Residual liquid recovery device for spherical pig ball receiving and sending valve

Abstract

The utility model relates to the technical field of receiving and sending ball valve residual liquid cleaning, and discloses a spherical pig receiving and sending ball valve residual liquid recovery device which comprises a blow-off pipe, a gas blocking oil conveyor and an adsorption tank, one end of the blow-off pipe is connected with the gas blocking oil conveyor, an exhaust pipe is arranged on one side of the gas blocking oil conveyor, an oil discharge pipe is arranged at the bottom end of the gas blocking oil conveyor, and the adsorption tank is connected with the blow-off pipe. One end of the oil discharge pipe is connected with a return pipe, one end of the return pipe is connected with one end of a discharge port of the ball receiving and sending valve, one end of the exhaust pipe is connected with an adsorption tank, and an exhaust valve is arranged at the top of the adsorption tank. The personal injury caused by residual liquid volatilization in the manual purging process is avoided, the safety is improved, and meanwhile, the purged nitrogen is adsorbed and purified, so that the environmental pollution is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of residual liquid cleaning of sending and receiving ball valves, in particular to a residual liquid recovery device for sending and receiving ball valves with a cleaning ball. Background Art

[0002] During oil loading and unloading operations, inert gases (such as nitrogen) are often used to purge pipeline systems to ensure safety and reduce environmental pollution. This operation is primarily used to remove residual liquid, gas, or vapor from the pipeline, prevent the mixing of different types of oil, and reduce the accumulation of flammable and explosive oil and gas, thereby reducing the risk of fire and explosion.

[0003] However, if the residual liquid from the nitrogen purge process is not properly treated and released directly into the environment, it can contaminate soil and water sources. Light components in residual oil can easily evaporate into VOCs, exacerbating the greenhouse effect and potentially forming photochemical smog, which harms human health. Some oils and their vapors are toxic, and long-term exposure can adversely affect workers' respiratory systems and skin. In enclosed spaces, without proper ventilation, the accumulation of toxic gases can lead to poisoning.

[0004] For this purpose, a residual liquid recovery device for a pig ball receiving and sending ball valve is provided to recover the residual liquid to avoid polluting the environment and causing dangers such as poisoning. Utility Model Content

[0005] The purpose of the utility model is to provide a residual liquid recovery device for a pig ball sending and receiving ball valve to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a residual liquid recovery device for a pipe cleaning ball and a sending and receiving ball valve, comprising: a drain pipe, an air-blocking oil conveyor and an adsorption tank, one end of the drain pipe is connected to the air-blocking oil conveyor, an exhaust pipe is provided on one side of the air-blocking oil conveyor, an oil drain pipe is provided at the bottom end of the air-blocking oil conveyor, one end of the oil drain pipe is connected to a return pipe, one end of the return pipe is connected to one end of the discharge port of the sending and receiving ball valve, one end of the exhaust pipe is connected to the adsorption tank, and an exhaust valve is provided on the top of the adsorption tank.

[0007] As a further explanation of the present invention, the air-blocking oil transfer device includes a shell and an upper cover. The upper cover is provided on the top of the shell, and one side of the outer wall of the upper half of the shell is connected to the sewage pipe.

[0008] As a further illustration of the present invention, the outer shell is a cylindrical shell, and the discharge direction of the sewage valve is tangent to the inner wall of the outer shell.

[0009] As a further explanation of the present invention, a guide sleeve is provided in the center of the bottom of the upper cover, a guide rod is slidingly provided inside the guide sleeve, a float is provided at the bottom end of the guide rod, a liquid phase conical sealing plug is provided in the center of the outer wall of the bottom of the float, a liquid phase sealing sleeve is provided on the inner wall of the bottom of the outer shell, and the liquid phase sealing sleeve is located outside the liquid phase conical sealing plug, and the bottom end of the liquid phase sealing sleeve is connected to the oil drain pipe.

[0010] As a further explanation of the present invention, a fixing rod is provided on one side of the outer wall of the guide sleeve, a vertical rod is provided at one end of the fixing rod, the bottom end of the vertical rod is rotatably connected to a rocker rod, one end of the rocker rod is provided with a gas phase conical sealing plug, and the other end is rotatably connected to the guide rod, and a gas phase sealing sleeve is provided on the inner wall of the outer shell on the outside of the gas phase conical sealing plug, and the bottom end of the gas phase sealing sleeve is connected to the exhaust pipe.

