Petroleum chemical storage tank safety pressure relief explosion-proof device

Abstract

The utility model discloses a kind of petroleum chemical industry storage tank safety pressure relief explosion-proof device, it is related to petroleum chemical industry storage and transportation safety technical field, including tank body, top cover and the float bowl of sliding installation in tank body, the outer periphery of float bowl is provided with the sealing ring of sealing cooperation with tank body inner wall, oil storage cavity is formed below float bowl, nitrogen cavity is formed above, tank body top is communicated with external nitrogen tank by constant-pressure nitrogen gas pipe.The top of float bowl is provided with nitrogen balance mechanism and pressure relief mechanism, nitrogen balance mechanism is used to when forming negative pressure in oil storage cavity, nitrogen in nitrogen cavity is transported to oil storage cavity to realize pressure balance, pressure relief mechanism is used to when forming positive pressure in oil storage cavity, volatile gas is discharged outside tank body;The device can realize the automatic regulation of oil storage cavity positive pressure in oil storage process, reduce oil product volatilization, avoid combustible gas accumulation, improve explosion-proof safety and stability in the operation process of storage tank.

Description

Technical Field

[0001] This utility model belongs to the field of chemical storage tank technology, specifically relating to a safety pressure relief and explosion-proof device for petrochemical storage tanks. Background Technology

[0002] In the petrochemical industry, crude oil, refined oil products, and other flammable liquid chemical media are typically stored in large vertical storage tanks. During storage and loading / unloading, the liquid level inside the tank changes as oil is injected or discharged, causing fluctuations in the volume and pressure of the gas phase space within the tank. Simultaneously, petroleum-based media are highly volatile and can easily generate flammable gases during storage. Abnormal increases or decreases in tank pressure can easily lead to safety accidents such as tank structural damage, media leakage, or even explosions.

[0003] In existing technologies, to reduce oil evaporation and improve safety, floating roof structures are often used to isolate the liquid from the air, while inert gases (such as nitrogen) are introduced into the storage tank for protection. However, in actual operation, due to frequent oil inflows and outflows, changes in ambient temperature, and fluctuations in equipment operating conditions, positive or negative pressure states can still easily occur inside the storage tank. When the drainage rate is too fast or the sealing is insufficient, negative pressure may form inside the oil storage chamber. If inert gas is not replenished in time, it can easily lead to tank deformation or air backflow, thereby introducing flammable gases. Conversely, when the pressure in the oil storage chamber becomes too high due to liquid injection or the accumulation of volatile gases, if the pressure is not released in time, it will increase the risk of tank rupture or media leakage.

[0004] In addition, in the process of pressure regulation, nitrogen replenishment and depressurization of some existing storage tanks often rely on independent devices or fixed threshold structures, making it difficult to accurately adjust the pressure balance and depressurization conditions according to the actual working conditions. This can easily lead to problems such as untimely nitrogen replenishment, excessive depressurization, or contamination of inert gas, affecting the safety and reliability of the storage tank in the long-term operation. Utility Model Content

[0005] To address the problems existing in the prior art, the purpose of this utility model is to provide a safety pressure relief and explosion-proof device for petrochemical storage tanks. It can achieve automatic pressure balance between the oil storage chamber and the nitrogen chamber based on the floating roof structure, and replenish inert gas and safely relieve pressure under different pressure conditions, while preventing combustible gases from entering the nitrogen space or the inert gas from being contaminated.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A safety pressure relief and explosion-proof device for a petrochemical storage tank includes a tank body, a top cover fixed to the top of the tank body, a floating plate slidably installed inside the tank body, and a sealing ring sleeved on the outer surface of the floating plate; Below the floating roof is an oil storage chamber and above it is a nitrogen chamber. A constant pressure nitrogen pipe is installed on the top of the tank body. The constant pressure nitrogen pipe is connected to the nitrogen chamber and is connected to the nitrogen tank through a delivery pump. A nitrogen balancing mechanism is provided on one side of the top of the floating roof. The nitrogen balancing mechanism is used to deliver nitrogen downward to balance the pressure when the oil storage chamber is under negative pressure. A pressure relief mechanism is provided on one side of the top of the floating roof, which is used to relieve pressure when the oil storage chamber is under positive pressure.

