Primary and secondary seal annular region vocs elimination structure

Abstract

This invention provides a VOCs elimination structure with a primary and secondary sealed annular region, including a mounting wall, a fixed corner bracket, a secondary sealing plate, and a primary sealing plate. The fixed corner bracket is connected to the mounting wall. One end of the secondary sealing plate is fixedly connected to the fixed corner bracket, and the other end is fixedly connected to the primary sealing plate. The end of the primary sealing plate furthest from the secondary sealing plate is connected to the mounting wall. By using the primary and secondary sealing plates, this invention seals the leaked gas phase from the storage tank between the primary and secondary sealing plates. Furthermore, the secondary sealing plates can overlap each other, preventing the entry of external water and impurities. This eliminates the need for a traditional secondary sealing membrane, thereby reducing the amount of material used, improving economic efficiency, and enhancing safety.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas storage sealing technology, and specifically relates to a VOCs elimination structure in the primary and secondary sealing annular region. Background Technology

[0002] Large storage tanks are generally used for oil and gas storage and transportation. With the increasing size and collectivity of storage tanks, a fire in a storage tank may cause a Doppler effect tank fire or explosion accident. Among the tank fires and explosion accidents, sealing ring fires are the main form of tank fires.

[0003] In existing storage tanks, there exists a certain space for the accumulation of volatile oil and gas between the primary seal and the oil surface, known as the explosion hazard zone. If the primary seal detaches from the tank wall due to factors such as deformation or floating roof drift, the explosive mixture will continue to diffuse between the primary and secondary seals, forming an explosion hazard zone within this area. Simultaneously, if the tank experiences frequent oil inflows and outflows, and the floating roof rises and falls frequently, residual volatiles on the tank wall can also accumulate explosive gases in this space. Furthermore, in the event of a lightning strike, the primary ignition point is at the edge sealing ring of the floating roof. The conductive plates installed every 1.8–3.0 m on the upper part of the secondary seal with its oil-gas diaphragm often fail to adhere tightly to the tank wall during operation, leaving gaps due to residual oil film. When the tank is struck by lightning, the instantaneous voltage difference between the floating roof and the tank wall can break down these gaps, creating a discharge spark that ignites the oil and gas accumulated between the primary and secondary seals.

[0004] Therefore, the traditional primary and secondary sealing annular areas of storage tanks currently only serve to prevent rain, sand and gravel, and volatilization. Moreover, the use of oil-gas diaphragms poses certain risks. With the increasing demands for environmental protection, safety, and economy, it is necessary to design VOCs elimination devices for the primary and secondary sealing annular areas. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a VOCs elimination structure for a primary and secondary sealed annular region. By considering the actual conditions of the storage tank and sealing facilities, and combining theoretical design, this VOCs elimination device for a primary and secondary sealed annular region is designed to eliminate VOCs in the sealed annular space of the storage tank, thereby improving the safety and reliability of the storage tank.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A VOCs elimination structure with primary and secondary sealing annular region includes a mounting wall, a fixed corner seat, a secondary sealing plate, and a primary sealing plate;

[0008] The fixed angle bracket is connected to the mounting wall;

[0009] One end of the secondary sealing plate is fixedly connected to the fixed corner seat, and the other end is fixedly connected to the primary sealing plate;

[0010] The end of the primary sealing plate furthest from the secondary sealing plate is connected to the mounting wall.

[0011] Preferably, both the secondary sealing plate and the primary sealing plate are spring plates.

[0012] Preferably, the fixed corner seat includes an L-shaped seat and a reinforcing rib, wherein the reinforcing rib is disposed on the surface corresponding to the right-angle side of the L-shaped seat.

[0013] Preferably, the secondary sealing plate includes a main body, a lower connecting plate, and an upper connecting plate, with the lower connecting plate and the upper connecting plate respectively installed on both sides of the main body.

[0014] Preferably, the lower connecting plate is fixedly connected to the main body and is inclined relative to the main body.

