Water seal type storage tank fire-retardant breather valve

Abstract

The water seal type storage tank fire-retardant breather valve comprises a box body, a buffer chamber, a negative pressure chamber and a positive pressure chamber are sequentially arranged in the box body, the buffer chamber is communicated with the upper portion of the negative pressure chamber, the negative pressure chamber is communicated with the bottom of the positive pressure chamber, and the negative pressure chamber and the positive pressure chamber are filled with liquid. An air pipe is connected to the upper portion of the buffer chamber, a pipeline located in the negative pressure chamber is inserted into the top of the negative pressure chamber, the pipeline can move up and down to adjust the height of the pipeline in the negative pressure chamber, and an elbow communicated with the negative pressure chamber is arranged on the upper left portion of the positive pressure chamber. The bottom of the elbow is connected with a straight pipe which can move up and down to adjust the height of the elbow in the positive pressure chamber, and an exhaust hole is formed in the top of the positive pressure chamber. According to the equipment, positive and negative pressure parameters set by the fire-retardant breather valve can be accurately expressed in a water column mode, and the convenience and accuracy of operation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fire-retardant breathing valves for ensuring the safety of storage tanks on top of storage tanks, and in particular to a water-sealed fire-retardant breathing valve for storage tanks. Background Art

[0002] Atmospheric pressure storage tanks that store Class A and B flammable, explosive, toxic and harmful chemicals usually have a nitrogen sealing device installed on the top of the tank to seal the tank with gas phase nitrogen in order to reduce material loss, environmental pollution caused by gas leakage from the tank and fire accidents during storage.

[0003] Typically, a nitrogen sealing device consists of a nitrogen supply valve, a flame-retardant single-call valve, and a flame-retardant breathing valve. The nitrogen supply valve and single-call valve primarily form the gaseous nitrogen sealing environment at the top of the tank. The nitrogen supply valve uses a self-operated balancing valve and a one-way valve, programmed to provide nitrogen to the gaseous space at the top of the tank. It supplies nitrogen in a one-way manner when the gaseous pressure is lower than the set value, and stops supplying nitrogen when the pressure reaches the set value. The single-call valve uses a mechanical design with a flame arrester. When the gaseous pressure at the top of the tank exceeds the set value, the single-call valve automatically opens to discharge gas. When the exhaust reaches the set lower limit, the valve automatically closes to stop exhaust. The gas discharged from the single-call valve is then directed to the exhaust gas treatment system through a connecting pipe.

[0004] Within the range of the nitrogen supply valve and the single call valve, the gas phase at the top of the tank remains sealed from the environment. However, to prevent excessive negative pressure in the gas phase during discharge and other processes, the nitrogen supply valve's insufficient nitrogen supply could cause the instantaneous negative pressure to exceed the tank's design strength, potentially leading to deformation of the tank. Furthermore, to prevent excessive positive pressure within the tank, insufficient exhaust from the single call valve could cause the instantaneous positive pressure to exceed the tank's design strength, potentially leading to deformation of the tank.

[0005] Storage tanks sealed with nitrogen at atmospheric pressure must be equipped with a flame-retardant breathing valve in addition to a nitrogen supply valve and a single-call valve for safety reasons. The flame-retardant breathing valve is set to a positive and negative pressure range that exceeds the nitrogen supply valve and single-call valve. When the positive pressure exceeds the set limit of the flame-retardant breathing valve, it opens to emergency exhaust to the environment to reduce the pressure. When the pressure inside the tank reaches the set lower limit, it automatically closes and stops exhausting. When the negative pressure inside the tank exceeds the set limit of the flame-retardant breathing valve, it opens to emergency air intake to the environment. When the air intake reaches the set lower limit, it automatically closes and stops intake.

[0006] Therefore, it is extremely important that the positive and negative setting ranges of the fire-arresting breathing valve are consistent with the actual operating range. If the actual positive pressure operating range is inconsistent with the setting range, the tank may exceed the positive pressure setting range without initiating the emergency exhaust action, resulting in the pressure inside the tank exceeding the design strength and causing deformation hazards. Similarly, if the actual negative pressure operating range is inconsistent with the setting range, that is, the tank exceeds the negative pressure setting range without initiating the emergency intake action, the negative pressure inside the tank may exceed the design strength and cause deformation hazards.

