A multi-stage gradient composite oil-gas separation filter

Abstract

The present invention discloses a multi-step gradient composite oil-gas separation filter, which belongs to the field of filter technology. The filter comprises a filter layer and flanges and lower end caps arranged at its upper and lower ends. The filter layer comprises at least two layers, and the length of the filter layer structure gradually decreases from the air inlet side to the air outlet side. The lower end cap has a connecting portion protruding inwardly and cooperating with the filter layer. The connecting portion has a stepped structure, and the number of steps of the connecting portion is equal to the number of layers of the filter layer structure. The multi-step gradient composite oil-gas separation filter of the present invention can effectively reduce the product pressure difference, improve separation efficiency, greatly extend the service life, and well meet the user's demand for high efficiency and energy saving.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a multi-stage gradient composite oil-gas separation filter. Background Art

[0002] The air compressor oil-gas separation filter is composed of several parts: a metal end cap, a metal support frame, a sealing glue, and a filter separation filter material. Its main function is to filter out the oil droplets and solid particles in the oil-gas mixture in the air compressor system to achieve the requirements of clean air. Among them, the oil droplets come from the head of the machine being carried out by the air flow, and the sources of solid particles are mainly attributed to the following four aspects: (1) impure new oil; (2) metal particles generated by the friction of the main engine; (3) pollutants generated by high-temperature oxidation in the lubrication system; (4) environmental pollution such as haze.

[0003] The filter element is the actual element that filters pollutants. During use, the microparticles deposited on the filter paper continue to accumulate, clogging the filter pores and reducing the filtration efficiency, causing the life and stability of the filter to frequently deteriorate, and even causing shutdowns in severe cases. As the number of intercepted pollutants increases, the pressure drop generated by the airflow through the filter element increases. When the filtration micropore area of the filter paper is gradually clogged, the filtration efficiency of the filter will be reduced. The increase in pressure drop will lead to increased energy consumption and shorten the service life of the filter.

[0004] In addition, the sealing ring surface of the lower end cover of the traditional air compressor oil-gas separation filter is flat. The separated lubricating oil is pushed inward along the air flow and adheres to the surface of the lower filter material, resulting in a reduced flow area and a large pressure difference. More lubricating oil is collected in the groove of the lower end cover, increasing the return oil load of the return oil pipe; on the other hand, the filter material has only one middle mesh skeleton wrapped around the filter material, resulting in low filter element separation efficiency and short service life. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a multi-stage gradient composite oil-gas separation filter, which can effectively reduce the product pressure difference, improve the separation efficiency, greatly extend the service life, and can well meet the user's needs for high efficiency and energy saving.

[0006] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0007] A multi-step gradient composite oil-gas separation filter comprises a filter layer and flanges and a lower end cover arranged at its upper and lower ends; the filter layer comprises at least two layers, and the length of the filter layer structure gradually decreases from the air inlet side to the air outlet side; the lower end cover has a connecting portion protruding toward its inner side and cooperating with the filter layer, the connecting portion has a stepped structure, and the number of steps of the connecting portion is equal to the number of layers of the filter layer structure.

[0008] As a preferred embodiment of the present invention, the distance between the step of the connecting portion and the bottom of the lower end cover gradually decreases from the inside to the outside, and the radius of the step gradually increases from the inside to the outside.

[0009] As a preferred embodiment of the present invention, the lower end cover further has an annular rib and an oil storage groove, the annular rib is connected to the lower end of the connecting portion, and the oil storage groove is connected to the upper end of the connecting portion and is recessed toward the outer side of the lower end cover.

[0010] Further preferably, the cross section of the oil storage groove is in the shape of an inverted trapezoid.

[0011] As a preferred embodiment of the present invention, the filter layer includes a pre-separation layer, a coarse separation layer and a fine separation layer arranged in sequence from the air inlet side to the air outlet side, and there is a gap between the pre-separation layer and the coarse separation layer, and between the coarse separation layer and the fine separation layer.