[0011] As a further explanation of the present invention, a strip groove is provided at the connecting end of the rocker arm and the guide rod, a fixed shaft is provided on one side of the outer wall of the guide rod, and the strip groove is sleeved on the outside of the fixed shaft.

[0012] As a further explanation of the present utility model, one end of the drain pipe is connected to a drain valve, one end of the drain valve is connected to a sending and receiving ball valve, one end of the upper part of the sending and receiving ball valve is connected to a nitrogen inlet pipe, a one-way valve is provided between the nitrogen inlet pipe and the sending and receiving ball valve, and a one-way valve is provided on the return pipe.

[0013] As a further illustration of the present invention, an activated carbon filler is provided inside the adsorption tank, the exhaust pipe outlet is located below the activated carbon filler, and the exhaust valve is located above the activated carbon filler.

[0014] As a further explanation of the present invention, a temperature sensor and a pressure sensor are provided on one side of the interior of the adsorption tank, and an automatic exhaust safety valve is provided on one side of the top of the adsorption tank.

[0015] As a further illustration of the present invention, the float is made of hollow stainless steel.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] The utility model connects the residual liquid recovery device with the drain valve at the bottom of the sending and receiving ball valve, and an air-blocking oil conveyor is arranged in the device. During the residual liquid recovery process, pressurized nitrogen is first used to evacuate the residual liquid in the sending and receiving ball valve, and the residual liquid and gas enter the air-blocking oil conveyor through the drain valve and the drain pipe. The air-blocking oil conveyor is used to emptie the residual liquid, and the oil-containing gas in the cavity is adsorbed and purified by the adsorption tank and then discharged into the atmosphere, meeting the national emission standard requirements. The oil of the air-blocking oil conveyor re-enters the oil product pipeline through the reflux pipe under the action of nitrogen pressure, and at the same time, the air-blocking oil conveyor blocks the nitrogen from entering the oil product pipeline, avoiding the impact damage to the inner floating plate caused by the nitrogen entering the tank. The entire residual liquid recovery device can automatically recover the residual liquid through the nitrogen pressure, avoiding personal injury caused by the volatilization of the residual liquid during the manual purging process, improving safety while adsorbing and purifying the nitrogen after purging, and avoiding environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of the residual liquid recovery device of the pig ball receiving and sending ball valve of the utility model;

[0019] Figure 2 This is a schematic diagram of the internal structure of the air-blocking oil feeder of the residual liquid recovery device of the pig ball receiving and sending ball valve of the utility model.

[0020] In the figure: 1. Sending and receiving ball valve; 2. Nitrogen inlet pipe; 3. Interlocking solenoid valve; 4. Drain valve; 5. Drain pipe; 6. Gas-blocking oil transfer device; 601. Housing; 602. Upper cover; 603. Guide sleeve; 604. Float; 605. Liquid phase conical sealing plug; 606. Liquid phase sealing sleeve; 607. Guide rod; 608. Fixed rod; 609. Vertical rod; 610. Rocker arm; 611. Gas phase conical sealing plug; 612. Gas phase sealing sleeve; 7. Exhaust pipe; 8. Oil drain pipe; 9. Adsorption tank; 10. Reflux pipe. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Example 1: Please refer to Figure 1-Figure 2The utility model provides a technical solution: a residual liquid recovery device for a pipe cleaning ball sending and receiving ball valve, comprising: a drain pipe 5, an air-blocking oil conveyor 6 and an adsorption tank 9, one end of the drain pipe 5 is connected to the air-blocking oil conveyor 6, one side of the air-blocking oil conveyor 6 is provided with an exhaust pipe 7, the bottom end of the air-blocking oil conveyor 6 is provided with an oil drain pipe 8, one end of the oil drain pipe 8 is connected to a return pipe 10, one end of the return pipe 10 is connected to one end of the discharge port of the sending and receiving ball valve 1, one end of the exhaust pipe 7 is connected to the adsorption tank 9, and an exhaust valve is provided on the top of the adsorption tank 9. The residual liquid recovery device is connected to the drain valve 4 at the bottom of the sending and receiving ball valve 1. A gas-blocking oil conveyor 6 is set in the device. During the residual liquid recovery process, pressurized nitrogen is first used to evacuate the residual liquid in the sending and receiving ball valve 1. The residual liquid and gas enter the gas-blocking oil conveyor 6 through the drain valve 4 and the drain pipe 5. The gas-blocking oil conveyor 6 is used to separate the mixture of residual liquid and gas, so that a part of the oil-containing gas is adsorbed and purified by the adsorption tank 9 and then discharged into the atmosphere, meeting the national emission standards. The remaining oil is re-entered into the oil product pipeline through the return pipe 10 under the action of nitrogen pressure. At the same time, the gas-blocking oil conveyor 6 blocks the nitrogen from entering the oil product pipeline, preventing the nitrogen from entering the tank from causing impact damage to the floating plate. The entire residual liquid recovery device can automatically recover the residual liquid through nitrogen pressure, avoiding personal injury caused by the volatilization of residual liquid during manual purging, improving safety, and adsorbing and purifying the nitrogen after purging to avoid environmental pollution. For oil and gas recovery systems that have already been configured, the activated carbon adsorption tank can be eliminated, and the exhaust gas directly enters the oil and gas recovery pipeline.

