Vacuum pump system and method of operating a vacuum pump

Abstract

This invention provides a vacuum pump system that reduces the risk of corrosion, even when the vacuum pump is operated at high temperatures during normal operation. [Solution] This vacuum pump system 1 comprises a vacuum pump 3, a temperature sensor 7, a rotation speed detection device 8, and a control unit 40. In addition to the normal operation mode, the control unit 40 stores a corrosion progression reduction operation mode as one of the abnormal operation modes. When it determines to switch the operation mode from the normal operation mode to the corrosion progression reduction operation mode, it automatically controls the rotation speed of the vacuum pump 3 to be lower than in the normal operation mode so that the measured value of the temperature sensor 7 converges to a set temperature for the corrosion progression reduction operation mode that is lower than the set temperature for the normal operation mode.

Description

Technical Field

[0001] The present invention relates to a vacuum pump system and a method for operating a vacuum pump, and more particularly, to a vacuum pump system in which temperature control is performed to reduce the progress of corrosion of the vacuum pump and a method for operating the vacuum pump.

Background Art

[0002] In semiconductor manufacturing processes and the like, a vacuum pump system including a vacuum pump for evacuating a vacuum chamber and control equipment for controlling the operation of the vacuum pump is used. In some vacuum pump systems, in addition to normal operation for sucking the gas used into the vacuum pump, an abnormal operation different from normal operation such as a cleaning operation for periodically replacing the sucked gas with a cleaning gas to clean the inside is performed.

[0003] For example, Patent Document 1 discloses a vacuum pump system including a heater (11), purge gas introduction ports (12, 13) and a purge gas valve (14), and an exhaust valve (16), and having a cleaning operation mode capable of sublimating deposits in a turbo molecular pump (100) as an operation mode. In this vacuum pump system, in the cleaning operation mode, at least one of the heater (11), the purge gas valve (14), or the exhaust valve (16) is controlled to increase the pressure of at least a part of the inside of the turbo molecular pump (100) to a temperature not lower than the sublimation temperature of the deposits in the turbo molecular pump (100) and in a pressure region where intermediate flow or viscous flow occurs. Thereby, according to this vacuum pump system, sublimation of deposits can be promoted and cleaning performance can be improved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] In semiconductor manufacturing processes and other applications, depending on the gas used, vacuum pumps may need to be operated at high temperatures during normal operation to prevent the gas from solidifying and sticking inside the pump. However, if a vacuum pump that has been operated at high temperatures is then subjected to an unconventional operation such as a cleaning run while still at high temperatures, there is a risk of corrosion occurring.

[0006] The object of the present invention has been made in view of these points, and is to provide a vacuum pump system that can reduce the risk of corrosion even when the vacuum pump is operated at high temperatures. Another object of the present invention is to provide a method for operating a vacuum pump that can reduce the risk of corrosion even when the vacuum pump is operated at high temperatures. [Means for solving the problem]

[0007] To solve the above problems, the vacuum pump system according to the present invention is a vacuum pump system having multiple operating modes, including a normal operating mode for vacuuming gas in a target container, and at least one non-normal operating mode that is different from the normal operating mode.

[0008] This vacuum pump system, A vacuum pump that pressurizes and discharges the inhaled gas, A temperature sensor for measuring the temperature of the vacuum pump, A rotation speed detection device for detecting the rotation speed of a vacuum pump, A control unit is electrically connected to a vacuum pump, a temperature sensor, and a rotational speed detection device, and is capable of acquiring the measured value from the temperature sensor and the detected value from the rotational speed detection device, as well as controlling the rotational speed of the vacuum pump. It also stores multiple operating modes and operates the vacuum pump according to the operating mode selected from the multiple operating modes. Equipped with, The control unit stores a corrosion reduction operation mode as one of the non-normal operation modes. When it determines to switch the operation mode from the normal operation mode to the corrosion reduction operation mode, it automatically controls the vacuum pump rotation speed to be lower than in the normal operation mode so that the temperature sensor reading converges to a set temperature for the corrosion reduction operation mode that is lower than the set temperature for the normal operation mode. It is characterized by the following.

[0009] In this vacuum pump system, When the control unit determines that it is time to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it is preferable to automatically control the vacuum pump rotation speed to be reduced by 20% to 60% or more compared to the normal operating mode, and it is even more preferable to automatically control the vacuum pump rotation speed to be reduced by 20% to 50% or more.

[0010] In this vacuum pump system, A heater section for heating the vacuum pump, A cooling unit for cooling the vacuum pump, A hot purge gas supply unit that supplies a hot purge gas for dilution, which is temperature-adjustable and adjusted to the set temperature of the purge gas, Furthermore, The control unit is electrically connected to the heater unit, the cooling unit, and the hot purge gas supply unit, and can control the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the purge gas set temperature of the hot purge gas supply unit. When it is determined to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it is preferable that the control unit automatically controls the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the purge gas set temperature of the hot purge gas supply unit to decrease compared to the normal operating mode, so that the measured value of the temperature sensor converges to the set temperature for the corrosion progression reduction operating mode.

[0011] Furthermore, in this vacuum pump system, When the control unit determines that it is time to switch the operating mode from the corrosion progression reduction operating mode to the normal operating mode, it is preferable that the control unit automatically controls the system to increase the rotation speed of the vacuum pump, increase the heating capacity of the heater section, decrease the cooling capacity of the cooling section, and increase the purge gas setting temperature of the hot purge gas supply section, compared to the corrosion progression reduction operating mode, so that the temperature sensor readings converge to the set temperature for the normal operating mode.

[0012] Furthermore, in this vacuum pump system, Preferably, the cooling unit includes a cooling plate installed on the surface of the vacuum pump and a variable valve that can adjust the amount of cooling water supplied to the cooling plate, and the control unit automatically controls the cooling capacity by adjusting the opening degree of the variable valve.

