Method for removing bubbles in grease

Abstract

The invention discloses a method for removing bubbles in grease. The method comprises the following steps: inputting high-pressure grease; reducing the pressure of the high-pressure grease to be less than 10bar through a precise pressure reducing valve, so as to increase the volume of bubbles in the grease by utilizing the reduction of the pressure intensity; detecting the depressurized grease by using a bubble detection sensor, and judging whether bubbles exist or not; if no bubble is detected, the grease enters a bubble-free grease collecting tank through a direction switching valve; if bubbles are detected, the grease enters a grease collector with the bubbles through a direction switching valve; bubble-free grease is stored in the bubble-free grease collecting tank; the pneumatic oil pump is used for pressurizing the grease in the bubble-free grease collecting tank to be larger than 100 bar, and then the pressurized grease is output to the lubricating oil system. The whole process is efficient and accurate, bubbles in grease can be rapidly removed, it is guaranteed that the grease amount of a lubricating oil system is stable, and the requirements of the lubricating oil system for grease supply timeliness and accuracy can be met.

Description

Technical Field

[0001] The invention relates to the field of grease treatment, in particular to a grease bubble removal method. Background Art

[0002] In many mechanical devices, the lubrication system plays a vital role. It is responsible for providing lubrication for mechanical parts, reducing friction and wear, thereby extending the service life of mechanical parts and improving the overall performance and efficiency of mechanical devices. For example, in the operation of large industrial equipment such as engines and machine tools, the lubrication system continuously provides grease lubrication for various key moving parts. However, the lubrication system has strict requirements on the quality and supply of grease.

[0003] At present, there are some conventional methods for dealing with the problem of bubbles in grease in lubrication systems. For example, some existing technologies use a simple static method to remove bubbles in grease. This method is to place the grease containing bubbles in a container and wait for a period of time to allow the bubbles to naturally rise to the surface of the grease and burst and disappear.

[0004] The static method requires a long time to basically remove the bubbles, which cannot meet the needs of the oil supply timeliness of the lubrication system. For example, in a continuously running industrial production line, if the static method is used to remove bubbles, it may cause the oil supply to be interrupted, affecting production efficiency.

[0005] Due to the viscosity and other characteristics of grease, some tiny bubbles may still be suspended in the grease and cannot be effectively removed simply by leaving it to stand. These residual bubbles will cause the grease amount to be unstable after entering the lubrication system. Because bubbles occupy a certain space, the volume of the grease will expand under normal pressure, thus affecting the lubrication system's requirement for precise grease supply. For example, in high-precision machining equipment, inaccurate lubrication amount may lead to reduced machining accuracy and increase the defective rate of products. Summary of the invention

[0006] The object of the present invention is to provide a method for removing bubbles from grease to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for removing bubbles from grease comprises the following steps:

[0009] Step S1, inputting high-pressure grease;

[0010] Step S2, reducing the pressure of the high-pressure grease to less than 10 bar by a precision pressure reducing valve, so as to increase the volume of bubbles in the grease by reducing the pressure;

[0011] Step S3, using a bubble detection sensor to detect the depressurized grease to determine whether there are bubbles;

[0012] Step S4, if no bubbles are detected, the grease is allowed to enter the bubble-free grease collection tank through the direction switching valve; if bubbles are detected, the grease is allowed to enter the bubble grease collector through the direction switching valve;

[0013] Step S5, storing the bubble-free grease in a bubble-free grease collection tank;

[0014] Step S6, using a pneumatic oil pump to pressurize the grease in the bubble-free grease collection tank to a pressure greater than 100 bar, and then output the pressurized grease to the lubrication system.

[0015] In the present invention, in step S2, the precision of the precision pressure reducing valve is ±0.5 bar, and the grease pressure can be stably controlled within a range of less than 10 bar to ensure that the bubble volume increases to a level that can be accurately detected. The ideal gas state formula is as follows:

[0016] PV=nRT

[0017] Wherein, P represents pressure, which is the pressure of grease in the process of reducing pressure of the precision pressure reducing valve, and the unit is Pascal; V represents volume, which is the volume of the bubbles in the grease, and the unit is cubic meter; n represents the amount of substance, which is related to the amount of substance of the gas in the bubble in step S2, and the unit is mole; R is the molar gas constant, R=8.314J / (mol·k); T represents temperature, which is the temperature of the environment in which the grease and the bubbles are located, and the unit is Kelvin.

