A vacuum drying system

Abstract

The present invention provides a vacuum drying system, comprising: a vacuum box, a degassing pipeline, a deoiling pipeline, a vacuum pump, an infrared heating device, a vacuum gauge and an oil and gas filtering device; a first air suction port is arranged on the top of the vacuum box, and a second air suction port is arranged on the bottom, the degassing pipeline connects the first air suction port with the vacuum pump, and the deoiling pipeline connects the second air suction port, the oil and gas filtering device and the vacuum pump in sequence; during drying, the vacuum pump extracts the gas in the vacuum box from the first air suction port, and when the vacuum box reaches a preset vacuum degree, the vacuum pump extracts the gas in the vacuum box from the second air suction port. The vacuum drying system of the present invention first quickly extracts a large amount of air in the extraction box without passing through the oil and gas filtering device, and then performs fine extraction and filtration to collect oil and gas, so as to prevent the gas flow from carrying out volatile oil and gas in the deoiling pipeline and the oil and gas filtering device.

Description

Technical Field

[0001] The invention relates to the field of vacuum technology, and in particular to a vacuum drying system. Background Art

[0002] After stamping and before welding, the fin heat exchanger needs to dry the volatile stamping oil remaining on the fin surface after stamping to prevent affecting the welding quality. The original drying method uses hot air drying, which cannot meet the exhaust emission requirements.

[0003] In ordinary vacuum infrared drying devices, oil and gas are extracted by a vacuum pump, and filtered and collected by a filter device installed on the vacuum pipeline. Usually, when the vacuum is started, most of the vacuum box contains no or very little oil and gas. At this time, the vacuum pump needs to extract a large amount of air quickly, causing these gases to bring out a large amount of volatile oil and gas in the filter device, affecting the filtering and collection of the stamping oil and the operation of the vacuum pump. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art and provide a vacuum drying system.

[0005] One embodiment of the present invention provides a vacuum drying system, comprising: a vacuum box, a degassing pipeline, an oil removal pipeline, a vacuum pump, an infrared heating device, a vacuum gauge and an oil and gas filtering device;

[0006] The vacuum box is provided with a first air extraction port on the top and a second air extraction port on the bottom. The degassing pipeline is provided with a first valve, which connects the first air extraction port with the vacuum pump. The deoiling pipeline is provided with a second valve, which sequentially connects the second air extraction port, the oil and gas filtering device and the vacuum pump. The infrared heating device is provided in the vacuum box. The vacuum gauge is connected to the inside of the vacuum box to detect the vacuum degree in the vacuum box.

[0007] During drying, the infrared heating device, the first valve and the vacuum pump are turned on, and the second valve is closed. The vacuum pump extracts the gas in the vacuum box from the first air suction port. When the vacuum box reaches a preset vacuum degree, the first valve is closed, the second valve is opened, and the vacuum pump extracts the gas in the vacuum box from the second air suction port.

[0008] Compared with the prior art, the vacuum drying system of the present invention first quickly extracts a large amount of air in the box without passing through the oil and gas filtering device, and then performs fine extraction and filtration to collect oil and gas, thereby avoiding the volatile oil and gas in the oil removal pipeline and the oil and gas filtering device being brought out by the gas flow, resulting in a reduction in the filtering and collecting effect of the oil and gas filtering device on the stamping oil and the influence of the oil and gas on the operation of the vacuum pump.

[0009] Further, it also includes a first air filter;

[0010] The degassing pipeline is connected to the first air extraction port, the first air filter and the vacuum pump in sequence. A small amount of oil, gas, solid impurities and particles in the air in the vacuum box are filtered through the first air filter.

[0011] Further, it also includes a second air filter;

[0012] The oil removal pipeline is connected to the second air extraction port, the oil and gas filtering device, the second air filter and the vacuum pump in sequence. A small amount of volatile oil and gas will be brought out in fine extraction and further filtered through the second air filter.

[0013] Furthermore, the second air filter is located at a higher level than the oil and gas filter device. A small amount of stamping oil filtered can flow back to the oil and gas filter device for collection.

[0014] Furthermore, the oil and gas filtering device is located at a lower level than the vacuum box, and a height difference is formed between the oil and gas filtering device and the vacuum box to prevent the oil and gas from condensing and flowing back into the vacuum box.

[0015] Furthermore, the bottom of the vacuum box is funnel-shaped, which is more conducive to extracting oil and gas and making it easier for liquid oil to flow out.

[0016] Furthermore, the oil and gas filtering device comprises a body and a filter element, wherein a cavity is formed in the body, the cavity is provided with an air inlet, an air outlet and an oil outlet, and the filter element is arranged in the cavity and located between the air inlet and the air outlet;

[0017] The air inlet is communicated with the second air extraction port, and the air outlet is communicated with the vacuum pump.