[0013] Furthermore, in this vacuum pump system, The vacuum pump has multiple stages, with a booster pump located on the intake side and a dry pump located on the exhaust side. It is preferable to perform automatic control at least for the dry pump when the control unit determines that it should switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode.

[0014] Furthermore, in this vacuum pump system, in addition to normal operation according to the normal operating mode, a cleaning operation is performed to clean the inside by replacing the intake gas with a cleaning gas, and it is preferable that the control unit automatically controls the system according to the corrosion progression reduction operation mode during the cleaning operation.

[0015] Furthermore, in order to solve the above problems, the vacuum pump operation method according to the present invention is a method of causing the vacuum pump to perform at least one non-normal operation that differs from the normal operation, in addition to the normal operation for vacuuming the gas in the target container.

[0016] The operating method for this vacuum pump is: A temperature sensor is placed to measure the temperature of the vacuum pump. A rotation speed detection device is installed to detect the rotation speed of the vacuum pump. Electrically connect a vacuum pump, a temperature sensor, and a rotation speed detection device to obtain the measured value of the temperature sensor and the detected value of the rotation speed detection device, and while controlling the rotation speed of the vacuum pump, store the control content of normal operation and corrosion progress reduction operation as abnormal operation, and arrange a control unit that controls various operations of the vacuum pump according to the control content. When it is determined that the control unit switches from normal operation to corrosion progress reduction operation, in the corrosion progress reduction operation, automatically control to reduce the rotation speed of the vacuum pump more than in normal operation so that the measured value of the temperature sensor converges to a set temperature for corrosion progress reduction operation lower than the set temperature for normal operation. It is characterized by this.

[0017] In this operation method of the vacuum pump, When it is determined that the control unit switches from corrosion progress reduction operation to normal operation, it is preferable to automatically control to reduce the rotation speed of the vacuum pump to 20% or more and 60% or less of that in normal operation as the corrosion progress reduction operation, and it is more preferable to automatically control to reduce the rotation speed of the vacuum pump to 20% or more and 50% or less.

[0018] In this operation method of the vacuum pump, Arrange a heater unit for heating the vacuum pump. Arrange a cooling unit for cooling the vacuum pump. Arrange a hot purge gas supply unit that can adjust the temperature and supplies a dilution hot purge gas adjusted to the purge gas set temperature. Electrically connect the heater unit, the cooling unit, and the hot purge gas supply unit to the control unit respectively, and cause the control unit to control the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the purge gas set temperature of the hot purge gas supply unit. When it is determined that the operation mode is to be switched from the normal operation mode to the corrosion progression reduction operation mode, as the corrosion progression reduction operation, the measured value of the temperature sensor is converged to the set temperature for the corrosion progression reduction operation mode. It is preferable to automatically control so as to lower the heating capacity of the heater unit, increase the cooling capacity of the cooling unit, and lower the purge gas set temperature of the hot purge gas supply unit compared to the normal operation mode.

[0019] Also, in this operation method of the vacuum pump, When it is determined that the control unit is to switch from the corrosion progression reduction operation to the normal operation, as the normal operation, the measured value of the temperature sensor is converged to the set temperature for the normal operation. It is preferable to automatically control so as to increase the rotation speed of the vacuum pump, increase the heating capacity of the heater unit, lower the cooling capacity of the cooling unit, and increase the purge gas set temperature of the hot purge gas supply unit compared to the corrosion progression reduction operation.

[0020] Also, in this operation method of the vacuum pump, It is preferably configured to include a cooling plate installed on the surface of the vacuum pump for the cooling unit and a variable valve capable of adjusting the amount of cooling water supplied to the cooling plate, and the control unit adjusts the opening degree of the variable valve to automatically control the cooling capacity.

[0021] Also, in this operation method of the vacuum pump, The vacuum pump is configured in multiple stages with a booster pump arranged on the intake side and a dry pump arranged on the exhaust side. When it is determined that the control unit is to switch from the normal operation to the corrosion progression reduction operation, it is preferable to perform at least the automatic control on the dry pump.

[0022] Also, in this operation method of the vacuum pump, it is preferable that the corrosion progression reduction operation is performed as the cleaning operation when the gas to be inhaled is replaced with a cleaning gas to clean the inside. [Effects of the Invention]

[0023] According to the vacuum pump system and vacuum pump operating method of the present invention, the risk of corrosion can be reduced even when the vacuum pump is operated under normal conditions at high temperatures. [Brief explanation of the drawing]

[0024] [Figure 1] This is a diagram illustrating the configuration of a vacuum pump system according to an embodiment. [Figure 2] Figure 1 is a diagram showing the configuration of the cooling section in the vacuum pump system. [Figure 3] This graph shows an example of the temperature change of the vacuum pump when switching from normal operation mode to cleaning operation mode in the vacuum pump system shown in Figure 1. [Figure 4] This graph shows an example of the temperature change of the vacuum pump when switching from cleaning operation mode to normal operation mode in the vacuum pump system shown in Figure 1. [Modes for carrying out the invention]

[0025] A vacuum pump system as one embodiment to which the present invention is applied will be described below with reference to the drawings. Note that Figures 1 and 2 do not necessarily show all configurations when the present invention is applied strictly, and Figures 3 and 4 show an example of when the present invention is applied.

