Gravity oil return structure for an oil and gas separator
By introducing an oil separator tray, return oil pipe, and drain device into the oil-gas separator, and using gravity and float control, the problem of secondary return oil pipe blockage is solved, achieving efficient oil circulation and reduced energy consumption.
Patent Information
- Authority / Receiving Office
- CN Β· China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU ZENIX COMPRESSOR CO LTD
- Filing Date
- 2025-08-26
- Publication Date
- 2026-07-31
AI Technical Summary
In existing compressors, the secondary oil return line is prone to blockage, leading to oil loss, machine shutdown or wear, and the existing solution cannot effectively prevent gas leakage, resulting in increased energy consumption.
An oil separator tray, a return oil pipe, and a drain device are added to the oil-gas separator. Liquid oil is collected by gravity and flows through the return oil pipe to the drain device. A metal float ball controls the discharge of oil and prevents gas loss.
It achieves efficient oil collection and circulation, avoids secondary oil return pipe blockage and oil loss, reduces machine downtime risk, and reduces energy consumption loss.
Smart Images
Figure CN224579485U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of compressor technology, specifically relating to a gravity oil return structure for an oil-gas separator. Background Technology
[0002] A screw compressor cylinder contains a pair of meshing helical rotors, each with several concave teeth, rotating in opposite directions. The clearance between the rotors and between the compressor housing and the rotor is only 5-10 micrometers. The main rotor is driven by an electric motor, while the other rotor is driven by the main rotor through an oil film formed by oil injection. The rotors generate high temperatures during gas compression, requiring the injection of cold lubricating oil for cooling. Since the lubricating oil mixes with the compressed gas, oil and gas separation is necessary to ensure the oil circulates within the system.
[0003] The oil-gas mixture ejected from the compressor undergoes most of the oil-gas separation in the coarse separator, and the separated oil returns to the main unit through an oil pipe. Compressed air then undergoes secondary fine separation through a separator core, and the oil after fine separation also returns to the main unit β this is called secondary oil return. A return check valve is used in the secondary oil return line. To prevent compressed gas from returning to the main unit through the secondary oil return line and being repeatedly compressed, thus wasting energy, the industry standard is to control the diameter of the check valve on the secondary oil return line within a very small range, just enough to return oil without air leakage, typically between 0.5mm and 2.0mm. Because the diameter is too small, impurities sucked into the air compressor can easily clog the return check valve, preventing secondary oil return. The oil will accumulate and eventually be carried away by the compressed air. This results in a lack of oil, preventing the machine from being lubricated and cooled, causing the machine to malfunction and shut down, or even causing irreparable wear due to oil shortage. Current solutions, to prevent clogging of the return valve, can only choose check valves with larger diameters, leading to unnecessary gas leakage and energy consumption. Summary of the Invention
[0004] To address the problems existing in the above-mentioned background technology, this utility model proposes a gravity oil return structure for an oil-gas separator.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A gravity-driven oil return structure for an oil-gas separator includes an oil-gas separator body, which comprises a separation tank, an oil separator core, and an oil return system. The upper part of the separation tank is provided with a mixing air inlet pipe, and the middle part of the separation tank is provided with an exhaust outlet. A one-way valve is installed at the exhaust outlet. The oil separator core is provided inside the separation tank, and an air pipe is provided in the middle of the oil separator core. The air pipe is connected to the exhaust outlet. An oil separator tray is located at the bottom of the oil separator core and is sleeved on the air pipe. The oil separator tray is provided with an oil inlet, and the oil separator tray is connected to a drain device through an oil return pipe.
[0006] Furthermore, the top of the oil separator core is provided with an oil seal cover, and the oil seal cover is provided with a pair of metal springs and a crossbar.
[0007] Furthermore, the top of the separation bucket is provided with a bucket lid.
[0008] Furthermore, the air tube is located on the side of the center of the separation barrel.
[0009] Furthermore, the drain device includes a metal float.
[0010] Furthermore, the oil separator tray is provided with grooves, which are connected to the drain device via an oil return pipe.
[0011] The above technical solution can achieve the following beneficial effects: This invention adds an oil separator tray, a return oil pipe, and a drainer to the existing oil-gas separator. Liquid oil flowing from the inner surface of the oil separator core into the grooves of the oil separator tray is collected by the drainer through the return oil pipe. When a certain amount of oil accumulates in the drainer, a metal float rises, opening the outlet channel and allowing the collected liquid oil to flow to the main unit. When the liquid in the drainer is emptied, the liquid level drops, sealing the drain hole to prevent gas loss. The process repeats when oil accumulates in the drainer. Attached Figure Description
[0012] Figure 1 This is an external view of an oil-gas separator.
[0013] Figure 2 This is a schematic diagram of the inside of an oil-gas separator.
[0014] Figure 3 This is a top-down view of the internal structure of an oil-gas separator.
[0015] Figure 4 This is a schematic diagram of the top of the oil separator core.
