-15 days for the regions east of the Urals, which is unacceptable.

In the description of the patent of the Russian Federation for invention No. 2366520, an apparatus for removing combustible gases from tanks, in particular a propane-butane mixture, is proposed. The installation includes a compressor, a line for exhausting gases from the tank connected to the suction pipe of the compressor, a cooler and a collection tank of liquid propane-butane mixture; the compressor is hydraulically driven and is equipped with an oil pump, an engine and oil lines, and the suction valves of the hydraulic compressor are installed with the possibility of forced opening and closing. The installation is additionally equipped with an ejector, the gas volume of the propane-butane mixture collection tank is connected to the working nozzle of the ejector, the receiving chamber of the ejector is connected to the gas exhaust line from the tank, the ejector diffuser is connected to the suction pipe of the hydraulic drive compressor, and shut-off bodies are installed on the connection lines. A receiver is installed between the ejector diffuser and the suction pipe of the hydraulic drive compressor. The installation is equipped with a heated evaporator, the evaporator is connected to the collection tank by a line equipped with a pump, the gas volume of the evaporator is connected to the working nozzle of the ejector, and shut-off bodies are installed on the connecting lines. The discharge line of the hydraulic compressor is connected to the working nozzle of the ejector by a line with a shut-off element. The engine of the oil pump is made in the form of a gas internal combustion engine. The installation is placed on a movable chassis. The removal of combustible gases from the tank is carried out not by displacing the propane-butane mixture with an inert gas, such as nitrogen, but by evacuating the volume of the tank. After evacuation, the volume of the tank is filled with atmospheric air. Further repairs are carried out after bringing the content of propane-butane in the mixture with atmospheric air to a level below the lower flammability limit. Based on standard data (see, for example, Staskevich NL and others. "Guide to gas supply and gas use", L., ed. "NEDRA" // L.O., 1990, p. 301) , evacuation should be carried out to a residual pressure in the tank at the level of 5-10 mm Hg. (at the lower flammability limit, the content of combustible gas in a mixture with air is not more than 1.7% by volume).

Based on RF patent No. 2366520, scientists from the Ural State University developed an industrial unit for removing residual vapors of liquefied gases (butane, propane, mixtures) from railway tanks (Electronic resource http://exterra.su/degazaciya-zhd-cistern), which has a wide range of application:

- removal of gases from railway tanks (butane, propane, their mixture, etc.) as part of a degassing station;

- preparation for the repair of industrial tanks (tanks, reservoirs and containers), with other hydrocarbon products and chemical compounds (ammonia, methanol, ethanol, etc.);

- maintenance of gas facilities and small tanks when using a mobile installation option.

The principle of operation of this installation is as follows:

- the installation pumps the gases from the tank and compresses them, turning them into a liquid state, after which the liquefied gas enters the receiving tank (receiver);

- the tank is filled with an inert gas, for example technical nitrogen, through a gas separation nitrogen block.

After purging with nitrogen, the tank is completely degassed. The gas collected in the receiver can be transferred to production as fuel or raw materials, or serve as fuel for the internal combustion engine of the installation, which drives the vacuum pump (directly or through a gas generator).

The specified stationary installation consists of a large number of equipment - a hydraulic compressor, an ejector, a gas receiver, a vacuum pump, a container for nitrogen, a heated evaporator. The mobile version of the installation for removing LPG from emergency CCs will require a large number of mobile modules, which limits its use in the field.

From the description of the RF patent for the invention of the Russian Federation No. 2317478, a method is known for removing gas from a vessel during its decommissioning. In accordance with the known method, during decommissioning, the inner cavity of the vessel in its upper part is communicated with the production line, and pressurized water is supplied to the lower part of the internal cavity of the vessel, the gas contained therein is forced out and removed, returning it to the production line. After that, the water supply is stopped, the inner cavity of the vessel in the upper part of the process line is disconnected and communicate with the atmosphere, and in the lower part the inner cavity of the vessel is connected to the outlet pipe through which water is removed from the vessel.

For the successful implementation and use of the known method, it is necessary that the design of the cargo tanks of gas carriers (and other vessels) ensures the filling of the entire interior space with water and the complete displacement of gas by water without the formation of bubbles, the removal of water without the formation of stagnant zones, collection and complete displacement. The use of the invention eliminates the cost of purging inert gas (nitrogen) for purging the vessels, avoiding the loss of commercial gas, reducing the cost of producing gas analyzes, increasing safety when removing combustible fire and explosion hazardous and toxic gases from vessels.

The method according to the patent of the Russian Federation No. 2317478 cannot be used for emptying and degassing the CC from LPG due to the impossibility of completely displacing the LPG with water. The design of the CC does not allow filling the entire internal space of the CC boiler with water, and also does not allow for the complete displacement of LPG by water without the formation of extensive stagnant zones. This is due to the design features of the CC for the transportation of LPG, which will be discussed below.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to the development of a method and installation for emptying and degassing a HV from LPG, which satisfy the following conditions:

- emptying the CC from the bulk of the LPG and pumping it into an empty CC for the LPG;

- degassing of the CC to the requirements of regulatory documentation;

- the possibility of creating an inexpensive small-sized mobile installation in railway transport using the equipment of fire and recovery trains operated on railways;

- the possibility of creating an inexpensive small-sized mobile installation based on road transport using the equipment of fire and recovery trains operated on railways;

- the possibility of creating an inexpensive small-sized stationary installation in a car repair depot.

The technical result of the present invention consists in the development of an installation with which it is possible to organize the emptying of an emergency CC from the liquid and vapor phase of the LPG and carry out its degassing at the accident site, as well as in stationary conditions without the use of expensive compressor units and liquid nitrogen.