[0026] (Vacuum pump system configuration) Figure 1 is a configuration diagram of a vacuum pump system 1 according to an embodiment, and Figure 2 is a configuration diagram of the cooling unit 20 in the vacuum pump system 1. As shown in Figure 1, the vacuum pump system 1 includes a pump housing 2, which is a frame that houses a device that performs pumping functions, and a vacuum pump 3 that is located inside the pump housing 2 and pumps and discharges the inhaled gas. For example, the vacuum pump 3 is composed of two stages: a front-stage mechanical booster pump 3A (hereinafter simply referred to as "booster pump 3A") located on the intake side and a rear-stage dry pump 3B located on the exhaust side. The intake port 4 of the vacuum pump system 1 extends from the booster pump 3A and opens upward on the top surface of the pump housing 2. The exhaust port 5 of the vacuum pump system 1 extends from the dry pump 3B and opens laterally on the side surface of the pump housing 2. The booster pump 3A and the dry pump 3B are connected by internal piping. The vacuum pump system 1 is used in semiconductor manufacturing sites and the like, with the intake port 4 connected to a vacuum chamber CH via external piping. The vacuum pump system 1 draws gas in from the intake port 4, passes it through the booster pump 3A and then the dry pump 3B in that order, and discharges it from the exhaust port 5, thereby creating a vacuum in the container connected to the intake port 4. The type of each pump is appropriately selected from various types of vacuum pumps such as Roots type, screw type, rotary vane type, claw type, diaphragm type, and scroll type.

[0027] Furthermore, the vacuum pump system 1 has multiple operating modes, including a normal operating mode for vacuuming the gas inside a target container, and at least one non-normal operating mode that differs from the normal operating mode. As one of these non-normal operating modes, the vacuum pump system 1 has a cleaning operating mode for cleaning the inside by replacing the gas drawn in between normal operating modes with a cleaning gas. The vacuum pump 3 is operated according to the operating mode selected from among the multiple operating modes, including the normal operating mode and the cleaning operating mode, and pumps and discharges the drawn-in gas. The vacuum pump system 1 has an operating mode selection input unit 6 located on the surface of the pump housing 2 for selecting and inputting the operating mode of the vacuum pump 3. The operating mode selection input unit 6 is an input device that can be selected from an operation panel, a changeover switch, etc., and is electrically connected to the control unit 40 described later. By operating the operating mode selection input unit 6, the operator can instruct the control unit 40 to switch the operating mode of the vacuum pump 3.

[0028] Furthermore, the vacuum pump system 1 is equipped with detection elements such as measuring devices or detection sensors, and each detection element detects operating parameters representing the operating state of the vacuum pump 3 from various perspectives. For example, the booster pump 3A and dry pump 3B of the vacuum pump system 1 are equipped with temperature sensors 7, which can measure the case temperature of the booster pump 3A and dry pump 3B, respectively. In addition, the booster pump 3A and dry pump 3B of the vacuum pump system 1 are equipped with rotation speed detection devices 8, which can detect the rotation speed of the booster pump 3A and dry pump 3B, respectively. The rotation speed detection device 8 includes not only devices that detect the actual rotation speed, but also devices that can determine the rotation speed by analyzing the digital signal used to instruct the rotation speed of a rotating body, and is selected as appropriate from a variety of methods. Also, although several temperature sensors 7 are shown in Figure 1, these are examples, and the installation location and number of temperature sensors 7 are set as appropriate so that the temperature conditions of the necessary parts can be understood.

[0029] Furthermore, the vacuum pump system 1 includes a heater unit 10 for heating at least the dry pump 3B of the vacuum pump 3, a cooling unit 20 for cooling at least the dry pump 3B of the vacuum pump 3, and a hot purge gas supply unit 30 for supplying hot purge gas to the vacuum pump 3.

[0030] The heater unit 10 has a heat source that generates heat electrically and is electrically connected to the control unit 40, which will be described later. The heat source of the heater unit 10 can be turned ON / OFF based on a command from the control unit 40. In semiconductor manufacturing processes and the like, the heater unit 10 heats the vacuum pump 3 when it is required to operate at a high temperature depending on the gas used. In Figure 1, the heater unit 10 is depicted as being located only on the exhaust side of the dry pump 3B, which is relatively hot, but the shape, power, location, number of heat sources, etc. can be appropriately set to heat the vacuum pump 3 based on the requirement for high temperature.

[0031] The cooling unit 20, also referring to Figure 2, includes a cooling water supply source 21 for supplying cooling water and a cooling plate 22 installed on the surface of the dry pump 3B. The cooling water supply source 21 and the cooling plate 22 are connected via piping, and cooling water is supplied to the cooling plate 22 from the cooling water supply source 21. The cooling unit 20 also includes a variable valve 23 in the piping connecting the cooling water supply source 21 and the cooling plate 22, whose opening degree can be adjusted by an electrical command. The variable valve 23 is electrically connected to the control unit 40, which will be described later. Based on a command from the control unit 40, the cooling unit 20 can adjust the amount of cooling water supplied to the cooling plate 22 by the variable valve 23. The cooling unit 20 concentrates the cooling of the dry pump 3B by the cooling plate 22 exchanging heat with the dry pump 3B, and the cooling capacity for the dry pump 3B can be changed by adjusting the amount of cooling water supplied to the cooling plate 22. Furthermore, the piping of the cooling unit 20 is branched into two upstream of the variable valve 23. One branch flows to the cooling plate 22 as described above, while the other branch is a bypass pipe 24 that bypasses the cooling plate 22 and discharges the water. This ensures that the cooling unit 20 has a route for discharging cooling water other than the cooling water that has become hot due to heat exchange with the dry pump 3B by flowing the cooling water through the bypass pipe 24. In this embodiment of the vacuum pump system 1, the cooling unit 20 is configured to be located only on the exhaust side, which is the dry pump 3B side, where the temperature is relatively high. However, although this has the disadvantage of increasing costs, it is preferable to also place a cooling means on the booster pump 3A side that is the same as the cooling unit 20 located on the dry pump 3B side, in order to cool the entire vacuum pump 3 more efficiently.

