A tail gas purification and flame arrestment device for workover rigs

Abstract

The present invention provides a tail gas purification and flame arrestment device for a workover rig, belonging to the technical field of diesel engine tail gas purification. The present invention includes a shock-absorbing steel wire tube, a front-stage cooling working chamber, a rear-stage cooling working chamber, a soot filtration and purification and flame arrestment system, and a purging recovery and safety pressure relief system. The internal structure of the present invention is compact, and the air dynamics principle is fully considered in each filtration and purification partition to ensure smooth tail gas emission, reduce exhaust back pressure, and at the same time meet the control of smoke density and sparks in tail gas emission.

Description

Technical Field

[0001] The present invention relates to a tail gas purification and fire prevention device for a workover rig, belonging to the technical field of diesel engine tail gas purification. Background Art

[0002] Patent No.: CN 109505681 A points out that a workover rig is a special device for workover in oil fields and is suitable for workover operations within a well depth of 4000 m. The disadvantage of the diesel engine of the workover rig is that the tail gas emission does not meet the standards, and the emission of black smoke is serious, polluting the environment. Especially during initial cold start and frequent load mutations during operation, the emission of black smoke is more obvious. Currently, the commonly used diesel black smoke purifier uses a cordierite ceramic filter element, abbreviated as DPF particulate trap, which can effectively intercept the black smoke carbon particles (pM) generated by the diesel engine. However, the components of the emitted tail gas are relatively complex. Especially during load mutations during workover operations, the exhaust gas volume suddenly increases, and diesel is not fully burned in the engine. In addition to pM particles and other components carried by the exhaust gas, there are also unburned gum oil droplets. These gum oil droplets enter the DPF trap with the air flow and adhere to the pore diameters of the ceramic wall. Subsequently, the carbon particles (pM) adhere to the gum oil droplets, causing the ceramic particulate trap to become blocked within a short time, increasing the back pressure of the engine and rendering the ceramic particulate trap ineffective. The existing technical solutions mainly have two types. One is to intercept soot particles through multiple filter meshes and a carbon collection and carbon removal device; the other is to use a chemical reaction method to convert soot particles through a catalytic purification device. There are the following problems: First, the device has a large volume and needs to be set up separately near the workover rig. Due to the working characteristics of the workover operation itself, the work site needs to be frequently changed, making it inconvenient to carry. Second, the purification devices for different models of workover rigs need to be customized separately and the purification core components need to be replaced regularly, resulting in a high cost and requiring professional personnel for daily maintenance. Third, according to different operating conditions of the workover rig, the device needs to be able to purify soot particles of different displacement volumes.

[0003] In order to make the tail gas emission of the workover rig meet the national and enterprise health, safety, and environmental protection requirements, it is extremely important to design a tail gas purification and fire prevention device for the workover rig. Summary of the Invention

[0004] To solve the above problems existing in the prior art, the present invention discloses a tail gas purification and fire prevention device for a workover rig, which can effectively purify some gaseous pollutants and soot particles in the exhaust pollutants of the workover diesel engine; at the same time, block and extinguish the sparks entrained in the tail gas to achieve a fire prevention effect.

[0005] The technical solution adopted by the present invention is: a tail gas purification and fire prevention device for a workover rig, including a shock-absorbing steel wire tube, a front-stage cooling working chamber, a rear-stage cooling working chamber, a soot filtration and purification and fire prevention system, and a purging recovery and safety pressure relief system.

[0006] The soot filtration and purification fire prevention system includes a pre-filter fire prevention box, a filter steel wool board, a DPF ceramic core board, a post-filter fire prevention box, a multi-layer thin sheet filter steel wool board, and an air flow guide plate. The purge recovery and safety pressure relief system includes a reverse purge pipe, a solenoid valve, a reverse purge controller, a gas source controller, a reverse purge gas storage tank, a soot filtration cotton bag, a soot recovery tank, a pressure alarm, a pneumatic switch control valve, a pressure sensor, and a safety pressure relief gas pipe.

[0007] One end of the shock-absorbing steel wire pipe is connected to the exhaust port of the diesel engine, and the other end of the shock-absorbing steel wire pipe is connected to the intake end of the pre-filter fire prevention box. The exhaust end of the pre-filter fire prevention box is connected to the pre-cooling working chamber through a steel pipe, and the pre-cooling working chamber and the post-cooling working chamber are connected and fixed through a sealing clamp. A number of filter steel wool boards are provided between the intake end and the exhaust end of the pre-filter fire prevention box.