The above problems are solved due to the fact that the installation for the discharge of liquefied petroleum gases (LPG) from a tank car (1) equipped with angular drain and fill valves (6 and 7), an angle valve for the selection and supply of LPG vapor (8), discharge bulk pipes (4) and a pipe for the selection and supply of LPG vapor (5), contains:

a tank car (12) for receiving LPG, equipped with angular drain valves (34 and 35), an angular valve for the selection and supply of vapor of LPG (36), drain pipes (37),

tank car (13) for displacing liquid,

equalization pipeline (40), the input of which is connected to the valve (8) of the tank (1), and the output to the valve (82) of the tank (12),

overflow pipe (38), the input of which is connected to the valve (7) of the tank (1), and the output to the valve (36) of the tank (12),

a discharge pipeline (15), the inlet of which is connected to the tank (13) above the bay level, and the outlet is connected to the valve (6) of the tank (1), while the pipeline (15) is equipped with a check valve for LPG (22) and valves (21 ) and (17) installed on the segment between the valve (22) and the tank (13),

a pump (20) for pumping the displacing fluid, configured to create a pressure of at least 2.5 MPa, the input of which is connected to a suction line (39), equipped with a check valve (16) and having an inlet located near the bottom of the tank ( 13), and the outlet is connected to the pipeline (15) on the segment between the taps (21) and (17), through the valve (30).

The aforementioned displacing liquid may be, in particular, water or an aqueous solution which does not freeze at a temperature below 0 ° C, preferably at a temperature below -15 ° C, particularly preferably at a temperature below -25 ° C, even more preferably at a temperature below -30 ° C.

In one of the preferred embodiments, the overflow line (40) can be equipped with an installation (11) for cleaning the LPG from drops and vapors of the displacing liquid.

In another preferred embodiment, a filter for cleaning the displacing liquid (19) can be installed on the suction line (39) of the aforementioned pump.

In another preferred embodiment, a tank car fire truck is used as a tank car (13).

In one preferred embodiment, a valve (18) is installed on the suction line (39) of the pump (20).

In another preferred embodiment, the pipeline (15) is equipped with pressure gauges mounted on a section between the valve (22) and the valve (21), and / or on a section between the valves (21) and (17), and / or on a section between the valve ( 22) and valve (6).

In another preferred embodiment, the pipeline and / or pressure gauge is mounted on an overflow pipe.

In one of the preferred forms of execution, the pipeline (15) is equipped with a liquid flow meter to control the volume of liquid pumped from the tank (13) to the tank (1).

In yet another preferred embodiment, the surge pipe is provided with a branch for sampling with a valve (29).

In another preferred embodiment, a sensor is arranged on the overflow conduit that is capable of determining the type of pumped liquid, preferably a proximity sensor.

In one preferred embodiment, the sensor is configured to automatically shut off the pump (20) when the type of pumped liquid changes.

In another preferred embodiment, the pump (20) is a high pressure plunger pump.

The above problem is also solved due to the fact that the installation for the degassing of the tank car (1), equipped with corner discharge valves (6 and 7), an angle valve for the selection and supply of LPG vapor (8), drain pipes (4) and pipe for the selection and supply of LPG vapor (5), after filling it with a displacing liquid to the level of the inlet of the pipe (5), contains:

discharge pipe (15) equipped with a check valve for LPG (22), the output of which is connected to the valve (6) of the tank (1),

a container (31) for inert gas under pressure, connected to the inlet of the pipeline (15) through a gas reducer (32) and a valve (33),

a mobile flare unit (27) for burning LPG,

a discharge pipe (41) equipped with a fire-retardant valve (28) and a valve (24), the inlet of which is connected to the valve (8), and the output to the input of the flare unit (27).

In one preferred embodiment, the aforementioned container (31) is a group of cylinders connected to a gas train with a total volume of at least 280 liters, preferably at least 400 liters, particularly preferably at least 520 liters.

In yet another preferred embodiment, the aforementioned cylinder is a 40 liter nitrogen cylinder.

In another preferred embodiment, the aforementioned balloon (31) is a balloon filled with helium, argon or krypton.

In one preferred embodiment, the installation further comprises a compressor (26) for pumping air connected to the inlet of the pipeline (15) through a valve (25).

In another preferred form, the discharge pipe (41) is equipped with a flow stabilization device to prevent sudden pulsations selected from the group, hydraulic resistance, a throttle and / or an automatic high-speed controller.

In another preferred embodiment, the discharge pipe is equipped with a flow stabilization device to prevent sudden pulsations, which is a receiver.

In one preferred embodiment, a gas tank pocket is used as a receiver (12).

The above problem is also solved due to the fact that in the proposed method of draining liquefied petroleum gas (LPG) from a tank car (1) equipped with angular drain and fill valves (6 and 7), an angular valve for the selection and supply of LPG vapor (8), drain pipes (4) and a pipe for the selection and supply of LPG vapor (5), use the above installation, while the tank (13) is filled with a displacing liquid, the check valve (16) is filled with a displacing liquid, and all taps and valves are closed; The method comprises the following steps:

(a) open the valves (8) and (36) and by means of the valve (35) equalize the pressure in the tank (1) and (12),

(b) provide for the circulation of the displacing fluid in the pipeline (15) by means of a pump (20) and valves (17), (18) and (30),

(c) by closing the valve (17), the pressure in the pipeline (15) is brought to 2.5? 3.0 MPa,

(d) by opening the valve (6), and then the valve (21), the displacing liquid (14) is supplied from the tank (13) to the tank (1) through the pipeline (15), at the same time as the LPG is displaced from the tank (1) into the tank ( 12) overflow pipe (40),

(e) when the displacing liquid reaches the level of the inlet of the pipe (5), its flow is stopped by closing the valve (21), opening the valve (17) and turning off the pump (20),

(e) close the taps (17), (18) and (30).

