An oil and gas recovery storage tank

Abstract

The utility model relates to oil gas recovery processing technical field discloses an oil gas recovery liquid storage tank. Aims at solving the oil gas leakage in the liquid discharge process, the oil gas separation efficiency is low, the technical problem of easy jamming, wear and tear, poor reliability in the prior art. The utility model discloses a tank body, is provided with liquid outlet, air inlet and vent on the tank body, is provided with spring pressure type liquid discharge valve at liquid outlet, is provided with the flow guide pipe extending to the lower part of tank body inner chamber in the air inlet, and the inlet end of flow guide pipe is provided with first filter, is provided with the second filter of corrosion -resistant at vent, and the outlet of second filter is connected with stainless steel coil pipe, and spring pressure type liquid discharge valve is normally closed valve. The utility model liquid outlet installs spring pressure liquid discharge valve, prevents liquid backflow, and the failure is low. The air inlet adopts the flow guide of stainless steel pipe, prevents liquid splashing on the filter. The vent adopts stainless steel filter, is corrosion -resistant, and is maintenance -free.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas recovery and treatment technology, and in particular to an oil and gas recovery storage tank. Background Technology

[0002] In the fields of petrochemicals, storage, transportation, and sales, the recovery and treatment of volatile organic compounds (VOCs) is a crucial aspect related to energy conservation, environmental protection, and safe production. In existing technologies, before a tanker truck unloads oil into an underground storage tank at a gas station, it needs to be connected to the underground storage tank using both oil and gas pipelines. The oil pipeline typically extends below the liquid surface in the underground storage tank, while the gas pipeline extends above the liquid surface. During unloading, the pressure in the tanker truck decreases, while the pressure in the underground storage tank increases. This pressure difference allows pre-evaporated oil and gas from the underground storage tank, along with newly evaporated oil and gas, to be introduced into the tanker truck through the gas pipeline, thus achieving pressure equilibrium between the tanker truck and the underground storage tank.

[0003] Chinese patent document 202311154047.9 discloses an oil and gas recovery testing device and method. The device includes a condenser and a temporary oil storage tank. The condenser is connected to an oil and gas pipeline and is used to condense the oil and gas in the oil and gas pipeline, thereby liquefying the oil and gas in the oil and gas pipeline. The temporary oil storage tank is located at the end of the condenser near the oil tank and is connected to the oil and gas pipeline, and is used to receive the liquefied oil in the oil and gas pipeline.

[0004] However, the above solutions have at least the following technical problems during implementation: When traditional drain valves are opened, pressurized oil and gas inside the tank may escape along with the liquid due to poor sealing, causing oil loss, environmental pollution, and safety hazards. The air inlet of the storage tank is directly located at the top of the tank body. After the oil and gas mixture enters the tank, it only diffuses naturally in the space above the liquid surface, resulting in a short oil-gas separation path and insufficient time, leading to incomplete separation. The discharged gas may still contain a large number of oil droplets, and the liquid entering the drain pipe may also contain dissolved gas. Oil and gas recovered from gas stations often contain impurities such as dust, rust, and particulate matter. These impurities can directly enter the tank, or even enter the subsequent vacuum pump or compressor with the gas, causing equipment wear, filter blockage, and increased maintenance costs and failure rates. Therefore, there is an urgent need to propose an oil and gas recovery storage tank. Summary of the Invention

[0005] In view of the above technical problems, this disclosure provides an oil and gas recovery storage tank, which solves the technical problems of oil and gas leakage, low oil and gas separation efficiency, easy blockage and wear, and poor reliability in the prior art during the liquid discharge process.

[0006] According to one aspect of this disclosure, an oil and gas recovery storage tank is provided, including a tank body, wherein the tank body is provided with a liquid outlet, an air inlet and an exhaust outlet; A spring-loaded drain valve is installed at the liquid outlet. The air inlet is provided with a guide pipe extending to the lower part of the tank cavity, and the inlet end of the guide pipe is provided with a first filter; A corrosion-resistant second filter is installed at the exhaust port, and a stainless steel coil is connected to the outlet of the second filter. The spring-loaded drain valve is a normally closed valve. The opening pressure of the normally closed valve is greater than the oil and gas pressure inside the tank and less than the input pressure of the drain pump.

