JP6875048B2 - Vacuum pump, vacuum pump cooling device, vacuum pump cooling method, vacuum exhaust system, and vacuum pump maintenance method - Google Patents

Description

The present invention relates to a vacuum pump, a vacuum pump cooling device, a vacuum pump cooling method, a vacuum exhaust system, and a vacuum pump maintenance method.

The vacuum state is currently used in a wide range of fields in industrial technology. For example, promoting the evaporation of water is for vacuum drying, and reducing intermolecular collisions is for various electron tubes, vapor deposition, and vacuum. It is used for money-making. Of the vacuum pumps, the rotary pump is the most common one, which is assembled eccentrically to the body and sucks and discharges air by a blade or a rotor rotating along the inner wall to create a vacuum. As one kind of this rotary pump, a vacuum for forming a vacuum atmosphere in a manufacturing process (for example, CVD process) of a semiconductor, a liquid crystal, etc., and for forming a vacuum atmosphere up to about 0.133 Pa in other industrial technical fields. As a pump, a dry vacuum pump is widely used.

Such a dry vacuum pump is used, for example, with its suction side connected to a manufacturing device for semiconductors, liquid crystals, etc., and its exhaust side connected to an abatement device via a supplement device (trap). The trap is a device that captures reaction by-products (hereinafter, also simply referred to as products) contained in the process gas from the manufacturing apparatus, and can efficiently capture the products in a predetermined temperature range according to the products. Is. The abatement device burns the exhaust gas after passing through the trap to make it harmless.

When the gas to be exhausted by the vacuum pump is a process gas, the process gas may contain a product having a high sublimation temperature. In such a case, if the temperature of the vacuum pump is not higher than a predetermined temperature, there is a problem that the product solidifies and adheres to the exhaust pipe of the vacuum pump. Therefore, if the temperature of the exhaust pipe is raised in order to prevent the product from adhering to the exhaust pipe, the trap installed on the exhaust side of the vacuum pump may not be able to capture the product. It is considered that this is because the temperature of the gas flowing into the trap becomes higher than the temperature range suitable for capturing the product, and it becomes difficult to deposit the product in the trap.

As a countermeasure, it is conceivable to pass cooling water through the trap body, but depending on the system specifications, this countermeasure may not be adopted. For example, when the cooling water flow path of the vacuum pump is connected to the trap body and used, if the trap is provided with a connection port (for example, a coupler) for the cooling water flow path, the required flow rate may not be secured due to the pressure loss of the coupler.

Therefore, in such a case, it is desired that the prevention of the product from adhering to the exhaust pipe of the vacuum pump and the capture of the product by the trap can be achieved at the same time.

Systems including conventional vacuum pumps include, for example, those described in Patent Documents 1 and 2. Patent Document 1 describes that a cooling mechanism is connected to the intake port of the vacuum pump in order to prevent damage due to the temperature of the vacuum pump, but the control of the temperature of the exhaust flowing into the trap is mentioned. Not. In Patent Document 2, in order to suppress the thermal expansion of the rotor, a cooling pipe and a cooling plate are provided in the gas discharge flow path of the vacuum pump, and a cooling water channel is provided in the housing adjacent to the gas discharge flow path. It is stated that it will be provided. This vacuum pump cools not only the inside of the gas discharge flow path but also the inside of the pump section, and does not consider prevention of adhesion of the product to the gas discharge flow path.

Japanese Unexamined Patent Publication No. 2006-9686 Japanese Unexamined Patent Publication No. 2004-293375

An object of the present invention is to solve at least a part of the above-mentioned problems.

[1] The vacuum pump according to one aspect of the present invention includes a pump chamber having a suction port and a discharge port, and a pump chamber.
An exhaust pipe connected to the discharge port, the exhaust pipe comprising an exhaust pipe for guiding the exhaust from the pump chamber to the outside of the vacuum pump and a cooling device for cooling the exhaust pipe. It has a first exhaust pipe portion and a second exhaust pipe portion, the first exhaust pipe portion is connected to the exhaust port of the pump chamber, and the second exhaust pipe portion is from the first exhaust pipe portion. Is also a vacuum pump located at a position far from the exhaust port of the pump chamber and in which the cooling device is arranged in the second exhaust pipe portion. The first exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes. The second exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes.

