Diaphragm for diaphragm compressor and method for increasing service life of diaphragm

Abstract

The present invention discloses a diaphragm for a diaphragm compressor and a method for increasing the service life of the diaphragm, and relates to the field of diaphragm compressors. It includes: a substrate diaphragm; a first coating, the first coating covers one side of the substrate diaphragm, and this side is set as the oil side; a second coating, the second coating covers the side of the substrate diaphragm opposite to the first coating, and this side is set as the gas side; an intermediate layer, the intermediate layer is set between the first coating and the substrate diaphragm, and between the second coating and the substrate diaphragm; a first anti-corrosion coating, the first anti-corrosion coating covers the side of the first coating away from the substrate diaphragm; a second anti-corrosion coating, the second anti-corrosion coating covers the side of the second coating away from the substrate diaphragm. The present invention enhances the hardness of the diaphragm itself, as well as its wear resistance, strong acid and alkali resistance, and moisture and heat aging resistance.

Description

Technical Field

[0001] The invention relates to the field of diaphragm compressors, and in particular to a diaphragm for a diaphragm compressor and a method for increasing the service life of the diaphragm. Background Art

[0002] Diaphragm compressor is a special structure of positive displacement compressor, with large compression ratio, good sealing, compressed gas is not contaminated by lubricating oil and other solid impurities. It is widely used in compression and transmission of various high-purity, rare and precious, flammable and explosive, toxic and harmful, corrosive and high-pressure gases.

[0003] The specific working process of the diaphragm compressor is as follows: when the piston reaches the top dead center, the hydraulic oil pressure on the lower side of the diaphragm reaches the maximum value, and the diaphragm is close to the curved surface of the diaphragm cavity; as the piston moves downward, the diaphragm follows the hydraulic oil to move to the equilibrium position, the volume of the diaphragm cavity gradually increases, and the gas pressure gradually decreases. When the gas pressure is lower than the external pressure, the intake valve opens and air begins to enter; as the piston moves to the bottom dead center, the diaphragm partially fits with the lower support plate, and the air intake ends; then the piston starts to move upward and pushes the diaphragm to compress the gas through the hydraulic oil. When the pressure in the diaphragm cavity reaches the exhaust pressure, the exhaust valve opens and exhaust begins; finally, the diaphragm is pushed by the hydraulic oil to press against the curved surface of the diaphragm cavity, the exhaust ends, and a working cycle is completed in the diaphragm cavity.

[0004] Furthermore, for multi-stage compression diaphragm compressors, the compression ratio of each stage has been determined during engineering calculations and design. This compression ratio is determined by setting the maximum hydraulic oil pressure on the oil side of the diaphragm of each stage; the diaphragm specifications of each stage are selected and configured according to the design points of specific working conditions and capacities, the specifications of the intermediate stage and final exhaust gas coolers are designed and configured, and the crankcase specifications are configured according to the piston thrust and total crankshaft power.

[0005] If the intake pressure changes too much, it will not only cause a series of imbalances, but also cause the diaphragm to rupture frequently. Because when the back pressure is too low, due to the determined oil pressure on the oil side of the diaphragm, every time the piston pushes the diaphragm to move toward the gas side through the hydraulic oil, it will eventually cling to the curved surface of the diaphragm cavity on the gas side, which will greatly shorten the service life of the diaphragm.

[0006] Therefore, we can see that the relative stability of the intake pressure and exhaust pressure of the diaphragm compressor is the basic element to ensure the trouble-free and smooth operation of the diaphragm compressor. For a multi-stage compression diaphragm compressor, only by ensuring the relative stability of the intake pressure from the first stage can the relative stability of the intake pressure and exhaust pressure of the next stage be ensured, and the heat exchange balance and piston force balance of the multi-stage compression diaphragm compressor can be ensured.