[0032] The hot purge gas supply unit 30 is temperature-adjustable and can supply hot purge gas adjusted to the set purge gas temperature. Generally, an inert gas such as nitrogen is used as the hot purge gas. The hot purge gas supply unit 30 is installed inside or outside the pump housing 2 and is connected to the vacuum pump 3. The hot purge gas supply unit 30 supplies high-temperature purge gas to dilute the gas drawn in from the vacuum chamber CH during normal operation mode, and relatively low-temperature purge gas to replace the gas in the vacuum pump 3 during cleaning operation mode. The hot purge gas supply unit 30 has a heat source for heating the hot purge gas, a hot purge gas temperature adjustment function unit for adjusting the temperature of the hot purge gas, etc. The hot purge gas supply unit 30 is electrically connected to the control unit 40 described later, and based on commands from the control unit 40, the hot purge gas temperature adjustment function unit can adjust the heat source and supply the hot purge gas at the correct temperature.

[0033] Furthermore, the vacuum pump system 1 is electrically connected to the vacuum pump 3 (booster pump 3A and dry pump 3B respectively), the operating mode selection input unit 6, the temperature sensors 7, the rotation speed detection devices 8, the heater unit 10, the cooling unit 20, the hot purge gas supply unit 30, and other electronic devices, and includes a control unit 40 for controlling the entire system.

[0034] The control unit 40 is a computer device that includes a memory unit and a calculation unit. According to the control program stored in the memory unit, it can automatically control electrically connected equipment to ensure the entire system functions, while obtaining information from electrically connected detection elements and input devices. For example, the memory unit of the control unit 40 stores the operating procedures of the vacuum pump 3 and control values ​​for each device in various operating modes, such as the normal operating mode for vacuuming gas from a target container such as a vacuum chamber CH, and the cleaning operating mode for cleaning the inside by replacing the intake gas with a cleaning gas. The control unit 40 also acquires the measured value from the temperature sensor 7, the detected value from the rotation speed detection device 8, and the selected input from the operating mode selection input unit 6, and temporarily stores them in the memory unit. The control unit 40 also refers to this input and stored information to determine the operating mode to be executed and controls the operation of the vacuum pump 3 according to the operating mode. At this time, the control unit 40 can automatically control the rotation speed of the vacuum pump 3 (booster pump 3A and dry pump 3B respectively), the heating capacity of the heater unit 10, the cooling capacity of the cooling unit 20, and the purge gas setting temperature of the hot purge gas supply unit 30 while changing them. The control unit 40, as is done in conventional vacuum pump systems, is responsible for controlling not only the operation but also various other system functions such as processing input instructions made to the operating members, displaying information on the display panel, monitoring the operating status, and communicating with external devices. The characteristic operation control according to the present invention will be described in more detail below.

[0035] (Characteristic operating control in vacuum pump system 1) Figure 3 is a graph showing the temperature change of the vacuum pump 3 when switching from the normal operation mode to the cleaning operation mode in the vacuum pump system 1, and Figure 4 is a graph showing the temperature change of the vacuum pump when switching from the cleaning operation mode to the normal operation mode. Referring to these figures, the characteristic operation control of the vacuum pump system 1, specifically the operation control of the vacuum pump 3 based on the normal operation mode and the cleaning operation mode in the vacuum pump system 1, will be explained.

[0036] As described above, in a vacuum pump system 1, the intake port 4 is connected to a vacuum chamber CH via external piping, and the vacuum pump 3, operating in normal mode, evacuates the gas inside the vacuum chamber CH in semiconductor manufacturing sites and the like. Depending on the gas used, agglutinating reaction byproducts may be generated, and it is effective to raise the temperature of the vacuum pump 3 using the heater unit 10 to suppress the reaction of these byproducts. Thus, in order to accommodate the high temperature of the vacuum pump 3, in the vacuum pump system 1, the rated temperature of the vacuum pump 3 (at least the dry pump 3B), the rated temperature (heating capacity) of the heater unit 10, and the rated temperature of the hot purge gas are set to a relatively high temperature in normal operation mode. Furthermore, in the vacuum pump system 1, since there is a demand for high pumping speed and atmospheric flow rate, the rated rotational speed of the vacuum pump 3 (rated rotational speed of the booster pump 3A and the rated rotational speed of the dry pump 3B) is set to a relatively high rotational speed in normal operation mode. Furthermore, in vacuum pump 3, the degree of compression of the gas inside increases and the temperature rises as you move towards the exhaust side.

[0037] Furthermore, in the vacuum pump system 1, the gas drawn in during normal operation often precipitates and adheres as reaction byproducts in the intake piping, inside the pump, and in the exhaust piping. Therefore, it is necessary to periodically replace the drawn-in gas with an active gas such as hydrogen fluoride to clean the inside of the vacuum pump 3. At this time, if the vacuum pump 3 remains at a high temperature under the same operating conditions as in normal operation, the risk of corrosion increases. For this reason, the vacuum pump system 1 has a cleaning operation mode separate from the normal operation mode, which is used to clean the inside of the vacuum pump 3 by replacing it with a cleaning gas, as described above. For this reason, in the cleaning operation mode of the vacuum pump system 1, the set temperature of the vacuum pump 3 (at least the dry pump 3B), the set temperature of the heater unit 10, and the set temperature of the hot purge gas are changed to a lower temperature than the rated temperature in normal operation mode. More specifically, in the vacuum pump system 1, in cleaning operation mode, the set temperature of the vacuum pump 3 (at least the dry pump 3B), the set temperature of the heater unit 10, and the set temperature of the hot purge gas are preferably changed to 20% to 60%, and more preferably to 20% to 50%, of the rated temperature in normal operation mode. Also, since a higher rotational speed of the vacuum pump 3 results in a higher temperature, in the vacuum pump system 1, in cleaning operation mode, the set rotational speed of the vacuum pump 3 (at least the set rotational speed of the dry pump 3B) is preferably changed to 20% to 60%, and more preferably to 20% to 50%, of the rated rotational speed in normal operation mode.