[0015] Preferably, the upper connecting plate is fixedly connected to the main body and is arranged perpendicular to the main body.

[0016] Preferably, both the lower connecting plate and the upper connecting plate are provided with several through holes.

[0017] Preferably, the upper connecting plate and the fixed corner bracket are fixedly connected by bolts.

[0018] Preferably, the lower connecting plate and the primary sealing plate are connected.

[0019] Preferably, a sealing gasket is further provided between the lower connecting plate and the primary sealing plate;

[0020] The primary sealing plate also abuts against a floating plate;

[0021] The secondary sealing plate, sealing gasket, primary sealing plate, and floating plate are stacked in sequence and connected by bolts.

[0022] Preferably, the main body has several discharge slots on both sides, the discharge slots are used to discharge VOCs gas, the discharge slots are strip-shaped, the cross-section is semi-circular, and the angle with the horizontal plane is 30° to 45°.

[0023] The beneficial effects of this invention are:

[0024] 1. By using a primary sealing plate and a secondary sealing plate, the gas phase leaking from the storage tank can be sealed between the primary sealing plate and the secondary sealing plate. Moreover, the secondary sealing plates can be overlapped to prevent external water and impurities from entering. This eliminates the need for the original secondary sealing membrane, thereby reducing the amount of equipment materials used, improving economic efficiency, and enhancing safety.

[0025] 2. This device is an innovative design based on the original secondary sealing, retaining the original sealing characteristics of the storage tank and ensuring the sealing effect; this device eliminates the VOCs concentration in the sealed annular space, eliminating the possibility of storage tank fire and explosion.

[0026] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This diagram illustrates the installation of a primary and secondary sealing annular region VOCs elimination structure according to the present invention.

[0029] Figure 2 It shows Figure 1 A magnified view of area A in the middle;

[0030] Figure 3 A schematic diagram of the secondary sealing plate of the present invention is shown;

[0031] Figure 4 A diagram showing the connection relationship between the secondary sealing plates of the present invention is provided.

[0032] In the diagram: 1. Mounting wall; 2. Fixed corner bracket; 3. Secondary sealing plate; 301. Main body; 302. Lower connecting plate; 303. Upper connecting plate; 304. Discharge trough; 4. Primary sealing plate; 5. Floating plate; 6. Sealing gasket. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] A VOCs elimination structure with primary and secondary sealing annular regions, such as Figure 1As shown, it includes a mounting wall 1, a fixed corner bracket 2, a secondary sealing plate 3, and a primary sealing plate 4; wherein, the fixed corner bracket 2 is connected to the mounting wall 1; one end of the secondary sealing plate 3 is fixedly connected to the fixed corner bracket 2, and the other end is fixedly connected to the primary sealing plate 4; the end of the primary sealing plate 4 away from the secondary sealing plate 3 is connected to the mounting wall 1.

[0035] It should be noted that the installation wall 1 is the inner wall of the storage tank. Below the primary sealing plate 4 is the oil surface. There is a certain space for the accumulation of volatile oil and gas between the primary sealing plate 4 and the oil surface, which is called the explosion hazard zone. If the primary sealing plate 4 detaches from the inner wall of the storage tank due to deformation, drift of the floating roof 5, or other factors, the explosive mixture will continue to diffuse into the space between the primary and secondary seals, forming an explosion hazard zone within this area. Simultaneously, if the storage tank is frequently filled and unfilled, and the floating roof rises and falls frequently, residual volatiles on the tank wall can also accumulate explosive gases in this space. Therefore, the secondary sealing plate 3 is used to prevent gas leakage. The secondary sealing plate 3 also acts as a shield, preventing pollutants brought by external rain and snow from entering the oil and gas space, and greatly reducing oil evaporation losses.