[0023] The gas-blocking oil transfer device 6 comprises a housing 601 and an upper cover 602. The upper cover 602 is located on top of the housing 601. One side of the upper outer wall of the housing 601 is connected to the drain pipe 5. The housing 601 serves as the primary container for the gas-blocking oil transfer device. The upper outer wall of the housing 601 is connected to the drain pipe 5 to receive the residual liquid and gas mixture from the transmitting and receiving ball valve 1. The upper cover 602 is mounted on top of the housing 601, sealing the housing 601 and forming a sealed space within the housing 601, ensuring the proper functioning of the internal components.

[0024] A guide sleeve 603 is provided at the bottom center of the upper cover 602. A guide rod 607 is slidably mounted within the sleeve 603. The sleeve 603 is mounted at the bottom center of the upper cover 602 to guide the up and down movement of the guide rod 607. The guide rod 607 is located within the sleeve 603 and can slide up and down along the sleeve 603. The bottom end of the guide rod 607 is connected to a float 604, and the movement of the guide rod 607 is controlled by the rise and fall of the float 604.

[0025] A float 604 is located at the bottom end of guide rod 607. A conical liquid-phase sealing plug 605 is located in the center of the bottom outer wall of float 604. A liquid-phase sealing sleeve 606 is located on the bottom inner wall of housing 601, outside of this conical liquid-phase sealing plug 605. The bottom end of this sealing sleeve 606 is connected to the oil drain pipe 8. Float 604 moves up and down with the changes in the residual liquid level, thereby controlling the position of conical liquid-phase sealing plug 605. When float 604 descends, conical liquid-phase sealing plug 605 engages with sealing sleeve 606, forming a seal and preventing liquid from passing through oil drain pipe 8. When float 604 ascends, conical liquid-phase sealing plug 605 disengages sealing sleeve 606, allowing liquid to pass.

[0026] A fixed rod 608 is provided on one side of the outer wall of the guide sleeve 603. A vertical rod 609 is provided at one end of the fixed rod 608. A rocker arm 610 is rotatably connected to the bottom end of the vertical rod 609. A gas-phase conical sealing plug 611 is provided at one end of the rocker arm 610, and the other end is rotatably connected to the guide rod 607. A gas-phase sealing sleeve 612 is provided on the inner wall of the housing 601, outside the gas-phase conical sealing plug 611. The bottom end of the gas-phase sealing sleeve 612 is connected to the exhaust pipe 7. A strip groove is provided at the connection between the rocker arm 610 and the guide rod 607. A fixed shaft is provided on one side of the outer wall of the guide rod 607, and the strip groove is sleeved outside the fixed shaft.