In one of the preferred forms of implementation, the achievement of the displacing fluid level of the inlet of the pipe (5) is controlled by briefly opening and closing the control valve (29).

In another preferred embodiment, the pressure equalization in step (1) is monitored by a pressure gauge (9).

The above problem is also solved due to the fact that in the method of degassing a tank car (1) equipped with angular drain valves (6 and 7), an angular valve for the selection and supply of LPG vapor (8), drain pipes (4) and pipe for the selection and supply of LPG vapor (5), after filling it with displacing liquid to the level of the inlet of the pipe (5), use the above installation, in which the tank (31) is filled with inert gas under high pressure and all valves and taps are closed; in accordance with the proposed method:

(a) control the pressure in the tank by means of a manometer (9) connected to the valve (7) of the tank (1),

(b) bleed the LPG from the tank (1) to the burning torch (27) by means of a crane (24) to the minimum normative excess pressure of the LPG in the CC

(c) inert gas is pumped into the tank (1) from the tank (31) through a pressure reducer (32), increasing the overpressure by at least 10% higher than in the tank (1) by means of a valve (33),

(d) allow the inert gas to mix with the LPG vapor in the tank (1),

(e) repeat steps (b), (c) and (d) until the LHG content in the mixture with inert gas decreases to the level at which the gas mixture in the tank (1) does not form flammable or explosive mixtures with air in any ratio .

In one preferred embodiment, the overpressure achieved at the end of step (b) is 0.1070.20 MPa, preferably 0.15 MPa.

In another preferred embodiment, the pressure in step (c) is increased at least 3 times, preferably at least 5 times, compared with the pressure reached at the end of step (b).

In another preferred embodiment, the inert gas and the LPG vapor are mixed for 20 minutes.

In one of the preferred forms of implementation, between the stages (b) and (c), an amount of air is pumped into the tank (1) by means of the compressor (26) to provide a concentration of LPG in the air above the upper explosive concentration limit.

In another preferred embodiment, the air is injected into the pipeline (15) after preliminary air injection into a large volume receiver parallel to the pipeline (15), in which at least 1.0 MPa is preliminarily created with the help of the compressor (26) preferably 1.5 MPa.

The above problem is also solved due to the fact that the proposed method for draining liquefied petroleum gases (LPG) and degassing LPG from a tank car (1) equipped with angular drain valves (6 and 7), an angular valve for the selection and supply of LPG vapor (8 ), a discharge pipe (4) and a pipe for the selection and supply of LPG vapor (5), is characterized by the following steps:

(a) in a first step, the first of the above methods is carried out,

(b) in a second step, the second of the above methods is carried out.

In a preferred embodiment, the installation used in stage (b) is at least partially mounted from the equipment of the installation used for stage (a).

In one of the preferred forms of implementation, the nodes of the installation used in stage (a) and the installation used in stage (b) are combined into a single installation.

Thus, as described above, the objectives of the invention are solved primarily with the help of the installation for emptying and degassing of the CC from the LPG (UODVTS). The design of the FFEP and its components are shown in FIG. 1, 2 and 3.

The composition of the UVODC (Fig. 1) includes the following main elements:

emergency CC containing LPG (1),

empty CC for intake of LPG (12),

a tank car with softened water (13) (a tank car truck of a fire train can be used as such a tank),

a high pressure water pump (20), which develops a pressure of more than 2.5 MPa (for example, small-sized high-pressure plunger pumps can be used as such a pump),

air compressor (26),

compressor air valve (30),

nitrogen cylinder 40 l (31),

balloon high pressure reducer (32),

installation for drying LPG from drops and water vapor (11),

small-sized flare mobile unit (27) for burning LPG in the field,

auxiliary equipment - non-return valve for water (16), valves for water (17, 18, 21), filter for water purification (19), pressure gauges (9), air and gas shutoff valve for propane (25 and 24), non-return valve for SUG (22), fire-retardant valve (28),

drain and armature of the emergency CC SUG - angle drain valves (6 and 7), an angle valve for the selection and supply of liquefied gas vapors (8), drain pipes (4) (shown schematically), a pipe for selection and supply of vapor liquefied gas (5) (shown schematically),

empty VTs drain-and-fill valves - angular drain-and-fill valves (34 and 35), an angle valve for the selection and supply of liquefied gas vapors (36), drain-and-fill pipes (37) (shown schematically).

In FIG. Figures 2 and 3 for the emergency CC show the location of the drain valves (6, 7, 8), drain pipes (4), pipes for the selection and supply of liquefied gas vapors (5), instrumentation valves (42, 43, 44, 45, 46). It should be noted that the drainage, control and measuring valves and the safety valve (not shown in Figs. 1, 2, 3) are placed on the hatch cover of the air handling unit and are closed with a protective cap during transportation. Drain and bulk valves (Fig. 2) includes three valves (two liquid (6 and 7), and one gas (8)). Instrumentation fittings (Fig. 3) include two valves for monitoring the preliminary (42) and maximum filling level (41), a drain control valve (44) and a valve for stripping product residues (45), connected to a drainage pipe (37).

