An integrated multi-stage gas fire extinguishing agent separation and recovery tower and recovery method

Abstract

The present invention relates to an integrated multi-stage gas fire extinguishing agent separation and recovery tower and a recovery method, belonging to the technical field of fire-fighting application equipment. The integrated multi-stage gas fire extinguishing agent separation and recovery tower comprises a tower body, the lower section of the tower body is connected to an air inlet pipe, a filter is provided on the air inlet pipe, a drain pipe is provided at the bottom of the tower body, and the drain pipe is connected to a balance recovery barrel I; an exhaust pipe is provided at the top of the tower body, and an exhaust valve is provided on the exhaust pipe; a plurality of recovery units are arranged in the tower body, and the recovery units include a cryogenic heat exchanger and a separation recovery device; a liquid storage tank is formed between the separation recovery device and the tower body, and each liquid storage tank is connected to a corresponding balance recovery barrel through a drain pipe, and the separation recovery device includes a separation cap, a gas collecting plate and a gas guide plate, and the separation cap is a multi-leaf structure. The device of the present invention enables the mixed gas to be cooled and liquefied step by step, which can save the amount of cold medium and reduce the energy consumption of separation and recovery. Through the method of the present invention, the mixed gas fire extinguishing agent can be separated and recovered.

Description

Technical Field

[0001] The invention belongs to the technical field of fire-fighting application equipment, and in particular relates to an integrated multi-stage gas fire-extinguishing agent separation and recovery tower and a recovery method. Background Art

[0002] In the field of firefighting, gaseous fire extinguishing agents such as heptafluoropropane, hexafluoropropane, and halon (1211, 1301) rely on high-pressure nitrogen to press out the fire extinguishing agent stored in the cylinder to achieve fire extinguishing. When inspecting the gas fire extinguishing system, the fire extinguishing agent needs to be released. Direct discharge after release will cause certain harm to the environment and also cause a large amount of waste of fire extinguishing agent. Therefore, the fire extinguishing agent is usually recovered. At present, the recovery of gaseous fire extinguishing agents generally adopts high pressure, adsorption and other means, which have the disadvantages of high energy consumption, high pressure, and low recovery rate. The fire extinguishing agent released on site may be a mixture of multiple gaseous fire extinguishing agents and nitrogen and carbon dioxide. After being recovered by traditional methods, it needs to be further separated before it can be used again. The recovery energy consumption is high and the efficiency is low.

[0003] Therefore, it is necessary to propose an integrated multi-stage gas fire extinguishing agent separation and recovery tower and a recovery method, which can separate and recover the mixed gas fire extinguishing agent, save energy consumption, and have a high recovery rate. Summary of the invention

[0004] In order to overcome the problems existing in the background technology, the present invention provides an integrated multi-stage gas fire extinguishing agent separation and recovery tower and a recovery method. By utilizing the physical properties that the gas fire extinguishing agent is liquefied at low temperature and different gas fire extinguishing agents have different dew point temperatures, an integrated recovery tower is adopted with multi-stage recovery units arranged therein. The mixed gas is cooled and liquefied step by step, which can save the amount of cold medium, especially the amount of high-grade cold medium, and reduce the energy consumption of separation and recovery. As the cooling temperature decreases successively, each gas fire extinguishing agent is separated and recovered.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] An integral multi-stage gas fire extinguishing agent separation and recovery tower, the integral multi-stage gas fire extinguishing agent separation and recovery tower comprises a tower body, the outer wall of the tower body is provided with a heat preservation layer, the lower section of the tower body is connected with an air inlet pipe, a filter is provided on the air inlet pipe, a drain pipe is provided at the bottom of the tower body, and the drain pipe is connected with a balance recovery barrel I; an exhaust pipe is provided at the top of the tower body, and an exhaust valve is provided on the exhaust pipe; a plurality of recovery units are provided in the tower body, the recovery units comprise a cryogenic heat exchanger and a separation recovery device, the separation recovery device is fixedly arranged in the tower body and located above the cryogenic heat exchanger, and the recovery units of each level are arranged from bottom to top; a liquid storage tank is formed in the gap between the separation recovery device and the tower body, and each liquid storage tank is respectively connected with a corresponding balance recovery barrel through a drain pipe; the separation recovery device comprises a separation cap, an air collecting plate and an air guide plate, the separation cap is welded to the air guide plate, the air guide plate is welded to the air collecting plate, and the separation cap is a multi-leaf structure.

