RU232566U1 - Double-walled tank for collecting gasoline vapors from road and rail tankers - Google Patents

Abstract

A double-walled tank for capturing gasoline vapors from automobile and railway tanks is a vapor-capturing device and can be used in the oil industry for transporting automobile gasolines. The utility model includes a vapor pipeline, a double-walled tank partially filled with A-76 gasoline, a heat exchanger, and drain pipes with valves. The space between the walls of the tank is filled with winter diesel fuel and is equipped with a filler neck with a thermometer. The double-walled tank is also covered on the outside with a layer of polyurethane with heat-reflecting paint. The tank's process hatch is equipped with a pressure gauge. The technical result is achieved by cooling the vapors entering the heat exchanger and turning them into liquid due to the temperature difference in the tank and the tank with subsequent absorption by A-76 gasoline. Cooling in the tank compared to the vapor space of the tank occurs due to the fact that the tank has an inter-wall space filled with diesel fuel, and on the outside it is covered with polyurethane with reflective paint. Diesel fuel and polyurethane have low thermal conductivity coefficients. The temperature of diesel fuel in the inter-wall space is controlled using a thermometer, and the vapor pressure in the tank is controlled using a manometer. In this case, a mixture of light fractions of gasoline with an absorbent can be used to add low-octane grades of commercial gasoline.

Description

The proposed utility model relates to devices for capturing vapors and can be used in the transportation of petroleum products by automobile and railway tanks. This utility model is most applicable in capturing vapors of automobile gasolines.

Pollution of the air basin during transportation of petroleum products by automobile and railway tankers occurs when fuel vapors are released during the process of "small" breathing of the tankers. Losses from "small" breathing are caused by daily fluctuations in temperature and partial pressure of fuel vapors (mainly automobile gasoline) in the gas space of the tanker. The temperature of petroleum products transported in railway tankers depends on the ambient temperature.

In summer, petroleum products in tanks heat up to 30-35 degrees Celsius and more. The boiling point of gasoline is 35 degrees Celsius [A.S. Safonov et al. Automobile Fuels. Chemmotology. Performance Properties. Assortment. St. Petersburg: NPITC, 2002].

At this temperature, the low-boiling fractions of gasoline turn into steam and are released into the environment through the breathing valve.

Pollution of the atmosphere with petroleum product vapors has a harmful effect on the environment and human health. Therefore, the main requirements for environmental safety during transportation of motor gasoline by rail and road transport are to reduce the concentration of petroleum product vapors released during the process of "small" breathing.

The fight against losses of commercial petroleum product vapors during transportation of fuel by road and rail tankers is becoming an important environmental and economic task.

A device for capturing vapors during transportation of petroleum products by rail tank cars is known [Matveev Yu.A. et al. Patent for utility model 137527 dated 20.02.2014].

In this installation, a common pipeline line for the removal of vapors with a check valve is additionally installed on the body of the safety inlet valve on a railway tank car having a safety inlet valve, connected to a double-walled tank partially filled with a low-octane component, which is equipped with a receiving device for fuel vapors and a safety valve with an absorber filter, while the inter-wall space of the tank is filled with air.

The low-octane component is used as an absorbent to absorb petroleum vapors. Diesel fuel is used as a low-octane component.

The tank is equipped with a drain pipeline with a valve for draining the mixture of the low-octane component with the petroleum product, as well as stiffening partitions with holes to reduce the speed of movement of the low-octane component and prevent hydraulic shock during the movement of the railway tank, as well as to absorb the vapors of petroleum products contained in the vapor-air space of the tank.

In order to determine the level of the low-octane component (absorbent), the double-walled tank has a measuring hatch.

The installation works as follows. At "small" breaths, the safety inlet valve opens and the oil product vapors enter the double-walled tank with the low-octane component via a common pipeline through a receiving device with grids having holes of different diameters. In this case, most of the vapors turn into liquid due to cooling in the double-walled tank and absorption by the low-octane component.

Another portion of the petroleum product vapors, as a result of the movement of the low-octane component through the holes in the stiffening partitions throughout the entire volume of the tank during the movement of the railway tank car, is absorbed by the low-octane component.

The disadvantages of a vapor recovery unit when transporting petroleum products in rail tank cars are:

1. Lack of additional heat-reflecting coating on the tank.

2. It is impossible to use a mixture of absorbent and petroleum products in commercial gasoline.

Also known is an installation for collecting vapors from automobile tanks using a two-section tank [Bogdanov A.Yu., Matveev Yu.A. patent for utility model No. 206214 dated 08/31/2021].

On the proposed automobile tank, in addition to the body of the breathing valve, a common pipeline line for the removal of vapors with a check valve is installed, connected to a double-walled, two-section tank.