Especially it is necessary to stop at the level of filling and discharge of LPG, as well as at the height of the pipe cut for the selection and supply of LPG vapor. In FIG. 3 shows H1 - the distance between the pipe section for the selection and supply of the LPG vapor phase and the upper inner surface of the tank vessel, H2 - the distance between the limit level of LPG filling and the upper inner surface of the tank vessel, H3 - the distance between the control level of the LPG filling and the upper inner surface tank vessels. For the CC model of type 15-9872, the distance Н1 = 0.215 m, the distance Н2 = 0.710 m, the distance Н3 = 0.790 m. Knowing the radius of the CC equal to 1.6 m and the length of the CC equal to 11 m, we can determine the volume of the CC segments over levels H1, H2 and H3.

Above the level H1 = 0.215 m, the volume (Vн1) of free space in the EC is 2.8 m ³ .

Above the level Н2 = 0.71 m, the volume (Vн2) of free space in the EC is 14.52 m ³ .

Above the level of H3 = 0.79 m, the volume (Vн2) of free space in the EC is 16.57 m ³ .

These data are necessary to calculate the mass of LPG vapor in free space.

The thickness of the layer enclosed in the CC between H3 and H2 is 0.08 m, and the volume of the specified layer along the length of the CC is 16.57-14.52 = 2.05 m ³ .

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Scheme of the installation for emptying and degassing the CC from LPG (UODVTS).

FIG. 2. The layout of the unloading pipes and pipes for the selection and supply of vapor of liquefied gas and angle valves in the CC.

FIG. 3. The layout of the control valves and level gauge in the CC.

The following notation is used in the figures:

1 - emergency CC,

2 - pipe hatch,

3 - manhole cover,

4 - discharge and loading pipes (shown schematically),

5 - pipe for the selection and supply of vapor of liquefied gas,

6 - the first corner discharge and filling valve,

7 - the second corner discharge and loading valve,

8 - angle valve for the selection and supply of vapor of liquefied gas,

9 - pressure gauge,

10 - liquid SUG,

11 - installation for drying the LPG from drops and water vapor,

12 - empty CC for receiving LPG,

13 - tank car with softened water,

14 - softened water,

15 - pipeline

16 - check valve for water,

17 - water supply valve,

18 - valve reverse flow of water,

19 is a filter for water purification,

20 - high pressure water pump,

21 - valve for supplying water to the emergency CC,

22 - check valve for LPG,

23 - pipeline for supplying water to the emergency CC,

24 - gas shutoff valve (propane),

25 - air shutoff valve,

26 - air compressor,

27 - flare mobile installation,

28 - fire safety valve,

29 - control valve of the liquid section SUG-water,

30 - air valve of the compressor,

31 - nitrogen cylinder 40 l,

32 - balloon high pressure reducer,

33 - gas valve.

34 - the first angular discharge valve of the empty tank,

35 - the second angular discharge valve of the empty tank,

36 - angle valve for the selection and supply of vapor of liquefied gas,

37 - unloading pipes of an empty tank car,

38 - overflow pipe

39 - suction line

40 - overflow pipe

41 - discharge pipe

42 - speed valves

43 - pocket for a thermometer,

44 - pan of the vessel of the tank,

45 - drainage pipe,

46 - bottom of the tank vessel,

47 - lower level drain

48 - the maximum level of liquefied gas,

49 - valve maximum level filling with a flywheel in red,

50 - valve for controlling the level of the upper loading with a green flywheel,

51 - gas valve to empty the drain control tube,

52 - drain control valve,

53 - drain valve

H1 is the distance between the pipe cut for the selection and supply of the vapor phase of the LPG and the upper inner surface of the tank vessel,

H2 - the distance between the limit level of the liquefied gas filling and the upper inner surface of the tank vessel,

H3 is the distance between the control level of the liquefied gas filling and the upper inner surface of the tank vessel.

DETAILED DESCRIPTION OF THE INVENTION

The emptying and degassing of the CC (hereinafter CC) from the LPG is carried out in two stages with the aid of the UWEC installation shown in FIG. 1. The following is a description of the methods of emptying and degassing the CC from LPG.

Stage 1. Emptying the CC from the liquid phase of the LPG and partially from the gas phase of the LPG;

Stage 2. Degassing of the CC. CC degassing, in turn, can be done in two ways: using nitrogen cylinders with a volume of 40 l; using 40 liter nitrogen cylinders and an air compressor.

The procedure for the stages of emptying and degassing of the CC from LPG is given below.

Emptying the CC from the liquid phase of the LPG and partially from the liquid phase of the LPG.

The order of emptying the CC from the liquid phase of the LPG and partially from the liquid phase of the LPG is given below:

1. In the initial period, all the valves UODVTS closed (Fig. 1).

2. Open the valves (8 and 36), then open the valve (35) to equalize the pressure in the CC (1) and the empty CC (12). Wait for full pressure equalization in the CC and the empty CC. Control the equalization of pressure by a pressure gauge (9) installed on an empty CC (12). After equalizing the pressure, the needle of the pressure gauge (9) will become stationary.

3. Pour water into the check valve (16) to bring it into working condition. Open the valves (17, 18 and 30), turn on the high pressure water pump (VNVD) to recirculate the water through the pipeline (15).

4. Raise the pressure in the pipeline (15) to 2.5 ÷ 3.0 MPa. To do this, gently close the valve (17).

5. To supply water to the emergency CC (1) to displace the LPG to the empty CC (12). To do this, open the valve (6), and then the valve (21). The density of water (1 t / m ³ ) is higher than the density of liquid LPG (the density of liquefied propane at a temperature of 15 ° C and normal atmospheric pressure is 0.51 t / m ³ , the density of liquefied butane is 0.58 t / m ³ ), and the level the injected water in the CC (1) is below the LPG level. When water is injected from the CC, the vapor phase of the LPG is displaced, and then the liquid phase of the LPG is displaced.