[0012] As a preferred embodiment of the present invention, the number of steps in the connecting portion is three, including a first step, a second step and a third step connected in sequence; the first step is bonded to the lower end of the pre-separation layer, the second step is bonded to the lower end of the coarse separation layer, and the third step is bonded to the lower end of the fine separation layer.

[0013] As a preferred embodiment of the present invention, a retaining rubber ring is provided between the pre-separation layer and the second step, and between the coarse separation layer and the third step.

[0014] As a preferred embodiment of the present invention, the pre-separation layer includes a pre-separation filter material and an outer supporting perforated plate mesh arranged in sequence from the outside to the inside; the pre-separation filter material is polyester fiber cotton.

[0015] As a preferred embodiment of the present invention, the coarse separation layer includes a coarse separation folded filter material and a medium support hole plate mesh arranged in sequence from the outside to the inside; the coarse separation folded filter material is composed of a galvanized folded wire mesh, a non-woven fabric layer, a glass fiber filter material, a non-woven fabric layer, and a galvanized folded wire mesh arranged in sequence from the outside to the inside.

[0016] As a preferred embodiment of the present invention, the fine separation layer includes a glass fiber winding layer, a first inner supporting perforated plate mesh, a condensing and guiding cotton layer, and a second inner supporting perforated plate mesh, which are arranged in sequence from the outside to the inside.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The multi-step gradient composite oil-gas separation filter provided by the present invention is configured to have a stepped structure at the connection portion connecting the lower end cover and the filter layer, so that the sealing ring surface of the lower end cover is a stepped ring surface with a height difference. Through the multi-step gradient composite method, the micro-oil droplets intercepted by the filter layer of the multi-layer structure can use their own weight to settle to the outermost side of the lower end cover along the stepped ring surface of the lower end cover and be discharged outward, reducing the accumulation of lubricating oil, greatly reducing the resistance of the entire filter element, and effectively avoiding the micro-oil droplets adhering to the lower surface of the filter layer to cause a reduction in flow area and a large pressure difference; at the same time, the connection portion protruding from the inner side of the lower end cover can increase the contact area between the oil-gas mixture and the outer side of the lower end cover, so that it can play a role in mechanical collision coarse separation of the rising oil-gas mixture, greatly reducing the content of micro-oil droplets carried in the airflow, reducing the oil resistance of the filter material in the filter layer, and greatly improving the separation efficiency. On the other hand, the connection part has a stepped design, and each step is bonded with an independent separation filter material. The filter material precision is distributed from coarse to fine from the outside to the inside. The multi-stage gradient composite separation greatly improves the separation efficiency of the filter element, has a large dust holding capacity, and the pressure difference increases more slowly, which greatly improves the service life of the product.

[0019] In summary, the present invention can effectively reduce product pressure difference and resistance, improve separation efficiency, greatly extend service life, can well meet the user needs of high efficiency and energy saving, and greatly improve the market competitiveness and brand influence of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a partial cross-sectional view of the multi-stage gradient composite oil-gas separation filter of the present invention;

[0021] Figure 2 For the present invention Figure 1 A magnified schematic diagram of part A in FIG;

[0022] Figure 3 For the present invention Figure 1 A magnified schematic diagram of part B in FIG.

[0023] Figure 4 This is a schematic structural diagram of the lower end cover of the present invention.