[0008] One side of the pre-cooling working chamber is connected to the soot recovery tank through a soot recovery pipe, and a soot filtration cotton bag is provided in the soot recovery tank. A pressure sensor is installed on the inner wall of the pre-cooling working chamber. A DPF ceramic core board is provided between the pre-cooling working chamber and the post-cooling working chamber, and the gas in the pre-cooling working chamber enters the post-cooling working chamber through the DPF ceramic core board. The post-cooling working chamber is connected to the post-filter fire prevention box through a connecting pipe. A multi-layer thin sheet filter steel wool board, an air flow guide plate, and an exhaust pipe are provided in the post-filter fire prevention box. The multi-layer thin sheet filter steel wool board is located above the air flow guide plate, and the other end of the exhaust pipe extends outside the post-filter fire prevention box.

[0009] A safety pressure relief gas pipe is further provided at the output end of the pre-cooling working chamber, and the safety pressure relief gas pipe is connected to the connecting pipe.

[0010] A first pneumatic switch control valve is installed on the soot recovery pipe.

[0011] A second pneumatic switch control valve is installed on the safety pressure relief gas pipe, and a third pneumatic switch control valve is installed on the connecting pipe.

[0012] A heat-insulating cover is provided between the reverse purge gas storage tank and the post-cooling working chamber, and a reverse purge controller, an air source controller, and a pressure alarm are installed on the upper end of the reverse purge gas storage tank. The reverse purge pipe is welded to the outer wall of the reverse purge gas storage tank and extends into the reverse purge gas storage tank to communicate with the solenoid valve, and the other end of the reverse purge pipe passes through the heat-insulating cover and extends into the post-cooling working chamber. The reverse purge controller, the air source controller, the pressure alarm, the first pneumatic switch control valve, the second pneumatic switch control valve, and the third pneumatic switch control valve are connected in the air circuit. A mechanical lever is provided between the first pneumatic switch control valve and the third pneumatic switch control valve. During normal operation, the first pneumatic switch control valve is closed, and the third pneumatic control valve is opened; during reverse purge, the first pneumatic switch control valve is opened, and the third pneumatic control valve is closed; that is, when one of the pneumatic switch control valves is closed, the other pneumatic switch control valve is opened synchronously.

[0013] The first pneumatic switch control valve, the second pneumatic switch control valve and the third pneumatic switch control valve are all provided with a switch flap and a pneumatic control valve.

[0014] The reverse purge controller adopts LFJX-DPF / 16L.

[0015] The brand model of the air source controller is AL-2000.

[0016] The material of the tail gas purification fire-blocking device is 304 stainless steel.

[0017] The reverse purge gas storage tank is respectively connected to the first pneumatic switch control valve, the second pneumatic switch control valve and the third pneumatic switch control valve with a gas supply metal pipeline, and each gas supply metal pipeline is connected to a gas source controller for controlling gas supply.

[0018] The beneficial effects of the present invention using the above technical solution are:

[0019] (1) The device is designed with front and rear two-stage filter fire-retardant boxes and front and rear cooling working chambers plus DPF ceramic core plates. The internal structure is compact, and each filter purification partition fully considers the aerodynamic principles to ensure smooth exhaust emission and reduce exhaust back pressure, while meeting the control of smoke and sparks in exhaust emissions.

[0020] (2) This device is made of 304 stainless steel, and the main material and accessories can be recycled, which is economical and reasonable.

[0021] (3) The device is designed with a pressure alarm that emits an audible and visual alarm, prompting the DPF ceramic core plate to be replaced in time if the circulation is blocked to avoid stalling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a three-dimensional schematic diagram of a tail gas purification and flame arrestment device for a workover rig;

[0024] Figure 2 It is a front view schematic diagram of a tail gas purification and flame arrestment device for a workover rig;

[0025] Figure 3 It is a schematic diagram of a pneumatic switch control valve for a tail gas purification and flame arrestment device of a workover rig.

[0026] The description of the numbers in the figure: 1. Shock-absorbing steel wire tube, 2. Pre-filter flame arrestment box, 3. Filter steel wire cotton board, 4. Steel pipe, 5. Smoke and dust recovery tank, 6. Smoke and dust filter cotton bag, 7. First pneumatic switch control valve, 8. Pre-cooling working chamber, 9. Second pneumatic switch control valve, 10. Pressure sensor, 11. Safety relief air duct, 12. DPF ceramic core board, 13. Sealing clamp, 14. Post-cooling working chamber, 15. Third pneumatic switch control valve, 16. Heat insulation cover, 17. Reverse purge pipe, 18. Solenoid valve, 19. Reverse purge gas storage tank, 20. Gas supply metal pipeline, 21. Air source controller, 22. Reverse purge controller, 23. Pressure alarm, 24. Post-filter flame arrestment box, 25. Multi-layer thin sheet filter steel wire cotton board, 26. Airflow guiding plate, 27. Exhaust pipe, 28. Switch flap, 29. Pneumatic control valve. Detailed implementation manners

