Gas-phase space pressure control liquid seal valve of atmospheric storage tank

Abstract

The invention relates to the technical field of normal pressure storage tank sealing, and provides a normal pressure storage tank gas phase space pressure control liquid seal valve which comprises a short section with a flange, a liquid storage cylinder, a sealing cover and a rainproof cover, one end of the short section with the flange is connected with a flange of a tank top pressure relief manhole, and the other end of the short section with the flange penetrates through a bottom plate of the liquid storage cylinder and extends into the liquid storage cylinder; the sealing cover is inversely buckled in the liquid storage barrel and covers the short section with the flange, sealing liquid in the liquid storage barrel submerges the opening end of the sealing cover, the sealing cover is vertically assembled in a sliding mode through a guide rod in the liquid storage barrel and can vertically move, an emptying valve and a liquid level meter are arranged on the outer side of a bottom plate of the liquid storage barrel, and a U-shaped differential pressure gauge is connected to the short section with the flange. The rain cover is inversely buckled and fixed to the top of the guide rod, the rain cover covers the liquid storage cylinder, and a static conducting wire is arranged between the rain cover and the sealing cover. According to the pressure control liquid seal valve for the gas phase space of the atmospheric storage tank, a conventional breather valve and a pressure relief manhole are combined into a whole, so that opening holes in the top of the tank can be reduced, and the maintenance workload is reduced; and the liquid level of the sealing liquid and the pressure in the tank are visualized.

Description

Technical Field

[0001] The present application belongs to the technical field of atmospheric pressure storage tank sealing, and more specifically, relates to a gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks. Background Art

[0002] "Petrochemical Enterprise Design Fire Protection Standard" - GB50160 2018 revised version 6.2.19: Fixed-roof tanks for Class A, B, and B liquids should be equipped with flame arresters and breathing valves; for storage tanks for Class A, B, and B liquids that are sealed with nitrogen or other gases, accident pressure relief equipment should also be installed. At present, the gas phase space pressure of atmospheric pressure storage tanks sealed with nitrogen or other gases is controlled by breathing valves and emergency pressure relief manholes. The breathing valves and pressure relief manholes are mainly mechanical. Its disadvantage is that when the storage tank is within the normal operating pressure range, the breathing valve and the pressure relief manhole are in the closed state. Because the sealing is ensured by the deadweight of the valve plate, the valve plate itself has a small mass, a large sealing surface, the sealing material is prone to aging and hardening, and the valve plate is deformed. Factors such as these cannot guarantee zero leakage when the valve plate is closed. In addition, the breathing valve and the pressure relief manhole are arranged separately, which increases the opening on the tank top and the leakage point. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the embodiments of the present application is to provide a liquid-sealed valve for controlling the gas phase pressure of an atmospheric pressure storage tank.

[0004] To achieve the above-mentioned purpose, the technical solution adopted in the present application is: to provide a gaseous space pressure control liquid sealing valve of a normal pressure storage tank, which is arranged on a short section reserved for a pressure relief manhole on the top of the tank, including: a short section with a flange, a liquid storage cylinder, a sealing cover and a rain cover, one end of the short section with a flange is connected to the short section reserved for the pressure relief manhole, and the other end passes through the bottom plate of the liquid storage cylinder and extends into the liquid storage cylinder, the sealing cover is inverted in the liquid storage cylinder and covers the short section with a flange, the sealing liquid in the liquid storage cylinder submerges the open end of the sealing cover, the sealing cover is vertically slidably assembled through the guide rod in the liquid storage cylinder, a drain valve and a liquid level gauge are provided on the outside of the bottom plate of the liquid storage cylinder, a U-shaped differential pressure gauge is connected to the short section with a flange, the rain cover is inverted and fixed on the top of the guide rod, the rain cover covers the liquid storage cylinder, and an electrostatic conductive wire is provided between the rain cover and the sealing cover.