The double-walled tank is made of two sections. The first section is partially filled with absorbent (automotive gasoline A-76), equipped with a receiving device for fuel vapors and a safety valve with an absorber filter.

It should be noted that the space between the walls of the two-section tank is filled with carbon dioxide.

The tank is equipped with drain pipes with valves, as well as stiffening partitions. In order to determine the absorbent level, the tank has measuring hatches.

To prevent the mixture of absorbent and petroleum product from overflowing, the common vapor discharge pipeline inside the first section of the double-walled tank has a horizontal section and is equipped with a mechanical float-type device to prevent overflows.

The mixture of absorbent and petroleum product enters the common vapor removal pipeline inside the double-walled tank through openings.

In order to remove petroleum product vapors when closing the mechanical device to prevent overflows in the first section of the tank, the common vapor removal pipeline is equipped with a high-pressure breathing valve with an absorber filter.

To reduce the temperature, the outer surface of the double-walled tank is treated with a layer of polyurethane, onto which a layer of heat-reflecting paint is applied.

The second section of the double-walled tank is designed to capture petroleum vapors from "big" breaths associated with pouring fuel into a tank truck. The tank is equipped with a partition to divide it into sections. The second section is partially filled with absorbent (aviation kerosene), equipped with a receiving pipe for fuel vapors, a safety valve with an absorber filter and a measuring hatch. The second section of the tank is also equipped with a drain pipe with a valve.

The common vapor discharge pipeline is equipped with a valve and an additional section with a valve. The valve is designed to supply vapor to a section of the tank, and the valve to the second section.

The utility model works as follows.

At "small" breaths, the breathing valve opens and the oil product vapors enter the first section of the double-walled tank with the absorbent via the common pipeline through the check valve, the gate valve and the receiving device. At the same time, the gate valve for feeding the vapors into the second section of the tank is closed. Most of the vapors turn into liquid due to cooling in the first section of the double-walled tank and absorption by the absorbent.

Another part of the oil product vapors as a result of the absorbent moving through the holes of the stiffening partitions throughout the entire volume of the first section of the tank during the movement of the tank truck is absorbed by the absorbent. The undissolved part of the oil product vapors at the outlet of the tank when the safety valve opens is captured by the filter-absorber.

When the level of the absorbent-oil product mixture increases to a certain level, a mechanical float-type overflow prevention device stops the supply of vapors to the first section of the double-walled tank. In this case, the vapors of oil products from the tank are discharged into the atmosphere through a high-pressure breathing valve. Upon arrival of the tank truck at the receiving point, the level of the absorbent-oil product mixture is checked through the measuring hatch of the first section of the tank. If necessary, the mixture is drained through the drain pipeline.

During "large" breathing, the breathing valve opens and the oil product vapors enter the second section of the tank with absorbent (aviation kerosene) via the common pipeline through the check valve, the additional section with the gate valve and the receiving pipe. In this case, the gate valve for feeding vapors into the first section of the tank is closed. The undissolved portion of the oil product vapors at the outlet of the tank when the safety valve opens is captured by the filter-absorber. Upon arrival of the tank truck at the receiving point, the level of the absorbent-oil product mixture is checked through the measuring hatch of the second section of the tank.

The disadvantages of this installation are:

1. Insufficient efficiency of vapor capture and conversion of gasoline vapors into liquid at high ambient temperatures (over 35 degrees Celsius).

2. The possibility of evaporation of the absorbent itself (gasoline A-76) at high ambient temperatures (over 35 degrees Celsius).

3. Mixing gasoline vapors during “big” breathing with an absorbent - aviation kerosene.

Also known is an installation for capturing vapors from automobile tanks with the return of evaporated light fractions to commercial gasoline [Matveev Yu.A. et al. Patent No. 172486 dated 11.07.2017].

On a tank truck with standard equipment, a common vapor discharge pipeline with a check valve is additionally installed on the valve body, connected to a double-walled tank partially filled with an absorbent - automobile gasoline A-76. The tank is equipped with a receiving device for petroleum vapors and a safety valve with an absorber filter, while the inter-wall space of the tank is filled with carbon dioxide.

The tank is equipped with a drain pipe with a valve, as well as stiffening partitions with holes. In order to determine the absorbent level, the double-walled tank has a measuring hatch.

To prevent the mixture of absorbent and petroleum product from overflowing, the common vapor discharge pipeline inside the double-walled tank has a horizontal section and is equipped with a mechanical float-type overflow prevention device.