[0007] Furthermore, the nitrogen balancing mechanism includes a first valve body fixed to the surface of the floating plate by bolts. An exhaust port is provided on the lower side of the first valve body, and the exhaust port is connected to the lower oil storage chamber. An air inlet is provided on one side of the first valve body, and the air inlet port is connected to the nitrogen chamber.

[0008] Furthermore, a first sealing cap is screwed onto the top of the first valve body, a first valve stem is vertically slidably mounted at the center of the first sealing cap, and a first valve plate is provided at the bottom of the first valve stem.

[0009] Furthermore, the top of the exhaust port is a stepped hole that is smaller at the top and larger at the bottom, and the first valve plate is placed on the upper inner side of the exhaust port.

[0010] Furthermore, an adjusting nut is screwed onto the top of the first valve stem, the adjusting nut being positioned above the first sealing cap, and a first spring is sleeved on the surface of the first valve stem, the first spring being positioned between the adjusting nut and the first sealing cap, the first spring applying an upward thrust to the adjusting nut.

[0011] Furthermore, the pressure relief mechanism includes a second valve body, the bottom of which has a connection port communicating with the oil storage chamber, and a pressure relief port on one side of the pressure relief mechanism. The end of the pressure relief port is connected to a telescopic pipe, which penetrates the top cover.

[0012] Furthermore, a second sealing cap is screwed onto the top of the second valve body, a second valve stem is vertically slidably mounted at the center of the second sealing cap, a second valve plate is provided at the bottom of the second valve stem, and the second valve plate is positioned above the connection port.

[0013] Furthermore, a second spring is sleeved on the surface of the second valve stem, the second spring is placed inside the body of the second valve body, the second spring is placed between the second valve plate and the second sealing cap, and the second spring applies a downward thrust to the second valve plate.

[0014] Furthermore, an inlet / outlet oil tank is installed at the bottom of the tank body, and the inlet / outlet oil tank is connected to the inside of the oil storage chamber.

[0015] Compared with the prior art, the beneficial effects of this utility model are: By installing a floating roof structure inside the tank that can move up and down with changes in liquid level, and installing a sealing ring structure on the outer periphery of the floating roof that seals with the inner wall of the tank, the petrochemical liquid in the oil storage chamber is effectively isolated from the gas phase space above. This reduces the contact area between the petroleum liquid and air during storage and handling, thereby reducing the amount of oil volatilization at the source, reducing the generation of flammable gases, and improving the problem of high explosion risk caused by volatilization accumulation in traditional storage tanks.

[0016] By setting the space above the floating roof as an independent nitrogen chamber and connecting it to an external nitrogen tank and delivery pump through a constant pressure nitrogen pipe, the nitrogen chamber can continuously maintain an inert gas environment, forming a stable isolation and protection layer between the oil storage chamber and the nitrogen chamber. Even if leakage occurs at the edge of the floating roof or at the sealing part, there will still be no flammable gas inside the nitrogen chamber, thereby further improving the explosion-proof safety of the entire tank during operation.

[0017] By installing a nitrogen balancing mechanism at the top of the floating roof that connects to the nitrogen chamber and the oil storage chamber respectively, the nitrogen compensation channel can be automatically opened under the action of pressure difference when the oil storage chamber is negatively pressured due to liquid discharge or changes in operating conditions. This allows the nitrogen in the nitrogen chamber to be directionally transported to the inside of the oil storage chamber, achieving timely compensation of the oil storage chamber pressure and avoiding the problem of tank deformation or air backflow that can introduce flammable gases due to negative pressure in traditional storage tanks.

[0018] By introducing a pressure control structure consisting of a valve plate, valve stem, spring, and adjusting nut into the nitrogen balancing mechanism, the nitrogen compensation action has a clear opening threshold. The preload of the first spring can be adjusted according to the actual operating requirements of the storage tank, thereby achieving precise control of nitrogen flow conditions, avoiding disordered nitrogen flow or excessive replenishment, and improving the stability and reliability of the storage tank pressure regulation process.