[0007] In addition, the inherent characteristics of the diaphragm of the diaphragm compressor also determine the durability of the diaphragm. Therefore, the strength of the diaphragm should be continuously strengthened, and a method for increasing the service life of the diaphragm should be provided. Summary of the invention

[0008] The purpose of the present invention is to provide a diaphragm for a diaphragm compressor and a method for increasing the service life of the diaphragm, thereby solving the problem of diaphragm cracking caused by instability of intake pressure and exhaust pressure due to improper use during the operation of existing diaphragm compressors, as well as the hardness and corrosion resistance of the diaphragm itself not being up to standard.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A diaphragm for a diaphragm compressor, comprising:

[0011] Base film;

[0012] A first coating layer, wherein the first coating layer covers one side of the substrate film and the side is set as the oil side;

[0013] A second coating layer, wherein the second coating layer covers a side of the substrate film opposite to the first coating layer, and the side is set as a gas side;

[0014] An intermediate layer, the intermediate layer being disposed between the first coating layer and the substrate film, and between the second coating layer and the substrate film;

[0015] A first anti-corrosion coating, wherein the first anti-corrosion coating covers a side of the first coating away from the substrate film;

[0016] The second anti-corrosion coating is covered on a side of the second coating away from the substrate film.

[0017] The gas side, oil side and middle layer of the diaphragm of the present invention are made of different materials. Since the gas side and the oil side are in direct contact with gas and hydraulic oil, a first anti-corrosion coating is provided on the gas side, and a second anti-corrosion coating is provided on the oil side, and the substrate diaphragm is completely encapsulated by the first anti-corrosion coating and the second anti-corrosion coating. When applying the first coating, the second coating, and the first anti-corrosion coating and the second anti-corrosion coating on the diaphragm, it is only necessary to use a tool to evenly apply the coating on the substrate diaphragm in sequence, and ensure that the coating thickness is uniform and there is no bubble residue, and the coating process is not complicated.

[0018] It is worth mentioning that the smoothness of the diaphragm should be ensured. After the first anti-corrosion coating and the second anti-corrosion coating are applied, they are polished to ensure that the diaphragm surface is smooth and free of impurities to reduce stress concentration. According to the situation of the diaphragm compressor, the thickness of the diaphragm is strictly controlled. The thickness of the diaphragm is inversely proportional to the stress. The thickness of the diaphragm is set to 0.4mm-0.5mm.

[0019] Furthermore, the substrate diaphragm is a 316L stainless steel substrate diaphragm, or a Hastelloy substrate diaphragm, or a tantalum metal substrate diaphragm, or a nickel metal substrate diaphragm, or a titanium metal substrate diaphragm, or a zirconium metal substrate diaphragm, or a platinum metal substrate diaphragm.

[0020] There are many materials that can be used for the base diaphragm. Especially when the middle layer is a metal layer, it should be ensured that the middle layer is made of the same material as the base diaphragm, or a material with a similar thermal conductivity, to ensure that a large amount of heat will not accumulate inside the diaphragm during the operation of the diaphragm compressor, which is also a way to increase the service life of the diaphragm from the side. Of course, the most commonly used material for the base diaphragm is 316L stainless steel, which is a type of stainless steel containing molybdenum. The overall performance of 316L stainless steel is better than that of 310 stainless steel and 304 stainless steel. It has certain corrosion resistance, and the thermal conductivity of 316L stainless steel is about 16.2W / m·K at room temperature.

[0021] Furthermore, the first coating is a DLC coating, and the DLC coating is tetrahedral diamond-like carbon or amorphous hydrogenated diamond-like carbon.

[0022] Wherein, the second coating layer is the same as the first coating layer.

[0023] DLC coating is a material composed of carbon elements, similar to diamond in nature, and has a graphite atomic structure; it is an amorphous film, and is very suitable as a wear-resistant coating due to its high hardness and high elastic modulus, low friction factor, wear resistance and good vacuum tribological properties. DLC coating has excellent corrosion resistance, and it is difficult to be corroded by various acids, alkalis and even aqua regia.