[0027] When the residual liquid and gas mixture enters the gas-blocking oil transfer device 6 through the drain pipe 5, the residual liquid level rises. As the residual liquid level rises, the float 604 drives the guide rod 607 upward. The liquid-phase conical sealing plug 605 separates from the liquid-phase sealing sleeve 606, allowing liquid to enter the oil discharge pipe 8. Simultaneously, the rising guide rod 607 causes the end of the rocker arm 610, which carries the gas-phase conical sealing plug 611, to swing downward. This gas-phase conical sealing plug 611 contacts the gas-phase sealing sleeve 612, forming a seal and preventing gas from passing through the exhaust pipe 7. This allows the liquid, under the action of gas pressure, to enter the oil discharge pipe 8 and be pressured back to the ship unloading pipeline through the return pipe 10. The residual liquid level within the housing 1 then drops. As the residual liquid level drops, the float 604 also descends, driving the guide rod 607 downward. The swinging of the rocker arm 610 forces the gas-phase conical sealing plug 611 to separate from the gas-phase sealing sleeve 612, allowing gas to enter the adsorption tank 9 through the exhaust pipe 7 for purification. Through such a design, the gas-blocking oil transfer device 6 can not only effectively separate the gas and residual liquid, but also control the sealing of the gas phase through mechanical linkage to ensure that the residual liquid is safely recovered, while preventing nitrogen from entering the oil pipeline and avoiding impact damage to the floating plate in the oil tank.

[0028] One end of the drain pipe 5 is connected to a drain valve 4, and one end of the drain valve 4 is connected to a sending and receiving ball valve 1. One end of the upper part of the sending and receiving ball valve 1 is connected to a nitrogen inlet pipe 2. A one-way valve is provided between the nitrogen inlet pipe 2 and the sending and receiving ball valve 1, and a one-way valve is provided on the return pipe 10. Prevent nitrogen from flowing in reverse and ensure that nitrogen can only flow from the nitrogen inlet pipe 2 to the sending and receiving ball valve 1, and cannot flow in the reverse direction. Ensure that the direction of nitrogen flow is correct during the nitrogen purge process to avoid poor purge effect or equipment damage caused by reverse flow. A one-way valve is provided on the return pipe 10. Prevent oil products from flowing in reverse and ensure that the residual liquid separated from the oil drain pipe 8 can only return to the oil pipeline through the return pipe 10, and cannot flow in the reverse direction. Prevent oil products or residual liquid from flowing back from the oil pipeline into the gas-blocking oil transfer device 6, affecting the separation effect and equipment safety.

[0029] Adsorption tank 9 is filled with activated carbon. The outlet of exhaust pipe 7 is located below the activated carbon packing, and the exhaust valve is located above it. After purification through activated carbon adsorption, the gas is released into the atmosphere, meeting the national emission standard of 25 grams per cubic meter. Field measurements show that the activated carbon adsorbs 50 grams per kilogram of oil and gas. Based on an oil and gas content of 100 grams per cubic meter, the internal volume of the ball valve is 72 liters, and a 4 kg configuration of activated carbon can adsorb 28 times. Adsorption tank 1 is configured with a quick-release interface. When the activated carbon adsorption reaches saturation, it is transferred to an oil and gas recovery unit and desorbed using a vacuum pump, effectively recovering the oil and gas and preventing atmospheric pollution. A temperature sensor and pressure sensor are installed on one side of the adsorption tank 9, and an automatic exhaust safety valve is installed on the top side of the adsorption tank 9. Adsorption tank 9 is equipped with a thermometer, pressure gauge, and safety valve to monitor the temperature rise during the accumulation of oil and gas adsorbed by the activated carbon. Under normal circumstances, nitrogen purge of the oil pipeline prevents air from entering, ensuring a relatively safe environment for oil and gas adsorbed by the activated carbon within the inert gas atmosphere without accumulation and temperature rise. For oil and gas recovery systems that have been configured, the activated carbon adsorption tank can be eliminated and the exhaust gas can directly enter the oil and gas recovery pipeline.

[0030] The float 604 is made of hollow stainless steel. Stainless steel has high corrosion resistance and is suitable for a variety of liquid environments.