[0019] By setting a pressure relief mechanism independent of the nitrogen balancing mechanism at the top of the floating roof and connecting the pressure relief channel directly to the oil storage chamber, excess gas can be released in time through the pressure relief mechanism when positive pressure is formed inside the oil storage chamber due to liquid injection or evaporation. This prevents the internal pressure of the oil storage chamber from rising continuously, thereby reducing the risk of excessive stress on the tank structure or rupture.

[0020] By setting a one-way controlled valve plate and spring structure in the pressure relief mechanism, the volatile gas in the oil storage chamber is only discharged to the outside of the tank when the pressure exceeds the set threshold, and the discharge process is not connected to the nitrogen chamber, thus avoiding the volatile gas from entering the nitrogen chamber and causing pollution to the inert gas. Structurally, this ensures that the nitrogen chamber maintains the pure inert environment required for explosion prevention for a long time.

[0021] By using the pressure relief port in conjunction with the telescopic pipe structure that penetrates the top cover, the pressure relief mechanism can adapt to the vertical displacement of the floating roof as the liquid level changes. It can maintain a stable pressure relief channel under different liquid level conditions, avoid the problem of pressure relief being limited or sealing failure caused by changes in the position of the floating roof, and improve the safe operation capability of the storage tank in the entire operating range. Attached Figure Description

[0022] Figure 1 This is a frontal three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the tank body of this utility model; Figure 3 This is a schematic diagram of the floating roof structure of this utility model; Figure 4 This is a schematic diagram of the nitrogen balancing mechanism of this utility model; Figure 5 This is a schematic diagram of the pressure relief mechanism of this utility model.

[0023] The attached diagram lists the components represented by each number as follows: 1. Tank body; 11. Inlet / outlet tank; 12. Constant pressure nitrogen pipe; 13. Oil storage chamber; 14. Nitrogen chamber; 2. Top cover; 3. Floating plate; 31. Sealing ring; 4. Nitrogen balance mechanism; 41. First valve body; 42. Air inlet; 43. Exhaust port; 44. First sealing cap; 45. First valve stem; 46. First valve plate; 47. Adjusting nut; 48. First spring; 5. Pressure relief mechanism; 51. Second valve body; 52. Connection port; 53. Pressure relief port; 54. Second sealing cap; 55. Second valve stem; 56. Second valve plate; 57. Second spring; 58. Telescopic pipe. Detailed Implementation

[0024] To make the objectives and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.

[0025] refer to Figures 1 to 5As shown, a safety pressure relief and explosion-proof device for a petrochemical storage tank includes a tank body 1. During the storage and handling of petrochemical media, pressure fluctuations within the tank can easily occur due to changes in liquid level and evaporation. If the pressure is unbalanced, it can easily lead to tank deformation or safety hazards. To solve the above problems, a multi-level safety protection structure is set on the structure of the tank body 1. A top cover 2 is fixed to the top of the tank body 1. The top cover 2 is used to seal and protect the upper end of the tank body 1 and serves as the installation base for the internal structure. A floating plate 3 is slidably installed on the inner side of the tank body 1. The floating plate 3 is used to move up and down with the changes in liquid level in the oil storage chamber 13 to reduce the contact area between the petroleum liquid and the gas, thereby reducing the risk of evaporation. A sealing ring 31 is sleeved on the outer surface of the floating plate 3. The sealing ring 31 is sealed with the inner wall of the tank body 1 to prevent flammable gas in the oil storage chamber 13 from diffusing into the nitrogen chamber 14, further improving the explosion-proof safety of the storage tank during operation.