[0018] In the present invention, in step S3, the bubble detection sensor adopts an optical detection principle or a capacitive detection principle, specifically including:

[0019] In step S301, when the optical detection principle is adopted, the bubbles are detected by emitting light through the grease according to the difference in refraction and scattering of the light in the grease with bubbles and without bubbles. The wavelength range of the light is 400-700nm, and the relationship between the light intensity and the bubbles is as follows:

[0020] I=I0e αL

[0021] Among them, I represents the light intensity after passing through the grease containing bubbles, the unit is candela, I0 represents the initial emission light intensity, the unit is candela, α represents the attenuation coefficient related to the bubbles, which is related to the size, number and distribution of the bubbles, and L represents the thickness of the grease layer, the unit is meter;

[0022] In step S302, when the capacitance detection principle is adopted, the difference in dielectric constant between bubbles and grease is used to detect bubbles. The capacitance measurement accuracy of the capacitance detection sensor is ±0.1pF, and the capacitor capacitance formula is as follows;

[0023]

[0024] Among them, C represents capacitance, that is, the capacitance value measured by the capacitance detection sensor, in farads, ∈ represents the dielectric constant, which will change when there are bubbles in the grease, S represents the area of ​​the capacitor plates, in square meters, and d represents the distance between the capacitor plates, in meters.

[0025] In the present invention, in step S4, the bubble-free grease collection tank is a sealed structure, and is provided with a structure inside to prevent the grease from shaking and generating new bubbles. The structure to prevent the grease from shaking and generating new bubbles is a plurality of baffles vertically arranged along the tank wall, and the distance between the baffles is 5 to 10 cm.

[0026] In the present invention, in step S6, the pneumatic oil pump has a stable pressurizing capability and can stably pressurize the bubble-free grease to a pressure greater than 100 bar and less than 150 bar to meet the requirements of the lubrication system for grease pressure. The pressure fluctuation range of the pneumatic oil pump is ±5 bar.

[0027] In the present invention, in step S4, the directional switching valve can quickly and accurately switch the flow direction of the grease within 0.5 seconds according to the detection result of the bubble detection sensor, ensuring that the bubble-free grease enters the bubble-free grease collection tank and the bubble-containing grease enters the bubble-containing grease collector, and the switching error rate of the directional switching valve is less than 1%.

[0028] In the present invention, the pressure range of the input high-pressure grease is 150-300 bar.

[0029] In the present invention, a defoaming structure is provided inside the bubble grease collector, and the defoaming structure is a spiral guide channel, which is used to burst bubbles when the bubble-containing grease flows in the channel, and the pitch of the spiral guide channel is 3 to 5 cm.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention first inputs high-pressure grease, then reduces the pressure of the high-pressure grease to less than 10 bar through a precision pressure reducing valve, and utilizes the pressure reduction to increase the volume of bubbles in the grease, so that tiny bubbles that were originally difficult to detect and remove can become easier to handle, and then a bubble detection sensor is used to detect the reduced-pressure grease, so as to accurately determine whether there are bubbles, and according to the detection result, the grease is respectively directed to a bubble-free grease collection tank and a bubble-containing grease collector through a direction switching valve to ensure that the bubble-free grease enters the oil lubrication system, and finally a pneumatic oil pump is used to pressurize the grease in the bubble-free grease collection tank to more than 100 bar and then output it to the oil lubrication system. The whole process is efficient and accurate, and can not only quickly remove bubbles in the grease and ensure the stability of the grease amount in the oil lubrication system, but also meet the requirements of the oil lubrication system for the timeliness and accuracy of grease supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a schematic flow chart of a method for removing bubbles from grease. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1 , the present invention provides a technical solution:

[0035] A method for removing bubbles from grease comprises the following steps:

[0036] Step S1, inputting high-pressure grease; the pressure range of the input high-pressure grease is 150-300 bar;