[0038] In the vacuum pump system 1, the control unit 40 determines to set the operating mode to normal operation mode based on an instruction from the operating mode selection input unit 6 to operate the vacuum pump 3 in normal operation, or an instruction pre-programmed to operate the vacuum pump 3 in normal operation, and performs automatic operation control in normal operation mode. At this time, the control unit 40 provides feedback control to the heater unit 10, the cooling unit 20, and the hot purge gas supply unit 30 so that the temperature of the vacuum pump 3 (at least the temperature of the dry pump 3B) reaches the rated temperature while monitoring the temperature detected from the temperature sensor 7. At this time, the control unit 40 also instructs each rotation speed detection device 8 to perform automatic control in normal operation mode.

[0039] On the other hand, in the vacuum pump system 1, the control unit 40 determines to set the operating mode to cleaning operation mode based on an instruction from the operating mode selection input unit 6 to perform cleaning operation on the vacuum pump 3, or an instruction pre-programmed to perform cleaning operation on the vacuum pump 3, and performs automatic operation control as cleaning operation mode. At this time, the control unit 40 provides feedback control to the heater unit 10, the cooling unit 20, and the hot purge gas supply unit 30 so that the temperature of the vacuum pump 3 (at least the temperature of the dry pump 3B) reaches the set temperature for cleaning operation mode, while observing the temperature detected from the temperature sensor 7. At this time, the control unit 40 also instructs each rotation speed detection device 8 to perform automatic control as cleaning operation mode.

[0040] In the vacuum pump system 1, the vacuum pump 3 is periodically cleaned between normal operation. In the vacuum pump system 1, when switching from normal operation to cleaning operation, the control unit 40 determines to switch the operation mode from normal operation mode to cleaning operation mode based on an instruction to perform cleaning operation on the vacuum pump 3 from the operation mode selection input unit 6 or a pre-programmed instruction to perform cleaning operation on the vacuum pump 3. Then, the control unit 40 automatically controls the vacuum pump 3 to reduce the rotation speed of the vacuum pump 3 (booster pump 3A and dry pump 3B), reduce the heating capacity of the heater unit 10, increase the cooling capacity of the cooling unit 20, and lower the set temperature of the purge gas supply unit 30, so that the measured value of the temperature sensor 7 (for example, the measured value of the temperature sensor 7 that measures the surface temperature of the dry pump 3B) converges to a set temperature for cleaning operation mode that is lower than the set temperature for normal operation mode (rated temperature). In this state, the control unit 40 automatically controls the rotation speed of the vacuum pump 3 to be 20% to 60% or less compared to the normal operation mode, and more preferably to be 20% to 50% or less, as a cleaning operation mode. At this time, the control unit 40 also automatically controls the cooling capacity by adjusting the opening degree of the variable valve 23. As a result, the temperature of the vacuum pump 3 is automatically lowered when starting the cleaning operation, as shown in Figure 3 as an example.

[0041] On the other hand, when switching from cleaning operation to normal operation, the control unit 40 determines to switch the operation mode from cleaning operation mode to normal operation mode based on instructions pre-programmed to operate the vacuum pump 3 in normal operation, such as when the operation mode selection input unit 6 instructs the vacuum pump 3 to operate in normal operation mode, or when the cleaning operation is completed. In this case, the control unit 40 automatically controls the vacuum pump 3 to increase the rotation speed of the vacuum pump 3 (booster pump 3A and dry pump 3B), increase the heating capacity of the heater unit 10, decrease the cooling capacity of the cooling unit 20, and increase the set temperature of the purge gas in the hot purge gas supply unit 30, so that the measured value of the temperature sensor 7 (for example, the measured value of the temperature sensor 7 that measures the surface temperature of the dry pump 3B) converges to the set temperature (rated temperature) for normal operation mode.

[0042] As described above, in the vacuum pump system 1, during cleaning operation, the control unit 40 automatically controls the vacuum pump 3 so that the value measured by the temperature sensor 7 converges to a set temperature for the cleaning operation mode, which is lower than the set temperature for the normal operation mode (rated temperature). This lowers the internal temperature of the vacuum pump 3 and reduces the risk of corrosion of the vacuum pump 3. In this vacuum pump system 1, the cleaning operation performed according to the cleaning operation mode is a corrosion reduction operation performed according to the corrosion reduction operation mode, which lowers the internal temperature of the vacuum pump 3 to reduce the progression of corrosion. In the embodiment, when the intake gas is replaced with a cleaning gas to clean the inside, the corrosion reduction operation is performed as a cleaning operation. However, the corrosion reduction operation according to the corrosion reduction operation mode can be applied even when the intake gas is not a cleaning gas, i.e., before and after normal operation. Hereafter, what has been described above as a cleaning operation according to the cleaning operation mode will also be referred to as a corrosion reduction operation according to the corrosion reduction operation mode.

[0043] (Effects / Actions) The vacuum pump system 1 is a vacuum pump system having at least multiple operating modes, including a normal operating mode and a corrosion progression reduction operating mode, and includes a vacuum pump 3 that operates according to the selected operating mode. The vacuum pump system 1 also includes a temperature sensor 7 for measuring temperature and a rotation speed detection device 8 for detecting rotation speed, connected to the vacuum pump 3. Furthermore, the vacuum pump system 1 includes a control unit 40 that is electrically connected to the vacuum pump 3, temperature sensor 7, and rotation speed detection device 8 and can control each of the electrically connected parts. In the vacuum pump system 1, when the control unit 40 determines to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it automatically controls the system so that the measured value of the temperature sensor 7 converges to a set temperature for corrosion progression reduction operation that is lower than the set temperature for the normal operating mode. Specifically, it automatically controls the rotation speed of the vacuum pump 3 to be lower than in the normal operating mode. Therefore, with the vacuum pump system 1, even when the vacuum pump 3 is normally operated at a high temperature, the system automatically controls the system to reliably avoid high temperatures in the corrosion progression reduction operation mode, thereby reducing the risk of corrosion to the vacuum pump 3. Furthermore, with the vacuum pump system 1, since the control unit 40 controls each part, the risk of corrosion can be reduced without requiring any operational effort from the vacuum pump 3.