[0026] Below the floating roof 3 is an oil storage chamber 13 and above it is a nitrogen chamber 14. The oil storage chamber 13 is used to store petrochemical liquids, and the nitrogen chamber 14 is used to fill inert nitrogen gas to isolate air and reduce the risk of explosion. During the process of oil entering and leaving the tank, a pressure difference is easily generated between the oil storage chamber 13 and the nitrogen chamber 14. In order to stabilize the pressure inside the nitrogen chamber 14 and continuously replenish inert gas, a constant pressure nitrogen pipe 12 is provided on the top of the tank body 1. The constant pressure nitrogen pipe 12 is used to continuously supply nitrogen gas to the nitrogen chamber 14. The constant pressure nitrogen pipe 12 is connected to the nitrogen tank through a delivery pump to ensure that the inside of the nitrogen chamber 14 is always in a stable pressure state.

[0027] A nitrogen balancing mechanism 4 is provided on one side of the top of the floating plate 3. When the oil storage chamber 13 is drained or the temperature changes and negative pressure is generated, if the gas cannot be replenished in time, it will easily lead to abnormal stress on the tank. The nitrogen balancing mechanism 4 is used to deliver nitrogen downward to balance the pressure when the oil storage chamber 13 is under negative pressure. The structure controls the nitrogen to enter the oil storage chamber 13 from the nitrogen chamber 14 in a directional manner, so as to achieve rapid pressure compensation while avoiding the entry of air.

[0028] A pressure relief mechanism 5 is provided on one side of the top of the floating plate 3. When the oil storage chamber 13 is under positive pressure due to liquid injection or evaporation, if the internal pressure cannot be released in time, it may cause safety risks. The pressure relief mechanism 5 is used to relieve pressure when the oil storage chamber 13 is under positive pressure. By limiting the direction, the volatile gas inside the oil storage chamber 13 is discharged to the outside of the tank body 1, thereby avoiding the continuous increase of pressure and preventing pollution of the inert gas in the nitrogen chamber 14.

[0029] refer to Figures 2 to 4As shown, the nitrogen balancing mechanism 4 includes a first valve body 41 fixed to the surface of the floating plate 3 by bolts. The first valve body 41 is used as the control body for nitrogen flow and is installed on the floating plate 3 to move synchronously with the floating plate 3. An exhaust port 43 is provided on the lower inner side of the first valve body 41. The exhaust port 43 is used to introduce nitrogen into the oil storage chamber 13. The exhaust port 43 is connected to the lower oil storage chamber 13. An air inlet 42 is provided on one side of the first valve body 41. The air inlet 42 is used to introduce nitrogen into the nitrogen chamber 14. The port of the air inlet 42 is connected to the nitrogen chamber 14.

[0030] refer to Figures 2 to 4 As shown, a first sealing cap 44 is screwed onto the top of the first valve body 41 by a thread. The first sealing cap 44 is used to seal the top of the first valve body 41 and provide guidance and sealing for the internal valve components. A first valve stem 45 is vertically slidably mounted at the center of the first sealing cap 44. The first valve stem 45 is used to transmit pressure changes and drive the valve components to move. A first valve plate 46 is provided at the bottom of the first valve stem 45. The first valve plate 46 is used to control the opening and closing of the exhaust port 43.

[0031] refer to Figures 2 to 4 As shown, the top of the exhaust port 43 is a stepped hole that is smaller at the top and larger at the bottom. This structure is used to improve the sealing stability of the first valve plate 46. The first valve plate 46 is placed above the inner side of the exhaust port 43 and closes the exhaust port 43 under the thrust of the first spring 48. It automatically opens when the pressure of the oil storage chamber 13 is lower than that of the nitrogen chamber 14.

[0032] refer to Figures 2 to 4 As shown, an adjusting nut 47 is screwed onto the top of the first valve stem 45. The adjusting nut 47 is used to adjust the preload of the first spring 48 to set the opening threshold for nitrogen compensation. The adjusting nut 47 is placed above the first sealing cap 44. The first spring 48 is sleeved on the surface of the first valve stem 45. The first spring 48 is used to apply a return force to the first valve plate 46. The first spring 48 is placed between the adjusting nut 47 and the first sealing cap 44. The first spring 48 applies an upward thrust to the adjusting nut 47 to maintain the normally closed state of the first valve plate 46.