6. To stop the water supply to the emergency CC when water appears from the control valve (30) of the CC (1). Water from the control valve (29) appears when the level of the liquid gas - water section rises to the cutoff level of the pipe (5) for the selection and supply of LPG vapor. To do this, control the first appearance of water from the control valve (29) by periodically opening and closing the valve. To stop the water supply, close the valve (21) gently, open the valve (17) and turn off the NVDV pump (20).

7. Close the valves (17, 18 and 30).

8. For example, propane, used as LPG. Almost all gaseous propane was squeezed from the CC (1) to the empty CC (12), and the liquid phase of the LPG was completely pumped, including the liquid gas located between the levels of Н3 and Н2. For the CC model of type 15-9872, this means the following: almost complete displacement of the vapor and liquid propane phases has been performed. Above the water layer with a depth of 2.985 m, above the level of H1 is gaseous propane with a volume of 2.8 m ³ at a pressure of about 1.6 MPa.

CC degassing requirements

It is known that before carrying out work inside the tank boiler, it is necessary to analyze the air in the boiler volume for the absence of a dangerous concentration of hydrocarbons and for the oxygen content. The oxygen content should be in the range of 19-20% (vol.). The concentration of combustible substances in the boiler volume should not exceed 20% of the value of the lower concentration limit of flame propagation (hereinafter - NKPR) LHG (PPB 01-03 of the Fire Safety Regulation in the Russian Federation).

Explosive limits (in%, by volume) of propane and butane are given in table 2 (A. Yanovich. Labor protection and safety measures in the gas industry. // M .: Nedra, 1975. 216 p.).

TABLE 2 Explosive limits (% by volume) propane and butane Substance Lower concentration limit of explosiveness (NKPV) Upper Concentration Explosive Limit (VKPV) Propane 2.1 9.5 n-butane 1,5 8.5

The permissible concentration of combustible substances (propane and butane) in the volume of the tank boiler before tank repair is shown in table 3.

TABLE 3 Permissible concentration of combustible substances (propane and butane) in the boiler volume Substance 20% of the lower explosive concentration limit (20% LEL) Propane 0.42 n-butane 0.3

In the present work, degassing of a CC (here the removal of LPG from a CC to safe concentrations) is performed in two ways:

- degassing of the CC using nitrogen cylinders with a volume of 40 liters (method No. 1);

- degassing of the CC using nitrogen cylinders with a volume of 40 liters and an air compressor (method No. 2).

Consider the main characteristics of nitrogen cylinders with a volume of 40 liters. The main characteristics of nitrogen tanks of 40 liters are as follows:

- volume 40 liters,

- cylinder mass 65 kg,

- working pressure 14.7 MPa,

- gas mass 7.5 kg

- type of locking device - valve (GOST 949-73 "Steel cylinders of small and medium volume for gases on PP no more than 19.6 MPa").

The density of nitrogen under normal conditions (pressure 0, 101325 MPa, temperature 0 ° C) is 1.251 kg / m ³ . Then the volume of gas in the cylinder will be equal to 7.5 / 1,251 = 6 m ³ . The indicated gas volume is sufficient for a 2-fold gas replacement in the tank volume equal to 2.8 m ³ .

EXAMPLE 1

Carrying out degassing of the CC using nitrogen cylinders with a volume of 40 liters (method 1)

1. All valves of the UODVC installation are closed.

2. Bleed the LPG from the CC to the burning torch (27) to a pressure of LPG to the CC equal to 0.15 MPa. To do this, first open the valve (6) - in order to control the pressure level using a manometer (9). Then open the valve (7) and the valve (24) sequentially, to ensure safe arson of the escaping propane on the mobile flare unit using the duty torch.

3. When the pressure in the EC reaches 0.15 MPa, close valve (7) and valve (24) in series. In CC (1) there is gaseous propane with a volume of 2.8 m ³ at a pressure of about 0.15 MPa. The density of gaseous propane under normal conditions is 2.019 kg / m ³ (then we take 2.0 kg / m ³ ). Then the mass of propane in the CC at a pressure of 0.15 MPa is 2.8 · 1.5 · 2.0 = 8.4 kg.

4. We pump nitrogen gas into the CC (1) until a pressure of 1.0 MPa is reached. To do this, open the valves of the cylinders with nitrogen (the pressure in the nitrogen cylinder is 40 l 15 MPa) (31), then open the high-pressure cylinder reducers (32) and provide a nitrogen supply to the line to increase the pressure in the CC no higher than 1.0 MPa. Open the valve (21). After reaching a pressure of 1.0 MPa in the CC, close valves (21), (33), (32) and (31) in sequence. Give a temporary exposure of 20 minutes to ensure mixing of nitrogen and LPG.

5. Pit the gas mixture of nitrogen and LPG from the CC to the burning torch (27) to a pressure of the gas mixture in the CC of 0.15 MPa. The propane content in the CC decreased by 6.6 times and became equal to 1.27 kg.

6. Repeat the steps in step 4 and step 5 a second time. The propane content in the CC again decreased by 6.6 times and became equal to 0.19 kg.

7. Repeat the steps in step 4 and step 5 a third time. The propane content in the CC decreased by 6.6 times and became equal to 0.029 kg.

8. Repeat the steps in step 4 and step 5 for the fourth time. The propane content in the CC decreased by 6.6 times and became equal to 0.0044 kg.