According to this vacuum pump, since the cooling device is provided in the second exhaust pipe portion far from the exhaust port of the pump chamber, the gas in the second exhaust pipe portion is suitable for processing the gas in the second exhaust pipe portion at a desired temperature (processing of the capture device in the subsequent stage, etc.). It is possible to cool to (temperature), and it is possible to suppress or prevent the temperature of the pump chamber and the first exhaust pipe portion from dropping without cooling the first exhaust pipe portion near the exhaust port of the pump chamber. As a result, precipitation and adhesion of products in the pump chamber and the first exhaust pipe portion can be suppressed or prevented, and the temperature of the gas can be adjusted to a temperature suitable for processing of the subsequent device.

[2] In the vacuum pump according to the above [1], it is possible to further include a heat insulating member interposed between the first exhaust pipe portion and the second exhaust pipe portion.
In this case, since the first exhaust pipe portion and the second exhaust pipe portion are insulated by the heat insulating member, the influence of cooling by the cooling device of the second exhaust pipe portion is further suppressed from affecting the first exhaust pipe portion. Can be prevented.

[3] In the vacuum pump according to the above [2], the heat insulating member includes a resin annular ring interposed between the first exhaust pipe portion and the second exhaust pipe portion, and the first exhaust pipe. It is possible to have a resin clamp that connects the portion and the second exhaust pipe portion. The annular ring is, for example, an O-ring.
In this case, heat insulation and connection between the first exhaust pipe portion and the second exhaust pipe portion can be easily and surely performed by the resin annular ring and clamp. Further, a stainless steel or resin ring (inner ring, outer ring) may be provided inside and outside the resin annular ring (for example, O-ring), or only the inner ring may be provided. The inner ring and outer ring can be made of stainless steel, which has a lower thermal conductivity than iron, for example. Further, the inner ring and the outer ring may be made of resin. If the inner ring and the outer ring are made of resin, the heat insulating property can be further improved.

[4] In the vacuum pump according to the above [2], the heat insulating member has a third exhaust pipe portion made of resin interposed between the first exhaust pipe portion and the second exhaust pipe portion. It is possible.
By interposing a third resin exhaust pipe portion between the first exhaust pipe portion and the second exhaust pipe portion, heat insulation between the first exhaust pipe portion and the second exhaust pipe portion is more reliable. It can be carried out. Further, if the first exhaust pipe portion and / or the second exhaust pipe portion and the third exhaust pipe portion are connected via a resin annular ring (O-ring), the first exhaust pipe portion and the second exhaust gas are connected. The heat insulating property between the pipe portion and the pipe portion can be further improved. Further, if the first exhaust pipe portion and / or the second exhaust pipe portion and the third exhaust pipe portion are connected by using a resin clamp, the first exhaust pipe portion and the second exhaust pipe portion can be obtained. The heat insulating property between the two can be further improved.

[5] In the vacuum pump according to any one of the above [1] to [4], the cooling device may be attached around the second exhaust pipe portion and have a cooling jacket for circulating a cooling medium. It is possible.
By adopting a cooling jacket, a cooling device having a high cooling effect can be easily configured. It is also possible to remove and replace the assembly of the cooling jacket and the second exhaust pipe portion from the first exhaust pipe portion. Further, only the cooling jacket may be removed from the second exhaust pipe portion so that it can be replaced.

[6] In the vacuum pump according to [5], the cooling device may be provided with one or more partition plates inside the cooling jacket.
The partition plate 1213 arranged in this way makes it possible to uniformly bring the cooling water flowing into the internal space of the cooling jacket 121 closer to each other and uniformly cool the second exhaust pipe portion 1132.