[0007] In addition, if the flame arrester valve operates within the pressure range set by the single call valve, it will open simultaneously with a portion of the single call valve, causing the tank gas to be directly discharged into the environment, increasing environmental pollution. If the flame arrester valve opens within the negative pressure range set by the nitrogen supply valve, it will inhale ambient air, reducing the nitrogen supply and reducing the nitrogen sealing effect in the tank. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a water-sealed fire-retardant breathing valve for storage tanks that can conveniently and accurately adjust pressure while having good sealing performance.

[0009] A water-sealed storage tank fire-retardant breathing valve of the present invention includes a box body, in which a buffer chamber, a negative pressure chamber and a positive pressure chamber are sequentially arranged, the buffer chamber is communicated with the upper part of the negative pressure chamber, and the negative pressure chamber is communicated with the bottom of the positive pressure chamber, the negative pressure chamber and the positive pressure chamber are filled with liquid, the upper part of the buffer chamber is connected to an air pipe, the top of the negative pressure chamber is plugged with a pipe located inside the negative pressure chamber, the pipe can be moved up and down to adjust its height in the negative pressure chamber, the upper left part of the positive pressure chamber is provided with an elbow communicating with the negative pressure chamber, the bottom of the elbow is connected with a straight pipe which can be moved up and down to adjust its height in the positive pressure chamber, and the top of the positive pressure chamber is provided with an exhaust hole.

[0010] According to some embodiments of the present invention, an observation window is provided on the top of the negative pressure chamber.

[0011] According to some embodiments of the present invention, a drain valve is installed at the bottom of the buffer chamber.

[0012] According to some embodiments of the present invention, the pipeline is sealed and installed in the negative pressure chamber through a sealing ring.

[0013] According to some embodiments of the present invention, the straight pipe is sealed and installed on the elbow through a sealing ring.

[0014] According to some embodiments of the present invention, an overflow pipe is installed on the right side of the positive pressure chamber.

[0015] According to some embodiments of the present invention, a water replenishment float valve is installed on the right side of the positive pressure chamber.

[0016] According to some embodiments of the present invention, a drain valve is installed at the bottom of the positive pressure chamber.

[0017] According to some embodiments of the present invention, the air pipe and the pipeline have the same diameter.

[0018] According to some embodiments of the present invention, the pipe and the straight pipe have the same diameter.

[0019] The present invention has at least the following beneficial effects: This product can precisely adjust the positive and negative gas pressure seals within a storage tank by adjusting the water seal depth of the pipe and straight pipe. This device can be used to easily and accurately adjust the water seal depth according to the positive and negative pressures set on the tank, preventing gas leakage within the set range while ensuring that gas is promptly released from or replenished into the tank if the set positive and negative pressure ranges are exceeded. This device accurately expresses the positive and negative pressure parameters set for the fire-arresting breathing valve using water columns, improving operational convenience and accuracy.

[0020] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0022] Figure 1 The working principle diagram of the present invention is when the pressure in the storage tank is at low pressure;

[0023] Figure 2 The figure is a working principle diagram of the present invention when the pressure in the storage tank is at high pressure. DETAILED DESCRIPTION

[0024] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] In the description of the present invention, "a plurality" refers to more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features, or implicitly indicating the order of the indicated technical features.

