A nitrogen liquid sealing device

Abstract

This utility model relates to a nitrogen-liquid sealing device. An air inlet is provided at the top of the tank. Upper and lower partition plates are installed inside the tank, dividing the internal cavity into a nitrogen buffer zone, a liquid sealing zone, and a liquid buffer zone from top to bottom. A cooling coil is installed in the liquid sealing zone. A liquid sealing pipe penetrating the upper partition plate and a gas-liquid balance pipe and overflow pipe penetrating the lower partition plate are installed inside the tank. The upper end of the liquid sealing pipe is vertically opposite to the air inlet at the top of the tank. A liquid connecting pipe leading to the liquid sealing zone is connected to the bottom surface of the upper partition plate. A circulation pump is installed outside the tank. A nitrogen inlet pipe is also connected to the top of the tank. An exhaust pipe is connected to the upper side wall of the tank in the liquid sealing zone, and a replenishment pipe is connected to the upper side wall of the tank in the liquid buffer zone. This utility model uses nitrogen and a liquid to absorb leaked gas to seal and absorb the leaked gas, preventing air from entering and the leaked gas from leaking again, thus improving sealing performance. It is simple to manufacture and saves costs.

Description

Technical Field

[0001] This utility model relates to a liquid sealing device, specifically a nitrogen liquid sealing device. Background Technology

[0002] In organic synthesis reaction systems, storage tanks serve as containers for material storage, reactors are the devices for the reaction, separation towers are for product purification, and loading is the crucial step in transferring the finished product from the storage tank to the transport vehicle. In these systems, to prevent the leakage of flammable, toxic, and volatile media or the entry of air to create an explosive atmosphere, liquid-sealed tanks (water seals or oil seals) are generally used. This involves using the height difference between the liquid levels on both sides of a U-shaped tube to form a U-shaped seal, which can prevent gas backflow. However, the seal stability is relatively poor. Taking a storage tank as an example, when liquid is stored in the U-shaped tube and one end of the U-shaped tube is connected to the storage tank, if the pressure in the tank is low, the liquid in the U-shaped tube can easily flow back into the storage tank. Moreover, when upstream overpressure occurs, or when liquid evaporates, leaks, or water is not replenished in time, the liquid seal is broken, and the medium is directly discharged into the atmosphere, leading to seal failure. Utility Model Content

[0003] The purpose of this invention is to provide a nitrogen liquid sealing device to solve the problem of poor sealing stability of existing liquid sealing devices.

[0004] The technical solution of this utility model is as follows: A nitrogen liquid sealing device includes an air inlet at the top of a tank; upper and lower partition plates inside the tank divide the internal cavity into an upper nitrogen buffer zone, a middle liquid sealing zone, and a lower liquid buffer zone; a cooling coil is installed in the middle liquid sealing zone, with its inlet and outlet extending through the side wall of the tank; a liquid sealing pipe penetrating the upper partition plate and a gas-liquid balance pipe and an overflow pipe penetrating the lower partition plate are installed inside the tank, with the upper end of the liquid sealing pipe aligned vertically with the air inlet at the top of the tank, and the upper end of the gas-liquid balance pipe... The inlet is positioned at a height higher than the upper port of the overflow pipe, and the lower port of the gas-liquid balance pipe is positioned at a height higher than the lower port of the overflow pipe. A liquid connecting pipe leading to the liquid seal zone is connected to the bottom surface of the upper partition plate. A circulation pump is installed outside the tank to pump liquid from the liquid buffer zone to the nitrogen buffer zone and to discharge liquid from the liquid buffer zone. A nitrogen inlet pipe is also connected to the top of the tank. An exhaust pipe is connected to the upper side wall of the tank in the liquid seal zone, and a replenishment pipe is connected to the upper side wall of the tank in the liquid buffer zone.

[0005] Furthermore, the exhaust pipe is also connected to a condenser pipe.

[0006] Furthermore, a pressure gauge is provided in the nitrogen buffer zone, and a level gauge is provided in the liquid buffer zone and the liquid seal zone.

[0007] Furthermore, there is a gap between the upper port of the liquid seal area and the air inlet.