[0007] Preferably, a drain valve is provided on the drain pipe, and a liquid level controller is provided at the bottom of the tower body and in each liquid storage tank, and each liquid level controller is respectively connected to the corresponding drain valve.

[0008] Preferably, the cryogenic heat exchanger is provided with a cold medium circulation pipeline, a flow control valve is provided on the pipeline at the liquid inlet end, a temperature sensor is provided in the cryogenic heat exchanger, a pressure control valve and a pressure sensor are provided in the separation recovery device, and the flow control valve, pressure control valve, temperature sensor and pressure sensor are all connected to the controller.

[0009] Preferably, the separation cap comprises conical blades and conical ring blades, the first stage of the separation cap is conical blades, the conical ring blades are connected to the conical blades through support rods, and the conical ring blades are connected to each other through support rods.

[0010] Furthermore, the diameter of the conical blade is larger than the diameter of the top ring of the conical ring blade closest to it and smaller than the diameter of the bottom ring of the conical ring blade. The top ring diameters of the conical ring blades are the same, and the bottom ring diameter increases step by step from top to bottom.

[0011] A method for separating and recovering a mixed gas fire extinguishing agent, comprising the following specific steps:

[0012] 1) Filtration: The mixed gas fire extinguishing agent is transported to the filter for filtration to remove solid impurities and moisture;

[0013] 2) Primary liquefaction recovery: The filtered mixed gas enters the first-stage recovery unit, and the gas is transferred from bottom to top through the cryogenic heat exchanger for heat exchange. The type and amount of cold medium are adjusted so that the gas fire extinguishing agent with a higher dew point is liquefied first. The liquefied gas fire extinguishing agent falls to the bottom of the tower body and is discharged into the balance recovery tank I for storage through the drain pipe;

[0014] 3) Secondary liquefaction recovery: The gas fire extinguishing agent that has not been liquefied in the first-stage recovery unit passes through the separation recovery device and enters the second-stage recovery unit. It is heat exchanged in the cryogenic heat exchanger, and the type and amount of the cold medium are adjusted. The gas fire extinguishing agent with a lower dew point is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank formed between the first-stage separation recovery device and the tower body, and is discharged into the balance recovery barrel of this stage through the pipeline for storage;

[0015] 4) n-stage liquefaction recovery: The unliquefied gas fire extinguishing agent in the previous stage recovery unit passes through the separation recovery device and enters the n-stage recovery unit. After heat exchange in the cryogenic heat exchanger, the type and amount of the cold medium are adjusted. Part of the gas fire extinguishing agent is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank formed between the previous stage separation recovery device and the tower body, and is discharged into the balance recovery barrel of this stage through a pipeline for storage. In this way, after multiple stages of treatment, the gas fire extinguishing agents are separated and recovered according to the different dew point temperatures of the components of the mixed gas fire extinguishing agent. Finally, the remaining nitrogen is discharged through the exhaust pipe.

[0016] Beneficial effects of the present invention: The present invention adopts an integral recovery tower with a multi-stage recovery unit installed therein. The mixed gas is cooled and liquefied step by step, which can save the amount of cold medium, especially the amount of high-grade cold medium, and reduce the energy consumption of separation and recovery. The physical properties of gas fire extinguishing agent liquefying at low temperature and different dew point temperatures of different gas fire extinguishing agents are utilized to reduce the temperature of the mixed gas from bottom to top in the tower body, thereby separating and recovering each gas fire extinguishing agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the separation recovery device of the present invention;

[0019] In the figure, 1-tower body, 2-air inlet pipe, 3-filter, 4-insulation layer, 5-drain pipe, 6-balance recovery barrel I, 7-exhaust pipe, 8-exhaust valve, 9-cryogenic heat exchanger, 10-liquid storage tank, 11-balance recovery barrel, 12-separation recovery device, 13-pressure control valve, 14-flow control valve, 15-controller, 16-liquid level controller, 17-drain valve, 18-gas collecting plate, 19-gas guide plate, 20-conical ring blade, 21-conical blade, 22-support rod. DETAILED DESCRIPTION

[0020] A method for separating and recovering a mixed gas fire extinguishing agent, comprising the following specific steps:

[0021] 1) Filtration: The mixed gas fire extinguishing agent is transported to the filter 3 for filtration to remove solid impurities and moisture;