The mixture of absorbent and oil product enters the common pipeline for vapor removal inside the double-walled tank through openings. In order to remove the vapors of oil products when the mechanical device is closed to prevent overflows, the common pipeline for vapor removal is equipped with a high-pressure breathing valve.

To reduce the temperature, the outer surface of the double-walled tank is treated with a layer of polyurethane, onto which a layer of heat-reflecting paint is applied.

Also, the drain pipeline of the double-walled tank for draining the mixture of absorbent and petroleum product into a separate container is equipped with an additional section of pipeline with a valve for draining A-76 gasoline directly into the tank.

The installation works as follows. At "small" breaths, the breathing valve opens, and the vapors of petroleum products through the common pipeline through the receiving device with grids enter the double-walled tank with the absorbent. In this case, most of the vapors turn into liquid due to cooling in the double-walled tank and absorption by the absorbent.

Another part of the oil product vapors is absorbed by the absorbent as a result of the absorbent moving through the holes of the stiffening partitions throughout the entire volume of the tank during the movement of the tank truck. The undissolved part of the oil product vapors at the outlet of the tank is captured by the filter-absorber when the safety valve opens.

Upon arrival of the tank truck at the receiving point, the level of the mixture of absorbent and petroleum product is checked through the tank's measuring hatch.

The disadvantages of this installation are:

1. Insufficient efficiency of vapor capture and conversion of gasoline vapors into liquid at high ambient temperatures (over 35 degrees Celsius).

2. The possibility of evaporation of the absorbent itself (gasoline A-76) at high ambient temperatures (over 35 degrees Celsius).

The closest to the specified problem is the installation of vapor recovery from railway tanks with the return of evaporated light fractions to commercial gasoline [Matveev Yu.A. et al. Patent No. 158753 dated 20.01.2016].

On the proposed railway tank car, which has standard equipment, a common pipeline line for the removal of vapors with a check valve is additionally installed on the body of the safety inlet valve, connected to a double-walled tank partially filled with an absorbent - summer grade A-76 gasoline, which is equipped with a coil-type heat exchanger for fuel vapors and a safety valve with an absorber filter. In this case, the inter-wall space of the tank is filled with carbon dioxide. The heat exchanger is rigidly connected to the common pipeline line for the removal of vapors.

The tank is equipped with a drain pipeline with a valve, as well as stiffening partitions with holes for absorbing petroleum product vapors contained in the vapor-air space of the tank.

To prevent the absorbent-oil product mixture from overflowing, the common vapor discharge pipeline inside the double-walled tank has a horizontal section and is equipped with a mechanical float-type device to prevent overflows. The absorbent-oil product mixture enters the common vapor discharge pipeline inside the double-walled tank through openings.

In order to reduce the temperature, the outer surface of the double-walled tank is treated with a layer of polyurethane, onto which a layer of heat-reflecting paint is applied. To remove petroleum vapors when the common vapor removal pipeline is closed, the tank of the railway tank is equipped with an additional high-pressure breathing valve with an absorber filter.

The utility model works as follows. At "small" breathing, the safety inlet valve opens in the tank and the oil product vapors enter the heat exchanger through a common pipeline and then into a double-walled tank with an absorbent. In this case, most of the vapors turn into liquid due to cooling in the heat exchanger knee and absorption by A-76 gasoline.

Another part of the oil product vapors is absorbed by the absorbent as a result of the absorbent moving through the holes of the stiffening partitions throughout the entire volume of the tank during the movement of the railway tank. The undissolved part of the oil product vapors at the outlet of the tank when the safety valve opens is captured by the filter-absorber.

When the level of the absorbent-oil product mixture increases to a certain level, a mechanical float-type device is activated to prevent overflows. As a result, the supply of vapors to the double-walled tank stops.

After closing the vapor discharge pipeline, petroleum vapors from the railway tank are discharged into the atmosphere through an additional high-pressure breathing valve.

Upon arrival of the railway tank car, the level of the absorbent mixture with the petroleum product is checked through the tank's measuring hatch and, if necessary, the mixture is drained through the drain pipe.

The disadvantages of this installation are:

1. Insufficient efficiency of vapor capture and conversion of gasoline vapors into liquid at high ambient temperatures (over 35 degrees Celsius).

2. The possibility of evaporation of the absorbent itself (gasoline A-76) at high ambient temperatures (over 35 degrees Celsius).

The proposed utility model allows solving the problem of increasing the efficiency of capturing gasoline vapors from automobile and railway tanks. Winter diesel fuel is used as a liquid in the inter-wall space of the tank.

The solution to this problem is achieved by filling the inter-wall space of the tank with diesel fuel and equipping it with a filler neck with a thermometer, a drain pipe with a valve, and also by equipping the tank’s process hatch with a pressure gauge.