[0031] The utility model connects the residual liquid recovery device with the drain valve at the bottom of the sending and receiving ball valve, and an air-blocking oil conveyor is arranged in the device. During the residual liquid recovery process, pressurized nitrogen is first used to evacuate the residual liquid in the sending and receiving ball valve, and the residual liquid and gas enter the air-blocking oil conveyor through the drain valve and the drain pipe. The air-blocking oil conveyor is used to emptie the residual liquid, and the oil-containing gas in the cavity is adsorbed and purified by the adsorption tank and then discharged into the atmosphere, meeting the national emission standard requirements. The oil of the air-blocking oil conveyor re-enters the oil product pipeline through the reflux pipe under the action of nitrogen pressure, and at the same time, the air-blocking oil conveyor blocks the nitrogen from entering the oil product pipeline, avoiding the impact damage to the inner floating plate caused by the nitrogen entering the tank. The entire residual liquid recovery device can automatically recover the residual liquid through the nitrogen pressure, avoiding personal injury caused by the volatilization of the residual liquid during the manual purging process, improving safety while adsorbing and purifying the nitrogen after purging, and avoiding environmental pollution.

[0032] For pig ball launchers and receivers requiring high automation, an interlocking solenoid valve can be configured. Upon initiation of the residual liquid recovery program, the residual liquid is automatically recovered, oil and gas are interlocked for discharge, and the valve automatically closes after pressure reduction. This can be configured with a PLC or a DCS within the storage area. The residual liquid recovery device can be used to recover residual liquid in both the pig launcher and receiver valves and the pig ball receiver at petrochemical terminals. The design pressure is 1.0 MPa and the nominal pressure is 2.0 MPa. For expansion into long-distance pipelines, the pressure rating will need to be increased accordingly.

[0033] Example 2: Please refer to Figure 1-Figure 2The utility model provides a technical solution: a residual liquid recovery device for a cleaning ball sending and receiving ball valve, comprising: a sending and receiving ball valve 1 and a nitrogen inlet pipe 2, a drain valve 4 is provided on one side of the bottom of the sending and receiving ball valve 1, one end of the feed port of the sending and receiving ball valve 1 is connected to the nitrogen inlet pipe 2, one end of the drain valve 4 is provided with a drain pipe 5, one end of the drain pipe 5 is connected to an air-blocking oil conveyor 6, one side of the air-blocking oil conveyor 6 is provided with an exhaust pipe 7, an oil drain pipe 8 is provided at the bottom end of the air-blocking oil conveyor 6, one end of the oil drain pipe 8 is connected to a reflux pipe 10, one end of the reflux pipe 10 is connected to one end of the discharge port of the sending and receiving ball valve 1, one end of the exhaust pipe 7 is connected to an adsorption tank 9, and an exhaust valve is provided on the top of the adsorption tank 9. The drain valve 4 at the bottom of the sending and receiving ball valve 1 is used to connect the residual liquid recovery device, and an air-blocking oil conveyor 6 is set in the device. During the residual liquid recovery process, pressurized nitrogen is first used to compress the residual liquid in the sending and receiving ball valve 1, and the residual liquid and gas enter the air-blocking oil conveyor 6 through the drain valve 4 and the drain pipe 5. The air-blocking oil conveyor 6 is used to separate the mixture of residual liquid and gas, so that a part of the oil-containing gas is adsorbed and purified by the adsorption tank 9 and then discharged into the atmosphere to meet the national emission standards. The remaining oil enters the oil pipeline through the reflux pipe 10 under the action of nitrogen pressure, and at the same time, the air-blocking oil conveyor 6 blocks the nitrogen from entering the oil pipeline to avoid impact damage to the floating plate caused by nitrogen entering the tank. The entire residual liquid recovery device can automatically recover the residual liquid through nitrogen pressure, avoids personal injury caused by volatilization of residual liquid during manual purging, improves safety, and adsorbs and purifies the nitrogen after purging to avoid environmental pollution.

[0034] The gas-blocking oil transfer device 6 comprises a housing 601 and an upper cover 602. The upper cover 602 is located on top of the housing 601. One side of the upper outer wall of the housing 601 is connected to the drain pipe 5. The housing 601 serves as the primary container for the gas-blocking oil transfer device. The upper outer wall of the housing 601 is connected to the drain pipe 5 to receive the residual liquid and gas mixture from the transmitting and receiving ball valve 1. The upper cover 602 is mounted on top of the housing 601, sealing the housing 601 and forming a sealed space within the housing 601, ensuring the proper functioning of the internal components.

[0035] In this embodiment, other settings are the same as those in Example 1, and the difference from Example 1 is that the outer shell 601 is a cylindrical shell, and the discharge direction of the sewage valve 5 is tangential to the inner wall of the outer shell 601. In the application of the gas-blocking oil feeder 6, the tangential feed helps to form a stable vortex, making it easier to separate the gas and liquid.