[0018] Furthermore, the filter element is cylindrical and vertically arranged in the cavity, dividing the cavity into an inner cavity and an outer cavity, the air inlet is located at the top of the inner cavity, the oil outlet is located at the bottom of the inner cavity, and the air outlet is connected to the outer cavity, thereby increasing the filtering area of ​​the oil and gas and improving the filtering effect.

[0019] Furthermore, it also includes a deflation mechanism, which includes a deflation pipeline and a deflation valve arranged in the deflation pipeline; the deflation mechanism is connected to the oil removal pipeline through the deflation pipeline. When the deflation mechanism connected to the oil removal pipeline is replenished with gas, the air flow can drive the oil in the oil removal pipeline to the oil and gas filtering device, so that the oil is quickly collected and the oil residue in the pipeline is reduced.

[0020] Furthermore, a temperature sensor is provided in the vacuum box for detecting temperature data in the vacuum box. The heating interval of the infrared heating device can be controlled according to the temperature data so that the temperature in the vacuum box is maintained within a certain range.

[0021] Compared with the prior art, the vacuum drying system of the present invention first quickly extracts a large amount of air in the box without passing through the oil and gas filtering device, and then performs fine extraction and filtration to collect oil and gas, so as to avoid the volatile oil and gas in the oil removal pipeline and the oil and gas filtering device being brought out by the gas flow, resulting in reduced filtering and collecting effect of the oil and gas filtering device on the stamping oil and the influence of oil and gas on the operation of the vacuum pump; further, the oil and gas, solid impurities and particles in the air in the vacuum box are filtered through the first air filter to avoid affecting the operation of the vacuum pump; further, a small amount of volatile oil and gas will be brought out in the fine extraction, and further filtered through the second air filter to avoid affecting the operation of the vacuum pump; further, a height difference is formed between the second air filter and the oil and gas filtering device. , a small amount of stamping oil filtered can flow back to the oil and gas filtering device for collection; further, a height difference is formed between the oil and gas filtering device and the vacuum box to prevent oil and gas condensation and backflow into the vacuum box; further, the vacuum box with a funnel-shaped bottom is guided to facilitate oil and gas extraction and make it easier for liquid oil to flow out; further, the cylindrical filter element surrounding the air inlet is used to increase the filtering area of ​​the oil and gas and improve the filtering effect; further, the venting mechanism is used to facilitate the re-supply of gas to the entire system after drying is completed, and the noise generated by the replenishment of gas is reduced; further, the temperature in the vacuum box is detected by a temperature sensor, and the heating interval of the infrared heating device is controlled according to the temperature data, so that the temperature in the vacuum box is maintained within a certain range.

[0022] In order to more clearly understand the present invention, the specific implementation of the present invention will be described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic structural diagram of a vacuum drying system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] 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.

[0025] See also Figure 1 , which is a structural schematic diagram of a vacuum drying system according to an embodiment of the present invention, the vacuum drying system comprises: a vacuum box 10, a degassing pipeline 20, an oil removal pipeline 30, a vacuum pump 40, an infrared heating device 50, a vacuum gauge 60 and an oil and gas filtering device 70;

[0026] The top of the vacuum box 10 is provided with a first air extraction port, and the bottom is provided with a second air extraction port. Preferably, the bottom of the vacuum box 10 is funnel-shaped, which is conducive to guiding the extraction of oil and gas and the outflow of liquid stamping oil.

[0027] The degassing pipeline 20 is provided with a first valve 21, which connects the first air extraction port with the vacuum pump 40; the de-oiling pipeline 30 is provided with a second valve 31, which sequentially connects the second air extraction port, the oil and gas filtering device 70 and the vacuum pump 40. In this embodiment, the vacuum pump 40 includes a first pump group and a second pump group, which are respectively connected to the degassing pipeline 20 and the de-oiling pipeline 30. Because the rough extraction and the fine extraction have different effects on the vacuum pump 40, the two pump groups can be separated to facilitate separate maintenance. In addition, in this embodiment, the degassing pipeline 20 and the de-oiling pipeline 30 are also connected to each other through a pipeline, and a third valve 22 is provided on the pipeline. Because it is necessary to quickly extract air during rough extraction, the first valve 21 and the third valve 22 can be opened to control the two pump groups to extract air at the same time, and the first valve 21 and the third valve 22 can be closed during fine extraction, and only the second valve 31 can be opened to extract air. Of course, the third valve 22 can also be opened. The first pump group is used to increase the efficiency of extracting oil and gas, which is convenient for adjusting the vacuum extraction method. It should be noted that the first pump group and the second pump group can also be interconnected through other connection methods, for example, the degassing pipeline 20 gathers the oil removal pipeline 30 into the same pipeline and then connects to the first pump group and the second pump group respectively, but this example is not limited.