These features are essential for solving the problem of the utility model, since the efficiency of capturing gasoline vapors is increased, boiling of the absorbent is prevented, and an economic effect is achieved due to the use of a mixture of gasoline (absorbent) with commercial gasolines.

The essence of the utility model is explained by the drawing Fig. 1, which shows a section of a double-walled tank for capturing vapors.

The automobile (railway) tank is equipped with a steam pipeline 1, which is connected to a double-walled reservoir 2. The reservoir 2 is filled with an absorbent - summer grade A-76 gasoline 3 and is equipped with a breathing valve 4 with an absorber filter and a process hatch 5. The process hatch is designed for measuring and pouring in the absorbent. The interwall space of the reservoir 2 is filled through the filler neck 6 with winter diesel fuel 7, which has a low thermal conductivity coefficient. The specific heat capacity of diesel fuel is 2.3 kJ. The specific heat capacity of carbon dioxide is 0.83 kJ, and the specific heat capacity of air is 1 kJ. That is, to heat the same volume of diesel fuel to a certain temperature, approximately twice as much heat is needed as to heat carbon dioxide (air).

In order to reduce the temperature, the outer surface of the double-walled tank 2 is treated with a layer of polyurethane 8, onto which a layer of heat-reflecting paint 9 is applied. The tank 2 and its inter-wall space are equipped with drain pipes 10 with valves 11 for draining the mixture of absorbent with petroleum product, as well as diesel fuel. The steam pipe inside the tank is connected to a large-area tubular heat exchanger 12 for converting gasoline vapors into liquid.

In order to control the pressure of the steam space in the tank, a pressure gauge 13 is installed on the process hatch. In order to control the temperature of diesel fuel 7, a thermometer 14 is installed on the filler neck 6 of the inter-wall space.

The average temperature in July in the Volga region (Ulyanovsk) is 21°C, and in June 20°C. The main evaporation of gasoline vapors occurs in the temperature range from 33 to 35°C. Therefore, in a double-walled tank, which has an inter-wall space with diesel fuel, a layer of polyurethane with heat-reflecting paint, the average maximum temperature can be 20-23°C. The specified temperature allows you to transfer gasoline vapors coming from a car (railway) tank from "small" breaths into a liquid state. On especially hot days with a daytime temperature of 35-40 degrees Celsius, the inter-wall space with carbon dioxide (air) of previous useful models can heat up to 33-35 degrees Celsius in a short time. This can cause evaporation of the absorbent itself (gasoline A-76). Replacing gases in the inter-wall space with diesel fuel practically reduces to a minimum (zero) the heating of the absorbent in the tank to the boiling point.

The utility model operates as follows. At "small" breathing of automobile gasolines, associated with temperature changes and an increase in the pressure of the vapor space in the tank, the safety inlet valve opens and gasoline vapors enter the heat exchanger 12 of the double-walled tank 2 with the absorbent 3 through the vapor line 1. In this case, the vapors turn into liquid due to cooling in the heat exchanger 12, tank 2, and also absorption by A-76 gasoline during the movement of the tank.

Cooling in the tank, compared to the steam space of a road (railway) tank, occurs due to the fact that the tank has an inter-wall space filled with diesel fuel, covered on the outside with polyurethane with reflective paint.

Upon arrival of the road (railway) tanker at the receiving point, if necessary, the mixture is drained through the drain pipe 10. The road tanker driver also monitors the vapor pressure in the tank 2 during filling (draining) and transportation of gasoline using the pressure gauge 13. When the vapor pressure increases, the driver drains the absorbent into a canister (container) through the drain pipe 10. The temperature of the diesel fuel is monitored using a thermometer 14.

The control of vapor pressure and temperature of diesel fuel during transportation of gasoline in railway tanks is carried out by the operator at the receiving and filling stations.

The utility model allows capturing gasoline vapors from automobile (railway) tanks. It should be noted that vapors of gasoline grades normal A-80, regular-92, premium-95 and super-98, turning into a liquid state, are mixed with summer gasoline A-76. This gasoline mixture can be added without loss of quality of petroleum products to commercial gasoline grades A-76 and normal A-80.

Therefore, the proposed utility model causes a large economic effect associated with the further use of petroleum product vapors in commercial gasolines.

Claims (1)

A double-walled tank for capturing gasoline vapors from automobile and railway tanks, including an inter-wall space, an absorbent, a steam line, a heat exchanger, a process hatch, characterized in that the inter-wall space of the tank is filled with diesel fuel and equipped with a filler neck with a thermometer, a drain pipe with a valve, and also in that the process hatch of the tank is equipped with a pressure gauge.