[0008] Furthermore, there is a gap between the lower port of the liquid connecting pipe and the lower partition plate.

[0009] Furthermore, the upper port of the gas-liquid balance pipe is set at a height higher than the lower port of the liquid seal pipe, but lower than the upper port of the liquid connecting pipe.

[0010] Furthermore, the upper port of the overflow pipe is set at a height higher than the lower port of the liquid seal pipe and lower than the gas-liquid balance pipe, while the lower port of the overflow pipe is set at a height lower than the lower port of the gas-liquid balance pipe.

[0011] Furthermore, the suction port of the circulating pump is connected to the lower tank side wall of the liquid buffer zone via a pipe, and the pipe connected to the discharge port of the circulating pump is divided into two paths: one is an upper liquid pipe connected to the side wall of the nitrogen buffer zone, and the other is an outlet liquid pipe.

[0012] Furthermore, valves are installed on the liquid inlet pipe, liquid outlet pipe, liquid replenishment pipe, and nitrogen inlet pipe.

[0013] This invention uses nitrogen to seal leaked gas in the process system. A nitrogen inlet pipe introduces nitrogen into a nitrogen buffer tank, while the tank's inlet introduces leaked gas. Because nitrogen is an inert gas with low density, after nitrogen is introduced into the buffer zone, it fills the top of the buffer zone, preventing air from entering and avoiding leakage of leaked gas from the inlet. The lower liquid absorbs the leaked gas, reducing VOCs and odor problems. This invention uses a circulation pump to replenish the liquid in the liquid-sealed zone in a timely manner, achieving liquid circulation. This invention uses simple materials, is easy to manufacture, and has low cost. It can be prefabricated; only the pipe inlet needs to be connected and fixed to the corresponding system.

[0014] This invention features a liquid seal pipe positioned at a distance from the inlet of the leaking gas to prevent backflow of liquid from the liquid seal zone into the process system. An overflow pipe is flush with the liquid surface, and the lower end of the liquid seal pipe is located in the upper half of the liquid. When the liquid absorbs the leaking gas, excess liquid is generated at the top and flows into the liquid buffer zone through the overflow pipe, without affecting the absorption of the leaking gas. A gas-liquid balance pipe balances the gas in the liquid seal zone and the liquid buffer zone, allowing the liquid in the liquid seal zone to flow smoothly into the liquid buffer zone. This invention also includes a pressure gauge and an exhaust pipe. Nitrogen is introduced when the pressure is low, and the exhaust pipe is opened when the pressure is high to prevent overpressure. Even if the pressure in the liquid seal zone is high and the liquid level drops, liquid can be supplied to the liquid seal zone through a circulation pump and a liquid flow pipe. Therefore, this invention offers better sealing stability. This invention also includes a cooling coil to cool the liquid in the liquid seal zone, facilitating the absorption of leaking gas. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] The components are as follows: 1. Nitrogen buffer zone; 2. Liquid seal zone; 3. Liquid buffer zone; 4. Condenser; 5. Upper partition plate; 6. Lower partition plate; 7. Circulation pump; 11. Liquid seal pipe; 12. Nitrogen inlet pipe; 13. Inlet; 21. Liquid connecting pipe; 22. Gas-liquid balance pipe; 23. Overflow pipe; 24. Cooling coil; 25. Exhaust pipe; 31. Liquid replenishment pipe; 71. Liquid inlet pipe; 72. Liquid outlet pipe. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

[0018] like Figure 1 As shown, the nitrogen liquid sealing device of this utility model includes a cylindrical or rectangular tank, a liquid sealing pipe 11, a liquid connecting pipe 21, a gas-liquid balance pipe 22, an overflow pipe 23, and a circulation pump 7. A nitrogen inlet pipe 12 and an inlet 13 are provided on the top of the tank; two parallel upper and lower partition plates (i.e., upper partition plate 5 and lower partition plate 6) are provided inside the tank, dividing the inner cavity of the tank into three parts, from top to bottom: a nitrogen buffer zone 1, a liquid sealing zone 2, and a liquid buffer zone 3.