[0044] Furthermore, the vacuum pump system 1 includes a heater unit 10 for heating, a cooling unit 20 for cooling, and a hot purge gas supply unit 30 for supplying hot purge gas at a controlled temperature. The control unit 40 is electrically connected to the heater unit 10, the cooling unit 20, and the hot purge gas supply unit 30, and can control the heating capacity of the heater unit 10, the cooling capacity of the cooling unit 20, and the purge gas set temperature of the hot purge gas supply unit 30. When the control unit 40 determines that it is time to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it automatically reduces the heating capacity of the heater unit 10, increases the cooling capacity of the cooling unit 20, and lowers the purge gas set temperature of the hot purge gas supply unit 30 compared to the normal operating mode. As a result, the vacuum pump system 1 can be automatically controlled to converge the measured value of the temperature sensor 7 to the set temperature for corrosion progression reduction operation, which is lower than the set temperature for the normal operating mode, in a shorter time.

[0045] Furthermore, in the vacuum pump system 1, when the control unit 40 determines that it is time to switch the operating mode from the corrosion progression reduction operating mode to the normal operating mode, it automatically controls the system to increase the rotation speed of the vacuum pump 3, increase the heating capacity of the heater unit 10, decrease the cooling capacity of the cooling unit 20, and raise the purge gas setting temperature of the hot purge gas supply unit 30, so that the measured value of the temperature sensor 7 converges to the set temperature for the normal operating mode.

[0046] Furthermore, in this vacuum pump system 1, the cooling unit 20 has a cooling plate 22 installed on the surface of the vacuum pump 3 and a variable valve 23 that can adjust the amount of cooling water supplied to the cooling plate 22, and the control unit 40 automatically controls the cooling capacity by adjusting the opening degree of the variable valve 23. With this configuration, a system can be constructed in which the control unit 40 can easily adjust the temperature during corrosion reduction operation of the vacuum pump 3.

[0047] In the corrosion reduction operation mode of the vacuum pump system 1, the rotational speed of the vacuum pump 3 is reduced, the heating capacity of the heater unit 10 is reduced, and the purge gas setting temperature of the hot purge gas supply unit 30 is lowered compared to the normal operation mode. Therefore, the corrosion reduction operation mode consumes less power than the normal operation mode. For this reason, the corrosion reduction operation mode can also be used to obtain benefits other than lowering the temperature of the vacuum pump 3.

[0048] (How to operate a vacuum pump) We have so far described the vacuum pump system 1 in which the vacuum pump 3 is packaged. The operating method of the vacuum pump 3 in the vacuum pump system 1 can be applied to existing vacuum pump operating methods that aim to perform corrosion progression reduction operation (for example, corrosion progression reduction operation as a cleaning operation) as an abnormal operation different from normal operation, and this will be explained below. For the sake of explanation, we will use symbols corresponding to the vacuum pump system 1.

[0049] To apply this to existing vacuum pump operation methods, first, a temperature sensor 7 for measuring the temperature of the vacuum pump 3 and a rotation speed detection device 8 for detecting the rotation speed of the vacuum pump 3 are installed. In addition, a control unit 40 is installed that is electrically connected to the vacuum pump 3, temperature sensor 7, and rotation speed detection device 8 to acquire the measured values ​​of the temperature sensor 7 and the detected values ​​of the rotation speed detection device 8, and to control the rotation speed of the vacuum pump 3, as well as to store the control contents of normal operation and corrosion progression reduction operation as an abnormal operation, and to control various operations of the vacuum pump 3 according to the control contents.

[0050] Furthermore, a heater unit 10 for heating the vacuum pump 3, a cooling unit 20 for cooling the vacuum pump 3, and a hot purge gas supply unit 30 that is temperature-adjustable and supplies hot purge gas adjusted to the set purge gas temperature may also be provided. In this case, the provided heater unit 10, cooling unit 20, and hot purge gas supply unit 30 are electrically connected to the control unit 40, and the control unit 40 controls the heating capacity of the heater unit 10, the cooling capacity of the cooling unit 20, and the set purge gas temperature of the hot purge gas supply unit 30.

[0051] Furthermore, when the control unit 40 determines to switch from normal operation to corrosion progression reduction operation mode, it automatically controls the rotation speed of the vacuum pump 3 to be lower than in normal operation so that the measured value of the temperature sensor 7 converges to a set temperature for corrosion progression reduction operation that is lower than the set temperature for normal operation. At this time, it is preferable to automatically control the rotation speed of the vacuum pump 3 to be reduced by 20% to 60% or more, and more preferably by 20% to 50% or more, compared to normal operation.

[0052] Furthermore, when the heater unit 10, cooling unit 20, and hot purge gas supply unit 30 are arranged, the control unit 40 is instructed to automatically control the system to reduce corrosion progression, thereby lowering the heating capacity of the heater unit 10, increasing the cooling capacity of the cooling unit 20, and lowering the purge gas setting temperature of the hot purge gas supply unit 30 compared to normal operation, so that the measured value of the temperature sensor 7 converges to a setting temperature for corrosion progression reduction operation that is lower than the setting temperature for normal operation. In this case, it is preferable to configure the cooling unit 20 to include a cooling plate 22 installed on the surface of the vacuum pump 3 and a variable valve 23 that can adjust the amount of cooling water supplied to the cooling plate 22, and to have the control unit 40 automatically control the cooling capacity by adjusting the opening degree of the variable valve 23.