[0028] The infrared heating device 50 is arranged in the vacuum box 10, wherein the infrared heating device 50 includes a plurality of infrared heating tubes, which can be evenly arranged on the top and / or inner wall of the vacuum box 10 to ensure that the infrared heating device 50 irradiates the inside of the vacuum box 10 without dead angles. It should be noted that the inner wall of the vacuum box 10 preferably has a material capable of absorbing infrared rays, such as a ceramic material or a black body material, etc., which absorbs infrared rays to raise the temperature, thereby raising the temperature inside the vacuum box 10, making it easier for the stamping oil to gasify.

[0029] The vacuum gauge 60 is connected to the inside of the vacuum box 10 and is used to detect the vacuum degree in the vacuum box 10 .

[0030] During drying, the infrared heating device 50, the first valve 21 and the vacuum pump 40 are turned on, and the second valve 31 is closed. The vacuum pump 40 extracts the gas in the vacuum box 10 from the first suction port and detects the vacuum degree in the vacuum box 10. When the vacuum box 10 reaches the preset vacuum degree, the first valve 21 is closed, the second valve 31 is opened, and the vacuum pump 40 extracts the gas in the vacuum box 10 from the second suction port. Since there is liquid stamping oil remaining in the de-oiling pipeline 30, the oil and gas filtering device 70 also collects liquid stamping oil. These liquid stamping oils will remain in the de-oiling pipeline 30 and the oil and gas filtering device 70 after volatilization. During fine extraction, the suction volume is small and the suction speed is relatively slow, which avoids taking out a large amount of volatilized oil and gas in the de-oiling pipeline 30 and the oil and gas filtering device 70.

[0031] In some embodiments, the oil and gas filtering device 70 includes a body 71 and a filter element 72. A cavity 73 is formed in the body 71. The cavity 73 is provided with an air inlet 74, an air outlet 75 and an oil outlet 76. The filter element 72 is disposed in the cavity 73 and is located between the air inlet 74 and the air outlet 75. The air inlet 74 is communicated with the second air suction port, the air outlet 75 is communicated with the vacuum pump 40, and the oil outlet 76 is preferably located on the same side of the filter element 72 as the air inlet 74. Preferably, the horizontal position of the oil and gas filtering device 70 is lower than the vacuum box 10 to prevent the stamping oil in the oil removal pipeline 30 from flowing back to the vacuum box 10. Preferably, the filter element 72 is cylindrical and vertically arranged in the cavity 73, dividing the cavity 73 into an inner cavity 731 and an outer cavity 732, the air inlet 74 is located at the top of the inner cavity 731, the oil outlet 76 is located at the bottom of the inner cavity 731, and the air outlet 75 is connected to the outer cavity 732, and the inner and outer cavities 732 are formed by the filter element 72. The air first converges in the inner cavity 731 and then flows to the outer cavity 732 around through the filter element 72, increasing the passage for air circulation and improving the filtering effect of oil and gas. Preferably, the air inlet 74 is located directly above the oil outlet 76, so that the stamping oil condensed in the oil removal pipeline 30 can flow directly from the oil outlet 76. It should be noted that the oil and gas filtering device 70 can also be a cold trap, an oil and gas filter, or some other device that can be used on a vacuum pipeline to achieve filtering and collection of oil and gas.

[0032] In some embodiments, a first air filter 23 is further included, and the degassing pipeline 20 sequentially connects the first air extraction port, the first air filter 23, and the vacuum pump 40. Before vacuuming, the stamping oil evaporates, causing a small amount of oil gas to exist in the air in the vacuum box 10. Therefore, during rough extraction, the first air filter 23 is used to filter the evaporated stamping oil. In addition, a collection tank for collecting stamping oil may also be provided below the first filter.

[0033] In some embodiments, a second air filter 32 is further included; the de-oiling pipeline 30 is sequentially connected to the second air extraction port, the oil and gas filtering device 70, the second air filter 32 and the vacuum pump 40. Since there is liquid stamping oil in the de-oiling pipeline 30 and the oil and gas filtering device 70, the liquid stamping oil will remain in the de-oiling pipeline 30 and the oil and gas filtering device 70 after volatilization, and a small amount will be taken out during fine extraction. The volatilized oil and gas can be filtered by the second air filter 32. Preferably, the horizontal position of the second air filter 32 is higher than the oil and gas filtering device 70, so that the small amount of stamping oil filtered by the second filter can flow to the oil and gas filtering device 70 for collection when the de-oiling pipeline 30 is not evacuated.