[0019] The tank body is made of steel plate, and the upper partition plate 5 and lower partition plate 6 are also made of steel plate and welded into the tank body. The liquid seal pipe 11, liquid connecting pipe 21, gas-liquid balance pipe 22, and overflow pipe 23 are all steel pipes, which can also be connected to the partition plates by welding.

[0020] Nitrogen inlet pipe 12 is connected to a container storing nitrogen. A valve is installed on nitrogen inlet pipe 12 to allow nitrogen to enter the container. The valve is closed when nitrogen is not needed. To prevent gas leakage from the target device through the exhaust port, inlet port 13 is connected to the exhaust port of the target device in the organic synthesis reaction process system via a pipeline. A valve is installed on the pipeline to allow leaked gas from the target device to enter the liquid seal zone 2. To prevent gas leakage from other outlets in the device, inlet port 13 can also be connected to any outlet of the target device.

[0021] The target device can be a gas-containing device in an industrial system, such as a storage tank, reactor, or separation tower.

[0022] An exhaust pipe 25 is installed on the upper side wall of the tank in the liquid seal zone 2; a replenishment pipe 31 is installed on the upper side wall of the tank in the liquid buffer zone 3 to replenish liquid to the liquid buffer zone 3. The replenishment pipe 31 is connected to the tank at a position higher than the set liquid level of the liquid buffer zone 3. Valves are installed on both the exhaust pipe 25 and the replenishment pipe 31.

[0023] Nitrogen buffer zone 1 stores nitrogen, while liquid seal zone 2 and liquid buffer zone 3 store liquids that absorb leaked gas from the target device.

[0024] The liquid seal pipe 11 passes through the upper partition plate 5, connecting the nitrogen buffer zone 1 and the liquid seal zone 2. The upper port of the liquid seal pipe 11 is vertically opposite to the air inlet 13, and there is a gap between the two ports to prevent liquid in the liquid seal zone 2 from flowing back into the process system.

[0025] The axis of the upper end of the liquid seal pipe 11 is collinear with the axis of the air inlet 13, which facilitates the entry of leaked gas from the process system into the liquid seal zone 2. At the same time, nitrogen is used to seal the leaked gas. The upper end of the liquid seal pipe 11 is spaced from the air inlet 13 to prevent the liquid in the liquid seal zone 2 from flowing back into the process system through the liquid seal pipe 11 due to low gas pressure in the tank.

[0026] The upper partition plate 5 has a through hole, which is the same size as the upper end of the liquid connecting pipe 21. The liquid connecting pipe 21 is welded to the lower part of the upper partition plate 5, and its upper end communicates with the through hole. The lower end of the liquid connecting pipe 21 is positioned at a lower height than the lower end of the liquid seal pipe 11.

[0027] Both the gas-liquid balance pipe 22 and the overflow pipe 23 penetrate the lower partition plate 6. The upper port of the gas-liquid balance pipe 22 is positioned lower than the upper port of the liquid connecting pipe 21, but higher than the lower port of the liquid seal pipe 11. The upper port of the overflow pipe 23 is positioned higher than the lower port of the liquid seal pipe 11, but lower than the upper port of the gas-liquid balance pipe 22. The lower port of the gas-liquid balance pipe 22 is positioned higher than the lower port of the overflow pipe 23. The overflow pipe 23 is positioned on the lower partition plate 6 away from the liquid connecting pipe 21.

[0028] The height at which the exhaust pipe 25 connects to the tank body of the liquid seal zone 2 is greater than the setting height of the upper port of the overflow pipe 23.

[0029] The gas-liquid balance pipe 22 connects the upper gas chamber of the liquid seal zone 2 and the upper gas chamber of the liquid buffer zone 3 to balance the pressure in the liquid seal zone 2 and the liquid buffer zone 3, ensuring that the overflow process and the process of leaked gas entering the liquid seal zone can proceed smoothly. When the liquid level in the liquid seal zone 2 exceeds the upper port of the overflow pipe 23, the liquid overflows from the overflow pipe 23 into the liquid buffer zone 3, that is, the set liquid level in the liquid seal zone 2 is the same as the height of the upper port of the overflow pipe 23.

