Dry oil-free air compressor
Patent Information
- Application Number
- CN202522133662.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-10
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-10-10
AI Technical Summary
[0002]现有的空压机输出的压缩空气的温度不稳定，无法满足冶金、化工、医药及石油等用气品质较高的行业
[0008]优选地，所述油箱的溢流孔连接有溢流管，该溢流管的溢流进口与连接所述油泵和所述油冷却器的泵油管连通，且所述溢流管上设置有溢流阀。这样，当油泵抽出的润滑油过多时，可开启溢流阀使过量的润滑油经溢流管回流到油箱中，减小润滑系统的能耗，进而降低本实用新型干式无油空压机的能耗。
Smart Images
Figure CN224903392U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air compression technology, and in particular to a dry oil-free air compressor. Background Technology
[0002] The temperature of the compressed air output by existing air compressors is unstable, which cannot meet the high-quality air requirements of industries such as metallurgy, chemical industry, pharmaceutical industry and petroleum industry. Utility Model Content
[0003] To improve the temperature stability of compressed air, this utility model proposes a dry oil-free air compressor. The dry oil-free air compressor includes a drive motor, a primary compressor, a secondary compressor, and a lubrication system. The drive motor is connected to and drives the primary and secondary compressors via a gearbox. An intercooler is provided between the primary and secondary compressors, and an aftercooler is provided at the output end of the secondary compressor. An oil cooler is provided in the lubrication system. An intermediate variable frequency fan in the intercooler is connected to the control system via an intermediate variable frequency controller. A rear variable frequency fan in the aftercooler is connected to the control system via a rear variable frequency controller, and an oil-cooled variable frequency fan in the oil cooler is connected to the control system via an oil-cooled variable frequency controller. This utility model of dry oil-free air compressor can use a control system to set the temperature according to the user's requirements and control the intermediate variable frequency fan in the intercooler, the rear variable frequency fan in the aftercooler, and the oil-cooled variable frequency fan in the oil cooler in real time, so as to keep the temperature of the compressed air output by the dry oil-free air compressor constant, thereby meeting the user's air requirements.
[0004] Preferably, a primary outlet temperature sensor connected to the control system is installed on the primary outlet pipe connecting the first-stage compressor and the intercooler; a dew point meter and a secondary inlet temperature sensor connected to the control system are installed on the secondary inlet pipe connecting the intercooler and the second-stage compressor; a secondary outlet temperature sensor connected to the control system is installed on the secondary outlet pipe connecting the two-stage compressor and the aftercooler; and an end outlet temperature sensor connected to the control system is installed on the end outlet pipe connected to the outlet of the aftercooler. Thus, during the operation of this novel oil-free air compressor, a dew point meter monitors the dew point of the primary cooled compressed air obtained from the intercooler in real time; a primary outlet temperature sensor monitors the temperature of the primary compressed air entering the intercooler in real time; a secondary inlet temperature sensor monitors the temperature of the primary cooled compressed air obtained from the intercooler's cooling of the primary compressed air in real time; a secondary outlet temperature sensor monitors the temperature of the secondary compressed air obtained from the secondary compression of the secondary compressor in real time; and an end outlet temperature sensor monitors the temperature of the cooled compressed air obtained from the aftercooler's cooling of the secondary compressed air in real time. The control system can adjust the temperature of the air in the intercooler based on the dew point monitored by the dew point meter, the temperature of the primary compressed air monitored by the primary outlet temperature sensor, and the temperature of the primary cooled compressed air monitored by the secondary inlet temperature sensor. The control system adjusts the speed of the intermediate variable frequency fan to regulate its airflow, thus regulating the cooling effect of the intercooler. This ensures that the temperature of the primary cooled compressed air is above the dew point, generating unsaturated compressed air that is then sent to the secondary compressor for secondary compression. The control system adjusts the speed of the aftercooler's variable frequency fan based on the client's temperature settings, the temperature of the primary cooled compressed air monitored by the secondary intake temperature sensor, and the temperature of the cooled compressed air monitored by the terminal outlet temperature sensor. This adjusts the airflow of the aftercooler, thus regulating its cooling effect. The system ensures that the temperature of the cooled compressed air monitored by the terminal outlet temperature sensor remains consistent with the set temperature, thereby maintaining a constant temperature of cooled compressed air output from the dry oil-free air compressor and delivering it to the client. Therefore, this dry oil-free air compressor can automatically control and adjust the cooling effects of the intercooler and aftercooler through a control system, making control simple and convenient.