[7] In the vacuum pump according to [6], the partition plate is one or more plate-shaped members extending in a direction crossing the extending direction of the second exhaust pipe portion and having an opening, or the cooling jacket. It can be one or more spiral members that spirally extend between the inner wall and the second exhaust pipe portion.
When the partition plate is composed of one or a plurality of plate-shaped members, the partition plate can be easily constructed and can be easily attached. When the partition plate is composed of a spiral member, the flow of cooling water inside the cooling jacket can be smoothed. When the partition plate is composed of a spiral member, a single member can form a continuous spiral flow path.

[8] In the vacuum pump according to [7], the partition plate has a plurality of the plate-shaped members, and the plate-shaped members are arranged so that the openings do not overlap in the adjacent plate-shaped members. It is possible. For example, the plate-shaped members can be arranged so that the openings are staggered in the adjacent plate-shaped members.
When the partition plate is composed of one or more plate-shaped members, the flow of the cooling water can be made more uniform by, for example, staggering the openings of the adjacent plate-shaped members so that they do not overlap. Is.

[9] In the vacuum pump according to any one of the above [1] to [8], at least a part of the exhaust pipe and a housing for accommodating the pump chamber are further provided, and the cooling device is provided in the housing. It is possible that it has been placed.
In this case, since the cooling device is installed in the vacuum pump, it is not necessary to separately install the cooling device when connecting the pipes. Further, it is not necessary to change the length of the pipe connected to the catching device on the exhaust side.

[10] In the vacuum pump according to any one of [1] to [8], the vacuum pump further includes at least a part of the exhaust pipe and a housing for accommodating the pump chamber, and the cooling device is the housing of the housing. It is possible that it is located outside.
In this case, since the cooling device is located outside the vacuum pump, it is easy to remove and replace the cooling device, or to remove and replace the cooling device together with the second exhaust pipe portion.

[11] In the vacuum pump according to any one of the above [1] to [10], a first cooling medium flow path for supplying a cooling medium to the second exhaust pipe portion and the first cooling medium flow path. It is possible to further have a first valve, which is arranged in the above and controls the supply of the cooling medium to the second exhaust pipe portion.
In this case, the degree of cooling by the cooling device can be adjusted by opening / closing or controlling the opening / closing of the first valve.

[12] In the vacuum pump according to the above [11], the second cooling medium flow path that bypasses the second exhaust pipe portion and the second cooling medium flow path that are arranged in the second cooling medium flow path and are arranged in the second cooling medium flow path. It is possible to further have a second valve that controls the flow of the cooling medium.
In this case, the degree of cooling by the cooling device can be adjusted by controlling the opening / closing or opening degree of the first valve and the second valve. Further, since the cooling medium can flow by bypassing the second exhaust pipe portion, it becomes easy to use the existing cooling medium flow path for cooling the motor, gear, etc. of the vacuum pump.

[13] In the vacuum pump according to the above [11] or [12], the first valve controls the flow rate of the cooling medium supplied to the second exhaust pipe portion continuously or in a plurality of steps. It can be a valve. By using the flow rate control valve for the first valve, the flow rate of the cooling medium to the second exhaust pipe portion can be controlled with higher accuracy, and the temperature of the second exhaust pipe portion can be controlled with higher accuracy.

[14] In the vacuum pump according to [13], which cites the above [12] or [12], the second valve continuously or a plurality of flow rates of the cooling medium supplied to the second exhaust pipe portion. It can be a step-adjustable flow control valve.
In this case, the flow rate of the second cooling medium flow path (bypass flow path) can be controlled with higher accuracy.

[15] In the vacuum pump according to any one of the above [11] to [14], it is possible to further include a temperature sensor provided in the exhaust pipe.
By controlling the cooling device based on the detection value of the temperature sensor, the second exhaust pipe portion can be accurately controlled to a desired temperature / temperature range.

[16] In the vacuum pump according to any one of the above [11] to [15], it is possible to further include a flow rate sensor provided in the exhaust pipe.
By controlling the cooling device based on the detection value of the flow rate sensor, it is possible to accurately control the supply of the cooling medium to the second exhaust pipe portion.