[0053] Furthermore, when the control unit 40 determines to switch from corrosion progression reduction operation to normal operation, it is preferable to automatically control the system to increase the rotation speed of the vacuum pump 3, increase the heating capacity of the heater unit 10, decrease the cooling capacity of the cooling unit 20, and increase the cleaning gas setting temperature of the cleaning gas supply unit 30, in order to converge the measured value of the temperature sensor 7 to the set temperature for normal operation, compared to corrosion progression reduction operation.

[0054] Alternatively, the vacuum pump 3 may be configured as a multi-stage system consisting of a booster pump 3A located on the intake side and a dry pump 3B located on the exhaust side. In this case, the control unit 40 is instructed to perform automatic control on at least the dry pump 3B when it determines that it is time to switch from normal operation to corrosion progression reduction operation.

[0055] Since this method of operating a vacuum pump is controlled in the same way as the vacuum pump system 1, it produces the same effects as when using the vacuum pump system 1, and even when the vacuum pump is normally operated at high temperatures, it can be operated in an unconventional manner while reducing the risk of corrosion.

[0056] (Other forms) Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments. It can be implemented in various forms without departing from the spirit of the invention, and for example, the following modifications are also possible.

[0057] (1) The vacuum container, the number of components, their positions, temperature changes, temperature control means, type of hot purge gas, etc., described in the above embodiment are examples and can be changed within the scope that does not impair the effects of the present invention.

[0058] (2) In the embodiments described above, the vacuum pump system 1 was described as comprising a multi-stage vacuum pump 3 consisting of a booster pump 3A and a dry pump 3B, but the present invention is not limited thereto. The vacuum pump can perform normal operation as well as corrosion progression reduction operation, and may consist of one stage or multiple stages.

[0059] (3) In the embodiments described above, the vacuum pump system 1 was described using Figure 1 as having a vacuum pump 3, a heater unit 10, a cooling unit 20, a hot purge gas supply unit 30, and a control unit 40 arranged inside the pump housing 2, but the present invention is not limited thereto. The way in which each part is enclosed in a frame such as the pump housing 2 is arbitrary, and for example, the control panel as the control unit may be located outside the frame, or the hot purge gas supply unit may be located outside the frame.

[0060] (4) In the embodiments described above, Figures 3 and 4 were used to illustrate an example in which normal operation and corrosion progression reduction operation as a cleaning operation are performed continuously without interruption. However, the present invention is not limited thereto. For example, there may be a temporary pause between normal operation and corrosion progression reduction operation, or operation in a different operating mode other than the normal operation mode and corrosion progression reduction operation mode may be interspersed.

[0061] (5) In the above-described embodiment, it was explained that when switching from normal operation to corrosion progression reduction operation, the rotation speed of the vacuum pump 3 is reduced, the heating capacity of the heater unit 10 is reduced, the cooling capacity of the cooling unit 20 is increased, and the purge gas setting temperature of the hot purge gas supply unit 30 is lowered compared to normal operation in order to lower the temperature of the vacuum pump 3 compared to normal operation. On the other hand, it was explained that when switching from corrosion progression reduction operation to normal operation, the rotation speed of the vacuum pump 3 is increased, the heating capacity of the heater unit 10 is increased, the cooling capacity of the cooling unit 20 is reduced, and the purge gas setting temperature of the hot purge gas supply unit 30 is raised compared to corrosion progression reduction operation in order to raise the temperature of the vacuum pump 3 compared to corrosion progression reduction operation. Regarding the adjustment of the rotational speed of the vacuum pump 3, the heating capacity of the heater unit 10, the cooling capacity of the cooling unit 20, and the cleaning gas set temperature of the cleaning gas supply unit 30, it is preferable to start the control simultaneously in order to complete the temperature change quickly, but the control of each unit may be started with a time delay as appropriate. Furthermore, the system may not have all of these units (at least one may be provided), and at least one of the following items—the rotational speed of the vacuum pump 3, the heating capacity of the heater unit 10, the cooling capacity of the cooling unit 20, and the purge gas set temperature of the hot purge gas supply unit 30—may be automatically controlled. [Explanation of Symbols]

[0062] 1...Vacuum pump system, 2...Pump housing, 3...Vacuum pump, 3A...Mechanical booster pump (booster pump), 3B...Dry pump, 4...Intake port, 5...Exhaust port, 6...Operating mode selection input, 7...Temperature sensor, 8...Rotation speed detection device, 10...Heater unit, 20...Cooling unit, 21...Cooling water supply source, 22...Cooling plate, 23...Variable valve, 24...Bypass piping, 30...Hot purge supply unit, 40...Control unit, CH...Vacuum chamber

Claims

1. A vacuum pump system having multiple operating modes, including a normal operating mode for vacuuming gas from a target container, and at least one non-normal operating mode different from the normal operating mode, A vacuum pump that pressurizes and discharges the inhaled gas, A temperature sensor for measuring the temperature of the vacuum pump, A rotation speed detection device for detecting the rotation speed of the vacuum pump, The vacuum pump, the temperature sensor, and the rotational speed detection device are electrically connected to the control unit, which is capable of acquiring the measured value of the temperature sensor and the detected value of the rotational speed detection device, as well as controlling the rotational speed of the vacuum pump, and which stores the plurality of operating modes and operates the vacuum pump according to the operating mode selected from the plurality of operating modes. The control unit stores a corrosion progression reduction operation mode as one of the non-normal operation modes, and when it determines to switch the operation mode from the normal operation mode to the corrosion progression reduction operation mode, it automatically controls the rotation speed of the vacuum pump to be lower than in the normal operation mode so that the measured value of the temperature sensor converges to a set temperature for the corrosion progression reduction operation mode that is lower than the set temperature for the normal operation mode. A vacuum pump system characterized by the following features.

2. In the vacuum pump system according to claim 1, When the control unit determines that it is time to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it automatically controls the rotation speed of the vacuum pump to be reduced to preferably 20% to 60%, and more preferably 20% to 50%, compared to the normal operating mode, as the corrosion progression reduction operating mode. Vacuum pump system.