[0024] Furthermore, the intermediate layer is a metal layer or an inorganic non-metal layer, the metal layer is titanium, or tantalum, or chromium; the inorganic non-metal layer is an alumina ceramic coating.

[0025] Furthermore, the first anti-corrosion coating includes a phenolic resin coating and a fluorocarbon coating arranged in sequence from inside to outside.

[0026] Among them, phenolic resin coating has good anti-corrosion performance and is resistant to acid, alkali and salt corrosion; fluorocarbon coating is a water-based two-component fluorocarbon coating obtained by using water-based fluorocarbon emulsion as the base material and combining it with water-based isocyanate curing agent. It has excellent weather resistance, adhesion and resistance to wet heat aging. According to the characteristics of the anti-corrosion material selected for the first anti-corrosion coating, it can be known that the first anti-corrosion coating is suitable for the oil side of the diaphragm.

[0027] Furthermore, the second anti-corrosion coating includes an epoxy resin coating and a two-component polyurethane coating which are sequentially arranged from the inside to the outside.

[0028] Among them, the epoxy resin coating has excellent resistance to concentrated acid, even 98% concentrated sulfuric acid, and is easy to apply, can be directly applied by brush or roller, and has excellent bonding properties; the two-component polyurethane coating has excellent properties such as low film-forming temperature, strong adhesion, good wear resistance, high hardness, chemical resistance, and good weather resistance. According to the characteristics of the anti-corrosion material selected for the second anti-corrosion coating, it can be known that the second anti-corrosion coating is suitable for the gas side of the diaphragm.

[0029] The present invention also provides a method for increasing the service life of a diaphragm, comprising the above-mentioned diaphragm, a control system and the following steps:

[0030] S1: A pressure reducing valve is arranged on an end of the air inlet pipeline of the diaphragm compressor away from the diaphragm compressor, and the pressure reducing valve is electrically connected to the control system;

[0031] S2: a back pressure valve is arranged at one end of the exhaust pipeline of the diaphragm compressor away from the diaphragm compressor, and the back pressure valve is electrically connected to the control system;

[0032] S3: Pressure transmitters are installed on both the oil side and the gas side of the diaphragm to convert the pressure data collected by the pressure transmitter into a standard electrical signal and transmit it to the control system;

[0033] S4: The control system performs feedback regulation on the pressure reducing valve and the back pressure valve.

[0034] Among them, a pressure reducing valve is set, and by adjusting the pressure reducing valve, the diaphragm compressor has a relatively stable intake pressure, and relying on the characteristics of the medium itself, the exhaust pressure is automatically kept stable. Then, relying on the adjustment of the control system, the pressure fluctuation after the pressure reducing valve is balanced with the spring force inside the diaphragm compressor, and the pressure fluctuation after the pressure reducing valve is limited to a certain range and kept constant within a certain error range.

[0035] Among them, a back-pressure valve is set, and by adjusting the back-pressure valve, the diaphragm compressor has a relatively stable exhaust pressure, and can play a role in cutting off and throttling; when the pressure of the pipeline or equipment container is unstable, the required pressure of the pipeline is maintained, and the pressure fluctuation after the back-pressure valve is limited to a certain range, and kept constant within a certain error range, so that the diaphragm compressor can have a normal output flow.

[0036] The electrical working process of the control system and the oil side pressure transmitter, gas side pressure transmitter, pressure reducing valve and back pressure valve is as follows: the oil side pressure transmitter and gas side pressure transmitter can collect the oil side pressure data and gas side pressure data in real time during the operation of the diaphragm compressor, and convert the oil side pressure data and gas side pressure data into their own standard electrical signals, and transmit the standard electrical signals to the control system. After receiving the standard electrical signal, the control system adjusts the pressure on the side that generates the standard electrical signal according to a preset threshold value, that is, if the gas side pressure data is larger, the pressure reducing valve is started to regulate the inlet pressure; if the oil side pressure data is larger, the back pressure valve is started to regulate the outlet pressure.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. The present invention relates to a diaphragm for a diaphragm compressor and a method for increasing the service life of the diaphragm. A new coating is applied to the surface of the diaphragm, and an anti-corrosion coating is added to enhance the hardness of the diaphragm itself, as well as its wear resistance, strong acid and alkali resistance, and wet heat aging resistance. During the processing, the diaphragm surface is ensured to be smooth and free of impurities to reduce stress concentration. The design life of the diaphragm is 5000-8000 hours.