[0037] Step S2, reducing the pressure of high-pressure grease to less than 10 bar by a precision pressure reducing valve, so as to increase the volume of bubbles in the grease by reducing the pressure; the precision pressure reducing valve has an accuracy of ±0.5 bar, and can stably control the grease pressure within a range of less than 10 bar to ensure that the volume of bubbles increases to a level that can be accurately detected. The ideal gas state formula is as follows;

[0038] PV=nRT

[0039] Among them, P represents pressure, which is the pressure of the grease during the pressure reduction process of the precision pressure reducing valve, with the unit of Pascal; V represents volume, which is the volume of the bubble in the grease, with the unit of cubic meter; n represents the amount of substance, which is related to the amount of gas in the bubble in step S2, with the unit of mole; R is the molar gas constant, R = 8.314 J / (mol·K); T represents temperature, which is the temperature of the environment where the grease and the bubble are located, with the unit of Kelvin;

[0040] In this step, it is assumed that in a closed micro-space, the bubble in the grease can be approximately regarded as an ideal gas. There is no mass exchange between this micro-space and the outside world, and only heat exchange occurs to maintain a relatively stable temperature.

[0041] First, assume that the initial pressure of the bubble is P1, the volume is V1, the amount of substance is n, and the temperature is T (since it is assumed that there is heat exchange with the outside world to maintain a stable temperature, the temperature remains unchanged). According to the ideal gas state equation, at this time, P1V1 = nRT.

[0042] Then, when the grease passes through the precision pressure reducing valve and the pressure drops to P2 (P2 < P1 and P2 < 10 bar). Since the temperature T and the amount of substance n remain unchanged (because there is no gas inlet or outlet, that is, the amount of substance remains unchanged, and it is assumed that the temperature is stable), according to the ideal gas state equation, P2V2 = nRT.

[0043] Next, from P1V1 = P2V2 (because nRT remains unchanged), we can obtain This indicates that when the pressure decreases, the volume V of the bubble will increase.

[0044] The specific calculation steps of the ideal gas state formula are as follows:

[0045] Input the initial pressure P1, the initial volume V1, and the target pressure P2.

[0046] According to the formula Calculate the volume V2 of the bubble after pressure reduction.

[0047] Compare V2 with the initial volume V1 to verify whether the volume increases to ensure that the pressure reduction operation achieves the purpose of increasing the bubble volume.

[0048] In step S3, use a bubble detection sensor to detect the grease after pressure reduction to determine whether there are bubbles; the bubble detection sensor adopts an optical detection principle or a capacitance detection principle, specifically including:

[0049] In step S301, when the optical detection principle is adopted, emit light through the grease, and detect the bubbles according to the differences in refraction and scattering of light in the grease with bubbles and without bubbles. The wavelength range of the light is 400 - 700 nm, and the relationship between the light intensity and the bubbles is as follows:

[0050] I=I0e αL

[0051] Among them, I represents the light intensity after passing through the grease containing bubbles, the unit is candela, I0 represents the initial emission light intensity, the unit is candela, α represents the attenuation coefficient related to the bubbles, which is related to the size, number and distribution of the bubbles, and L represents the thickness of the grease layer, the unit is meter;

[0052] In the above step S301, it is assumed that the light passes vertically through the grease layer, the distribution of bubbles in the grease layer is relatively uniform, and the absorption and scattering effects of the bubbles on the light can be represented by the attenuation coefficient α.

[0053] First, when there are no bubbles in the grease, let the initial light intensity be I0. After passing through the grease layer with a thickness of L, the light intensity will attenuate due to the absorption of the grease. Assuming that the attenuation coefficient when there are no bubbles is α0, then the light intensity after passing through the grease is

[0054] Then, when there are bubbles in the grease, the bubbles will increase the attenuation of the light. If the attenuation coefficient at this time becomes α (α>α0), then the light intensity after passing through the bubble-containing grease is I=I0e -αL .

[0055] Next, the change in light intensity By detecting the light intensity change ΔI, it is possible to determine whether bubbles exist.

[0056] The specific calculation steps of the relationship between light intensity and bubbles are as follows:

[0057] Measure the thickness K of the grease layer when there are no bubbles, record the initial light intensity I0, and determine the attenuation coefficient when there are no bubbles.