[0005] In one embodiment, an outer ring is formed between the outer side surface of the sealing cover and the inner side surface of the liquid storage cylinder, and an inner ring is formed between the inner side surface of the sealing cover and the outer side surface of the flanged short section, and the cross-sectional area of ​​the outer ring is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole;

[0006] A plurality of rectangular exhaust windows are arranged on the side wall of the sealing cover, and the sum of the cross-sections of the rectangular exhaust windows is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole.

[0007] In one embodiment, a circle of cofferdam is provided on the top of the sealing cover, and the volume formed by the cofferdam and the top plate of the sealing cover is larger than the volume of sealing liquid discharged from the outer ring into the cofferdam when the maximum positive pressure of the storage tank is opened; a small hole is provided at the bottom of the cofferdam for the sealing liquid to return to the liquid storage cylinder.

[0008] In one embodiment, four guide rods are provided at equal arc distances, and four groups of guide lugs are provided at equal arc distances on the outer side of the sealing cover, with two vertically spaced guide lugs forming a group, and the guide lugs are slidably assembled with the guide rods.

[0009] In one embodiment, the weight of the sealing cover is equal to the force exerted on the top plate of the sealing cover by the designed positive pressure of the storage tank minus the weight of the sealing liquid discharged into the cofferdam.

[0010] In one embodiment, the sealing cover is made of copper alloy or aluminum alloy; and the static conductive wire is a spring-shaped copper soft wire.

[0011] In one embodiment, the height of the liquid storage cylinder is greater than twice the height of the sealing cover;

[0012] A circle of sieve holes is provided in the middle of the wall of the liquid storage cylinder, the lowest position of the sieve holes is higher than the height of the cofferdam, and the sum of the areas of the sieve holes is equal to the cross-sectional area of ​​the pressure relief pipe of the storage tank.

[0013] In one embodiment, the depth of the sealing liquid in the liquid storage cylinder is equal to the height of the upper edge of the rectangular exhaust window + the height of the liquid column of the sealing liquid converted from the designed negative pressure of the storage tank.

[0014] In one embodiment, an annular sieve plate is provided at the open end of the rain shield, the opening area of ​​the annular sieve plate is larger than the cross-sectional area of ​​the pressure relief pipe of the storage tank, and an annular fire-blocking net is installed on the annular sieve plate.

[0015] The beneficial effects of the gas phase space pressure control liquid seal valve for atmospheric pressure storage tanks provided in this application are:

[0016] 1. The atmospheric pressure storage tank gas phase space pressure control liquid seal valve combines the conventional breathing valve and pressure relief manhole into one, which can reduce the number of holes on the tank top and reduce the maintenance workload.

[0017] 2. It can solve the leakage of traditional mechanical breathing valves and pressure relief manholes when they are closed.

[0018] 3. Visualization of sealing liquid level and pressure inside the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 This is a simplified structural diagram of the gas phase space pressure control liquid seal valve of the atmospheric pressure storage tank provided in an embodiment of the present application.

[0021] Among them, the reference numerals in the figures are:

[0022] 1. Flange nipple; 2. Liquid storage cylinder; 21. Sieve hole; 3. Sealing cover; 31. Rectangular exhaust window; 32. Cofferdam; 4. Rain cover; 41. Annular sieve plate; 42. Annular flame arrester; 5. Guide rod; 51. Guide lug; 52. Nut; 6. Drain valve; 7. Liquid level gauge; 8. Static conductor; 9. U-shaped differential pressure gauge; 10. Connecting flange. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0024] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0025] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply 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 this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0027] like Figure 1 As shown, a gas phase space pressure control liquid seal valve for a normal pressure storage tank provided in an embodiment of the present application will now be described. The gas phase space pressure control liquid seal valve for a normal pressure storage tank is arranged on a short section reserved for the pressure relief manhole of the tank body. Specifically, the gas phase space pressure control liquid seal valve for a normal pressure storage tank comprises: a short section with a flange 1, a liquid storage cylinder 2, a sealing cover 3 and a rain cover 4. Among them, one end of the short section with a flange 1 is provided with a connecting flange 10, and the specifications of the connecting flange 10 are consistent with the specifications and models of the connecting flange at the short section reserved for the pressure relief manhole on the top of the tank, and the connecting flange 10 and the connecting flange are connected by bolts. The other end of the short section with a flange 1 passes through the bottom plate of the liquid storage cylinder 2 and extends into the liquid storage cylinder 2. The depth of the short section with a flange 1 extending into the liquid storage cylinder 2 is greater than the liquid seal height generated when the storage tank is designed for negative pressure. Generally, when the storage tank is designed for negative pressure, the height of the liquid column of the sealing liquid is 2.95 cm. Preferably, the depth of the flanged nipple 1 inserted into the liquid storage cylinder 2 is greater than the upper edge of the rectangular exhaust window on the sealing cover + 5 cm.