[0036] It needs to be further explained that, Figure 1 The overall structure of the floating roof 5 is not shown. The floating roof 5 is a device that covers the liquid surface by rising and falling with the liquid level in the storage tank through buoyancy. It is generally designed in a spider web shape, with uniform buoyancy distribution and good stability.

[0037] Furthermore, both the secondary sealing plate 3 and the primary sealing plate 4 are spring plates.

[0038] It should be noted that the magnitude of the pressure exerted by the elasticity on the tank wall is a key factor in determining whether the new sealing device has a large compensation amount. In this invention, the secondary sealing plate 3 and the primary sealing plate 4 can be made of 55CrMnA material.

[0039] Furthermore, the fixed corner seat 2 includes an L-shaped seat and a reinforcing rib, with the reinforcing rib disposed on the surface corresponding to the right-angle side of the L-shaped seat.

[0040] It should be noted that the fixed corner seat 2 is a welded corner seat. The reinforcing ribs can improve the structural strength of the L-shaped seat and make the fixed corner seat 2 more impact resistant.

[0041] Furthermore, the secondary sealing plate 3 includes a main body 301, a lower connecting plate 302, and an upper connecting plate 303, with the lower connecting plate 302 and the upper connecting plate 303 respectively installed on both sides of the main body 301; in addition, the lower connecting plate 302 is fixedly connected to the main body 301 and is inclined relative to the main body 301; at the same time, the upper connecting plate 303 is fixedly connected to the main body 301 and is perpendicular to the main body 301; and several through holes are provided in both the lower connecting plate 302 and the upper connecting plate 303.

[0042] It should be noted that the lower connecting plate 302 and the upper connecting plate 303 are for easier connection with other structures.

[0043] Furthermore, the upper connecting plate 303 is fixedly connected to the fixed angle seat 2 by bolts; in addition, the lower connecting plate 302 is connected to the primary sealing plate 4.

[0044] It should be noted that fixing both ends of the secondary sealing plate 3 prevents gas leakage between the primary sealing plate 4 and the secondary sealing plate 3, thus improving the sealing effect.

[0045] like Figure 2 As shown, a sealing gasket 6 is provided between the lower connecting plate 302 and the primary sealing plate 4, and the primary sealing plate 4 also abuts against the floating plate 5. In addition, the secondary sealing plate 3, the sealing gasket 6, the primary sealing plate 4 and the floating plate 5 are stacked in sequence and connected by bolts.

[0046] It should be noted that the use of sealing gasket 6 can improve the sealing performance between the primary sealing plate 4 and the secondary sealing plate 3, while the floating plate 5 abuts against the lower surface of the primary sealing plate 4. The above structure... Figure 2 They are stacked together and then connected with bolts to prevent air leakage.

[0047] like Figure 3 As shown, the main body 301 has several discharge troughs 304 on both sides. The discharge troughs 304 are used to discharge VOCs (volatile organic compounds) gases, including benzene, toluene, xylene, styrene, trichloroethylene, chloroform, trichloroethane, diisocyanate, and diisocyanate. The discharge troughs 304 are strip-shaped with a semi-circular cross-section and an angle of 30° to 45° with the horizontal plane.

[0048] It should be noted that, from Figure 3 As can be seen, the discharge trough 304 is not only located on both sides of the main body 301, but also opened on the inner and outer sides of the main body 301. This facilitates the stacking and installation of the discharge trough 304. Moreover, when the included angle is 30° to 45°, it can prevent external rainwater or other impurities from entering the inner side of the secondary sealing plate 3 through the gaps in the stack. In addition, the end face of the discharge trough 304 has no baffle and is directly connected to the outside. In this way, the VOCs gas between the primary sealing plate 4 and the secondary sealing plate 3 will be discharged from the discharge trough 304.

[0049] like Figure 4As shown, the secondary sealing plates 3 can be connected side by side. During installation, installation positions are reserved on both sides of the main body 301. Therefore, the width of the main body 301 is greater than the width of the lower connecting plate 302 and the upper connecting plate 303. This can prevent interference between the secondary sealing plates 3. The discharge groove 304 is located at the installation position. Two adjacent secondary sealing plates 3 can overlap, and the discharge groove 304 will also be nested together to ensure stable installation.