[0039] 2. The present invention provides a diaphragm for a diaphragm compressor and a method for increasing the service life of the diaphragm. A control system is provided, as well as an oil-side pressure transmitter, a gas-side pressure transmitter, a pressure reducing valve, and a back pressure valve electrically connected to the control system. The pressure data collected by the pressure transmitter is converted into an electrical signal and then transmitted to the control system. The control system performs feedback adjustment on the pressure reducing valve and the back pressure valve to control the intake pressure and the exhaust pressure to remain constant within a certain error range. The service life of the diaphragm of the diaphragm compressor is increased from a good and healthy use method. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0041] Figure 1 is a schematic diagram of a diaphragm of the present invention;

[0042] Figure 2 It is a workflow diagram of the control system of the present invention;

[0043] In the figure, 1-substrate membrane, 2-first coating, 3-second coating, 4-intermediate layer, 5-first anti-corrosion coating, 6-second anti-corrosion coating. Implementation

[0044] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0045] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0046] Combine the following Figure 1 The present invention is described in detail.

[0047] Example 1

[0048] A diaphragm for a diaphragm compressor, such as Figure 1 As shown, including:

[0049] Base film 1;

[0050] A first coating layer 2, wherein the first coating layer 2 covers one side of the substrate film 1 and the side is set as the oil side;

[0051] A second coating layer 3, the second coating layer 3 covers a side of the substrate film 1 opposite to the first coating layer 2, and the side is set as the gas side;

[0052] An intermediate layer 4, wherein the intermediate layer 4 is disposed between the first coating layer 2 and the substrate film 1, and between the second coating layer 3 and the substrate film 1;

[0053] A first anti-corrosion coating 5, wherein the first anti-corrosion coating 5 covers a side of the first coating 2 away from the substrate film 1;

[0054] The second anti-corrosion coating 6 covers a side of the second coating 3 away from the substrate film 1 .

[0055] The gas side, oil side and middle layer 4 of the diaphragm of the present invention are made of different materials respectively. Since the gas side and the oil side are in direct contact with gas and hydraulic oil, a first anti-corrosion coating 5 is provided on the gas side, and a second anti-corrosion coating 6 is provided on the oil side, and the substrate diaphragm 1 is completely encapsulated by the first anti-corrosion coating 5 and the second anti-corrosion coating 6. When the first coating 2, the second coating 3, and the first anti-corrosion coating 5 and the second anti-corrosion coating 6 are coated on the diaphragm, it is only necessary to use a tool to evenly apply the coating on the substrate diaphragm 1 in sequence, and ensure that the coating thickness is uniform and there is no bubble residue, and the coating process is not complicated.

[0056] Example 2

[0057] This embodiment is a supplementary explanation of Embodiment 1.

[0058] It is worth mentioning that the smoothness of the diaphragm should be ensured. After the first anti-corrosion coating 5 and the second anti-corrosion coating 6 are applied, they are polished to ensure that the surface of the diaphragm is smooth and free of impurities to reduce stress concentration. According to the situation of the diaphragm compressor, the thickness of the diaphragm is strictly controlled. The thickness of the diaphragm is inversely proportional to the stress. The thickness of the diaphragm is set to 0.4mm-0.5mm.

[0059] Example 3

[0060] The substrate diaphragm 1 is a 316L stainless steel substrate diaphragm, or a Hastelloy substrate diaphragm, or a tantalum metal substrate diaphragm, or a nickel metal substrate diaphragm, or a titanium metal substrate diaphragm, or a zirconium metal substrate diaphragm, or a platinum metal substrate diaphragm.