[0027] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0028] Reference Figure 1 、 Figure 2 , a water-sealed storage tank fire-retardant breathing valve, which includes a box body, and the entire box body is divided into three spaces, wherein a buffer chamber 1, a negative pressure chamber 2 and a positive pressure chamber 3 are sequentially arranged in the box body, the buffer chamber 1 is communicated with the upper part of the negative pressure chamber 2, and the negative pressure chamber 2 is communicated with the bottom of the positive pressure chamber 3, the negative pressure chamber 2 and the positive pressure chamber 3 are filled with liquid, and an air pipe 11 connected to the top of the storage tank is provided at the upper part of the buffer chamber 1, and the gas leaked from the top of the storage tank and the gas absorbed from the environment enter the storage tank through the buffer chamber 1. The main function of the buffer chamber 1 is to allow the gas entering and leaving the storage tank to stay in the buffer chamber. During the gas phase process of the storage tank is closed, part of the gas leaked from the storage tank is condensed into liquid in the buffer chamber. When the air is sucked into the storage tank through the water seal, part of the water vapor condenses in the buffer chamber 1, reducing the water vapor brought into the storage tank. The buffer chamber 1 is subjected to negative and positive pressure at the same time. The top of the negative pressure chamber 2 is plugged with a pipe 22 located inside the negative pressure chamber 2. The pipe 22 can be moved up and down to adjust its height in the negative pressure chamber 2. The main function of the negative pressure chamber 2 is to convert the maximum negative pressure into the water column height and adjust the depth of the pipe 22 inserted into the water seal. When the tank reaches the maximum negative pressure, refer to Figure 1 , the air is sucked from the environment through the pipe 22 into the buffer chamber 1 and then into the storage tank; when it is under positive pressure, refer to Figure 2 The height of the water column in the pipe 22 increases according to the pressure, so that the gas phase space of the negative pressure chamber 2 is a closed space. The upper left part of the positive pressure chamber 3 is provided with an elbow 32 connected to the negative pressure chamber 2. The bottom of the elbow 32 is connected to a straight pipe 33 that can be moved up and down to adjust its height in the positive pressure chamber 3. The top of the positive pressure chamber 3 is provided with an exhaust hole 31. The operator can adjust the straight pipe 33 to the required height for insertion into the positive pressure chamber 3 through the exhaust hole 31 according to the maximum positive pressure parameter in the storage tank. The main function of the positive pressure chamber 3 is to convert the maximum positive pressure into the water column height and adjust it to be inserted into the water seal. When the storage tank reaches the maximum positive pressure, refer to Figure 2 The exhausted gas is discharged from the positive pressure chamber 3 through the straight pipe 33 inserted into the set water seal depth from the exhaust hole 31. When the tank is subjected to negative pressure, refer to Figure 1 The height of the water column in the straight pipe 33 increases according to the negative pressure it receives, and the gas phase space in the positive pressure chamber 3 is an open space communicating with the environment.

[0029] For ease of operation, an observation window 21 is provided on the top of the negative pressure chamber 2. The operator can operate the pipe 22 to move up and down to adjust its height in the negative pressure chamber 2 according to the maximum negative pressure parameter in the tank and observe through the observation window 21.

[0030] A drain valve 12 is installed at the bottom of the buffer chamber 1. The drain valve 12 regularly discharges the condensed liquid in the buffer chamber.

[0031] In order to ensure the sealing between the side wall of the pipe 22 and the negative pressure chamber 2, the pipe 22 is sealed and installed in the negative pressure chamber 2 through a sealing ring. Similarly, the straight pipe 33 is also sealed and installed on the elbow 32 through a sealing ring.

[0032] Since the negative pressure chamber 2 and the positive pressure chamber 3 are connected to the gas machine leaking in the storage tank, while preventing gas leakage, a small amount of gas will dissolve into the water and a small amount of condensation will be deposited on the upper layer of the water seal, so a drain valve 36 is installed at the bottom of the positive pressure chamber 3. The drain valve 36 is opened regularly to drain the water seal. After the water is drained, a water replenishment float valve 35 is installed on the right side of the positive pressure chamber 3. The water replenishment float valve 35 can meet the precise water replenishment height at the water seal water level line. An overflow pipe 34 is installed on the right side of the positive pressure chamber 3, and the height of the overflow pipe 34 is slightly higher than the water seal water level.

[0033] The diameters of the air pipe 11, the pipeline 22 and the straight pipe 33 are the same, so as to facilitate calculation of the amount of inhaled and exhausted gas.

[0034] Assume that the fire-arresting breathing valve in a storage tank is designed for positive and negative pressures ranging from -295Pa to +1750Pa. That is, when the tank's minimum negative pressure falls below -295Pa, the tank must be closed after replenishing air from the environment to a pressure greater than -295Pa. When the tank's pressure exceeds 1750Pa, the tank must exhaust air to the environment to reduce the pressure below 1750Pa. Based on the principle that 1Pa equals 0.1mm of water column, as required by the design, pipe 22 of negative pressure chamber 2 is adjusted to a point -29.5mm underwater, and straight pipe 33 of positive pressure chamber 3 is adjusted to a point 175mm underwater.

[0035] When the pressure in the tank is lower than -295Pa, the negative pressure chamber 2 and the straight pipe 33 of the positive pressure chamber 3 are subjected to a negative pressure lower than -295Pa. Figure 1 The ambient atmosphere will pass through the pipe 22 of the negative pressure chamber 2 into the negative pressure chamber 2, the buffer chamber 1 and then into the storage tank. When the gas passes through the pipe 22 of the negative pressure chamber 2, the volume of the seal water decreases. At the same time, the straight pipe 33 of the positive pressure chamber 3 is subjected to the same negative pressure, causing the seal water in the straight pipe 33 to rise. Since the pipe 22 and the straight pipe 33 have the same diameter, the descending height is equal to the rising height, and the seal water level remains unchanged.