[0007] In some embodiments of this disclosure, the guide tube is a stainless steel tube.

[0008] In some embodiments of this disclosure, the first filter and the second filter are stainless steel filters.

[0009] In some embodiments of this disclosure, an airflow diffuser is provided at the outlet end of the guide pipe, and the airflow diffuser has a hemispherical or inverted funnel-shaped structure.

[0010] In some embodiments of this disclosure, a wave-damping plate is provided on the top of the tank, and the wave-damping plate is an annular baffle plate arranged around the exhaust port.

[0011] In some embodiments of this disclosure, the tank is further provided with a liquid level monitoring module, which includes a magnetostrictive liquid level gauge connected to a control unit for real-time monitoring of the liquid level in the storage tank and outputting an alarm signal.

[0012] In some embodiments of this disclosure, the second filter is a composite structure filter, which includes, from the inside out, a stainless steel sintered mesh layer, a polymer coalescing filter element layer, and a hydrophobic and breathable membrane layer.

[0013] In some embodiments of this disclosure, the valve core of the spring-pressure drain valve is coated with fluororubber or polytetrafluoroethylene, and the valve seat sealing surface of the spring-pressure drain valve is made of hard alloy or engineering ceramic material.

[0014] In some embodiments of this disclosure, the bottom of the tank is a conical bottom structure, and the liquid outlet is located at the lowest point of the conical bottom structure; the spring pressure type drain valve is installed perpendicular to the inclined surface of the conical bottom structure.

[0015] The beneficial effects of this utility model are as follows: It can reduce the maintenance of solenoid valves and is more stable than float switches; An air inlet guide pipe prevents liquid from splashing onto the filter and being carried into the equipment, causing damage. The exhaust port uses a stainless steel filter, which is corrosion-resistant and maintenance-free.

[0016] The normally closed state of the spring-loaded drain valve and its setting that the opening pressure is greater than the oil and gas pressure inside the tank ensure that, in non-drainage conditions, oil and gas inside the tank cannot leak back through the outlet, effectively preventing oil evaporation and environmental pollution. When the drain pump starts, the input pressure it generates is sufficient to overcome the valve's opening pressure, causing the valve to open and allowing for smooth drainage. The entire process requires no manual intervention and is highly automated. Compared to electric controls such as solenoid valves, mechanical pressure control is simpler in structure, more reliable, and has a lower failure rate.

[0017] Oily gas is guided into the lower part of the liquid through a guide tube, increasing the contact path and time between the gas and liquid. Utilizing the natural gravitational difference during the bubble's ascent, the oil and gas are separated more thoroughly. The liquid remains at the bottom of the tank, while the separated gas rises to the top space. This avoids the gas directly impacting the liquid surface, preventing violent splashing and atomization, thus reducing the possibility of liquid oil droplets being carried into the exhaust gas. Multiple filtration protections are provided, including a first filter and a second filter. The first filter intercepts most solid particles at the inlet, preventing them from entering the tank or subsequent equipment such as vacuum pumps and compressors, causing wear or blockage. The second filter effectively captures tiny droplets and particles that may evaporate or be entrained from the liquid, ensuring the cleanliness of the exhaust gas and meeting environmental emission standards. Its corrosion-resistant properties guarantee long-term stable filtration performance.

[0018] The guide pipe and filter are made of stainless steel, which greatly enhances the corrosion resistance of the entire storage tank, enabling it to adapt to various chemical substances that may be present during the oil and gas recovery process, extending the service life of the equipment, and reducing maintenance costs and replacement frequency.

[0019] The airflow diffuser prevents high-speed oil and gas flow from directly impacting the liquid surface at the bottom of the tank, thus preventing droplet splashing and secondary evaporation of oil and gas. By dispersing the airflow, the flow velocity is reduced, allowing oil and gas to enter the area below the liquid surface more smoothly, improving condensation recovery efficiency. At the same time, it reduces the risk of turbulence and static electricity buildup within the tank, enhancing safety.