[0005] Preferably, the secondary intake pipe is equipped with a gas-water separator, a secondary safety valve, and a secondary intake pressure sensor. The gas-water separator is located between the dew point meter and the secondary compressor, the secondary safety valve is located between the intercooler and the dew point meter, and the secondary outlet pipe is equipped with a secondary outlet pressure sensor. Both the secondary intake pressure sensor and the secondary outlet pressure sensor are connected to the control system. Thus, during the operation of this dry oil-free air compressor, the gas-water separator can separate the primary cooling compressed air from the water, removing moisture and effectively reducing the moisture content of the compressed air output by the dry oil-free air compressor, thereby improving the purity of the output compressed air. When the secondary intake pressure sensor detects excessive gas pressure in the secondary intake pipe or the secondary outlet pressure sensor detects excessive pressure of the secondary compressed air in the secondary outlet pipe, the control system can open the secondary safety valve as needed to release some of the primary cooling compressed air, improving the safety performance of the dry oil-free air compressor. Furthermore, a pipe silencer and a check valve are installed on the secondary outlet pipe, with the check valve located between the pipe silencer and the aftercooler. In this way, before the secondary compressed air enters the aftercooler for cooling, the pipe silencer can reduce noise during the transmission of the secondary compressed air, thereby reducing the operating noise of the dry oil-free air compressor of this invention. During the transmission of the secondary compressed air to the aftercooler, the check valve can prevent the secondary compressed air from flowing back along the secondary outlet pipe towards the secondary compressor unit, thus avoiding any impact on the production efficiency of the dry oil-free air compressor of this invention.
[0006] Preferably, the inlet end of the primary compressor is equipped with an inlet valve, and the secondary outlet pipe is equipped with a return air pipe communicating with the inlet of the inlet valve. This return air pipe is connected to the secondary outlet pipe at the inlet end of the pipe silencer, and a return air control valve is installed on the return air pipe. Thus, when the amount of compressed air produced by the dry oil-free air compressor exceeds the user's requirements, the return air control valve can be opened to recover the secondary compressed air via the return air pipe. This avoids waste of compressed air due to excessive production and also avoids the need for the aftercooler to cool the excess secondary compressed air, reducing the energy consumption of the dry oil-free air compressor and preventing energy waste. Furthermore, a return air control pipe is provided on the secondary outlet pipe. The control inlet of the return air control pipe is connected to the inlet of the pipe silencer and the secondary outlet pipe. The control outlet of the return air control pipe is connected to the control inlet of the return air control valve, and an loading / unloading solenoid valve is provided on the return air control pipe. Thus, during the operation of the dry oil-free air compressor of this invention, the return air control pipe can be used to input compressed air into the secondary stage to control the on / off state of the return air control valve, making control simple and convenient.