[0028] In this embodiment, sealing cover 3 has an opening at one end. It is mounted upside down within liquid reservoir 2 and covers flanged sub 1. The height of sealing cover 3 is greater than the depth of flanged sub 1 inserted into liquid reservoir 2. The sealing liquid within liquid reservoir 2 submerges the open end of sealing cover 3. Liquid reservoir 2 is provided with a plurality of vertically arranged guide rods 5, which are located outside sealing cover 3. Sealing cover 3 slides vertically along these guide rods within liquid reservoir 2, ensuring horizontal movement of sealing cover 3.

[0029] In this embodiment, a drain valve 6 and a liquid level gauge 7 are provided on the outside of the bottom plate of the liquid storage cylinder 2. The drain valve 6 is used to discharge the sealing liquid; the liquid level gauge 7 is used to display the height of the sealing liquid in the liquid storage cylinder 2; a U-shaped differential pressure gauge is connected to the flanged short section 1 to display the actual pressure in the storage tank.

[0030] In this embodiment, the rain cover 4 is inverted and fixed on the top of the guide rod 5, and is specifically fastened by a nut 52 provided on the top of the guide rod 5; the diameter of the rain cover 4 is larger than the diameter of the liquid storage cylinder 2, and the rain cover 4 covers the liquid storage cylinder 2 to prevent external objects from falling into the liquid storage cylinder 2; an electrostatic conductive wire 8 is provided between the rain cover 4 and the sealing cover 3, and the electrostatic conductive wire 8 is used to conduct away the static electricity generated when the sealing cover 3 moves up and down.

[0031] In this embodiment, four guide rods 5 are set at equal arc distances, and four groups of guide ears 51 are set at equal arc distances on the outer side of the sealing cover 3. Two vertically spaced guide ears 51 form a group, and the guide ears 51 are slidably assembled with the guide rods 5 to ensure that the up and down movement of the sealing cover 3 is in a vertical state.

[0032] In this embodiment, the liquid storage cylinder 2 and the sealing cover 3 are made of copper alloy or aluminum alloy to avoid sparks when the sealing cover 3 moves up and down; the static conductive wire 8 is a spring-shaped copper soft wire, so that the length of the static conductive wire 8 can be extended to cooperate with the up and down movement of the sealing cover 3.

[0033] In this embodiment, an annular sieve plate 41 is provided at the open end of the rain cover 4. The opening area of ​​the annular sieve plate 41 is larger than the cross-section of the pressure relief pipe of the storage tank. An annular fire-blocking net 42 is installed on the annular sieve plate 41 to prevent external sparks from entering the rain cover 4.

[0034] In this embodiment, a circle of rectangular exhaust windows 31 arranged at intervals is provided on the side wall of the sealing cover 3. The rectangular exhaust windows 31 are arranged near the open end of the sealing cover 3. A circle of sieve holes 21 is provided in the middle of the liquid storage cylinder 2 to achieve communication between the internal and external spaces. Under normal conditions, the sealing liquid submerges the rectangular exhaust windows 31 to achieve liquid sealing.

[0035] In this embodiment, when the sealing cover 3 is inverted in the liquid storage cylinder 2, an outer annular space is formed between the outer side surface of the sealing cover 3 and the inner side surface of the liquid storage cylinder 2, and an inner annular space is formed between the inner side surface of the sealing cover 3 and the outer side surface of the flanged short section 1. The cross-sectional area of ​​the outer annular space is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole on the storage tank.