[0030] A pressure gauge is installed in nitrogen buffer zone 1; a thermometer and a level gauge are installed in liquid seal zone 2; and a level gauge is installed in liquid buffer zone 3. The gas pressure in liquid seal zone 2 is set to a slightly positive pressure, meaning the gas pressure is no more than 500 Pa higher or lower than atmospheric pressure. The set height of the liquid level in the liquid buffer zone is higher than the set height of the lower port of overflow pipe 23, but lower than the set height of the lower port of gas-liquid balance pipe 22.

[0031] A circulation pump 7 is installed outside the tank to pump liquid from the liquid buffer zone 3 to the nitrogen buffer zone 1 and to discharge liquid from the liquid buffer zone. The suction inlet of the circulation pump 7 is connected to the lower side wall of the tank body of the liquid buffer zone via a pipe. The pipe connected to the discharge outlet of the circulation pump 7 is divided into two paths: one is an upper liquid pipe 71, the other end of which is connected to the side wall of the nitrogen buffer zone; the other is an outlet pipe 72, the other end of which is connected to a designated tank (i.e., a tank for storing waste liquid). The location where the circulation pump 7 connects to the tank body is on the lower side wall of the tank body, away from the location where the tank body connects to the replenishment pipe 31.

[0032] Valves are installed on both the liquid inlet pipe 71 and the liquid outlet pipe 72.

[0033] Since the gas pressure in liquid-sealed zone 2 is the same as that in nitrogen buffer zone 1, when the gas pressure in liquid-sealed zone 2 is lower than the set pressure, the valve on nitrogen inlet pipe 12 is opened to bring the gas pressure within the set range. When the gas pressure in liquid-sealed zone 2 is higher than the set pressure, the valve on exhaust pipe 25 is opened to prevent overpressure. Even if the liquid level in liquid-sealed zone 2 drops, and the level gauge detects the drop, liquid can be supplied to liquid-sealed zone 2 through circulation pump 7 and upper liquid pipe 71.

[0034] The upper liquid pipe 71 connects to the nitrogen buffer zone 1 at a position on the lower side wall of the nitrogen buffer zone 1, near the liquid connecting pipe 21. This proximity of the upper liquid pipe 71 to the upper port of the connecting pipe 21 facilitates liquid entry into the liquid seal zone 2; it also avoids openings within the liquid seal zone, which would compromise its sealing performance.

[0035] During the absorption process, the gas leaking from the liquid absorption process system in the liquid seal zone 2 increases the liquid level in the liquid seal zone and flows into the liquid buffer zone 3 through the overflow pipe 23.

[0036] A cooling coil 24 is also installed in the liquid seal zone 2. The cooling coil 24 is a coil filled with cooling water. The inlet and outlet of the cooling coil 24 extend through the side wall of the tank and are connected to pipes. Valves are installed on the pipes. Cooling water is supplied to the cooling coil 24 through the inlet and discharged from the cooling coil 24 through the outlet. Generally, the inlet of the cooling coil 24 is at the bottom and the outlet is at the top. The cooling coil 24 makes it easier for the liquid to absorb the gas output from the air inlet 13.

[0037] It is also equipped with a condenser 4, which is connected to the exhaust pipe 25, so that the gas is condensed into liquid for further processing.

[0038] Staff can monitor the data detected by pressure gauges, level gauges, and thermometers in real time. When the pressure in the nitrogen buffer zone is high, the time and approximate volume of the emitted gas can be monitored when the gas is discharged through exhaust tank 25, allowing for the supervision of the emitted gas.

[0039] The liquids in liquid seal zone 2 and liquid buffer zone 3 are the same type of liquid, namely the liquid that absorbs leaked gas from the process system.

[0040] The method of using this utility model is as follows: First, set up the utility model by connecting the air inlet 13 to the exhaust port of the target device in the process system. Select a liquid that can absorb the leaked gas from the target device in the process system; connect the replenishment pipe 31 to the container storing the liquid, and connect the outlet pipe 72 to the designated tank for placing waste liquid; connect the container storing nitrogen to the nitrogen inlet pipe 12. First, close all valves, then open the valves on the replenishment pipe 31 and the top liquid pipe 71, allowing the liquid to enter the liquid seal zone 2 through the replenishment pipe 31. When the liquid level in the liquid seal zone 2 exceeds the upper port of the overflow pipe 23, the liquid flows in through the overflow pipe 23. When the liquid in the liquid buffer zone 3 exceeds the set liquid level, it enters the liquid buffer zone 3 through the overflow pipe 23.