[0036] When the pressure in the tank is higher than +1750Pa, the straight pipe 33 of the negative pressure chamber 2 and the positive pressure chamber 3 is subjected to a positive pressure higher than +1750Pa. Figure 2As shown, the gas within the storage tank passes through buffer chamber 1 and negative pressure chamber 2 before entering straight pipe 33 of positive pressure chamber 3, passing through the seal water level and escaping into the ambient atmosphere. As the gas passes through pipe 22 of negative pressure chamber 2, the volume of the seal water increases. Simultaneously, the same positive pressure is applied to straight pipe 33 of positive pressure chamber 3, causing the seal water level within straight pipe 33 to rise. Because pipes 22 and 33 have the same diameter, the height of the drop is equal to the height of the rise, and the seal water level remains constant.

[0037] This product precisely controls the positive and negative gas pressures within the tank by adjusting the insertion depth of pipe 22 and straight pipe 33 into the water seal. For example, when the tank's positive pressure is set to >1750Pa, exhaust is achieved through the breather valve. Straight pipe 33 in positive pressure chamber 3 can be inserted into the water seal to a depth of 175mm. When the tank's upper gas pressure exceeds 1750Pa, the gas in the tank passes through buffer chamber 1, negative pressure chamber 2, and the 175mm water seal in the positive pressure chamber before being discharged from vent 31 in positive pressure chamber 3. When the tank's minimum negative gas pressure is set to <-295Pa, and the upper gas pressure falls below -295Pa, air drawn in through pipe 22 in negative pressure chamber 2 enters negative pressure chamber 2, passes through the 29.5mm water seal, then through buffer chamber 1, enters the flame arrester breather valve, and finally exits the tank. When the tank's internal pressure is between -295Pa and 1750Pa, the water seals in positive and negative pressure chambers 3 and 2 seal the gas within the tank, preventing leakage.

[0038] The present invention proposes a device for simply and accurately adjusting the water seal depth according to the positive and negative pressures set on the storage tank to prevent gas leakage within the set range, while also ensuring that gas is promptly released from the tank or replenished into the tank when the set positive and negative pressure ranges are exceeded. This device can accurately express the positive and negative pressure parameters set by the fire-arresting breathing valve in the form of water columns, improving the convenience and accuracy of operation.

[0039] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A water-sealed fire-retardant breathing valve for a storage tank, characterized in that: The invention comprises a box body, wherein a buffer chamber (1), a negative pressure chamber (2) and a positive pressure chamber (3) are sequentially arranged in the box body, the buffer chamber (1) is communicated with the upper part of the negative pressure chamber (2), the negative pressure chamber (2) is communicated with the bottom of the positive pressure chamber (3), the negative pressure chamber (2) and the positive pressure chamber (3) are filled with liquid, the upper part of the buffer chamber (1) is connected with an air pipe (11), the top of the negative pressure chamber (2) is plugged with a pipe (22) located inside the negative pressure chamber (2), the pipe (22) can move up and down to adjust its height in the negative pressure chamber (2), the upper left part of the positive pressure chamber (3) is provided with an elbow (32) communicating with the negative pressure chamber (2), the bottom of the elbow (32) is connected with a straight pipe (33) that can move up and down to adjust its height in the positive pressure chamber (3), and the top of the positive pressure chamber (3) is provided with an exhaust hole (31).

2. A water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: An observation window (21) is provided on the top of the negative pressure chamber (2).

3. A water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: A drain valve (12) is installed at the bottom of the buffer chamber (1).

4. A water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: The pipe (22) is sealed and installed in the negative pressure chamber (2) via a sealing ring.

5. The water-sealed fire-retardant breathing valve for storage tanks according to claim 1 is characterized in that: The straight pipe (33) is sealed and mounted on the elbow (32) via a sealing ring.

6. The water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: An overflow pipe (34) is installed on the right side of the positive pressure chamber (3).

7. The water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: A water replenishment float valve (35) is installed on the right side of the positive pressure chamber (3).

8. The water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: A drain valve (36) is installed at the bottom of the positive pressure chamber (3).

9. The water-sealed fire-retardant breathing valve for storage tanks according to claim 1, characterized in that: The diameter of the air pipe (11) and the pipe (22) are the same.

10. A water-sealed fire-retardant breathing valve for storage tanks according to claim 9, characterized in that: The pipe (22) and the straight pipe (33) have the same diameter.

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