[0058] When performing bubble detection, measure the light intensity I after passing through the grease again.

[0059] According to the formula Calculate the light intensity change ΔI.

[0060] Set a threshold ΔI th , if ΔI th >ΔI th , it is judged that there are bubbles; otherwise, it is judged that there are no bubbles.

[0061] In step S302, when the capacitance detection principle is adopted, the difference in dielectric constant between bubbles and grease is used to detect bubbles. The capacitance measurement accuracy of the capacitance detection sensor is ±0.1pF, and the capacitor capacitance formula is as follows;

[0062]

[0063] Where, C represents capacitance, i.e., the capacitance value measured by the capacitance detection sensor, in farads, ∈ represents the dielectric constant, which will change when there are bubbles in the grease, S represents the area of ​​the capacitor plates, in square meters, and d represents the distance between the capacitor plates, in meters;

[0064] In the above step S302, it is assumed that in the capacitance detection sensor, the mixed medium composed of grease and bubbles can be regarded as the dielectric in the parallel plate capacitor, and the plate area S and the plate distance d remain unchanged.

[0065] First, when there are no bubbles in the grease, let the dielectric constant of the grease be ∈0. According to the capacitance formula, the capacitance is

[0066] Then, when there are bubbles in the grease, since the dielectric constant of the bubbles is different from that of the grease, the equivalent dielectric constant of the mixed medium is assumed to become ∈(∈≠∈0), and the capacitance becomes

[0067] Next, the change in capacitance By detecting the change in capacitance, it is possible to determine whether bubbles exist.

[0068] The specific steps for calculating the capacitance of a capacitor are as follows:

[0069] Measure the dielectric constant of grease ∈0 when there are no bubbles. Given the plate area S and the plate spacing d, calculate the capacitance when there are no bubbles.

[0070] When the bubble detection is performed, the capacitance C at that time is measured.

[0071] According to the formula Calculate the capacitance change ΔC.

[0072] Set a threshold ΔC th , if Δc>ΔC th , it is judged that there are bubbles; otherwise, it is judged that there are no bubbles.

[0073] Step S4, if no bubbles are detected, the grease is allowed to enter the bubble-free grease collection tank through the direction switching valve; if bubbles are detected, the grease is allowed to enter the bubble grease collector through the direction switching valve; the bubble-free grease collection tank is a sealed structure, and a structure is provided inside to prevent the grease from shaking and generating new bubbles, and the structure to prevent the grease from shaking and generating new bubbles is a plurality of baffles vertically arranged along the tank wall, and the distance between the baffles is 5 to 10 cm; the direction switching valve can quickly and accurately switch the flow direction of the grease within 0.5 seconds according to the detection result of the bubble detection sensor, to ensure that the bubble-free grease enters the bubble-free grease collection tank, and the bubble-containing grease enters the bubble grease collector, and the switching error rate of the direction switching valve is less than 1%; the bubble grease collector is provided with a defoaming structure, and the defoaming structure is a spiral guide channel, which is used to make the bubbles burst when the bubble-containing grease flows in the channel, and the pitch of the spiral guide channel is 3 to 5 cm;

[0074] Step S5, storing the bubble-free grease in a bubble-free grease collection tank;

[0075] Step S6, use a pneumatic oil pump to pressurize the grease in the bubble-free grease collection tank to a pressure greater than 100 bar, and then output the pressurized grease to the lubrication system; the pneumatic oil pump has a stable pressurization capacity, and can stably pressurize the bubble-free grease to a pressure greater than 100 bar and less than 150 bar to meet the lubrication system's requirements for grease pressure, and the pressure fluctuation range of the pneumatic oil pump is ±5 bar.

[0076] It should be noted that, in this article, relational terms such as first and second, etc. are only used 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.