[0016] In the diagram: 1. Separator; 2. Tank lid; 3. Drainer; 4. One-way valve; 5. Mixing air inlet pipe; 6. Air pipe; 7. Oil separator core; 8. Oil separator tray; 9. Oil inlet; 10. Oil return pipe; 11. Metal spring; 12. Horizontal bar; 13. Oil seal cover. Detailed Implementation
[0017] The present invention will be further described below with reference to the accompanying drawings: like Figure 1-4As shown, a gravity-driven oil return structure for an oil-gas separator includes an oil-gas separator body. The oil-gas separator includes a separation tank 1, an oil separator core 7, and an oil return system. The upper part of the separation tank is provided with a mixing air inlet pipe 5, and the middle part of the separation tank is provided with an exhaust outlet. A one-way valve 4 is installed at the exhaust outlet. The oil separator core 7 is provided inside the separation tank. An oil seal cover 13 is provided on the top of the oil separator core. A pair of metal springs 11 and a crossbar 12 are provided on the oil seal cover, and then a tank cover 2 is installed on it. An air pipe 6 is provided in the middle of the oil separator core and is connected to the exhaust outlet. An oil separator tray 8 is located at the bottom of the oil separator core and is fitted on the air pipe. The oil separator tray is provided with an oil inlet 9 and a groove. The groove is connected to a drain device 3 through a return oil pipe 10. The drain device 9 (commonly a float switch type drain device AHD20B) includes a metal float. The return oil pipe 10 passes through a flange at the exhaust outlet. A connector is provided on the flange to lead out the return oil pipe 10 and connect it to the drain device 3.
[0018] The oil separator core 7 has an upper seal and a lower opening, which sit on the oil separator tray. Its seal adopts a special radial soft seal. The oil separator tray is a step to prevent the oil separator from falling. The oil separator is a cover with a sealing ring, which is fastened on the tray. The radial seal forms a closed environment. There are holes on the side of the tray. When the liquid level rises to the hole position, the liquid flows to the drain due to gravity.
[0019] A horizontal bar is welded above the oil seal cover 13 for disassembling or lifting the oil separator core 7. The oil seal cover 13 has a screw-on metal spring for pressing the oil separator core to prevent it from moving during use.
[0020] In the above embodiments: Figure 3 As shown, the air pipe 6 is designed to be placed on the central side. Replacing the oil separator core only requires opening the tank cover, without disassembling other pipes and valve groups. The oil return is also located on the side of the tank body. There are no pipes on the tank cover that need to be disassembled. This solution is simple and convenient to maintain, and there are no problems such as damage from secondary disassembly of other pipes.
[0021] Figure 2 As shown, when the air compressor is running normally, the oil-gas mixture indicated by the arrow passes through the oil separator core. The mixture accumulates into liquid oil droplets on the surface of the oil separator core and flows from the outer surface to the oil separator tank. The liquid oil hanging on the inner surface of the oil separator core flows into the groove of the oil separator tray and is collected in the drainer through the return oil pipe. When a certain amount of oil accumulates in the drainer, the float is lifted by buoyancy. The connecting rod with the conical plug on the metal float is driven to deviate from the drain hole, opening the outlet channel. The collected liquid oil flows to the main unit. When the liquid in the drainer is emptied, the liquid level drops, the float drops, and the plug on the connecting rod resets to seal the drain hole, preventing gas loss. When oil accumulates in the drainer, the cycle repeats.
[0022] The above descriptions are all preferred embodiments of this utility model. For those skilled in the art, any modifications to this utility model in various equivalent forms without departing from the principle of this utility model shall fall within the protection scope of the appended claims.
Claims
1. A gravity-driven oil return structure for an oil-gas separator, comprising an oil-gas separator body, the oil-gas separator including a separation tank (1), an oil separator core, and an oil return system, wherein the upper part of the separation tank (1) is provided with a mixing air inlet pipe (5), the middle part of the separation tank (1) is provided with an exhaust outlet, and a one-way valve (4) is installed at the exhaust outlet, characterized in that: The separator (1) is equipped with an oil separator core (7) inside. The oil separator core (7) is equipped with an air pipe (6) in the middle. The air pipe (6) is connected to the exhaust outlet. The oil separator tray (8) is located at the bottom of the oil separator core (7) and is fitted on the air pipe (6). The oil separator tray (8) is equipped with an oil inlet (9). The oil separator tray (8) is connected to the drainer (3) through the return oil pipe (10).
2. The gravity oil return structure of an oil-gas separator according to claim 1, characterized in that: The top of the oil separator core (7) is provided with an oil seal cover (13), and the oil seal cover (13) is provided with a pair of metal springs (11) and a crossbar (12).
3. The gravity oil return structure of an oil-gas separator according to claim 1, characterized in that: The top of the separation bucket (1) is provided with a bucket lid (2).
4. The gravity oil return structure of an oil-gas separator according to claim 1, characterized in that: The air tube (6) is located on the side of the center of the separation barrel.
5. The gravity return oil structure of an oil-gas separator according to claim 1, characterized in that: The drain device includes a metal float.
6. The gravity oil return structure of an oil-gas separator according to claim 1, characterized in that: The oil separator tray (8) is provided with grooves, which are connected to the drain device (3) outside the separator (1) via the return oil pipe (10).