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. The description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] To further understand the content of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and embodiments:

[0029] Such as Figures 1 to 3As shown in the figure, the present invention provides a workover rig tail gas purification and flame arrestment device, which includes a shock-absorbing steel wire tube 1, a front-stage cooling working chamber 8, a rear-stage cooling working chamber 14, a soot filtration and purification and flame arrestment system, and a purge recovery and safety pressure relief system.

[0030] The soot filtration and purification and flame arrestment system includes a front-stage filtration and flame arrestment box 2, a filter steel wool board 3, a DPF ceramic core board 12, a rear-stage filtration and flame arrestment box 24, a multi-layer thin sheet filter steel wool board 25, and an air flow guiding plate 26. The purge recovery and safety pressure relief system includes a reverse purge pipe 17, a solenoid valve 18, a reverse purge controller 22, a gas source controller 21, a reverse purge gas storage tank 19, a soot filtration cotton bag 6, a soot recovery tank 5, a pressure alarm 23, a pneumatic switch control valve, a pressure sensor 10, and a safety pressure relief air duct 11.

[0031] One end of the shock-absorbing steel wire tube 1 is connected to the exhaust port of the diesel engine, and the other end of the shock-absorbing steel wire tube 1 is connected to the intake end of the front-stage filtration and flame arrestment box 2. The exhaust end of the front-stage filtration and flame arrestment box 2 is connected to the front-stage cooling working chamber 8 through a steel pipe 4. The front-stage cooling working chamber 8 and the rear-stage cooling working chamber 14 are connected and fixed through a sealing clamp 13. A plurality of filter steel wool boards 3 are provided between the intake end and the exhaust end of the front-stage filtration and flame arrestment box 2.

[0032] One side of the front-stage cooling working chamber 8 is connected to the soot recovery tank 5 through a soot recovery pipe. A soot filtration cotton bag 6 is provided inside the soot recovery tank 5. A pressure sensor 10 is installed on the inner wall of the front-stage cooling working chamber 8. A DPF ceramic core board 12 is provided between the front-stage cooling working chamber 8 and the rear-stage cooling working chamber 14. The gas in the front-stage cooling working chamber 8 enters the rear-stage cooling working chamber 14 through the DPF ceramic core board 12. The rear-stage cooling working chamber 14 is connected to the rear-stage filtration and flame arrestment box 24 through a connecting pipe. A multi-layer thin sheet filter steel wool board 25, an air flow guiding plate 26, and an exhaust pipe 27 are provided inside the rear-stage filtration and flame arrestment box 24. The multi-layer thin sheet filter steel wool board 25 is located above the air flow guiding plate 26. The other end of the exhaust pipe 27 extends out of the rear-stage filtration and flame arrestment box 24.

[0033] A safety pressure relief air duct is further provided at the output end of the front-stage cooling working chamber 8, and the safety pressure relief air duct is connected to the connecting pipe.

[0034] A first pneumatic switch control valve 7 is installed on the soot recovery pipe.

[0035] A second pneumatic switch control valve 9 is installed on the safety pressure relief air duct 11, and a third pneumatic switch control valve 15 is installed on the connecting pipe.

[0036] An insulation cover 16 is provided between the reverse purge gas storage tank 19 and the post-cooling working chamber 14. A reverse purge controller 22, a gas source controller 21, and a pressure alarm 23 are installed at the upper end of the reverse purge gas storage tank 19. The reverse purge pipe 17 is welded to the outer wall of the reverse purge gas storage tank 19 and extends into the tank of the reverse purge gas storage tank 19 to communicate with the solenoid valve 18. The other end of the reverse purge pipe 17 passes through the insulation cover 16 and extends into the post-cooling working chamber 14. The reverse purge controller 22, the gas source controller 21, the pressure alarm 23, the first pneumatic switch control valve 7, the second pneumatic switch control valve 9, and the third pneumatic switch control valve 15 are connected by a gas circuit. A mechanical lever is provided between the first pneumatic switch control valve 7 and the third pneumatic switch control valve 15 to ensure that when one of the pneumatic switch control valves is closed, the other pneumatic switch control valve is opened synchronously.