9. Repeat the steps in step 4 and step 5 for the fifth time. The propane content in the CC decreased by 6.6 times and became equal to 0,00066 kg.

The density of nitrogen under normal conditions at 1,251 kg / m ³ . The nitrogen mass in the CC at a pressure of 0.15 MPa is 1.25 · 1.5 · 2.8 = 5.25 kg. Then the percentage of propane in nitrogen will be 0.00066 · 100 / 5.24 = 0.083%. CC degassing is completed - the propane concentration of 0.0083% in the nitrogen-propane gas mixture is less than 0.42%, which is 20% of the LEL propane.

It should be noted that to carry out the indicated operation, 10 nitrogen cylinders with a capacity of 40 liters each are required. The total nitrogen consumption for the degassing of one tank car was 60 m ^{3 of} nitrogen. It would take 270 ÷ 300 to degass one CC using the technology of draining - filling and degassing the CC from LPG (http://www.vipgaztech.ru/index.php/ct-menu-item-4/ct-menu-item-6) m ³ nitrogen (i.e., 4.5 ÷ 5 times more than in accordance with the proposed method).

For storage of 10 cylinders it is supposed to use a nitrogen ramp of the RA-10spec type (2 × 5), designed to continuously supply nitrogen to consumers from cylinders with a pressure of up to 20 MPa (http://www.cryocom.ru/catalog/index.php/rampa-azotnaya -tip-ra). Nitrogen cylinders can be stored in a fire or recovery train using a 10-cylinder ramp.

EXAMPLE 2

Carrying out the degassing of the CC using nitrogen cylinders and an air compressor (method 2)

1. All valves of the UODVC installation are closed.

2. Bleed the LPG from the CC to the burning torch (27) to a pressure of LPG to the CC equal to 0.15 MPa. To do this, first open the valve (6) in order to control the pressure level using a pressure gauge (9). Then open the valve (7) and the valve (24) sequentially, to ensure safe arson of the escaping propane on the mobile flare unit using the duty torch.

3. When the pressure in the EC reaches 0.15 MPa, close valve (7) and valve (24) in series. In CC (1) there is gaseous propane with a volume of 2.8 m ³ at a pressure of about 0.15 MPa.

The density of gaseous propane under normal conditions is 2.019 kg / m ³ (then we take 2.0 kg / m ³ ). Then the mass of propane gas in the CC at a pressure of 0.15 MPa will be equal to 2.8 · 1.5 · 2.0 = 8.4 kg.

4. To pump in an air-conditioning center (1) with propane such an amount of air that the concentration of propane in the air is higher than VKPV. To do this, inject air into the CC (1) until a pressure of 1.5 MPa is reached. To do this, open valve (25) and (17). Then turn on the air compressor (26). By closing the valve (17), increase the air pressure in the line to 1.5 MPa. Open the valve (21), close the valve (17) and ensure that the pressure of the propane-air mixture in the CC (1) rises to 1.5 MPa. Close the valves (21), turn off the air compressor (26), close the valve (25). Give a temporary exposure of 20 minutes to ensure mixing of air and LPG. The volume concentration of propane in the propane-air mixture decreased to 11.11%. This concentration of propane in the propane-air mixture is greater than the upper concentration limit of explosiveness (VKPV propane equal to 9.5%), and is safe to handle.

5. We pump nitrogen gas into the CC (1) until a pressure of 1.0 MPa is reached. To do this, open the valves of the cylinders with nitrogen (the pressure in the nitrogen cylinder is 40 l 15 MPa) (31), then open the high-pressure cylinder reducers (32) and provide a nitrogen supply to the line to increase the pressure in the CC no higher than 1.0 MPa. Open the valve (21). After reaching 1.0 MPa in the CC, the valves (21, 33, 32 and 31) should be closed in series. Give a temporary exposure of 20 minutes to ensure mixing of nitrogen and LPG.

6. Bleed a gas mixture of nitrogen and LPG from the CC to the burning torch (27) to a gas mixture pressure in the CC of 0.15 MPa. The propane content in the CC decreased by 10 times, and the herd was equal to 0.84 kg.

7. Repeat the steps in step 5 and step 6 a second time. The propane content in the CC again decreased by 10 times and became equal to 0.084 kg.

8. Repeat the steps in step 5 and step 6 a third time. The propane content in the CC decreased by 6.6 times and became equal to 0.0084 kg.

9. Repeat the steps in step 4 and step 5 for the fourth time. The propane content in the CC decreased by 10 times and became equal to 0,00084 kg.

The density of nitrogen under normal conditions at 1,251 kg / m ³ . The nitrogen mass in the CC at a pressure of 0.15 MPa is 1.25 · 1.5 · 2.8 = 5.25 kg. Then the percentage of propane in nitrogen will be 0.00084 · 100 / 5.25 = 0.016%. The propane concentration of 0.016% in the nitrogen-propane gas mixture is less than 0.42% (20% of the LEL propane). The degassing of the CC is completed - the propane concentration of 0.016% in the nitrogen-propane gas mixture is less than 0.42%, which is 20% of the LEL propane.

It should be emphasized that this operation did not require 10, but 8 nitrogen cylinders with a capacity of 40 liters each. The total nitrogen consumption for the degassing of one tank car was 48 m ³ nitrogen. For the degassing of one CC using the technology of discharge - filling and degassing of the CC from LPG (http://www.vipgaztech.ru/index.php/ct-menu-item-4/ct-menu-item-6), 270 ÷ 300 m are required ³ nitrogen (5.6 ÷ 6.25 times more than this method).