[0050] The VOCs elimination structure of the primary and secondary sealing annular regions of the present invention has been tested and evaluated, and the process is as follows:

[0051] 1. Based on different tank volumes and tank wall deformation degrees, 10,000 cubic meter, 30,000 cubic meter, and 100,000 cubic meter tanks were selected as models for installation. A VOCs elimination structure for the primary and secondary sealing annular regions was designed to simultaneously meet the requirements of the sealing devices installed on the 10,000, 30,000, and 100,000 cubic meter tanks. The tank wall deformation was simulated by adjusting the gap between the floating plate 5 and the mounting wall 1, and the pressure performance of the primary sealing plate 4 and the secondary sealing plate 3 was tested to verify the performance of the VOCs elimination structure for the primary and secondary sealing annular regions.

[0052] 2. The pressure exerted by the primary sealing plate 4 and the secondary sealing plate 3 on the tank wall is a key factor in determining whether they have a large compensation capacity. Therefore, by adjusting the horizontal distance between the mounting wall 1 and the edge of the floating roof 5, pressure sensors were used to measure the pressure of the primary sealing plate 4 and the secondary sealing plate 3, made of different materials, on the mounting wall 1, thereby determining the material selection for the spring plate. According to the standard GB50341-2014, the compensation range of the sealing area is ±100mm. Therefore, this experiment controlled the sealing gap to be adjusted within the range of ±100mm, using a spring plate pressure of 15kg / m as the test criterion. By analyzing and comparing the elastic properties of different materials, the materials for the primary sealing plate 4 and the secondary sealing plate 3 were determined. Finally, materials such as 20SiMn2MoV, 20MnV, 55CrMnA, and 16MnR were compared, and 55CrMnA was selected as the material for both the primary sealing plate 4 and the secondary sealing plate 3.

[0053] 3. Based on the design requirements, the pressure of the spring plates (primary sealing plate 4 and secondary sealing plate 3) at 15 kg / m was used as the test criterion. Pressure test data for 20SiMn2MoV, 20MnV, 55CrMnA, and 16MnR were obtained. The test data included sealing distance, contact point location, contact point arc length, maximum pressure point, and spring plate pressure. The data for 20SiMn2MoV is as follows:

[0054] Table 1: Test data of 20SiMn2MoV for a 10,000 cubic meter storage tank

[0055]

[0056] Table 2: Test data of 20SiMn2MoV for 30,000 cubic meter storage tank

[0057]

[0058] Table 3: Test data of 20SiMn2MoV for 100,000 cubic meter storage tank

[0059]

[0060] As shown in Tables 1 to 3, when the sealing distance is 150mm, 200mm, 250mm, 300mm and 350mm, the pressure of the 20SiMn2MoV spring plate is in the range of 16.3 to 25.3 kg / m.

[0061] Then, when the spring plate material is 20MnV, the data is as follows:

[0062] Table 4: Material Test Data for 10,000 Cubic Meter Storage Tank B

[0063]

[0064] Table 5: Material Test Data for 30,000 Cubic Meter Storage Tank B

[0065]

[0066] Table 6: Test data of material B for 100,000 cubic meter storage tank

[0067]

[0068]

[0069] As shown in Tables 4 to 6, when the sealing distance is 150mm, 200mm, 250mm, 300mm and 350mm, the pressure of the 20MnV spring plate ranges from 7.6 to 19.3 kg / m.

[0070] Then, when the spring plate material is 55CrMnA, the data is as follows:

[0071] Table 7: Test data of material C for a 10,000 cubic meter storage tank

[0072]

[0073] Table 8: Test data of material C for 30,000 cubic meter storage tanks

[0074]

[0075] Table 9: Test data of material C for 100,000 cubic meter storage tanks

[0076]

[0077] As shown in Tables 7 to 9, when the sealing distance is 150mm, 200mm, 250mm, 300mm and 350mm, the pressure of the 55CrMnA spring plate is in the range of 15.2 to 22.3 kg / m.