[0033] refer to Figure 2 , Figure 3 and Figure 5As shown, the pressure relief mechanism 5 includes a second valve body 51, which forms the main structure for gas release from the oil storage chamber 13. The bottom of the second valve body 51 is provided with a connection port 52 communicating with the oil storage chamber 13. The connection port 52 is used to introduce volatile gas from the oil storage chamber 13. A pressure relief port 53 is provided on one side of the pressure relief mechanism 5. The pressure relief port 53 is used to discharge gas to the outside of the tank 1. A telescopic pipe 58 is connected to the end of the pressure relief port 53. The telescopic pipe 58 is used to guide the gas out and adapt to the lifting and lowering displacement of the floating plate 3. The telescopic pipe 58 passes through the top cover 2 to achieve communication with the outside of the tank 1.

[0034] refer to Figure 2 and Figure 5 As shown, a second sealing cap 54 is screwed onto the top of the second valve body 51. The second sealing cap 54 is used to seal the top of the second valve body 51 and provide valve stem guidance. A second valve stem 55 is vertically slidably mounted at the center of the second sealing cap 54. The second valve stem 55 is used to respond to changes in the internal pressure of the oil storage chamber 13. A second valve plate 56 is provided at the bottom of the second valve stem 55. The second valve plate 56 is used to control the opening and closing of the connection port 52. The second valve plate 56 is positioned above the connection port 52.

[0035] refer to Figure 2 and Figure 5 As shown, a second spring 57 is sleeved on the surface of the second valve stem 55. The second spring 57 is used to provide a return force to the second valve plate 56. The second spring 57 is placed inside the second valve body 51 and between the second valve plate 56 and the second sealing cap 54. The second spring 57 applies a downward thrust to the second valve plate 56 to keep the connection port 52 in a normally closed state and to open for pressure relief when the positive pressure in the oil reservoir 13 exceeds a set threshold.

[0036] refer to Figure 1 and Figure 2 As shown, an inlet / outlet tank 11 is installed at the bottom of the tank body 1. The inlet / outlet tank 11 is used to inject and discharge petrochemical liquids. The inlet / outlet tank 11 is connected to the inside of the oil storage chamber 13. During the oil inlet / outlet process, it works with the floating plate 3, the nitrogen balance mechanism 4 and the pressure relief mechanism 5 to achieve dynamic balance and safe control of the pressure in the oil storage chamber 13.

[0037] The working principle of this utility model is as follows: When in use, petroleum liquid is injected into the tank 1 through the inlet and outlet oil tank 11. As the liquid level rises, the floating plate 3 will also rise. The floating plate 3 can reduce the contact between the liquid and the air, and then evaporate. Nitrogen gas is delivered to the nitrogen chamber 14 through the pump body and the constant pressure nitrogen pipe 12. When the floating plate 3 rises, nitrogen gas is extracted; when it falls, nitrogen gas is delivered to the nitrogen chamber 14 to ensure that the nitrogen gas is in a constant pressure state. Normally, both the nitrogen balancing mechanism 4 and the pressure relief mechanism 5 are closed. When the pressure in the oil storage chamber 13 is lower than that in the nitrogen chamber 14 due to the discharge, the first valve plate 46 can be forced to move down against the thrust of the first spring 48. This allows the nitrogen in the nitrogen chamber 14 to enter through the air inlet 42 and flow into the oil storage chamber 13 through the exhaust port 43, thereby achieving pressure balance between the oil storage chamber 13 and the nitrogen chamber 14. The nitrogen filled inside the oil storage chamber 13 can also have an explosion-proof effect. Even if the edge of the float 3 leaks, the nitrogen filled in the nitrogen chamber 14 will not produce any flammable gas, further preventing explosion. The preload of the first spring 48 can be controlled by tightening the adjusting nut 47 to control the threshold of nitrogen flow. Conversely, when the pressure in the oil storage chamber 13 is greater than that in the nitrogen chamber 14, the second valve plate 56 can be pushed upward against the thrust of the second spring 57. At this time, the petroleum vapor inside the oil storage chamber 13 is discharged into the range of the tank 1 through the pressure relief port 53 and the telescopic pipe 58 to achieve the effect of pressure relief. At the same time, it will not pollute the nitrogen in the nitrogen chamber 14. By screwing on the second sealing cap 54, its pre-tightening force on the second spring 57 can be controlled to adjust the pressure relief threshold.