The reduction in nitrogen consumption is due to the use of an air compressor.

After degassing of the CC (according to method 1 and method 2), the pressure of the gas mixture is 0.15 MPa, and the LPG concentration is less than 20% of the LEL LPG. Such a CC can be safely transported either for the next LPG filling (in the absence of boiler damage after inspection of the CC) or for steaming the CC with hot steam and for other operations before repairing the CC boiler (see electronic resource http://rpp.nashaucheba.ru /docs/index-107829.html).

We will carry out the estimated cost of the equipment of the installation for emptying and degassing the CC (UWEC) in two ways - using a compressor unit and a cryogenic nitrogen gasifier and the proposed method. The cost of a mobile compressor unit for pumping LPG and a cryogenic nitrogen gasifier for degassing a CC without taking into account the cost of a vehicle and a diesel generator is more than 3 million rubles. At the same time, the equipment according to the proposed method (excluding the cost of the vehicle and diesel generator) is much cheaper. So, the total cost of 10 revolving nitrogen cylinders per 40 l, a high-pressure plunger pump, an air compressor and other necessary equipment and accessories is at least 15 ÷ 20 times less. Approximately an order of magnitude less and the weight necessary for the acquisition of equipment when using the proposed installation UODVTS.

The proposed mobile installation of fire-fighting equipment based on a fire train and a mobile installation based on road transport will use the existing diesel generator and railway tank car for the water of the fire train.

Nitrogen ramp type RA-10 special (2 × 5), designed for continuous supply of nitrogen from the cylinders, can be kept with cylinders on a fire train or motor vehicle continuously, or loaded with cylinders if necessary. An empty CC for receiving LPG from an emergency CC should be part of a fire train, and the capacity of an empty CC should be no less than the capacity of the operating CCs. It is possible to supply an empty CC with a cargo owner.

Due to the fact that water freezes at 0 ° C, antifreezes can be used as a displacing liquid instead of water in winter, for example, antifreezes based on methyl alcohol, ethylene glycol, propylene glycol and water. With their help, it is possible to provide a freezing point of antifreeze up to -60 ° C.

Claims (33)