[0077] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for removing bubbles from grease, characterized in that: The following steps are involved: Step S1, inputting high-pressure grease; Step S2, reducing the pressure of the high-pressure grease to less than 10 bar by a precision pressure reducing valve, so as to increase the volume of bubbles in the grease by reducing the pressure; Step S3, using a bubble detection sensor to detect the depressurized grease to determine whether there are bubbles; Step S4, if no bubbles are detected, the grease is allowed to enter the bubble-free grease collection tank through the direction switching valve; if bubbles are detected, the grease is allowed to enter the bubble grease collector through the direction switching valve; Step S5, storing the bubble-free grease in a bubble-free grease collection tank; Step S6, using a pneumatic oil pump to pressurize the grease in the bubble-free grease collection tank to a pressure greater than 100 bar, and then output the pressurized grease to the lubrication system.

2. A method for removing bubbles from grease according to claim 1, characterized in that: In step S2, the precision of the precision pressure reducing valve is ±0.5 bar, and the grease pressure can be stably controlled within a range of less than 10 bar to ensure that the bubble volume increases to a level that can be accurately detected. The ideal gas state formula is as follows: PV=nRT Wherein, P represents pressure, which is the pressure of grease in the process of reducing pressure of the precision pressure reducing valve, and the unit is Pascal; V represents volume, which is the volume of the bubbles in the grease, and the unit is cubic meter; n represents the amount of substance, which is related to the amount of substance of the gas in the bubble in step S2, and the unit is mole; R is the molar gas constant, R=8.314J / (mol·k); T represents temperature, which is the temperature of the environment in which the grease and the bubbles are located, and the unit is Kelvin.

3. A method for removing bubbles from grease according to claim 1, characterized in that: In step S3, the bubble detection sensor adopts an optical detection principle or a capacitive detection principle, specifically including: In step S301, when the optical detection principle is adopted, the bubbles are detected by emitting light through the grease according to the difference in refraction and scattering of the light in the grease with bubbles and without bubbles. The wavelength range of the light is 400-700nm, and the relationship between the light intensity and the bubbles is as follows: I=I0e αL Among them, I represents the light intensity after passing through the grease containing bubbles, the unit is candela, I0 represents the initial emission light intensity, the unit is candela, α represents the attenuation coefficient related to the bubbles, which is related to the size, number and distribution of the bubbles, and L represents the thickness of the grease layer, the unit is meter; In step S302, when the capacitance detection principle is adopted, the difference in dielectric constant between bubbles and grease is used to detect bubbles. The capacitance measurement accuracy of the capacitance detection sensor is ±0.1pF, and the capacitor capacitance formula is as follows; Among them, C represents capacitance, that is, the capacitance value measured by the capacitance detection sensor, in farads, ∈ represents the dielectric constant, which will change when there are bubbles in the grease, S represents the area of ​​the capacitor plates, in square meters, and d represents the distance between the capacitor plates, in meters.

4. A method for removing bubbles from grease according to claim 1, characterized in that: In step S4, the bubble-free grease collection tank is a sealed structure and is provided with a structure inside to prevent the grease from shaking and generating new bubbles. The structure to prevent the grease from shaking and generating new bubbles is a plurality of baffles vertically arranged along the tank wall, and the distance between the baffles is 5 to 10 cm.

5. A method for removing bubbles from grease according to claim 1, characterized in that: In step S6, the pneumatic oil pump has a stable pressurizing capability and can stably pressurize the bubble-free grease to a pressure greater than 100 bar and less than 150 bar to meet the grease pressure requirement of the lubrication system. The pressure fluctuation range of the pneumatic oil pump is ±5 bar.

6. A method for removing bubbles from grease according to claim 1, characterized in that: In step S4, the directional switching valve can quickly and accurately switch the flow direction of the grease within 0.5 seconds according to the detection result of the bubble detection sensor, ensuring that the bubble-free grease enters the bubble-free grease collection tank and the bubble-containing grease enters the bubble-containing grease collector, and the switching error rate of the directional switching valve is less than 1%.

7. A method for removing bubbles from grease according to claim 1, characterized in that: The pressure range of the input high-pressure grease is 150-300 bar.

8. A method for removing bubbles from grease according to claim 1, characterized in that: The bubble grease collector is provided with a defoaming structure inside. The defoaming structure is a spiral guide channel, which is used to burst bubbles when the bubble-containing grease flows in the channel. The pitch of the spiral guide channel is 3 to 5 cm.

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