[0022] 2) First-stage liquefaction recovery: The filtered mixed gas enters the first-stage recovery unit, and the gas is transferred from bottom to top through the cryogenic heat exchanger 9 for heat exchange. The type and amount of the cold medium are adjusted so that the gas fire extinguishing agent with a higher dew point is liquefied first. The liquefied gas fire extinguishing agent falls to the bottom of the tower body 1 and is discharged into the balance recovery barrel Ⅰ6 for storage through the drain pipe;

[0023] 3) Secondary liquefaction recovery: The gas fire extinguishing agent that has not been liquefied in the first-stage recovery unit passes through the separation recovery device 12 and enters the second-stage recovery unit, and is heat exchanged through the cryogenic heat exchanger 9. The type and amount of the cold medium are adjusted, and the gas fire extinguishing agent with a lower dew point is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank 10 formed between the first-stage separation recovery device 12 and the tower body 1, and is discharged into the balance recovery barrel 11 of this stage for storage through a pipeline;

[0024] 4) n-stage liquefaction recovery: The unliquefied gas fire extinguishing agent in the previous stage recovery unit passes through the separation recovery device 12 and enters the n-stage recovery unit, and is heat exchanged through the cryogenic heat exchanger 9. The type and amount of the cold medium are adjusted, and part of the gas fire extinguishing agent is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank 10 formed between the previous stage separation recovery device 12 and the tower body 1, and is discharged into the balance recovery barrel 11 of this stage for storage through a pipeline. In this way, the multi-stage treatment is carried out, and the gas fire extinguishing agents are separated and recovered according to the different dew point temperatures of the components of the mixed gas fire extinguishing agent. Finally, the remaining nitrogen is discharged through the exhaust pipe.

[0025] According to the above-mentioned separation and recovery method of mixed gas fire extinguishing agent, an integrated multi-stage gas fire extinguishing agent separation and recovery tower is provided, and the specific structure is as follows:

[0026] like Figure 1 , Figure 2 As shown, the integrated multi-stage gas fire extinguishing agent separation and recovery tower includes a tower body 1, the cross section of the tower body 1 is circular, the outer wall of the tower body 1 is provided with a heat preservation layer 4, which can maintain the coldness in the tower body 1 without loss and reduce the amount of cold medium. The lower section of the tower body 1 is connected with the air inlet pipe 2, and the air inlet pipe 2 is provided with a filter 3. The filter 3 can filter the moisture and impurities in the mixed gas, purify the gas entering the tower body 1, and reduce the impurities in the recovered gas fire extinguishing agent; the bottom of the tower body 1 is provided with a drain pipe 5, and the drain pipe 5 is connected to the flat The tower body 1 is connected to the balance recovery barrel Ⅰ6, a drain valve 17 is provided on the drain pipe 5, and a liquid level controller 16 is provided at the bottom of the tower body 1. The liquid level controller 16 is connected to the drain valve 17. The liquid level controller 16 is a mature component available on the market, and can set upper and lower liquid level values. When the liquid level at the bottom of the tower body 1 reaches the upper liquid level value, the liquid level controller 16 controls the drain valve 17 to open, and discharges the liquid gas fire extinguishing agent into the balance recovery barrel Ⅰ6 for storage. When the liquid level reaches the lower liquid level value, the liquid level controller 16 controls the drain valve 17 to close.

[0027] An exhaust pipe 7 is provided at the top of the tower body 1, and an exhaust valve 8 is provided on the exhaust pipe 7. When the exhaust valve 8 is opened, the remaining nitrogen and other gases after being processed by the multi-stage recovery units in the tower body 1 are discharged through the exhaust pipe 7. A plurality of recovery units are provided in the tower body 1, and the recovery units include a cryogenic heat exchanger 9 and a separation recovery device 12. The separation recovery device 12 is fixedly arranged in the tower body 1 and is located above the cryogenic heat exchanger 9. The recovery units at each level are arranged from bottom to top. The gap between the separation recovery device 12 and the tower body 1 forms a liquid storage tank 10. Each liquid storage tank 10 is connected to the corresponding balance recovery barrel 11 through a liquid discharge pipe 5. A liquid level controller 16 is provided in each liquid storage tank 10, which is respectively connected to the liquid discharge valve 17 on the liquid discharge pipe 5 at each level, so that the liquid gas fire extinguishing agent in the liquid storage tank 10 is respectively stored in the balance recovery barrel 11. The cryogenic heat exchanger 9 is provided with a cold medium circulation pipeline, a flow control valve 14 is provided on the pipeline at the liquid inlet end, a temperature sensor is provided in the cryogenic heat exchanger 9, and a pressure control valve 13 and a pressure sensor are provided in the separation recovery device 12. The flow control valve 14, the pressure control valve 13, the temperature sensor and the pressure sensor are all connected to the controller 15. The controller 15 controls the opening of the pressure control valve 13 according to the pressure value to adjust the pressure in each level of the separation recovery device 12; the controller 15 controls the opening of the flow control valve 14 according to the temperature value to adjust the amount of cold medium introduced into each level of the cryogenic heat exchanger 9 to adjust the temperature in each level of the separation recovery device 12.