[0037] The first pneumatic switch control valve 7, the second pneumatic switch control valve 9, and the third pneumatic switch control valve 15 are all provided with a switch flap 28 and a pneumatic control valve 29.

[0038] The reverse purge controller 22 adopts LFJX-DPF / 16L.

[0039] The brand model of the gas source controller 21 is AL-2000.

[0040] The materials of the tail gas purification and flame arrestment device are all 304 stainless steel.

[0041] A supply metal pipeline 20 is connected between the reverse purge gas storage tank 19 and the first pneumatic switch control valve 7, the second pneumatic switch control valve 9, and the third pneumatic switch control valve 15 respectively. The gas source controller 21 for controlling the gas supply is communicated with each supply metal pipeline 20.

[0042] Working principle:

[0043] The excessive smoke with sparks discharged by the engine enters the pre-filter fire-blocking box 2 through the shock-absorbing steel wire pipe 1, and the filtering steel wool plate 3 intercepts and filters the large particles of smoke, and the soluble organic matter (SOF) in the black smoke particles (PM) is filtered, absorbed and the sparks are extinguished; then the smoke enters the pre-cooling working chamber 8 through the steel pipe 4 and contacts the DPF ceramic core plate 12, and the DPF ceramic core plate 12 purifies, intercepts and absorbs the smoke particles, and filters out most of the insoluble organic matter (IOF) in the black smoke particles (PM) in the smoke. The exhaust gas temperature drops from 400℃-450℃ to 120℃-150℃; the flue gas cooled by the DPF ceramic core plate 12 enters the post-cooling working chamber 14 and enters the post-filter fire-blocking box 24 along the connecting pipe. The interception airflow channel formed by the airflow guide plate 26 and the multi-layer thin-sheet filter steel wool plate 25 intercepts and filters the secondary smoke particles, and re-filters and absorbs the soluble organic matter (SOF) in the black smoke particles (PM). The purified exhaust gas is discharged from the exhaust pipe 27, and the exhaust gas temperature drops below 100℃. A heat insulation cover 16 is installed at the connection between the smoke filtration and purification fire-blocking system and the purge recovery and safety pressure relief system to prevent the high temperature of the machine body from affecting the performance of the solenoid valve 18 and the air source controller 21, so that their temperature is controlled below 35℃.

[0044] In order to extend the service life of the DPF ceramic core plate 12 and reduce the replacement frequency, the DPF ceramic core plate 12 needs to be purged to push the smoke particles adsorbed in the DPF ceramic core plate 12 into the smoke recovery tank 5. The reverse purge air storage tank 19 is connected to the air circuit control air bag of the well repair machine, and part of the compressed air in the well repair machine air bag is stored in the reverse purge air storage tank 19. According to the self-cleaning time set by the LFJX-DPF / 16L reverse purge controller 22, the third pneumatic switch control valve 15 is driven to control the switch flap 28 to close, and the first pneumatic switch control valve 7 is driven to control the switch flap 28 to open. At the same time, the solenoid valve 18 in the reverse purge gas storage tank 19 receives an electrical signal, releases the compressed gas in the reverse purge gas storage tank 19, and the switch flap 28 is closed to form a temporary closed working chamber, and the compressed gas is ejected instantly, forming a pressure difference between the front and rear ends of the DPF ceramic core plate 12, and the DPF ceramic core plate 12 is reversely purged, pushing the smoke particles into the smoke recovery tank 5 and collected by the smoke filter cotton bag 6. After the purge is completed, the first pneumatic switch control valve 7 and the third pneumatic switch control valve 15 control the corresponding switch flap 28 to automatically reset.

[0045] For safety redundancy considerations, once the DPF ceramic core plate 12 is blocked, the pressure in the front cooling working chamber 8 will increase, and the pressure sensing device in the front cooling working chamber 8 will send an electrical signal to the gas source controller 21. The gas source controller 21 drives the second pneumatic switch control valve 9 to control the front control switch flap 28 of the pressure relief air duct 11 to open, and the flue gas directly enters the post-filter fire-blocking box 24. The multi-layer thin-film filter steel wool board 25 also has a fire-blocking function to extinguish sparks. At this time, the pressure alarm 23 sends out an audible and visual alarm, prompting the DPF ceramic core plate 12 to be replaced in time if the circulation is not smooth to avoid stalling.

[0046] The present invention was installed and put into use at the XJ90Z workover rig (factory number: 06031501000046) at the workover operation site, and the tail gas emissions of the workover rig were tested by a third-party environmental protection testing agency in accordance with GB3847-2018 "Emission Limits and Measurement Methods for Pollutants from Diesel Vehicles". Before the installation of the device, when the engine speed was 735r / min, the smoke density measurement value was 11.26m -1 After installing this device, when the engine speed reaches 4840r / min, the smoke measurement value is 0.01m -1 , meets the standards, and exhaust sparks are completely eliminated.