1. Installation for draining liquefied petroleum gases (LPG) from a tank car (1) equipped with angular drain valves (6 and 7), an angular valve for sampling and supplying LPG vapor (8), and drain pipes (4) and a pipe for the selection and supply of LPG vapor (5), characterized in that it contains:
a tank car (12) for receiving LPG, equipped with angular drain valves (34 and 35), an angular valve for the selection and supply of vapor of LPG (36), drain pipes (37),
tank car (13) for displacing liquid,
equalization pipeline (40), the input of which is connected to the valve (8) of the tank (1), and the output to the valve (82) of the tank (12),
overflow pipe (38), the input of which is connected to the valve (7) of the tank (1), and the output to the valve (36) of the tank (12),
a discharge pipeline (15), the inlet of which is connected to the tank (13) above the bay level, and the outlet is connected to the valve (6) of the tank (1), while the pipeline (15) is equipped with a check valve for LPG (22) and valves (21 ) and (17) installed on the segment between the valve (22) and the tank (13),
a pump (20) for pumping the displacing fluid, configured to create a pressure of at least 2.5 MPa, the input of which is connected to a suction line (39), equipped with a check valve (16) and having an inlet located near the bottom of the tank ( 13), and the outlet is connected to the pipeline (15) on the segment between the taps (21) and (17) through the valve (30). 2. Installation according to claim 1, in which the aforementioned displacing liquid is water or an aqueous solution that does not freeze at a temperature below 0 ° C, preferably at a temperature below -15 ° C, particularly preferably at a temperature below -25 ° C, even more preferably at temperatures below -30 ° C. 3. Installation according to claim 1, in which the overflow pipe (40) is equipped with a installation (11) for cleaning the LPG from drops and vapors of the displacing liquid. 4. Installation according to claim 1, in which a filter for cleaning the displacing liquid (19) is installed on the suction line (39) of the aforementioned pump. 5. Installation according to claim 1, in which a tank car of a fire train is used as a tank car (13). 6. Installation according to claim 1, in which a valve (18) is installed on the suction line (39) of the pump (20). 7. Installation according to claim 1, characterized in that the pipeline (15) is equipped with pressure gauges installed in the interval between the valve (22) and the valve (21), and / or in the interval between the valves (21) and (17) and / or between the valve (22) and the valve (6). 8. Installation according to claim 1, characterized in that the pipeline and / or pressure gauge is installed on the overflow pipe. 9. Installation according to claim 1, characterized in that the pipeline (15) is equipped with a liquid flow meter to control the volume of liquid pumped from the tank (13) to the tank (1). 10. Installation according to claim 1, characterized in that the equalization pipeline is equipped with a branch for sampling with a valve (29). 11. Installation according to claim 1, characterized in that a sensor is arranged on the overflow pipe, configured to determine the type of pumped liquid, preferably a proximity sensor. 12. Installation according to claim 11, characterized in that the sensor is configured to automatically turn off the pump (20) when changing the type of pumped liquid. 13. Installation according to claim 1, in which the pump (20) is a high pressure plunger pump. 14. Installation for degassing a tank car (1), equipped with angular drain valves (6 and 7), an angular valve for the selection and supply of LPG vapor (8), a drain pipe (4) and a pipe for vapor recovery and supply LPG (5), after filling it with displacing liquid to the level of the inlet pipe (5), characterized in that it contains:
discharge pipe (15) equipped with a check valve for LPG (22), the output of which is connected to the valve (6) of the tank (1),
a container (31) for inert gas under pressure, connected to the inlet of the pipeline (15) through a gas reducer (32) and a valve (33),
a mobile flare unit (27) for burning LPG,
a discharge pipe (41) equipped with a fire-retardant valve (28) and a valve (24), the inlet of which is connected to the valve (8), and the output to the input of the flare unit (27). 15. Installation according to claim 14, characterized in that the aforementioned container (31) is a group of cylinders connected to a gas train with a total volume of at least 280 liters, preferably at least 400 liters, particularly preferably at least 520 liters. 16. The installation according to p. 14, characterized in that the aforementioned cylinder is a nitrogen cylinder of 40 liters. 17. Installation according to claim 14, characterized in that the aforementioned cylinder (31) is a cylinder filled with helium, argon or krypton. 18. Installation according to claim 14, characterized in that it further comprises a compressor (26) for pumping air connected to the inlet of the pipeline (15) through a valve (25). 19. Installation according to claim 14, characterized in that the discharge line (41) is equipped with a flow stabilization device to prevent sudden pulsations selected from the group: hydraulic resistance, throttle and / or automatic high-speed controller. 20. Installation according to p. 14, characterized in that the discharge pipe is equipped with a flow stabilization device to prevent sudden pulsations, which is a receiver. 21. Installation according to claim 20, characterized in that a gas pocket of the tank is used as a receiver (12). 22. A method for draining liquefied petroleum gas (LPG) from a tank car (1) equipped with angular drain valves (6 and 7), an angular valve for sampling and supplying LPG vapor (8), and drain pipes (4) and pipe for the selection and supply of LPG vapor (5), which use the installation according to any one of paragraphs. 1-13, in which the tank (13) is filled with a displacing liquid, the non-return valve (16) is filled with a displacing liquid, and all taps and valves are closed, which includes the following stages:
(a) open the valves (8) and (36) and by means of the valve (35) equalize the pressure in the tank (1) and (12),
(b) provide for the circulation of the displacing fluid in the pipeline (15) by means of a pump (20) and valves (17), (18) and (30),
(c) by closing the valve (17), the pressure in the pipeline (15) is adjusted to 2.5 ÷ 3.0 MPa,
(d) by opening the valve (6), and then the valve (21), the displacing liquid (14) is supplied from the tank (13) to the tank (1) via the pipeline (15), at the same time as the LPG is displaced from the tank (1) to a tank (12) through an overflow pipe (40),
(e) when the displacing liquid reaches the level of the inlet of the pipe (5), its flow is stopped by closing the valve (21), opening the valve (17) and turning off the pump (20),
(e) close the taps (17), (18) and (30). 23. The method according to p. 22, characterized in that the achievement of the displacing fluid level of the inlet of the pipe (5) is controlled by briefly opening and closing the control valve (29). 24. The method according to p. 22, characterized in that the control of pressure equalization at the stage (1) is carried out according to the manometer (9). 25. The method of degassing a tank car (1) equipped with angular drain valves (6 and 7), an angular valve for the selection and supply of LPG vapor (8), a drain pipe (4) and a pipe for sampling and supply of LPG vapor (5), after filling it with displacing liquid to the level of the inlet of the pipe (5), in which the installation according to any one of paragraphs is used. 14-21, in which the container (31) is filled with inert gas under high pressure, and all valves and taps are closed, characterized in that:
(a) control the pressure in the tank by means of a manometer (9) connected to the valve (7) of the tank (1),
(b) bleed the LPG from the tank (1) to the burning torch (27) by means of a crane (24) to the minimum normative excess pressure of the LPG in the CC,
(c) inert gas is pumped into the tank (1) from the tank (31) through a pressure reducer (32), increasing the overpressure by at least 10% higher than in the tank (1) by means of a valve (33),
(d) allow the inert gas to mix with the LPG vapor in the tank (1),
(e) repeat steps (b), (c) and (d) until the LHG content in the mixture with inert gas decreases to the level at which the gas mixture in the tank (1) does not form flammable or explosive mixtures with air in any ratio . 26. The method according to p. 25, characterized in that the excess pressure reached at the end of stage (b) is 0.10 ÷ 0.20 MPa, preferably 0.15 MPa. 27. The method according to p. 25, characterized in that the pressure in stage (C) is increased at least 3 times, preferably at least 5 times compared with the pressure reached at the end of stage (b). 28. The method according to p. 25, characterized in that the inert gas and LPG vapor are mixed for 20 minutes. 29. The method according to p. 25, characterized in that between the stages (b) and (c) in the tank (1) through the compressor (26) is pumped such an amount of air to provide a concentration of LPG in the air above the upper explosive concentration limit. 30. The method according to p. 29, characterized in that the injection of air into the pipeline (15) is carried out after preliminary pumping of air into a large volume receiver parallel to the pipeline (15), in which the pressure (at least at least 1.0 MPa, preferably 1.5 MPa. 31. A method of safely emptying emergency tank wagons from liquefied petroleum gases (LPG), including draining the LPG and degassing from the LPG of the tank car (1), equipped with corner drain and fill valves (6 and 7), an angle valve for the selection and supply of vapors LPG (8), a discharge pipe (4) and a pipe for the selection and supply of LPG vapor (5), characterized in that:
(a) at the first stage, the method according to claims. 22-24,
(b) in the second stage, the method according to claims. 25-30. 32. The method according to p. 31, in which the installation used in stage (b), at least partially mounted from the equipment of the installation used to carry out stage (a). 33. The method according to p. 31, in which the nodes of the installation used in stage (a) and the installation used in stage (b) are combined into a single installation.

Images