[0036] In this embodiment, the total cross-sectional area of ​​the rectangular exhaust windows 31 is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole.

[0037] In this embodiment, a circle of cofferdam 32 is provided on the top of the sealing cover 3, which can be understood as that the axial section of the sealing cover 3 is "H"-shaped; the volume formed by the cofferdam 32 and the top plate of the sealing cover 3 is greater than the volume of the sealing liquid discharged from the outer ring into the cofferdam 32 when the maximum positive pressure of the storage tank is opened; the purpose of this setting is to ensure that the top of the sealing cover 3 can fully receive the sealing liquid pressed out by the maximum positive pressure; a small hole is opened at the bottom of the cofferdam 32 for the sealing liquid to return to the liquid storage cylinder 2, and the aperture of the small hole is small, so that the sealing liquid can slowly return to the liquid storage cylinder 2.

[0038] In this embodiment, the weight of the sealing cover 3 is equal to the force exerted on the top plate of the sealing cover 3 by the design positive pressure of the storage tank minus the weight of the sealing liquid discharged into the cofferdam 32. That is, the sealing cover 3 will be pushed up only when the pressure generated in the storage tank reaches the design pressure.

[0039] In this embodiment, the height of the liquid storage cylinder 2 is greater than twice the height of the sealing cover 3; the lowest position of the sieve hole 21 is higher than the height of the cofferdam 32, and the area of ​​the sieve hole 21 is equal to the cross-section of the tank pressure relief pipe.

[0040] Specifically, when the gas phase pressure in the storage tank reaches the exhalation pressure but does not reach the designed positive pressure of the storage tank, the sealing cover 3 will not rise, and the gas in the tank will press the sealing liquid at the bottom of the sealing cover 3 into the annular space between the sealing cover 3 and the liquid storage cylinder 2 (that is, the sealing liquid in the inner ring is pressed into the outer ring through the rectangular exhaust window 31), and flows into the cofferdam 32 of the sealing cover 3, and normal exhaust begins.

[0041] When the gas phase pressure in the storage tank reaches the designed maximum positive pressure, the sealing cover 3 rises. When it rises to the opening position in the middle of the wall of the liquid storage cylinder 2, the exhaust area becomes larger and the gas phase displacement in the tank increases at any time. At this time, the liquid seal control valve begins to enter the pressure relief manhole working state. When the gas phase pressure in the tank drops below the designed positive pressure, the sealing cover 3 begins to descend and enters the breathing valve exhalation working state.

[0042] When the sealing cover 3 is under negative pressure due to the gas phase pressure in the storage tank, the atmospheric pressure forces the sealing liquid in the outer ring space into the inner ring space. Since the sealing cover 3 is far away from the flanged nipple 1, the sealing liquid in the inner ring will not rise along the inner wall of the sealing cover as a whole and enter the tank. When the negative pressure in the tank reaches the minimum operating negative pressure of the tank, the air breaks through the sealing liquid and enters the tank, and the liquid seal control valve enters the suction working state.

[0043] In this embodiment, the sealing liquid is selected from a substance that is difficult to volatilize, has a low freezing point, is difficult to dissolve in the tank medium, and is not miscible with water, preferably transformer oil.

[0044] In this embodiment, the depth of the sealing liquid in the liquid storage cylinder 2 is equal to the height of the upper edge of the rectangular exhaust window 31 + the height of the liquid column of the sealing liquid converted according to the maximum operating negative pressure of the storage tank.