[0024] Explanation of the accompanying figures: 1. Lower end cover; 101. Connecting part; 102. Circular rib; 103. Oil storage groove; 2. Primary retaining rubber ring; 3. Secondary retaining rubber ring; 4. Pre-separation filter material; 5. External support orifice plate mesh; 6. Coarse separation folded filter material; 7. Middle support orifice plate mesh; 8. Glass fiber winding layer; 9. First inner support orifice plate mesh; 10. Cohesion and diversion cotton layer; 11. Second inner support orifice plate mesh; 12. Flange. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1 The figure shows the multi-stage gradient composite oil-gas separation filter according to the present invention, which comprises a filter layer, a flange 12, and a lower end cap 1. The flange 12 is located at the upper end of the filter layer for connection, sealing, and installation. The flange 12 has an opening in its center, which serves as an exhaust port for discharging clean airflow after oil-gas separation. The filter layer, serving as the main body of the filter element, is primarily used to intercept and filter fine solid particles such as oil droplets and dust from the oil-gas mixture. The filter layer of the present invention comprises at least two layers of filter material, with the length of the filter layer gradually decreasing from the air inlet side to the air outlet side. The end faces of all layers near the flange 12 are flush, while the end faces of each layer near the lower end cap 1 have a height difference. Accordingly, the lower end cap 1 is located at the lower end of the filter layer and has a connecting portion 101 protruding inwardly and mating with the filter layer. The connecting portion 101 has a stepped structure, with the number of steps equal to the number of layers in the filter layer structure. Preferably, the step height of the connecting portion 101 is equal to the height difference between every two adjacent layer structures, the distance between the step of the connecting portion 101 and the bottom of the lower end cover 1 gradually decreases from inside to outside, and the step radius gradually increases from inside to outside. It can be seen from the above scheme that the present invention sets the connecting portion 101 of the lower end cover 1 to a stepped structure, so that the sealing annular surface of the lower end cover 1 is a stepped annular surface with a height difference. Through a multi-step gradient composite method, the micro-oil droplets intercepted by the filter layer of the multi-layer structure can use their own weight to settle to the outermost side of the lower end cover 1 along the stepped annular surface of the lower end cover 1 and be discharged outward, reducing the accumulation of lubricating oil, greatly reducing the resistance of the entire filter element, and effectively avoiding the micro-oil droplets adhering to the lower surface of the filter layer to cause a reduction in flow area and a large pressure difference; on the other hand, the connecting portion 101 protruding toward the inner side of the lower end cover 1 can increase the contact area between the oil-gas mixture and the outer side of the lower end cover 1, so that it can play a role in mechanical collision coarse separation of the rising oil-gas mixture, greatly reducing the content of micro-oil droplets carried in the airflow, reducing the oil resistance of the filter material in the filter layer, and greatly improving the separation efficiency.

[0027] Specifically, refer to Figure 4The lower end cover 1 also has an annular rib 102 and an oil storage groove 103. The annular rib 102, the connecting portion 101 and the oil storage groove 103 are integrally stamped. The annular rib 102 is connected to the lower end of the connecting portion 101, and is used to connect to the filter layer and seal and fix the filter layer. The oil storage groove 103 is connected to the upper end of the connecting portion 101 and is recessed toward the outer side of the lower end cover 1, so that the oil storage groove 103 forms an oil storage space in the filter layer, so that the extremely small oil droplets in the filtered air flow can converge in the oil storage space and finally be sucked away by the return oil pipe. Preferably, the cross-section of the oil storage groove 103 is in the shape of an inverted trapezoid. The inverted trapezoid structure can further increase the contact area between the oil-gas mixture and the outer side of the lower end cover 1, so that the mechanical collision and coarse separation effect of the oil-gas mixture is stronger, so as to reduce the content of micro-oil droplets carried in the air flow and reduce the oil resistance of the filter material in the filter layer, thereby further improving the oil and gas separation efficiency.