[0061] There are many materials that can be used for the substrate diaphragm 1. Especially when the middle layer 4 is a metal layer, it should be ensured that the middle layer 4 is made of the same material as the substrate diaphragm 1, or a material with a similar thermal conductivity, to ensure that a large amount of heat will not accumulate inside the diaphragm during the operation of the diaphragm compressor, which is also a method to increase the service life of the diaphragm from the side. Of course, the most commonly used material for the substrate diaphragm 1 is 316L stainless steel, which is a type of stainless steel containing molybdenum, and the overall performance of 316L stainless steel is better than 310 stainless steel and 304 stainless steel, and has certain corrosion resistance, and the thermal conductivity of 316L stainless steel is about 16.2W / m·K at room temperature.

[0062] Example 4

[0063] The first coating 2 is a DLC coating, and the DLC coating is tetrahedral diamond-like carbon or amorphous hydrogenated diamond-like carbon.

[0064] The second coating layer 3 is the same as the first coating layer 2 .

[0065] DLC coating is a material composed of carbon elements, similar to diamond in nature, and has a graphite atomic structure; it is an amorphous film, and is very suitable as a wear-resistant coating due to its high hardness and high elastic modulus, low friction factor, wear resistance and good vacuum tribological properties. DLC coating has excellent corrosion resistance, and it is difficult to be corroded by various acids, alkalis and even aqua regia.

[0066] Example 5

[0067] The first anti-corrosion coating 5 includes a phenolic resin coating and a fluorocarbon coating arranged in sequence from the inside to the outside.

[0068] Among them, the phenolic resin coating has good anti-corrosion performance and is resistant to acid, alkali and salt corrosion; the fluorocarbon coating is a water-based two-component fluorocarbon coating obtained by using water-based fluorocarbon emulsion as the base material and combining it with water-based isocyanate curing agent, which has excellent weather resistance, adhesion and resistance to wet heat aging. According to the characteristics of the anti-corrosion material selected for the first anti-corrosion coating 5, it can be known that the first anti-corrosion coating 5 is suitable for the oil side of the diaphragm.

[0069] Example 6

[0070] The second anti-corrosion coating 6 includes an epoxy resin coating and a two-component polyurethane coating which are sequentially arranged from the inside to the outside.

[0071] Among them, the epoxy resin coating has excellent concentrated acid resistance, even 98% concentrated sulfuric acid, and is easy to apply, can be directly applied by brush or roller, and has excellent bonding properties; the two-component polyurethane coating has excellent properties such as low film-forming temperature, strong adhesion, good wear resistance, high hardness, and good chemical resistance and weather resistance. According to the characteristics of the anti-corrosion material selected for the second anti-corrosion coating 6, it can be known that the second anti-corrosion coating 6 is suitable for the gas side of the diaphragm.

[0072] Example 7

[0073] A method for increasing the service life of a diaphragm comprises the above-mentioned diaphragm, a control system and the following steps:

[0074] S1: A pressure reducing valve is arranged on an end of the air inlet pipeline of the diaphragm compressor away from the diaphragm compressor, and the pressure reducing valve is electrically connected to the control system;

[0075] S2: a back pressure valve is arranged at one end of the exhaust pipeline of the diaphragm compressor away from the diaphragm compressor, and the back pressure valve is electrically connected to the control system;

[0076] S3: Pressure transmitters are installed on both the oil side and the gas side of the diaphragm to convert the pressure data collected by the pressure transmitter into a standard electrical signal and transmit it to the control system;

[0077] S4: The control system performs feedback regulation on the pressure reducing valve and the back pressure valve.

[0078] Among them, a pressure reducing valve is set, and by adjusting the pressure reducing valve, the diaphragm compressor has a relatively stable intake pressure, and relying on the characteristics of the medium itself, the exhaust pressure is automatically kept stable. Then, relying on the adjustment of the control system, the pressure fluctuation after the pressure reducing valve is balanced with the spring force inside the diaphragm compressor, and the pressure fluctuation after the pressure reducing valve is limited to a certain range and kept constant within a certain error range.