[0007] Preferably, the lubrication system includes an oil tank, an oil pump, and a branch block. The oil pump is located between the oil tank and the oil cooler, drawing lubricating oil from the oil tank and delivering it to the oil cooler. The cooling oil outlet of the oil cooler is connected to the oil inlet of the branch block via an oil delivery pipe. The branch block is connected to the first-stage compressor, the second-stage compressor, and the gearbox via oil delivery branch pipes, delivering lubricating oil to these components. The branch block is connected to the oil tank via a return oil pipe. Thus, when the lubrication system supplies lubricating oil to the first-stage compressor, the second-stage compressor, and the gearbox in this dry oil-free air compressor, it only needs to use the oil pump to draw lubricating oil stored in the oil tank and distribute it to these components via the branch block. Simultaneously, the branch block can also directly return excess lubricating oil to the oil tank via the return pipe, preventing excess lubricating oil from accumulating in the oil delivery pipeline. Furthermore, a primary oil filter is installed in the oil tank, located at the oil outlet of the oil tank; an oil filter is installed on the oil delivery pipe, near the cooling oil outlet of the oil cooler. Thus, the primary filter in the oil tank provides preliminary filtration of the lubricating oil drawn by the oil pump, preventing impurities in the lubricating oil from entering the oil pump and damaging the oil pump and oil cooler. The oil filter between the oil cooler and the branch block further filters the cooled lubricating oil, thereby further improving the purity of the lubricating oil and preventing impurities from entering the primary compressor, secondary compressor, and gearbox with the lubricating oil, thus preventing damage to these components. Therefore, the installation of a primary oil filter and an oil filter in the lubrication system effectively extends the service life of the oil pump, oil cooler, primary compressor, secondary compressor, and gearbox in this invention's dry oil-free air compressor, thereby extending the service life of this invention's dry oil-free air compressor. More preferably, a pressure reducing valve is provided on the oil supply pipe, and the pressure reducing valve is located between the oil filter and the branch block. In this way, when the oil pressure in the oil supply pipe is too high, the pressure reducing valve can be opened to reduce the pressure, so as to avoid the lubrication and cooling effect of the dry oilless air compressor of this utility model being affected by the excessively high oil pressure of the lubricating oil supplied by the lubrication system.
[0008] Preferably, the overflow hole of the oil tank is connected to an overflow pipe, the overflow inlet of which is connected to the pump oil pipe connecting the oil pump and the oil cooler, and an overflow valve is provided on the overflow pipe. Thus, when the oil pump pumps out too much lubricating oil, the overflow valve can be opened to allow the excess lubricating oil to flow back into the oil tank through the overflow pipe, reducing the energy consumption of the lubrication system and thereby lowering the energy consumption of the dry oil-free air compressor of this invention. Attached Figure Description
[0009] Figure 1This is a schematic diagram of the structure of the dry oil-free air compressor of this utility model. Detailed Implementation
[0010] Below, in conjunction with Figure 1 This utility model provides a detailed description of the dry oil-free air compressor.
[0011] like Figure 1As shown, the dry oil-free air compressor of this utility model includes a drive motor 1, a primary compressor 21, a secondary compressor 22, and a lubrication system. The drive motor 1 is connected to and drives the primary and secondary compressors 21 and 22 via a gearbox 3. An intercooler 41 is provided between the primary and secondary compressors 21 and 22. A post-cooler 42 is provided at the output end of the secondary compressor 22. An oil cooler 51 is provided in the lubrication system. An intermediate variable frequency fan (not shown) in the intercooler 41 is connected to the control system 6 via an intermediate variable frequency controller 411. A post-variable frequency fan (not shown) in the post-cooler 42 is connected to the control system 6 via a post-variable frequency controller 421. An oil-cooled variable frequency fan (not shown) in the oil cooler 51 is connected to the control system 6 via an oil-cooled variable frequency controller 511. This utility model of a dry oil-free air compressor can utilize a control system to set the temperature according to the client's usage requirements and control the intermediate variable frequency fan in the intercooler 41, the rear variable frequency fan in the aftercooler 42, and the oil-cooled variable frequency fan in the oil cooler 51 in real time, so as to keep the temperature of the compressed air output by the dry oil-free air compressor constant, thereby meeting the client's air usage