[0028] The number of steps of the lower end cover 1 depends on the number of layers of the filter layer. The specific number can be set according to actual needs, and is generally preferably 2 to 4 levels. Taking the three-stage gradient composite oil-gas separation filter with better effect as an example, Figure 1 As shown, the filter layer of the composite oil-gas separation filter specifically includes a pre-separation layer, a coarse separation layer and a fine separation layer arranged in sequence from the air inlet side to the air outlet side, and there is a gap between the pre-separation layer and the coarse separation layer, and between the coarse separation layer and the fine separation layer. Leaving gaps between each layer structure can increase the contact area between the airflow and the filter material. Correspondingly, the number of steps of the connecting portion 101 is three, including a first step, a second step and a third step connected in sequence from top to bottom; the first step is bonded to the lower end of the pre-separation layer, the second step is bonded to the lower end of the coarse separation layer, and the third step is bonded to the lower end of the fine separation layer. Furthermore, a retaining rubber ring is provided between the pre-separation layer and the second step, and between the coarse separation layer and the third step; wherein the retaining rubber ring set between the pre-separation layer and the second step is a first-level retaining rubber ring 2, and the retaining rubber ring set between the coarse separation layer and the third step is a second-level retaining rubber ring 3, both of which are used to prevent the glue from flowing to the outside during bonding.

[0029] Specifically, refer to Figure 2 and Figure 3The pre-separation layer comprises pre-separation filter material 4 and outer support perforated plate mesh 5, arranged in sequence from the outside inward. Pre-separation filter material 4 intercepts and separates large oil droplets in the oil-gas mixture, reducing the load on the inner filter material layers. Outer support perforated plate mesh 5 is bonded and fixed between flange 12 and lower end cap 1 to support pre-separation filter material 4. Pre-separation filter material 4 utilizes low-precision, porous filter material with a large dust holding capacity and slower pressure differential growth, significantly extending the product's service life. Fiber filter materials such as polyester fiber, polyurethane fiber, polyamide fiber, polypropylene fiber, spandex fiber, and polyester fiber are preferred, with polyester fiber cotton having a thickness of 10 mm being preferred. The coarse separation layer includes a coarse separation folded filter material 6 and a medium support hole plate mesh 7 arranged in sequence from the outside to the inside; wherein, the coarse separation folded filter material 6 is composed of a layer of galvanized folded wire mesh, a layer of non-woven fabric layer, six layers of glass fiber filter material, a layer of non-woven fabric layer, and a layer of galvanized folded wire mesh arranged in sequence from the outside to the inside. The folded structure of the filter material can coarsely separate most of the tiny oil droplets and play a role in holding dust and pollution; the medium support hole plate mesh 7 is bonded and fixed between the flange 12 and the lower end cover 1 to support the coarse separation folded filter material 6. The fine separation layer includes a glass fiber winding layer 8, a first inner support orifice plate mesh 9, a condensation and diversion cotton layer 10 and a second inner support orifice plate mesh 11, which are arranged in sequence from the outside to the inside; wherein, the glass fiber winding layer 8 is made of six layers of medium and high precision glass fiber filter materials. The main function of the glass fiber winding layer 8 is to finely separate the fine oil droplets of the residual particle size separated by the previous filter material to ensure that the exhaust oil content reaches ≤1ppm after multi-stage filter material separation; the first inner support orifice plate mesh 9 is also bonded and fixed between the upper and lower end covers to support the glass fiber winding layer 8; the function of the condensation and diversion cotton layer 10 is to target a part of the oil droplets condensed and separated from the glass fiber winding layer 8. When the air flow blows inward, the condensation and diversion cotton will capture the oil droplets, and the oil droplets will be diverted to the oil storage groove 103 of the lower end cover 1 by gravity sedimentation, so that the oil droplets are sucked away by the return oil pipe for reuse; the second inner support orifice plate mesh 11 is also bonded and fixed between the upper and lower end covers to support the condensation and diversion cotton layer 10. From the structure of the above-mentioned filter layer, it can be seen that an independent separation filter material is bonded to each step of the lower end cover 1 of the present invention, and the filter material precision is distributed from coarse to fine from the outside to the inside, and multi-stage gradient composite separation is performed: the residual micro-oil droplets after the first stage separation enter the second stage separation, so that the tiny dust and other solid particles contained in them are intercepted, and the trace residue after the second stage separation enters the fine separation layer for the third stage fine separation, which greatly improves the separation efficiency of the filter element, has a large dust holding capacity, and the pressure difference increases more slowly, which greatly improves the service life of the product.