[0041] Then, open the valve on the exhaust pipe 25, and then open the valve on the nitrogen inlet pipe 12 to purge the nitrogen buffer zone 1 with nitrogen. The purging should be repeated at least three times. The nitrogen is then discharged through the valve on the exhaust pipe 25, and then pressurized to a slightly positive pressure. During the absorption process, the pressure in the nitrogen buffer zone 1 is kept at a slightly positive pressure.

[0042] Finally, turn on the cooling coil 24 to lower the temperature of the liquid seal zone 2 to the operating temperature, and turn on the condenser 4 to cool it down. When the nitrogen in the nitrogen buffer zone 1 has been replaced with nitrogen and the pressure is slightly positive, the temperature in the liquid seal zone 2 is within the preset temperature range, and the liquid level in the liquid buffer zone 3 has reached the set liquid level, open the valve on the pipe of the air inlet 13 to allow the gas leaking from the target device to enter the tank.

Claims

1. A nitrogen liquid sealing device, characterized in that, An air inlet is located at the top of the tank. Inside the tank, upper and lower partition plates divide the internal cavity into an upper nitrogen buffer zone, a middle liquid seal zone, and a lower liquid buffer zone. A cooling coil is installed in the middle liquid seal zone, with its inlet and outlet extending through the side wall of the tank. A liquid seal pipe penetrates the upper partition plate, and a gas-liquid balance pipe and overflow pipe penetrate the lower partition plate. The upper end of the liquid seal pipe is vertically aligned with the air inlet at the top of the tank, and the upper end of the gas-liquid balance pipe... The height of the upper part of the tank is higher than that of the upper port of the overflow pipe, and the height of the lower port of the gas-liquid balance pipe is higher than that of the lower port of the overflow pipe; a liquid connecting pipe leading to the liquid seal zone is connected to the bottom surface of the upper partition plate; a circulation pump is installed outside the tank to pump the liquid in the liquid buffer zone to the nitrogen buffer zone and to discharge the liquid in the liquid buffer zone; a nitrogen inlet pipe is also connected to the top of the tank, an exhaust pipe is connected to the upper side wall of the tank in the liquid seal zone, and a replenishment pipe is connected to the upper side wall of the tank in the liquid buffer zone.

2. The nitrogen liquid sealing device according to claim 1, characterized in that, The exhaust pipe is also connected to a condenser pipe.

3. The nitrogen liquid sealing device according to claim 1, characterized in that, A pressure gauge is installed in the nitrogen buffer zone, and a level gauge is installed in the liquid buffer zone and the liquid seal zone.

4. The nitrogen liquid sealing device according to claim 1, characterized in that, There is a gap between the upper port of the liquid seal area and the air inlet.

5. The nitrogen liquid sealing device according to claim 1, characterized in that, There is a gap between the lower port of the liquid connecting pipe and the lower partition plate.

6. The nitrogen liquid sealing device according to claim 1, characterized in that, The upper port of the gas-liquid balance pipe is set at a height higher than the lower port of the liquid seal pipe, but lower than the upper port of the liquid connecting pipe.

7. The nitrogen liquid sealing device according to claim 6, characterized in that, The upper port of the overflow pipe is set at a higher height than the lower port of the liquid seal pipe.

8. The nitrogen liquid sealing device according to claim 1, characterized in that, The suction port of the circulating pump is connected to the lower tank side wall of the liquid buffer zone via a pipe. The pipe connected to the discharge port of the circulating pump is divided into two paths: one is the upper liquid pipe, which is connected to the side wall of the nitrogen buffer zone, and the other is the liquid outlet pipe.

9. The nitrogen liquid sealing device according to claim 8, characterized in that, Valves are installed on the liquid inlet pipe, liquid outlet pipe, liquid replenishment pipe, and nitrogen inlet pipe.

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