[0038] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.

Claims

1. A safety pressure relief and explosion-proof device for a petrochemical storage tank, comprising a tank body (1), characterized in that: The top of the tank (1) is fixed with a top cover (2), and a floating plate (3) is slidably installed on the inner side of the tank (1). A sealing ring (31) is sleeved on the outer surface of the floating plate (3). Below the floating plate (3) is an oil storage chamber (13) and above it is a nitrogen chamber (14). A constant pressure nitrogen pipe (12) is provided on the top of the tank body (1). The constant pressure nitrogen pipe (12) is connected to the nitrogen chamber (14). The constant pressure nitrogen pipe (12) is connected to the nitrogen tank through a delivery pump. A nitrogen balancing mechanism (4) is provided on one side of the top of the floating plate (3). The nitrogen balancing mechanism (4) is used to deliver nitrogen downward to balance the pressure when the oil storage chamber (13) is under negative pressure. The floating roof (3) is provided with a pressure relief mechanism (5) on one side of the top. The pressure relief mechanism (5) is used to relieve pressure when the oil storage chamber (13) is under positive pressure.

2. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 1, characterized in that: The nitrogen balance mechanism (4) includes a first valve body (41) fixed to the surface of the floating plate (3) by bolts. An exhaust port (43) is provided on the lower inner side of the first valve body (41). The exhaust port (43) is connected to the lower oil storage chamber (13). An air inlet (42) is provided on one side of the first valve body (41). The port of the air inlet (42) is connected to the nitrogen chamber (14).

3. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 2, characterized in that: The first valve body (41) has a first sealing cap (44) screwed onto its top by a thread, and a first valve stem (45) is vertically slidably mounted on the center of the first sealing cap (44). A first valve plate (46) is provided at the bottom of the first valve stem (45).

4. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 3, characterized in that: The top of the exhaust port (43) is a stepped hole that is smaller at the top and larger at the bottom, and the first valve plate (46) is placed above the inner side of the exhaust port (43).

5. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 4, characterized in that: An adjusting nut (47) is screwed onto the top of the first valve stem (45). The adjusting nut (47) is positioned above the first sealing cap (44). A first spring (48) is sleeved on the surface of the first valve stem (45). The first spring (48) is positioned between the adjusting nut (47) and the first sealing cap (44). The first spring (48) applies an upward thrust to the adjusting nut (47).

6. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 1, characterized in that: The pressure relief mechanism (5) includes a second valve body (51), the bottom of the second valve body (51) is provided with a connection port (52) communicating with the oil storage chamber (13), the pressure relief mechanism (5) is provided with a pressure relief port (53) on one side, and the end of the pressure relief port (53) is connected to a telescopic pipe (58), which penetrates the top cover (2).

7. A safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 6, characterized in that: The second valve body (51) is screwed with a second sealing cap (54) at the top. The second valve cap (54) is vertically slidably mounted with a second valve stem (55) at the center. The second valve stem (55) is provided with a second valve plate (56) at the bottom. The second valve plate (56) is positioned above the connection port (52).

8. The safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 7, characterized in that: A second spring (57) is sleeved on the surface of the second valve stem (55). The second spring (57) is placed inside the second valve body (51). The second spring (57) is placed between the second valve plate (56) and the second sealing cap (54). The second spring (57) applies a downward thrust to the second valve plate (56).

9. A safety pressure relief and explosion-proof device for petrochemical storage tanks according to claim 1, characterized in that: The bottom of the tank body (1) is equipped with an inlet / outlet oil tank (11), which is connected to the inside of the oil storage chamber (13).

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