[0079] Among them, a back-pressure valve is set, and by adjusting the back-pressure valve, the diaphragm compressor has a relatively stable exhaust pressure, and can play a role in cutting off and throttling; when the pressure of the pipeline or equipment container is unstable, the required pressure of the pipeline is maintained, and the pressure fluctuation after the back-pressure valve is limited to a certain range, and kept constant within a certain error range, so that the diaphragm compressor can have a normal output flow.

[0080] Example 8

[0081] This embodiment is a supplementary explanation of Embodiment 7.

[0082] like Figure 2 As shown, the electrical working process of the control system and the oil side pressure transmitter, the gas side pressure transmitter, the pressure reducing valve and the back pressure valve is as follows: the oil side pressure transmitter and the gas side pressure transmitter can collect the oil side pressure data and the gas side pressure data in real time during the operation of the diaphragm compressor, and convert the oil side pressure data and the gas side pressure data into their own standard electrical signals, and transmit the standard electrical signals to the control system. After receiving the standard electrical signal, the control system adjusts the pressure on the side that generates the standard electrical signal according to a preset threshold value, that is, if the gas side pressure data is larger, the pressure reducing valve is started to regulate the inlet pressure, and if the oil side pressure data is larger, the back pressure valve is started to regulate the outlet pressure.

[0083] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by a person skilled in the art within the technical scope disclosed by the present invention without creative work should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A diaphragm for a diaphragm compressor, characterized in that: include: A substrate film (1), a first coating (2), wherein the first coating (2) covers one side of the substrate film (1) and the side is set as the oil side; a second coating (3), wherein the second coating (3) covers the side of the substrate film (1) opposite to the first coating (2) and the side is set as the gas side; an intermediate layer (4), wherein the intermediate layer (4) is arranged between the first coating (2) and the substrate film (1), and between the second coating (3) and the substrate film (1); a first anti-corrosion coating (5), wherein the first anti-corrosion coating (5) covers the side of the first coating (2) away from the substrate film (1); and a second anti-corrosion coating (6), wherein the second anti-corrosion coating (6) covers the side of the second coating (3) away from the substrate film (1); The substrate diaphragm (1) is a 316L stainless steel substrate diaphragm, or a Hastelloy substrate diaphragm, or a tantalum metal substrate diaphragm, or a nickel metal substrate diaphragm, or a titanium metal substrate diaphragm, or a zirconium metal substrate diaphragm, or a platinum metal substrate diaphragm; The first coating (2) is a DLC coating, and the DLC coating is tetrahedral diamond-like carbon or amorphous hydrogenated diamond-like carbon; The second coating (3) is the same as the first coating (2); The intermediate layer (4) is a metal layer or an inorganic non-metal layer, the metal layer is titanium, tantalum, or chromium; the inorganic non-metal layer is an aluminum oxide ceramic coating; The first anti-corrosion coating (5) comprises a phenolic resin coating and a fluorocarbon coating arranged in sequence from the inside to the outside; The second anti-corrosion coating (6) comprises an epoxy resin coating and a two-component polyurethane coating which are sequentially arranged from the inside to the outside.

2. A method for increasing the service life of a diaphragm, characterized in that: The method comprises the membrane according to claim 1, further comprising a control system and the following steps: S1: A pressure reducing valve is arranged on an end of the air inlet pipeline of the diaphragm compressor away from the diaphragm compressor, and the pressure reducing valve is electrically connected to the control system; S2: a back pressure valve is arranged at one end of the exhaust pipeline of the diaphragm compressor away from the diaphragm compressor, and the back pressure valve is electrically connected to the control system; S3: Pressure transmitters are installed on both the oil side and the gas side of the diaphragm to convert the pressure data collected by the pressure transmitter into a standard electrical signal and transmit it to the control system; S4: The control system performs feedback regulation on the pressure reducing valve and the back pressure valve.

Images