requirements. Preferably, the drive motor 1 is connected to the gearbox 3 through a coupling (not shown in the figure), which is simple and convenient. Preferably, a permanent magnet synchronous motor is used as the drive motor 1, which allows the control system 6 to control the speed of the first-stage compressor 21 and the second-stage compressor 22 by controlling the speed of the permanent magnet synchronous motor, thereby facilitating the control of the production efficiency of the first-stage compressor 21 and the second-stage compressor 22, and thus facilitating the control of the production efficiency of the dry oil-free air compressor of this utility model. Preferably, an air filter 211 is provided at the air inlet of the primary compressor unit 21 to filter the air drawn in by the primary compressor unit 21, removing moisture, dust, and other impurities from the air, thereby improving the cleanliness of the compressed air produced by the dry oil-free air compressor of this invention. Preferably, an intake valve 212 is provided between the air filter 211 and the primary compressor unit 21 to control the amount of air entering the primary compressor unit 21 as needed. Preferably, the control system 6 is connected to the Internet of Things (IoT) device 61. Thus, during the operation of the dry oil-free air compressor of this invention, the operator can send control commands to the control system 6 via the IoT device 61.Preferably, a primary outlet temperature sensor 412 connected to the control system 6 is installed on the primary outlet pipe (not shown in the figure) connecting the first-stage compressor 21 and the intercooler 41; a dew point meter 413 and a secondary intake temperature sensor 414 connected to the control system 6 are installed on the secondary inlet pipe (not shown in the figure) connecting the intercooler 41 and the second-stage compressor 22; a secondary outlet temperature sensor 422 connected to the control system 6 is installed on the secondary outlet pipe (not shown in the figure) connecting the two-stage compressor 22 and the aftercooler 42; and an end outlet temperature sensor 423 connected to the control system 6 is installed on the end outlet pipe connected to the outlet of the aftercooler 42. Thus, during the operation of the oil-free air compressor of this utility model, the dew point meter 413 monitors the dew point of the primary cooled compressed air obtained by the intercooler 41 in real time; the primary outlet temperature sensor 412 monitors the temperature of the primary compressed air entering the intercooler 41 in real time; the secondary inlet temperature sensor 414 monitors the temperature of the primary cooled compressed air obtained by the intercooler 41 cooling the primary compressed air; the secondary outlet temperature sensor 422 monitors the temperature of the secondary compressed air obtained by the secondary compressor 22 in real time; and the end outlet temperature sensor 423 monitors the temperature of the cooled compressed air obtained by the aftercooler 42 cooling the secondary compressed air. The control system 6 can then adjust the temperature based on the dew point monitored by the dew point meter 413, the temperature of the primary compressed air monitored by the primary outlet temperature sensor 412, and the temperature of the primary cooled compressed air monitored by the secondary inlet temperature sensor 414. The speed of the intermediate variable frequency fan in the intercooler 41 is adjusted to regulate the airflow, thus regulating the cooling effect of the intercooler 41. This ensures that the temperature of the primary cooled compressed air is higher than the dew point temperature, generating unsaturated compressed air that is sent to the secondary compressor 22 for secondary compression. The control system 6 adjusts the speed of the secondary variable frequency fan in the aftercooler 42 according to the user's requirements, the temperature of the primary cooled compressed air monitored by the secondary intake temperature sensor 414, and the temperature of the cooled compressed air monitored by the terminal outlet temperature sensor 423. This regulates the airflow of the secondary variable frequency fan, thus regulating the cooling effect of the aftercooler 42. This ensures that the temperature of the cooled compressed air monitored by the terminal outlet temperature sensor 423 remains consistent with the set temperature, thereby maintaining a constant temperature for the cooled compressed air output by the dry oil-free air compressor and delivering it to the user. Therefore, the dry oil-free air compressor of this invention can automatically control and adjust the cooling effects of the intercooler 41 and the aftercooler 42 through the control system, making control simple and convenient.Preferably, a gas-water separator 415, a secondary safety valve 416, and a secondary intake pressure sensor 417 are provided on the secondary intake pipe. The gas-water separator 415 is located between the dew point meter 413 and the secondary compressor 22. The secondary safety valve 416 is located between the