[0034] In some embodiments, a deflation mechanism 80 is also included, and the deflation mechanism 80 includes a deflation pipeline and a deflation valve disposed in the deflation pipeline; the deflation mechanism 80 is connected to the oil removal pipeline 30 through the deflation pipeline, and a muffler is also disposed at the end of the deflation valve to reduce noise. In the direction of air extraction along the oil removal pipeline 30, the connection between the deflation mechanism 80 connected to the oil removal pipeline 30 and the oil removal pipeline 30 is preferably after the second air filter, so that the oil collected by the second air filter 32 can also be flushed to the oil and gas filtering device 70. In addition, in some embodiments, a deflation mechanism 80 is also disposed at the vacuum box 10, and the deflation mechanism 80 of the vacuum box 10 breaks the vacuum of the vacuum box after drying is completed.

[0035] In some embodiments, a temperature sensor is provided in the vacuum box 10 to detect the temperature data in the vacuum box 10. When the heating temperature reaches a preset value or a predetermined range, the infrared heating device 50 is controlled to perform intermittent heating to maintain the temperature in the vacuum box 10. It should be noted that a plurality of temperature sensors can be provided in different places in the vacuum box 10. When the temperature of a plurality of positions in the vacuum box 10 is detected, if the temperature of a certain position is lower than a preset value or a predetermined range, the infrared heating tubes around the position are controlled to be turned on for heating to ensure that the temperature in the vacuum box 10 is uniform.

[0036] Compared with the prior art, the vacuum drying system of the present invention first quickly extracts the air with less oil and gas content in the box without passing through the oil and gas filtering device, and then performs fine extraction and filtration to collect the oil and gas, thereby avoiding the volatile oil and gas in the oil removal pipeline and the oil and gas filtering device being brought out by the gas flow, resulting in a reduction in the filtering and collection effect of the oil and gas filtering device on the stamping oil and the influence of the oil and gas on the operation of the vacuum pump.

[0037] 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 vacuum drying system, characterized in that: include: Vacuum box, degassing pipeline, deoiling pipeline, vacuum pump, infrared heating device, vacuum gauge and oil and gas filtering device; The vacuum box is provided with a first air extraction port on the top and a second air extraction port on the bottom. The degassing pipeline is provided with a first valve, which connects the first air extraction port with the vacuum pump. The deoiling pipeline is provided with a second valve, which sequentially connects the second air extraction port, the oil and gas filtering device and the vacuum pump. The infrared heating device is provided in the vacuum box. The vacuum gauge is connected to the inside of the vacuum box to detect the vacuum degree in the vacuum box. During drying, the infrared heating device, the first valve and the vacuum pump are turned on, and the second valve is closed, and the vacuum pump extracts the gas in the vacuum box from the first air extraction port. When the vacuum box reaches a preset vacuum degree, the first valve is closed, and the second valve is opened, and the vacuum pump extracts the gas in the vacuum box from the second air extraction port. The vacuum pump includes a first pump group and a second pump group, the first pump group and the second pump group are respectively connected to the degassing pipeline and the oil removal pipeline, the degassing pipeline and the oil removal pipeline are connected to each other through a pipeline, and a third valve is arranged on the pipeline. During rough pumping, the first valve and the third valve are opened to control the first pump group and the second pump group to pump air at the same time, and during fine pumping, the first valve and the third valve are closed and the second valve is opened.

2. A vacuum drying system according to claim 1, characterized in that: Also included is a first air filter; The degassing pipeline is sequentially connected to the first air suction port, the first air filter and the vacuum pump.

3. A vacuum drying system according to claim 1, characterized in that: Also included is a second air filter; The oil removal pipeline is connected to the second air extraction port, the oil and gas filtering device, the second air filter and the vacuum pump in sequence.

4. A vacuum drying system according to claim 3, characterized in that: The second air filter is located at a higher level than the oil and gas filtering device.

5. A vacuum drying system according to claim 1, characterized in that: The oil and gas filtering device is located at a level lower than the vacuum box.

6. A vacuum drying system according to claim 1, characterized in that: The bottom of the vacuum box is funnel-shaped.

7. A vacuum drying system according to any one of claims 1 to 6, characterized in that: The oil and gas filtering device comprises a body and a filter element. A cavity is formed in the body. The cavity is provided with an air inlet, an air outlet and an oil outlet. The filter element is arranged in the cavity and located between the air inlet and the air outlet. The air inlet is communicated with the second air extraction port, and the air outlet is communicated with the vacuum pump.

8. A vacuum drying system according to claim 7, characterized in that: The filter element is cylindrical and vertically arranged in the cavity, dividing the cavity into an inner cavity and an outer cavity, the air inlet is located at the top of the inner cavity, the oil outlet is located at the bottom of the inner cavity, and the air outlet is connected to the outer cavity.

9. A vacuum drying system according to claim 1, characterized in that: It also includes an air release mechanism, which includes an air release pipeline and an air release valve arranged in the air release pipeline; the air release mechanism is connected with the oil removal pipeline through the air release pipeline.

10. A vacuum drying system according to claim 1, characterized in that: A temperature sensor is arranged in the vacuum box for detecting temperature data in the vacuum box.

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