[17] In the vacuum pump according to any one of the above [1] to [16], a control device for controlling the cooling of the second exhaust pipe portion by the cooling device is further provided, and the control device is the vacuum pump. It is possible to control the cooling of the second exhaust pipe portion by the cooling device according to the type and flow rate of the gas flowing into the.
Assuming the product (produced gas) and the concentration of the produced gas from the type and flow rate of the inflowing gas, the temperature is above the temperature at which the product vaporizes, and the range in which the subsequent capture device (trap) can be efficiently processed. It becomes possible to control the temperature of the second exhaust pipe portion and the gas by the temperature.

[18] In the vacuum pump according to the above [17], the control device acquires the type and flow rate of the gas by receiving an input from a host system or a user.
In this case, even if the type and flow rate of the gas to be introduced into the vacuum pump are changed, the control device of the vacuum pump can change the type and flow rate of the gas from the host system (device to be exhausted, etc.) or the user. It becomes possible to acquire and control the temperature of the second exhaust pipe portion and the gas. Here, the user includes a vacuum pump manufacturer, a person who maintains the vacuum pump, a person who uses the vacuum pump, and other human beings.

[19] In the vacuum pump according to the above [18], the vacuum pump holds vapor pressure data including data on the temperature at which a product contained in the gas flowing into the vacuum pump becomes a gas. The type and concentration of the product are determined from the type and flow rate of the gas flowing into the vacuum pump, and the target set temperature of the second exhaust pipe portion is determined from the type and concentration of the product and the vapor pressure data of the product. It is possible to do.
In this case, the target set temperature can be calculated more accurately from the type and concentration of the product (produced gas) and the vapor pressure data.

[20] In the vacuum pump according to any one of [1] to [19] above, the exhaust pipe is used by being fluidly connected to a trapping device for catching products in the exhaust. It is possible.
In this case, it is possible to capture the product in the capture device from the gas exhausted from the vacuum pump.

[21] In the vacuum pump according to the above [20], the temperature in the exhaust pipe is equal to or higher than the lower limit temperature at which the product in the exhaust does not adhere to the exhaust pipe, and the product can be captured by the capture device. It is possible that the cooling device is controlled so that the temperature is equal to or lower than the upper limit temperature.
In this case, it is possible to efficiently capture the product in the trapping device while suppressing or preventing the product from adhering to the exhaust pipe of the vacuum pump. Since the cooling device is attached to the second exhaust pipe portion far from the exhaust port of the pump chamber, even if some products adhere to the second exhaust pipe portion due to cooling, the first exhaust pipe portion and the pump chamber The effect on is suppressed or prevented.

[22] The vacuum pump cooling device according to one aspect of the present invention includes an exhaust pipe portion with a cooling function that can be interchangeably connected to the exhaust pipe of the vacuum pump.

According to this cooling device, the exhaust pipe portion with a cooling function can be replaced, and maintenance (maintenance work) is easy. For example, when a product is deposited on the cooling function exhaust pipe portion, only the cooling function exhaust pipe portion can be replaced to continue using the vacuum pump. Further, as compared with the configuration in which the entire exhaust pipe is cooled, it is possible to suppress or prevent the temperature drop of the uncooled exhaust pipe portion and the pump chamber.

[23] In the cooling device according to the above [22], a heat insulating member that can be arranged between the exhaust pipe of the vacuum pump and the exhaust pipe portion with a cooling function is further provided. Since the heat insulating member can insulate between the exhaust pipe of the vacuum pump and the exhaust pipe portion with the cooling function, the influence of cooling of the exhaust pipe portion with the cooling function extends to the exhaust pipe and the pump chamber of the vacuum pump. It can be suppressed more.

[24] In the cooling device according to the above [22] or [23], the exhaust pipe portion with a cooling function is attached to an exhaust pipe portion that can communicate with the exhaust pipe of the vacuum pump and around the exhaust pipe portion. It is possible to have a cooling jacket and. In this case, the exhaust pipe portion with a cooling function can be easily configured. Further, only the cooling jacket may be replaced separately from the exhaust pipe portion.