[0028] The separation recovery device 12 includes a separation cap, an air collecting plate 18 and an air guide plate 19. The air collecting plate 18 is a frustum-shaped plate, and the air guide plate 19 is a cylindrical plate. The air collecting plate 18 collects the gas passing through the cryogenic heat exchanger 9 and guides the gas to move upward through the air guide plate 19. The separation cap is welded to the air guide plate 19, and the air guide plate 19 is welded to the air collecting plate 18. The separation cap is a multi-leaf structure. The separation cap comprises conical blades 21 and conical ring blades 20. The first stage of the separation cap is the conical blades 21. The conical ring blades 20 are connected to the conical blades 21 through support rods 22. The conical ring blades 20 are connected to each other through support rods 22. The diameter of the conical blades 21 is larger than the diameter of the top ring of the conical ring blade 20 closest to it and smaller than the diameter of the bottom ring of the conical ring blade 20. The top ring diameters of the conical ring blades 20 are the same, and the bottom ring diameters increase step by step from top to bottom. The multi-leaf structure design of the separation cap can ensure that the gas can pass smoothly and the gas reaches the next level recovery unit. It can also ensure that the fire extinguishing agent liquefied by the next level cryogenic heat exchanger 9 does not fall into the recovery unit of this level, so that the gas fire extinguishing agents are separated and not mixed with each other.

[0029] Example

[0030] The mixed gas components are heptafluoropropane, hexafluoropropane, halon (1301) and nitrogen.

[0031] Physical properties of heptafluoropropane: boiling point is -16.4℃, freezing point is -131℃, critical temperature is 101.7℃, critical pressure is 2.912Mpa;

[0032] Physical properties of hexafluoropropane: boiling point is -1.4°C, freezing point is -93.6°C, critical temperature is 124.9°C, critical pressure is 3.20Mpa;

[0033] Physical properties of 1301: boiling point is -57.85℃.

[0034] Physical properties of nitrogen: boiling point is -195.55℃.

[0035] The mixed gas is transported to the filter for filtration to remove solid impurities and moisture; the filtered mixed gas enters the first-stage recovery unit, where the temperature is reduced to -10°C. The gas is transferred from bottom to top through the cryogenic heat exchanger for heat exchange, so that the hexafluoropropane gas fire extinguishing agent with a higher dew point is first liquefied and falls to the bottom of the tower body, and is discharged into the balance recovery tank I6 for storage through the drain pipe 5;

[0036] The gaseous fire extinguishing agent and nitrogen that are not liquefied in the first-stage recovery unit pass through the separation recovery device and enter the second-stage recovery unit. After heat exchange in the cryogenic heat exchanger, the temperature is reduced to -25°C. The heptafluoropropane is liquefied and falls into the liquid storage tank formed between the first-stage separation recovery device and the tower body after liquefaction. It is discharged into the balance recovery barrel 11 of this stage through the discharge pipe 5 for storage.

[0037] The unliquefied gaseous fire extinguishing agent and nitrogen in the second-stage recovery unit pass through the separation recovery device and enter the third-stage recovery unit. After heat exchange in the cryogenic heat exchanger, the temperature is reduced to -65°C, and the Halon (1301) is liquefied. After liquefaction, it falls into the liquid storage tank formed between the second-stage separation recovery device and the tower body, and is discharged into the balance recovery barrel 11 of this stage for storage through the discharge pipe 5; finally, the nitrogen is discharged through the exhaust pipe 7.

[0038] The present invention adopts an integral recovery tower with a multi-stage recovery unit. The mixed gas is cooled and liquefied step by step, which can save the use of high-grade cold medium and reduce the energy consumption of separation and recovery. The physical properties of gas fire extinguishing agent liquefying at low temperature and different dew point temperatures of different gas fire extinguishing agents are utilized to reduce the temperature of the mixed gas from bottom to top in the tower body, thereby separating and recovering each gas fire extinguishing agent.