[0020] During transportation or shaking, the baffle plate can effectively suppress the violent shaking of the liquid inside the tank, prevent the liquid from directly impacting the second filter at the exhaust port, avoid filter failure due to liquid seal or contamination, ensure that the exhaust channel is always unobstructed, and improve the reliability and adaptability of the equipment.

[0021] Liquid level monitoring not only enables precise management of the stored liquid volume, but also provides early warnings when the liquid level is too high to prevent overflow accidents. Furthermore, it is linked with the start-up and shutdown of the entire oil and gas recovery system, achieving automated operation and safety management, which surpasses the simple functions of traditional liquid storage tanks.

[0022] The multi-layer composite design enables graded filtration. The stainless steel sintered mesh provides primary coarse filtration and structural support; the coalescing filter element coalesces the penetrating tiny oil mist droplets into larger droplets that fall back into the tank; the outermost hydrophobic and breathable membrane ensures that only gas molecules are allowed to pass through, almost completely blocking the passage of liquid oil and water, greatly improving exhaust purity and protecting downstream vacuum pumps or the atmospheric environment.

[0023] The sealing solution targets corrosive and swelling components that may be present in oil and gas media. The combination of soft and hard sealing ensures zero leakage even under frequent opening and closing and high pressure differentials, greatly improving the durability and reliability of the valve and solving the technical problems of conventional valves being prone to wear and corrosion under these specific operating conditions.

[0024] The conical bottom structure ensures that the liquid inside the tank can be completely drained without any residual dead corners. The drain valve is installed perpendicular to the inclined plane, which conforms to fluid dynamics, reduces drain resistance and lateral impact on the valve core, and avoids the oil and gas space contamination and cross-contamination problems caused by residual liquid in flat-bottom structures. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of an oil and gas recovery storage tank; Figure 2 Another structural diagram of an oil and gas recovery storage tank; Figure 3 Another structural diagram of an oil and gas recovery storage tank; The components in the diagram are named as follows: 1. Tank body; 2. Liquid outlet; 3. Air inlet; 4. Exhaust outlet; 5. Guide pipe; 6. Second filter; 7. Conical bottom structure; 8. Wave baffle; 9. Stainless steel coil; 10. Spring pressure type drain valve. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0027] This example discloses an oil and gas recovery storage tank. See [link to relevant documentation]. Figures 1 to 3 , It includes a tank body 1, which is provided with a liquid outlet 2, an air inlet 3 and an exhaust outlet 4; A spring-pressure type drain valve 10 is installed at the two liquid outlets; An air inlet 3 is provided with a guide pipe 5 extending to the lower part of the tank cavity, and a first filter is provided at the inlet end of the guide pipe; A corrosion-resistant second filter 6 is installed at the exhaust port 4, and a stainless steel coil 9 is connected to the outlet of the second filter 6; The spring-loaded drain valve is a normally closed valve. The opening pressure of the normally closed valve is greater than the oil and gas pressure inside the tank and less than the input pressure of the drain pump.

[0028] The guide tube 5 is made of stainless steel.

[0029] The first and second filters are stainless steel filters.

[0030] An airflow diffuser is provided at the outlet end of the guide pipe 5. The airflow diffuser has a hemispherical or inverted funnel-shaped structure.

[0031] A wave-damping plate 8 is provided on the top of the tank body 1. The wave-damping plate 8 is an annular baffle plate arranged around the exhaust port.

[0032] The tank body 1 is also equipped with a liquid level monitoring module, which includes a magnetostrictive liquid level gauge. The magnetostrictive liquid level gauge is connected to the control unit and is used to monitor the liquid level of the storage tank in real time and output an alarm signal.

[0033] The second filter 6 is a composite structure filter, which consists of a stainless steel sintered mesh layer, a polymer coalescing filter element layer, and a hydrophobic and breathable membrane layer from the inside out.

[0034] The valve core of the spring-loaded drain valve is covered with fluororubber or polytetrafluoroethylene, and the valve seat sealing surface is made of hard alloy or engineering ceramic material.

[0035] The bottom of the tank 1 is a conical bottom structure 7, and the liquid outlet 2 is located at the lowest point of the conical bottom structure 7; the spring pressure type liquid drain valve is installed perpendicular to the inclined surface of the conical bottom structure.