[0045] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A liquid sealing valve for controlling the gas phase pressure of an atmospheric storage tank, which is installed on the short section reserved for the pressure relief manhole on the tank top, and is characterized by: include: A flanged short section (1), a liquid storage cylinder (2), a sealing cover (3) and a rain cover (4), wherein one end of the flanged short section (1) is connected to the pressure relief manhole reserved short section, and the other end passes through the bottom plate of the liquid storage cylinder (2) and extends into the liquid storage cylinder (2); the sealing cover (3) is buckled upside down in the liquid storage cylinder (2) and covers the flanged short section (1); the sealing liquid in the liquid storage cylinder (2) submerges the open end of the sealing cover (3); The sealing cover (3) is assembled by vertical sliding through the guide rod (5) in the liquid storage cylinder (2); a drain valve (6) and a liquid level gauge (7) are provided on the outer side of the bottom plate of the liquid storage cylinder (2); a U-shaped differential pressure gauge is connected to the flanged short section (1); the rain cover (4) is buckled and fixed on the top of the guide rod (5); the rain cover (4) covers the liquid storage cylinder (2); and a static electricity conductive wire (8) is provided between the rain cover (4) and the sealing cover (3).

2. The atmospheric pressure storage tank gas phase space pressure control liquid sealing valve according to claim 1, characterized in that: An outer ring is formed between the outer side surface of the sealing cover (3) and the inner side surface of the liquid storage cylinder (2), and an inner ring is formed between the inner side surface of the sealing cover (3) and the outer side surface of the flanged short section (1), and the cross-sectional area of ​​the outer ring is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole; A plurality of arranged rectangular exhaust windows (31) are provided on the side wall of the sealing cover (3), and the total area of ​​the rectangular exhaust windows (31) is equal to the cross-sectional area of ​​the short section reserved for the pressure relief manhole.

3. The gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks according to claim 2, characterized in that: A circle of cofferdam (32) is provided on the top of the sealing cover (3); the volume formed by the cofferdam (32) and the top plate of the sealing cover (3) is larger than the volume of sealing liquid discharged from the outer ring into the cofferdam (32) when the maximum positive pressure of the storage tank is opened; and a small hole is provided at the bottom of the cofferdam (32) for the sealing liquid to flow back into the liquid storage cylinder (2).

4. The atmospheric pressure storage tank gas phase space pressure control liquid sealing valve according to claim 1, characterized in that: Four guide rods (5) are arranged at equal arc distances, and four groups of guide lugs (51) are arranged at equal arc distances on the outer side of the sealing cover (3), two guide lugs (51) arranged vertically at intervals form a group, and the guide lugs (51) are slidably assembled with the guide rods (5).

5. The gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks according to claim 3, characterized in that: The weight of the sealing cover (3) is equal to the force exerted on the top plate of the sealing cover (3) by the designed positive pressure of the storage tank minus the weight of the sealing liquid discharged into the cofferdam (32).

6. The atmospheric pressure storage tank gas phase space pressure control liquid sealing valve according to claim 1, characterized in that: The sealing cover (3) is made of a copper alloy or an aluminum alloy; the static electricity conducting wire (8) is a spring-shaped copper soft wire.

7. The atmospheric pressure storage tank gas phase space pressure control liquid sealing valve according to claim 3, characterized in that: The height of the liquid storage cylinder (2) is greater than twice the height of the sealing cover (3).

8. The gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks according to claim 3, characterized in that: A circle of sieve holes (21) is provided in the middle of the wall of the liquid storage cylinder (2), the lowest position of the sieve holes (21) is higher than the height of the cofferdam (32), and the total area of ​​the sieve holes (21) is equal to the cross-sectional area of ​​the storage tank pressure relief pipe.

9. The gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks according to claim 3, characterized in that: The depth of the sealing liquid in the liquid storage cylinder (2) is equal to the height of the upper edge of the rectangular exhaust window (31) + the height of the liquid column of the sealing liquid converted into the designed negative pressure of the storage tank.

10. The gas phase space pressure control liquid sealing valve for atmospheric pressure storage tanks according to any one of claims 1 to 9, characterized in that: The open end of the rain cover (4) is provided with an annular sieve plate (41), the opening area of ​​the annular sieve plate (41) is larger than the cross-sectional area of ​​the pressure relief pipe of the storage tank, and an annular fire-blocking net (42) is installed on the annular sieve plate (41).

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