[0039] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An integrated multi-stage gas fire extinguishing agent separation and recovery tower, characterized in that: The integrated multi-stage gas fire extinguishing agent separation and recovery tower comprises a tower body and a plurality of recovery units. The outer wall of the tower body is provided with an insulation layer. The lower section of the tower body is connected to the air inlet pipe. The air inlet pipe is provided with a filter. The bottom of the tower body is provided with a drain pipe. The drain pipe is connected to the balance recovery barrel I. The drain pipe is provided with a drain valve. The bottom of the tower body and each liquid storage tank are provided with a liquid level controller. Each liquid level controller is respectively connected to the corresponding drain valve; the top of the tower body is provided with an exhaust pipe, and the exhaust pipe is provided with an exhaust valve; the recovery unit is arranged in the tower body, and the recovery unit comprises a cryogenic heat exchanger and a separation recovery device. The separation recovery device is fixedly arranged in the tower body and is located at the cryogenic heat exchanger. Above, recovery units of various levels are arranged from bottom to top; the gap between the separation recovery device and the tower body forms a liquid storage tank, and each liquid storage tank is connected to the corresponding balance recovery barrel through a drain pipe; the separation recovery device includes a separation cap, an air collecting plate and an air guide plate, the separation cap is welded to the air guide plate, the air guide plate is welded to the air collecting plate, and the separation cap is a multi-leaf structure; the cryogenic heat exchanger is provided with a cold medium circulation pipeline, a flow control valve is provided on the pipeline at the liquid inlet end, a temperature sensor is provided in the cryogenic heat exchanger, a pressure control valve and a pressure sensor are provided in the separation recovery device, and the flow control valve, pressure control valve, temperature sensor and pressure sensor are all connected to the controller.

2. The integrated multi-stage gas fire extinguishing agent separation and recovery tower according to claim 1, characterized in that: The separation cap comprises conical blades and conical ring blades. The first stage of the separation cap is the conical blades. The conical ring blades are connected with the conical blades through supporting rods, and the conical ring blades are connected with each other through supporting rods.

3. The integrated multi-stage gas fire extinguishing agent separation and recovery tower according to claim 2 is characterized in that: The diameter of the conical blade is larger than the diameter of the top ring of the conical ring blade closest to it and smaller than the diameter of the bottom ring of the conical ring blade. The top ring diameters of the conical ring blades are the same, and the bottom ring diameter increases step by step from top to bottom.

4. A method for separating and recovering a mixed gas fire extinguishing agent using the integrated multi-stage gas fire extinguishing agent separation and recovery tower as claimed in claim 1, characterized in that: The specific steps are: 1) Filtration: The mixed gas fire extinguishing agent is transported to the filter for filtration to remove solid impurities and moisture; 2) Primary liquefaction recovery: The filtered mixed gas enters the first-stage recovery unit, and the gas is transferred from bottom to top through the cryogenic heat exchanger for heat exchange. The type and amount of cold medium are adjusted so that the gas fire extinguishing agent with a higher dew point is liquefied first. The liquefied gas fire extinguishing agent falls to the bottom of the tower body and is discharged into the balance recovery tank I for storage through the drain pipe; 3) Secondary liquefaction recovery: The gas fire extinguishing agent that has not been liquefied in the first-stage recovery unit passes through the separation recovery device and enters the second-stage recovery unit. It is heat exchanged in the cryogenic heat exchanger, and the type and amount of the cold medium are adjusted. The gas fire extinguishing agent with a lower dew point is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank formed between the first-stage separation recovery device and the tower body, and is discharged into the balance recovery barrel of this stage through the pipeline for storage; 4) n-stage liquefaction recovery: The unliquefied gas fire extinguishing agent in the previous stage recovery unit passes through the separation recovery device and enters the n-stage recovery unit. After heat exchange in the cryogenic heat exchanger, the type and amount of cold medium are adjusted, and the gas fire extinguishing agent is liquefied. The liquefied gas fire extinguishing agent falls into the liquid storage tank formed between the previous stage separation recovery device and the tower body, and is discharged into the balance recovery barrel of this stage through a pipeline for storage. Finally, the remaining nitrogen is discharged through the exhaust pipe.

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