intercooler 41 and the dew point meter 413. A secondary outlet pressure sensor 424 is provided on the secondary outlet pipe. The secondary intake pressure sensor 417 and the secondary outlet pressure sensor 424 are connected to the control system 6. Thus, during the operation of this dry oil-free air compressor, the air-water separator 415 can be used to separate the air and water in the primary cooling compressed air, removing the moisture and effectively reducing the moisture content of the compressed air output by the dry oil-free air compressor, thereby improving the purity of the compressed air output by the dry oil-free air compressor. When the secondary intake pressure sensor 417 detects that the gas pressure in the secondary intake pipe is too high, or the secondary outlet pressure sensor 424 detects that the pressure of the secondary compressed air in the secondary outlet pipe is too high, the control system 6 can open the secondary safety valve 416 as needed to release part of the primary cooling compressed air, improving the safety performance of the dry oil-free air compressor. Preferably, a pipe silencer 425 and a check valve 426 are provided on the secondary outlet pipe, and the check valve 426 is located between the pipe silencer 425 and the aftercooler 42. Thus, before the secondary compressed air enters the aftercooler 42 for cooling, the transmission noise of the secondary compressed air can be reduced by the pipe silencer 425, thereby reducing the operating noise of the dry oil-free air compressor of this invention. During the transmission of the secondary compressed air to the aftercooler 42, the check valve 426 can be used to prevent the secondary compressed air from flowing back along the secondary outlet pipe towards the secondary compressor host 22, thus affecting the production efficiency of the dry oil-free air compressor of this invention. Preferably, a return air pipe (not shown in the figure) is provided on the secondary outlet pipe, which is connected to the inlet of the inlet valve 212. This return air pipe is connected to the secondary outlet pipe at the inlet end of the pipe silencer 425, and a return air control valve 213 is provided on the return air pipe. Thus, when the amount of compressed air produced by the dry oil-free air compressor of this invention exceeds the user's requirements, the return air control valve 213 can be opened to recover the secondary compressed air through the return air pipe. This avoids waste of compressed air due to excessive production and also avoids the aftercooler 42 cooling the excess secondary compressed air, reducing the energy consumption of the dry oil-free air compressor and preventing energy waste. Preferably, a return air control pipe (not shown in the figure) is provided on the secondary outlet pipe. The control inlet end of the return air control pipe is connected to the secondary outlet pipe at the inlet end of the pipe silencer 425, and the control outlet end of the return air control pipe is connected to the control inlet of the return air control valve 213. An loading / unloading solenoid valve 214 is also provided on the return air control pipe. Thus, during the operation of the dry oil-free air compressor of this invention, the return air control pipe can be used to input secondary compressed air to control the opening and closing of the return air control valve 213, making control simple and convenient.Preferably, a venting silencer 215 is connected to the return air control valve 213 to reduce return air noise and lower the operating noise of the dry oil-free air compressor of this invention. Preferably, an air supply safety valve (not shown in the figure) is provided on the end outlet pipe, which is located near the outlet of the aftercooler 42. This allows the air supply safety valve to be opened to release pressure when the pressure of the compressed air output from the end outlet pipe is too high. Preferably, both the drain ports of the intercooler 41 and the aftercooler 42 are connected to drain pipes (not shown in the figure), which are equipped with an automatic drain valve 401 and a drain control valve 402, with the automatic drain valve 401 connected to the drain end of the drain pipe. This allows the drain control valve 402 to control the automatic drain valve 401 to discharge wastewater from the intercooler 41 or the aftercooler 42 during operation of the dry oil-free air compressor of this invention. Preferably, the drain pipe is equipped with a single-return valve 403 and a Y-type filter 404, wherein the Y-type filter 404 is close to the drain port, and the single-return valve 403 is located between the Y-type filter 404 and the drain control valve 402. In this way, when draining wastewater from the intercooler 41 or the aftercooler 42, the single-return valve 403 can be used to prevent wastewater backflow, and the Y-type filter 404 can be used to filter the discharged wastewater, preventing impurities in the wastewater from clogging the drain pipe. Preferably, a ball valve can be used as the drain control valve 402, which is simple and convenient to install and control.