[0047] Finally, it should be noted that the above 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 with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tail gas purification and fire prevention device for a workover rig, characterized in that, it includes a shock-absorbing steel wire tube (1), a front cooling working chamber (8), a rear cooling working chamber (14), a soot filtration and purification and fire prevention system, and a purging recovery and safety pressure relief system; The soot filtration and purification and fire prevention system includes a front filtration and fire prevention box (2), a filter steel wool board (3), a DPF ceramic core board (12), a rear filtration and fire prevention box (24), a multi-layer thin sheet filter steel wool board (25) and an air flow guiding plate (26); The purging recovery and safety pressure relief system includes a reverse purging pipe (17), a solenoid valve (18), a reverse purging controller (22), a gas source controller (21), a reverse purging gas storage tank (19), a soot filtration cotton bag (6), a soot recovery tank (5), a pressure alarm (23), a pneumatic switch control valve and a pressure sensor (10); The pneumatic switch control valves are respectively a first pneumatic switch control valve (7), a second pneumatic switch control valve (9) and a third pneumatic switch control valve (15); One end of the shock-absorbing steel wire tube (1) is connected to the exhaust port of the diesel engine, and the other end of the shock-absorbing steel wire tube (1) is connected to the intake end of the front filtration and fire prevention box (2). The exhaust end of the front filtration and fire prevention box (2) is connected to the front cooling working chamber (8) through a steel pipe (4). The front cooling working chamber (8) is communicated with the rear cooling working chamber (14); A plurality of filter steel wool boards (3) are arranged between the intake end and the exhaust end of the front filtration and fire prevention box (2); One side of the front cooling working chamber (8) is connected to the soot recovery tank (5) through a soot recovery pipe. A soot filtration cotton bag (6) is arranged in the soot recovery tank (5); A pressure sensor (10) is installed on the inner wall of the front cooling working chamber (8). A DPF ceramic core board (12) is arranged between the front cooling working chamber (8) and the rear cooling working chamber (14); The rear cooling working chamber (14) is communicated with the rear filtration and fire prevention box (24) through a connecting pipe. A multi-layer thin sheet filter steel wool board (25), an air flow guiding plate (26) and an exhaust pipe (27) are arranged in the rear filtration and fire prevention box (24). The multi-layer thin sheet filter steel wool board (25) is located above the air flow guiding plate (26). The other end of the exhaust pipe (27) extends out of the rear filtration and fire prevention box (24); The upper end of the reverse purging gas storage tank (19) is equipped with a reverse purging controller (22), a gas source controller (21) and a pressure alarm (23); The reverse purging pipe (17) is welded to the outer wall of the reverse purging gas storage tank (19) and extends into the reverse purging gas storage tank (19) and is communicated with the solenoid valve (18). The other end of the reverse purging pipe (17) extends into the rear cooling working chamber (14); The reverse purging controller (22), the gas source controller (21), the pressure alarm (23), the first pneumatic switch control valve (7), the second pneumatic switch control valve (9) and the third pneumatic switch control valve (15) are connected by air circuits.

2. A tail gas purification and fire prevention device for a workover rig according to claim 1, characterized in that, The described front cooling working chamber (8) and the rear cooling working chamber (14) are connected and fixed through a sealing clamp (13).

3. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, A safety relief air duct is further provided at the output end of the described front cooling working chamber (8), and the safety relief air duct is communicated with the connecting pipe.

4. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, The described first pneumatic switch control valve (7) is located on the soot recovery pipe.

5. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, The described second pneumatic switch control valve (9) is arranged on the safety relief air duct (11).

6. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, The described third pneumatic switch control valve (15) is located on the connecting pipe.

7. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, A mechanical lever is provided between the described first pneumatic switch control valve (7) and the third pneumatic switch control valve (15).

8. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, One supply air metal pipeline (20) is respectively connected between the described reverse purge gas storage tank (19) and the first pneumatic switch control valve (7), the second pneumatic switch control valve (9) and the third pneumatic switch control valve (15), and a gas source controller (21) for controlling the supply air is communicated on each supply air metal pipeline (20).

9. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, A heat insulation cover (16) is provided between the described reverse purge gas storage tank (19) and the rear cooling working chamber (14).

10. A workover rig tail gas purification and fire prevention device according to claim 1, characterized in that, The material of the described reverse purge controller (22) is 304 stainless steel.

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