[25] The method for cooling a vacuum pump according to one aspect of the present invention cools the second exhaust pipe portion of the first exhaust pipe portion and the second exhaust pipe portion of the exhaust pipe of the vacuum pump, which is far from the pump chamber. To do. The first exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes. The second exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes.

According to this cooling method, since the second exhaust pipe portion far from the pump chamber is cooled, it is possible to suppress or prevent the temperature of the first exhaust pipe portion and the pump chamber from dropping due to the cooling of the second exhaust pipe portion.

[26] In the cooling method according to the above [25], the second exhaust pipe portion far from the pump chamber is cooled while the first exhaust pipe portion is insulated from the second exhaust pipe portion.
In this case, it is possible to further suppress or prevent the temperature of the first exhaust pipe portion and the pump chamber from dropping due to the cooling of the second exhaust pipe portion.

[27] The vacuum exhaust system according to one aspect of the present invention includes a vacuum pump and a capture device connected to the exhaust side of the vacuum pump. The vacuum pump includes a pump chamber having a suction port and an exhaust port, an exhaust pipe connected to the exhaust port, an exhaust pipe that guides exhaust from the pump chamber to the outside of the vacuum pump, and the exhaust pipe. A cooling device for cooling is provided. The exhaust pipe has a first exhaust pipe portion and a second exhaust pipe portion, the first exhaust pipe portion is connected to the exhaust port of the pump chamber, and the second exhaust pipe portion is the first. The cooling device is arranged in the second exhaust pipe portion at a position farther from the exhaust port of the pump chamber than in the first exhaust pipe portion.

According to this vacuum exhaust system, since the cooling device is provided in the second exhaust pipe portion far from the exhaust port of the pump chamber of the vacuum pump, the gas in the second exhaust pipe portion is brought to a desired temperature (processing of the capture device in the subsequent stage). It is possible to cool to a temperature suitable for such as), and it is possible to suppress or prevent the temperature of the pump chamber and the first exhaust pipe portion from dropping without cooling the first exhaust pipe portion near the exhaust port of the pump chamber. .. As a result, precipitation and adhesion of products in the pump chamber and the first exhaust pipe portion can be suppressed or prevented, and the temperature of the gas can be adjusted to a temperature suitable for processing of the subsequent device. The first exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes. The second exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes.

[28] The storage medium containing the program to be executed by the computer according to one aspect of the present invention acquires information on the type of gas and the flow rate of gas used in the device connected to the vacuum pump. The type of produced gas and the concentration of the produced gas are determined from the acquired information, and the temperature at which the produced gas becomes a gas is determined based on the determined type and concentration of the produced gas and the vapor pressure data of the produced gas. Then, the computer is made to set the target setting temperature of the exhaust pipe of the vacuum pump to a temperature at which the produced gas becomes a gas or a temperature obtained by adding a predetermined temperature to the temperature at which the produced gas becomes a gas. Concerning the storage medium that stores the program for.

According to this recording medium, even if the type and flow rate of the gas introduced into the vacuum pump are changed, the control device of the vacuum pump can be used by the host system (device to be exhausted, etc.) or the user. By acquiring the type and flow rate, it becomes possible to control the temperature of the second exhaust pipe portion and the gas. Here, the user includes a vacuum pump manufacturer, a person who maintains the vacuum pump, a person who uses the vacuum pump, and other human beings.

[29] In the vacuum pump maintenance method according to one aspect of the present invention, the exhaust pipe of the vacuum pump has a first exhaust pipe portion having no cooling function and a second exhaust pipe portion having a cooling function. Then, the second exhaust pipe portion is removed from the first exhaust pipe portion and replaced. The first exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes. The second exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes.

According to this maintenance method, only the exhaust pipe portion with a cooling function can be replaced, and maintenance (maintenance work) is easy. For example, when a product is deposited on an exhaust pipe portion with a cooling function, only the exhaust pipe portion can be replaced to continue using the vacuum pump.