[0012] like Figure 1As shown, in the dry oilless air compressor of this utility model, the lubrication system includes an oil tank 52, an oil pump 53, and a branch block 54. The oil pump 53 is located between the oil tank 52 and the oil cooler 51 and draws lubricating oil from the oil tank 52 and delivers it to the oil cooler 51. The cooling oil outlet of the oil cooler 51 is connected to the oil inlet of the branch block 54 through an oil delivery pipe (not shown in the figure). The branch block 54 is connected to the first-stage compressor 21, the second-stage compressor 22, and the gearbox 3 through an oil delivery branch pipe (not shown in the figure) and delivers lubricating oil to the first-stage compressor 21, the second-stage compressor 22, and the gearbox 3. The branch block 54 is connected to the oil tank 52 through a return oil pipe (not shown in the figure). Thus, when the lubrication system supplies lubricating oil to the primary compressor 21, secondary compressor 22, and gearbox 3 in the dry oil-free air compressor of this utility model, it only needs to use the oil pump 53 to extract the lubricating oil stored in the oil tank 52 and distribute it to the primary compressor 21, secondary compressor 22, and gearbox 3 through the branch block 54. At the same time, the branch block 54 can also be used to directly transport excess lubricating oil back to the oil tank 52 through the return pipe, avoiding the accumulation of excess lubricating oil in the oil supply pipeline. Preferably, a primary oil filter 521 is provided in the oil tank 52, which is located at the oil outlet of the oil tank 52; an oil filter 55 is provided on the oil supply pipe, which is close to the cooling oil outlet of the oil cooler 51. Thus, by installing a primary filter 521 in the oil tank 52, the lubricating oil drawn by the oil pump 53 can be initially filtered, preventing impurities in the lubricating oil from entering the oil pump 53 and causing damage to the oil pump 53 and oil cooler 51. An oil filter 55 is installed between the oil cooler 51 and the branch block 54 to further filter the cooled lubricating oil, thereby further improving the purity of the lubricating oil and preventing impurities from entering the primary compressor 21, secondary compressor 22, and gearbox 3 with the lubricating oil, thus preventing damage to these components. Therefore, installing a primary oil filter 521 and an oil filter 55 in the lubrication system can effectively extend the service life of the oil pump 53, oil cooler 51, primary compressor 21, secondary compressor 22, and gearbox 3 in this invention's dry oil-free air compressor, thereby extending the service life of this invention's dry oil-free air compressor. Preferably, a pressure reducing valve 56 is provided on the oil supply pipe, and the pressure reducing valve 56 is located between the oil filter 55 and the branch block 54. In this way, when the oil pressure in the oil supply pipe is too high, the pressure reducing valve 56 can be opened to reduce the pressure, so as to avoid the lubrication and cooling effect of the dry oilless air compressor of this utility model being affected by the excessively high oil pressure of the lubricating oil supplied by the lubrication system. Preferably, the overflow hole of the oil tank 52 is connected to an overflow pipe (not shown in the figure), the overflow inlet of which is connected to the pump oil pipe (not shown in the figure) connecting the oil pump 53 and the oil cooler 51, and an overflow valve 57 is provided on the overflow pipe.Thus, when the oil pump 53 draws out too much lubricating oil, the overflow valve 57 can be opened to allow the excess lubricating oil to flow back into the oil tank 52 through the overflow pipe, reducing the energy consumption of the lubrication system and thus lowering the energy consumption of the dry oil-free air compressor of this invention. Preferably, the branch block 54 is equipped with a branch pressure sensor 541 and a branch temperature sensor 542 connected to the control system 6. Thus, during the operation of the dry oil-free air compressor of this invention, the control system can adjust the speed of the oil-cooled variable frequency fan based on the pressure and temperature data fed back by the branch pressure sensor 541 and the branch temperature sensor 542.