[0036] During operation, the recovered oil-gas mixture enters through inlet 3 and is transported to the bottom of the tank via guide pipe 5. The oil and gas flow out from the airflow diffuser at the end of the guide pipe. The hemispherical / inverted funnel-shaped structure effectively reduces airflow velocity, prevents violent impact on the liquid surface, and disperses the large airflow into numerous small bubbles, greatly increasing the gas-liquid contact area. The dispersed fine bubbles rise slowly under buoyancy, passing through the liquid oil in the tank. During this process, oil droplets fully condense and settle, achieving deep gas-liquid separation. The separated clean gas continues to rise to the top space of the tank. The baffle plate 8 effectively suppresses liquid surface fluctuations caused by vehicle movement or airflow impact, preventing liquid splashing directly into the exhaust port. The clean gas gathered at the top of the tank flows towards the exhaust port 4 under pressure. The gas passes through the second filter 6, where a stainless steel sintered mesh layer first performs coarse filtration, intercepting larger particles that may be entrained by the gas. The polymer coalescing filter layer coalesces and fuses tiny oil mist particles into larger droplets, thereby achieving efficient gas-liquid separation. The hydrophobic and breathable membrane layer allows gas molecules to pass through but completely blocks liquid water and oil droplets, ensuring extremely clean exhaust gas. The separated liquid collects at the bottom of the tank. The conical bottom structure 7 ensures that the liquid collects completely without residue at the lowest outlet 2. A magnetostrictive level gauge monitors the liquid level in real time and transmits the data to the control unit. When the liquid level reaches the high limit, an automatic alarm is triggered and the drain pump is activated. The drain pump starts, providing an input pressure higher than the opening pressure of the spring-loaded drain valve, causing the valve to open and drain. The drain valve offers excellent sealing and wear resistance, ensuring long-term sealing and a long service life under frequent opening and closing. The drain valve's installation method, perpendicular to the conical bottom slope, is most compliant with fluid dynamics, facilitating liquid drainage and reducing residue.

[0037] Although some preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0038] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An oil and gas recovery storage tank characterized by: Includes a tank body, which is provided with a liquid outlet, an air inlet, and an exhaust outlet; A spring-loaded drain valve is installed at the liquid outlet. The air inlet is provided with a guide pipe extending to the lower part of the tank cavity, and the inlet end of the guide pipe is provided with a first filter; A corrosion-resistant second filter is installed at the exhaust port, and a stainless steel coil is connected to the outlet of the second filter. The spring-loaded drain valve is a normally closed valve. The opening pressure of the normally closed valve is greater than the oil and gas pressure inside the tank and less than the input pressure of the drain pump.

2. The oil and gas recovery storage tank of claim 1, wherein: The guide tube is made of stainless steel.

3. The oil and gas recovery storage tank of claim 1, wherein: The first and second filters are stainless steel filters.

4. The oil and gas recovery storage tank of claim 1, wherein: An airflow diffuser is provided at the outlet end of the guide pipe. The airflow diffuser has a hemispherical or inverted funnel-shaped structure.

5. The oil and gas recovery storage tank of claim 1, wherein: The top of the tank is provided with a wave-damping plate, which is an annular baffle plate arranged around the exhaust port.

6. The oil and gas recovery storage tank of claim 1, wherein: The tank is also equipped with a liquid level monitoring module, which includes a magnetostrictive liquid level gauge connected to a control unit for real-time monitoring of the liquid level in the storage tank and outputting an alarm signal.

7. The oil and gas recovery storage tank of claim 1, wherein: The second filter is a composite structure filter, which consists of a stainless steel sintered mesh layer, a polymer coalescing filter element layer, and a hydrophobic and breathable membrane layer from the inside out.

8. The oil and gas recovery storage tank of claim 1, wherein: The valve core of the spring-pressure type drain valve is covered with fluororubber or polytetrafluoroethylene, and the valve seat sealing surface of the spring-pressure type drain valve is made of hard alloy or engineering ceramic material.

9. The oil and gas recovery storage tank of claim 1, wherein: The bottom of the tank is a conical bottom structure, and the liquid outlet is located at the lowest point of the conical bottom structure; the spring pressure type drain valve is installed perpendicular to the inclined surface of the conical bottom structure.

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