[30] In the maintenance method according to the above [29], the exhaust pipe is provided with a heat insulating member between the first exhaust pipe portion and the second exhaust pipe portion, and the second exhaust pipe is provided. Replace a part or all of the heat insulating member together with the part. The first exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes. The second exhaust pipe portion may be composed of an integral exhaust pipe or may be composed of a plurality of exhaust pipes.
When a heat insulating member is arranged between the first exhaust pipe portion and the second exhaust pipe portion, the reliability of the vacuum pump can be further improved by replacing a part or all of the heat insulating member. it can. When the heat insulating member is composed of a plurality of members and the replacement cycle is different for each member, each member may be replaced in a different cycle, or all of the plurality of members may be replaced regardless of the replacement cycle.

It is a block diagram of the vacuum exhaust system including the vacuum pump which concerns on one Embodiment. It is a schematic vertical sectional view of a vacuum pump. It is a schematic cross-sectional view of a vacuum pump. It is a detailed view of an exhaust pipe. It is an enlarged sectional view of a center ring. It is an enlarged view of an example of the connection structure of the 1st exhaust pipe part and the 2nd exhaust pipe part. It is an enlarged view of another example of the connection structure of the 1st exhaust pipe part and the 2nd exhaust pipe part. It is a block diagram of the fluid circuit for cooling an exhaust pipe. The control flow of the fluid circuit when the on-off valve is used is shown. It is a time chart of control of a fluid circuit when an on-off valve is used. The control flow of the fluid circuit when the flow rate control valve is used is shown. The configuration of the vacuum exhaust system connected to the device to be exhausted is shown. The flow of the process of setting the target set temperature of the exhaust pipe temperature is shown. It is a block diagram of the vacuum exhaust system including the vacuum pump which concerns on another embodiment.

FIG. 1 is a configuration diagram of a vacuum exhaust system including a vacuum pump according to an embodiment. FIG. 2 is a schematic vertical sectional view of the vacuum pump. FIG. 3 is a schematic cross-sectional view of the vacuum pump.

The vacuum exhaust system 1 is connected to a device 400 (see FIG. 11) to be exhausted, and sucks and discharges exhaust from the device 400. In this example, the vacuum exhaust system 1 further has a function of capturing products in the exhaust and a function of detoxifying the exhaust. The device 400 is, for example, a semiconductor manufacturing device, a liquid crystal manufacturing device, and more specifically, a CVD device, an etching device, a sputtering device, and the like.

The vacuum exhaust system 1 includes a vacuum pump 100 connected to the device 400, a capture device (trap) 200 connected to the exhaust side of the vacuum pump 100, and an abatement device 300 connected to the subsequent stage of the capture device 200. It has.

The vacuum pump 100 is connected to the exhaust side of the device 400 to be exhausted, and sucks and exhausts the gas in the device 400. Details of the vacuum pump 100 will be described later.

The trap 200 is a device that captures a product from the process gas exhausted from the vacuum pump 100. The product is produced by the reaction of the process gas introduced into the vacuum pump 100. It is necessary to control the temperature of the process gas within the range of the first predetermined temperature or higher and the second predetermined temperature or lower so that the product does not precipitate in the vacuum pump 100 and can be efficiently deposited by the capture device 200 in the subsequent stage. is there. Further, it is preferable to keep the temperature of the gas high in the vacuum pump 100 and lower the temperature of the gas at the inlet of the capture device 200. Therefore, in the present embodiment, as will be described later, of the exhaust pipe 113 of the vacuum pump 100, a configuration is adopted in which the second exhaust pipe portion 1132 on the side far from the exhaust port 1122 of the pump chamber 10 is cooled. As shown in FIG. 1, the exhaust pipe 113 includes a first exhaust pipe portion 1131 connected to the exhaust port 1121 and a second exhaust pipe portion 1132 on the downstream side of the first exhaust pipe portion 1131, and both exhausts. It is provided with a heat insulating member 114 for connecting the pipe portion.