Claims
1. A dry, oil-free air compressor, characterized in that, The dry oil-free air compressor includes a drive motor, a primary compressor, a secondary compressor, and a lubrication system. The drive motor is connected to and drives the primary and secondary compressors via a gearbox. An intercooler is provided between the primary and secondary compressors, and an aftercooler is provided at the output end of the secondary compressor. An oil cooler is provided in the lubrication system. The intermediate variable frequency fan in the intercooler is connected to the control system via an intermediate variable frequency controller. The rear variable frequency fan in the aftercooler is connected to the control system via a rear variable frequency controller. The oil-cooled variable frequency fan in the oil cooler is connected to the control system via an oil-cooled variable frequency controller.
2. The dry oil-free air compressor according to claim 1, characterized in that, A primary outlet temperature sensor connected to the control system is installed on the primary outlet pipe connecting the first-stage compressor and the intercooler. A dew point meter and a secondary inlet temperature sensor connected to the control system are installed on the secondary inlet pipe connecting the intercooler and the second-stage compressor. A secondary outlet temperature sensor connected to the control system is installed on the secondary outlet pipe connecting the two-stage compressor and the aftercooler. An end outlet temperature sensor connected to the control system is installed on the end outlet pipe connected to the outlet of the aftercooler.
3. The dry oil-free air compressor according to claim 2, characterized in that, The secondary intake pipe is equipped with a gas-liquid separator, a secondary safety valve, and a secondary intake pressure sensor. The gas-liquid separator is located between the dew point meter and the secondary compressor. The secondary safety valve is located between the intercooler and the dew point meter. The secondary outlet pipe is equipped with a secondary outlet pressure sensor, and the secondary intake pressure sensor and the secondary outlet pressure sensor are connected to the control system.
4. The dry oil-free air compressor according to claim 3, characterized in that, The secondary exhaust pipe is equipped with a pipe silencer and a check valve, and the check valve is located between the pipe silencer and the aftercooler.
5. The dry oil-free air compressor according to any one of claims 1-4, characterized in that, The intake end of the compressor unit is equipped with an intake valve, and the secondary outlet pipe is equipped with a return pipe that communicates with the intake port of the intake valve. The return pipe is connected to the secondary outlet pipe at the intake end of the pipe silencer, and a return control valve is provided on the return pipe.
6. The dry oil-free air compressor according to claim 5, characterized in that, The secondary exhaust pipe is equipped with a return air control pipe. The control air inlet of the return air control pipe is connected to the air inlet of the pipe silencer and the secondary exhaust pipe. The control air outlet of the return air control pipe is connected to the control air inlet of the return air control valve. The return air control pipe is also equipped with a loading and unloading solenoid valve.
7. The dry oil-free air compressor according to any one of claims 1-4, characterized in that, The lubrication system includes an oil tank, an oil pump, and a branch block. The oil pump is located between the oil tank and the oil cooler and draws lubricating oil from the oil tank and delivers it to the oil cooler. The cooling oil outlet of the oil cooler is connected to the oil inlet of the branch block through an oil delivery pipe. The branch block is connected to the first-stage compressor, the second-stage compressor, and the gearbox through an oil delivery branch pipe and delivers lubricating oil to the first-stage compressor, the second-stage compressor, and the gearbox. The branch block is connected to the oil tank through a return oil pipe.
8. The dry oil-free air compressor according to claim 7, characterized in that, The oil tank is equipped with a primary oil filter located at the oil outlet of the oil tank; an oil filter is installed on the oil pipeline near the cooling oil outlet of the oil cooler.
9. The dry oil-free air compressor according to claim 8, characterized in that, A pressure reducing valve is installed on the oil pipeline, and the pressure reducing valve is located between the oil filter and the branch block.
10. The dry oil-free air compressor according to claim 7, characterized in that, The overflow hole of the oil tank is connected to an overflow pipe, the overflow inlet of which is connected to the pump oil pipe connecting the oil pump and the oil cooler, and an overflow valve is provided on the overflow pipe.