[0030] The working principle of an air compressor is as follows: After the air compressor compresses air through the main engine, the airflow carries a mixture of oil and gas, including large and small oil droplets. This mixture is discharged through a pipeline into an oil-gas separation filter installed in an oil-gas tank. The oil-gas separation filter's function is to separate the lubricating oil from the oil-gas mixture as much as possible to achieve clean air and environmental protection. Therefore, the oil-gas separation filter must have low filter element resistance, high separation efficiency, and a long service life. The following will specifically analyze how the present invention achieves these beneficial effects from three aspects: reducing filter element resistance, improving separation efficiency, and extending service life.

[0031] 1. Reduce filter element resistance

[0032] like Figure 1 and Figure 4 As shown, the large arrow indicates the direction of airflow, and the small arrow indicates the direction of lubricating oil flow. An oil-air mixture, carrying large and small oil droplets, rises from the lower end cap 1. The airflow first collides with the lower end cap 1, where mechanical collision and separation separate the larger oil droplets, reducing the oil droplet content in the airflow. The airflow then bypasses the lower end cap 1 and continues upward, entering the filter element from the outside of the filter layer. The three filter layers are spaced apart, with a certain gap between each stage. The lubricating oil separated by each filter layer settles due to gravity onto the steps at the connection 101 of the lower end cap 1. As the height of the three steps gradually decreases from the inside to the outside, the lubricating oil drains downward under its own weight and eventually falls out of the outside of the lower end cap 1. The resistance of the filter element is related to the amount of lubricating oil adhering to the filter material. The fewer oil droplets entering and the less adhering, the lower the resistance of the filter element. Therefore, the lubricating oil separated by each level of filter material in the present invention settles to the step of the connecting portion 101 of the lower end cover 1 by gravity and is discharged outward, effectively reducing the adsorption amount of each level of filter material, thereby greatly reducing the resistance of the filter element.

[0033] 2. Improve separation efficiency:

[0034] like Figure 2 and Figure 3 As shown, each step of the lower end cap 1 is connected to a filter layer, forming a three-stage gradient composite separation structure with gradually increasing filtration accuracy from the outside to the inside. The pre-separation layer intercepts and separates large oil droplets in the oil-gas mixture, removing a portion of the large-particle oil droplets and effectively reducing the load on the filter media at subsequent levels. The coarse separation layer then performs coarse separation on the vast majority of the tiny-particle oil droplets. The fine separation layer primarily performs fine separation on the fine-particle oil droplets remaining from the previous filter media separation, ensuring that the exhaust oil content reaches ≤1ppm after multi-stage filter media separation. The lubricating oil content of the oil-gas mixture before entering the filter element is constant. The oil content gradually decreases with each separation unit the airflow passes through. After three stages of separation, pre-separation, coarse separation, and fine separation, the separation efficiency is significantly improved compared to traditional filter elements, and can well meet the requirements for extremely low oil content.

[0035] 3. Improve service life

[0036] like Figure 3 As shown, the folded structure of the coarse separation layer not only roughly separates the vast majority of tiny oil droplets but also serves as a dust and dirt holding layer, trapping fine dust in the airflow and scale in the lubricating oil. The folded coarse separation layer, when unfolded, offers a larger surface area, significantly enhancing its dust and dirt holding capacity. Alternatively, the coarse separation layer can utilize lower-precision glass fiber as the filter material. This material, with its large average pore size and numerous pores, offers enhanced dust and dirt holding capacity. Combined with the folded filter material, the filter element's pressure differential increases more slowly, extending its service life.