3. In the vacuum pump system according to claim 1, A heater unit for heating the vacuum pump, A cooling unit for cooling the vacuum pump, A hot purge gas supply unit that supplies a hot purge gas for dilution, which is temperature-adjustable and adjusted to the set temperature of the purge gas, Furthermore, The control unit is electrically connected to the heater unit, the cooling unit, and the hot purge gas supply unit, and is capable of controlling the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the purge gas set temperature of the hot purge gas supply unit. When it is determined to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, the control unit automatically controls the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the purge gas set temperature of the hot purge gas supply unit to decrease compared to the normal operating mode, so that the measured value of the temperature sensor converges to the set temperature for the corrosion progression reduction operating mode. Vacuum pump system.

4. In the vacuum pump system according to claim 3, When the control unit determines that it is time to switch the operating mode from the corrosion progression reduction operating mode to the normal operating mode, it automatically controls the vacuum pump rotation speed, the heating capacity of the heater section, the cooling capacity of the cooling section, and the purge gas setting temperature of the hot purge gas supply section to increase the rotation speed of the vacuum pump, increase the heating capacity of the heater section, decrease the cooling capacity of the cooling section, and increase the purge gas setting temperature of the hot purge gas supply section, so that the measured value of the temperature sensor converges to the set temperature for the normal operating mode. Vacuum pump system.

5. In the vacuum pump system according to claim 4, The cooling unit includes a cooling plate installed on the surface of the vacuum pump, and a variable valve capable of adjusting the amount of cooling water supplied to the cooling plate. The control unit automatically controls the cooling capacity by adjusting the opening degree of the variable valve. Vacuum pump system.

6. In the vacuum pump system according to claim 5, The vacuum pump comprises a booster pump located on the intake side and a dry pump located on the exhaust side in a multi-stage configuration. The control unit performs automatic control on at least the dry pump when it determines to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode. Vacuum pump system.

7. A vacuum pump system according to any one of claims 1 to 6, wherein in addition to normal operation according to the normal operating mode, a cleaning operation is performed to clean the inside by replacing the intake gas with a cleaning gas, In the cleaning operation, the control unit performs automatic control according to the corrosion progression reduction operation mode. Vacuum pump system.

8. A method for operating a vacuum pump, wherein the vacuum pump is made to perform at least one non-normal operation different from the normal operation, in addition to the normal operation for vacuuming the gas inside a target container, A temperature sensor is provided to measure the temperature of the vacuum pump. A rotation speed detection device is provided to detect the rotation speed of the vacuum pump. A control unit is provided that electrically connects the vacuum pump, the temperature sensor, and the rotational speed detection device to acquire the measured value from the temperature sensor and the detected value from the rotational speed detection device, and to control the rotational speed of the vacuum pump, as well as to store the control contents of the normal operation and the corrosion progression reduction operation as an abnormal operation, and to control various operations of the vacuum pump according to the said control contents. When the control unit determines to switch from normal operation to corrosion reduction operation, it automatically controls the vacuum pump to reduce its rotation speed compared to normal operation so that the measured value of the temperature sensor converges to a set temperature for corrosion reduction operation that is lower than the set temperature for normal operation. A method for operating a vacuum pump, characterized by the features described above.

9. In the method for operating a vacuum pump according to claim 8, When the control unit determines to switch from the corrosion progression reduction operation to the normal operation, it automatically controls the vacuum pump to reduce its rotation speed to preferably 20% to 60%, and more preferably 20% to 50%, compared to the normal operation, as part of the corrosion progression reduction operation. How to operate a vacuum pump.

10. In the method for operating a vacuum pump according to claim 8, A heater unit for heating the vacuum pump is provided. A cooling unit is provided for cooling the vacuum pump, A hot purge gas supply unit is provided that supplies a hot purge gas for dilution, which is temperature-adjustable and adjusted to the set temperature of the purge gas. The heater unit, the cooling unit, and the hot purge gas supply unit are electrically connected to the control unit, respectively, and the control unit controls the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the set temperature of the purge gas in the hot purge gas supply unit. When the control unit determines to switch the operating mode from the normal operating mode to the corrosion progression reduction operating mode, it automatically controls the heating capacity of the heater unit, the cooling capacity of the cooling unit, and the set temperature of the purge gas in the hot purge gas supply unit to decrease compared to the normal operating mode, so that the measured value of the temperature sensor converges to the set temperature for the corrosion progression reduction operating mode. How to operate a vacuum pump.

11. In the method for operating a vacuum pump according to claim 10, When the control unit determines to switch from the corrosion progression reduction operation to the normal operation, it automatically controls the vacuum pump to increase its rotation speed, the heating capacity of the heater section, the cooling capacity of the cooling section, and the purge gas setting temperature of the hot purge gas supply section to converge the measured value of the temperature sensor to the set temperature for the normal operation, compared to the corrosion progression reduction operation. How to operate a vacuum pump.

12. In the method for operating a vacuum pump according to claim 11, The cooling unit is configured to include a cooling plate installed on the surface of the vacuum pump, and a variable valve capable of adjusting the amount of cooling water supplied to the cooling plate. The control unit adjusts the opening degree of the variable valve to automatically control the cooling capacity. How to operate a vacuum pump.

13. In the method for operating a vacuum pump according to claim 12, The vacuum pump is configured in a multi-stage configuration, consisting of a booster pump located on the intake side and a dry pump located on the exhaust side. The control unit is instructed to perform automatic control on the dry pump when it determines to switch from normal operation to corrosion progression reduction operation. How to operate a vacuum pump.

14. A method for operating a vacuum pump according to any one of claims 8 to 13, wherein the corrosion progression reduction operation is performed as a cleaning operation when cleaning the inside by replacing the intake gas with a cleaning gas.

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