[0036] Vortexes help the lighter gas components move upward, while the heavier liquid components sink toward the center, achieving effective separation. Tangential feed fully utilizes the space within the cylindrical chamber, increasing fluid flow velocity and thus increasing processing capacity. By creating vortexes, processing volume per unit time can be increased without increasing equipment size. This significantly improves separation efficiency, reduces energy consumption, and lowers maintenance costs. Tangential feed helps form swirling flow, promoting effective gas and liquid separation and ensuring efficient operation during residual liquid recovery.

[0037] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. The residual liquid recovery device for the pig ball receiving and sending ball valve includes: A sewage pipe (5), an air-blocking oil conveyor (6) and an adsorption tank (9), characterized in that one end of the sewage pipe (5) is connected to the air-blocking oil conveyor (6), one side of the air-blocking oil conveyor (6) is provided with an exhaust pipe (7), the bottom end of the air-blocking oil conveyor (6) is provided with an oil drainage pipe (8), one end of the oil drainage pipe (8) is connected to a return pipe (10), one end of the return pipe (10) is connected to one end of the discharge port of the sending and receiving ball valve (1), one end of the exhaust pipe (7) is connected to the adsorption tank (9), and the top of the adsorption tank (9) is provided with an exhaust valve.

2. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 1 is characterized in that: The air-blocking oil transfer device (6) comprises a shell (601) and an upper cover (602). The upper cover (602) is provided on the top of the shell (601), and one side of the outer wall of the upper half of the shell (601) is connected to the sewage pipe (5).

3. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 2 is characterized in that: The outer shell (601) is a cylindrical shell, and the discharge direction of the sewage pipe (5) is tangent to the inner wall of the outer shell (601).

4. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 2 is characterized in that: A guide sleeve (603) is provided at the center of the bottom of the upper cover (602), a guide rod (607) is slidably provided inside the guide sleeve (603), a float (604) is provided at the bottom end of the guide rod (607), a liquid phase conical sealing plug (605) is provided at the center of the bottom outer wall of the float (604), a liquid phase sealing sleeve (606) is provided on the inner wall of the bottom of the housing (601) and located outside the liquid phase conical sealing plug (605), and the bottom end of the liquid phase sealing sleeve (606) is connected to the oil drain pipe (8).

5. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 4 is characterized in that: A fixing rod (608) is provided on one side of the outer wall of the guide sleeve (603), a vertical rod (609) is provided at one end of the fixing rod (608), a rocker rod (610) is rotatably connected to the bottom end of the vertical rod (609), a gas phase conical sealing plug (611) is provided at one end of the rocker rod (610), and the other end is rotatably connected to the guide rod (607), a gas phase sealing sleeve (612) is provided on the inner wall of the housing (601) outside the gas phase conical sealing plug (611), and the bottom end of the gas phase sealing sleeve (612) is connected to the exhaust pipe (7).

6. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 5 is characterized in that: A strip groove is provided at the connection end between the swing rod (610) and the guide rod (607), a fixed shaft is provided on one side of the outer wall of the guide rod (607), and the strip groove is sleeved on the outside of the fixed shaft.

7. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 1 is characterized in that: One end of the sewage pipe (5) is connected to a sewage valve (4), one end of the sewage valve (4) is connected to a sending and receiving ball valve (1), one end of the upper part of the sending and receiving ball valve (1) is connected to a nitrogen inlet pipe (2), a one-way valve is provided between the nitrogen inlet pipe (2) and the sending and receiving ball valve (1), and a one-way valve is provided on the return pipe (10).

8. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 1 is characterized in that: Activated carbon filler is provided inside the adsorption tank (9), the air outlet of the exhaust pipe (7) is located below the activated carbon filler, and the exhaust valve is located above the activated carbon filler.

9. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 1 is characterized in that: A temperature sensor and a pressure sensor are provided on one side of the interior of the adsorption tank (9), and an automatic exhaust safety valve is provided on one side of the top of the adsorption tank (9).

10. The residual liquid recovery device for the pig ball sending and receiving ball valve according to claim 4 is characterized in that: The float (604) is made of hollow stainless steel and can float in liquid.

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