[0037] In summary, the multi-stage gradient composite oil-gas separation filter of the present invention uses the stepped structure of the lower end cover 1 to mechanically collide the large oil droplets in the rising airflow for coarse separation, and then separates the oil droplets and impurities in the oil-gas mixture through the three-stage gradient composite separation filter layer, and finally uses the effect of gravity to discharge the lubricating oil separated from each level of filter material to the outside through the step height difference from the inside to the outside, thereby reducing the accumulation of lubricating oil and ultimately achieving a volume concentration of lubricating oil in the oil-gas mixture of ≤1ppm, greatly reducing the resistance of the entire filter element. Therefore, the multi-stage gradient composite oil-gas separation filter of the present invention has the advantages of high separation efficiency, low filtration resistance, and long service life, which can well meet the user needs of high efficiency and energy saving, and greatly improve the market competitiveness and brand influence of the product. The lower end cover and filter structure of the present invention are not only suitable for oil-gas separation, but also can be applied to other gas-liquid separations, with a wide range of applications and excellent market promotion prospects.

[0038] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A multi-stage gradient composite oil-gas separation filter, characterized by: It includes a filter layer and flanges and a lower end cover arranged at the upper and lower ends of the filter layer; the filter layer includes at least two layers, and the length of the filter layer structure gradually decreases from the air inlet side to the air outlet side; the lower end cover has a connecting part that protrudes toward the inside and cooperates with the filter layer, the connecting part has a stepped structure, and the number of steps of the connecting part is equal to the number of layers of the filter layer structure.

2. The multi-stage gradient composite oil-gas separation filter according to claim 1, characterized in that: The distance between the step of the connecting portion and the bottom of the lower end cover gradually decreases from the inside to the outside, and the radius of the step gradually increases from the inside to the outside.

3. The multi-stage gradient composite oil-gas separation filter according to claim 2, characterized in that: The lower end cover also has a circular rib and an oil storage groove. The circular rib is connected to the lower end of the connecting portion, and the oil storage groove is connected to the upper end of the connecting portion and is recessed toward the outer side of the lower end cover.

4. The multi-stage gradient composite oil-gas separation filter according to claim 3, characterized in that: The cross section of the oil storage groove is in an inverted trapezoidal shape.

5. The multi-stage gradient composite oil-gas separation filter according to any one of claims 1 to 4, characterized in that: The filter layer includes a pre-separation layer, a coarse separation layer and a fine separation layer arranged in sequence from the air inlet side to the air outlet side, and there is a gap between the pre-separation layer and the coarse separation layer, and between the coarse separation layer and the fine separation layer.

6. The multi-stage gradient composite oil-gas separation filter according to claim 5, characterized in that: The connecting portion has three steps, including a first step, a second step and a third step connected in sequence; the first step is bonded to the lower end of the pre-separation layer, the second step is bonded to the lower end of the coarse separation layer, and the third step is bonded to the lower end of the fine separation layer.

7. The multi-stage gradient composite oil-gas separation filter according to claim 6, characterized in that: A retaining rubber ring is provided between the pre-separation layer and the second step, and between the coarse separation layer and the third step.

8. The multi-stage gradient composite oil-gas separation filter according to claim 5, characterized in that: The pre-separation layer comprises a pre-separation filter material and an outer supporting perforated plate mesh which are sequentially arranged from the outside to the inside; the pre-separation filter material is polyester fiber cotton.

9. The multi-stage gradient composite oil-gas separation filter according to claim 5, characterized in that: The coarse separation layer includes a coarse separation folded filter material and a medium support hole plate mesh arranged in sequence from the outside to the inside; the coarse separation folded filter material is composed of a galvanized folded wire mesh, a non-woven fabric layer, a glass fiber filter material, a non-woven fabric layer, and a galvanized folded wire mesh arranged in sequence from the outside to the inside.

10. The multi-stage gradient composite oil-gas separation filter according to claim 5, characterized in that: The fine separation layer includes a glass fiber winding layer, a first inner supporting perforated plate mesh, a cohesive guide cotton layer and a second inner supporting perforated plate mesh, which are arranged in sequence from the outside to the inside.

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