[0078] Finally, when the spring plate material is 16MnR, the data is as follows:

[0079] Table 10: Material Test Data for 10,000 Cubic Meter Storage Tank D

[0080]

[0081] Table 11: Material Test Data for 30,000 Cubic Meter Storage Tank D

[0082]

[0083] Table 12: Material Test Data for 100,000 Cubic Meter Storage Tank D

[0084]

[0085] As shown in Tables 10 to 12, when the sealing distance is 150mm, 200mm, 250mm, 300mm and 350mm, the pressure of the 16MnR spring plate is in the range of 8.1 to 17kg / m.

[0086] Based on the above data, it can be seen that the test results of 20MnV and 16MnR do not meet the standard of 15kg / m, so these two materials are excluded. In addition, compared with 20SiMn2MoV and 55CrMnA, when the compensation range is 150mm and 350mm, the pressure on the 20SiMn2MoV spring plate is greater than that on the 55CrMnA spring plate, averaging more than 1.5kg / m. Considering the effect of atmospheric pressure and hydraulic pressure in the sealing space on the primary sealing device, and in order to avoid excessive pressure on the spring plate which may cause the floating plate to jam, 55CrMnA, which has lower spring plate pressure, is selected as the spring plate material.

[0087] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A VOCs elimination structure with primary and secondary sealing annular regions, characterized in that, It includes a mounting wall (1), a fixed corner bracket (2), a secondary sealing plate (3), and a primary sealing plate (4); The fixed angle bracket (2) is connected to the mounting wall (1); One end of the secondary sealing plate (3) is fixedly connected to the fixed corner seat (2), and the other end is fixedly connected to the primary sealing plate (4); The end of the primary sealing plate (4) away from the secondary sealing plate (3) is connected to the mounting wall (1); The secondary sealing plate (3) includes a main body (301), a lower connecting plate (302) and an upper connecting plate (303), wherein the lower connecting plate (302) and the upper connecting plate (303) are respectively installed on both sides of the main body (301); The lower connecting plate (302) is fixedly connected to the main body (301) and is inclined relative to the main body (301); the upper connecting plate (303) is fixedly connected to the main body (301) and is perpendicular to the main body (301). The main body (301) has several discharge slots (304) on both sides. The discharge slots (304) are used to discharge VOCs gas. The discharge slots (304) are strip-shaped with a semi-circular cross-section and an angle of 30°~45° with the horizontal plane. The secondary sealing plates (3) are connected side by side, and installation positions are reserved on both sides of the main body (301) during installation. When the discharge groove (304) is located in the installation position, the discharge grooves (304) on the adjacent secondary sealing plates (3) are nested together when the two adjacent secondary sealing plates (3) overlap.

2. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, Both the secondary sealing plate (3) and the primary sealing plate (4) are spring plates.

3. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, The fixed angle seat (2) includes an L-shaped seat and a reinforcing rib, wherein the reinforcing rib is disposed on the surface corresponding to the right angle side of the L-shaped seat.

4. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, Both the lower connecting plate (302) and the upper connecting plate (303) are provided with several through holes.

5. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, The upper connecting plate (303) and the fixed angle seat (2) are fixedly connected by bolts.

6. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, The lower connecting plate (302) is connected to the primary sealing plate (4).

7. The VOCs elimination structure for a primary and secondary sealing annular region according to claim 1, characterized in that, A sealing gasket (6) is also provided between the lower connecting plate (302) and the primary sealing plate (4); The primary sealing plate (4) also abuts against the floating plate (5); The secondary sealing plate (3), sealing gasket (6), primary sealing plate (4) and floating plate (5) are stacked in sequence and connected by bolts.

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