In the example of FIG. 1, the intake side of the capture device 200 is connected to the exhaust pipe 113 of the vacuum pump 100 by the pipe 130. The capture device 200 has, for example, a structure having a plurality of partition plates stacked at intervals. The partition plate is provided with one or more holes, and the partition plates are attached so that the positions of the holes of the adjacent partition plates do not match. When the gas exhausted from the vacuum pump 100 passes through the holes of the partition plates, the positions of the holes of the adjacent partition plates are staggered, so that the gas comes into contact with a wide range of the partition plates and is generated. An object is deposited on the partition plate and is captured by the capture device 200.

The abatement device 300 is fluidly connected to the capture device 200 via a pipe 210. The abatement device 300 is a device that detoxifies the gas that has passed through the capture device 200 and detoxifies it. The abatement treatment includes a method of burning gas, a method of decomposing using a catalyst, a method of physically or chemically fixing gas with a chemical, a method of filtering with a filter, a method of sprinkling water to capture solid matter, or a method of capturing solid matter. A method of dissolving and removing in water is included, and any method is adopted alone or in combination of two or more.

In the present embodiment, as the vacuum pump 100, a roots type twin-screw capacitance type dry vacuum pump will be described as an example. The roots type vacuum pump 100 is given as an example, but other structures such as a screw type may be used. Further, in the present embodiment, the vacuum pump 100 is a multi-stage type as an example, but a single-stage type may be used.

As shown in FIGS. 1 and 2, the vacuum pump 100 includes a pump casing 101 having a plurality of pump chambers 10 partitioned by a partition wall, a motor frame 102 provided on one end side of the pump casing 101, and a pump casing 101. It includes a gear case 103 provided on the other end side, and a housing (exterior cover) 116 for accommodating the pump casing 101, the motor frame 102, and the gear case 103. Further, the vacuum pump 100 includes a control device 140. The control device 140 controls the drive of the motor 20 that rotates the roots rotor 11 and the cooling of the vacuum pump 100. The control device 140 is attached to the inside or the outside of the housing 116. Further, all or a part of the exhaust pipe 113, which will be described later, is housed in the housing 116.

The pump chamber 10 at one end of the plurality of pump chambers 10 is fluidly connected to the intake port 1121, and the pump chamber 10 at the other end is fluidly connected to the exhaust port 1122. The intake port 1121 is fluidly connected to the intake pipe 111. One end of the intake pipe 111 is connected to the intake port 1121, and the other end is arranged so as to project to the outside of the housing 116. The other end of the intake pipe 111 is fluidly connected to the device 400 via the pipe 410 as shown in FIG.

The vacuum pump 100 is a multi-stage vacuum pump, and a 5-stage rotor 13 is provided in a 5-stage pump chamber 10. A pair of roots rotors 11 are arranged in these pump chambers 10 (only one roots rotor is shown in FIG. 2). Each roots rotor 11 includes a rotating shaft 12 and a rotor 13 provided on the rotating shaft 12 corresponding to each pump chamber 10. In each pump chamber 10, the pair of rotors 13 are arranged so as to maintain a slight gap between the wall surfaces of the pump chambers 10 and between the rotors 13. The rotating shaft 12 is rotatably supported by bearings (not shown) near both ends. A gas passage 14 is provided on the outer side in the radial direction of each pump chamber 10, and the gas introduced from the intake port 1121 is compressed by the rotor 13 of each stage, and is compressed into the rotor 13 of the subsequent stage via the gas passage 14. It is supposed to be transferred.

A motor 20 is arranged on the motor frame 102, and the motor 20 is an electric motor. A pair of timing gears 30 (only one gear is shown in FIG. 2) that mesh with each other are arranged in the gear case 103. The drive shaft of the motor 20 is connected to the first end of one of the pair of rotating shafts 12, the rotating shaft 12, so as to rotate the rotating shaft 12. The second end of the pair of rotating shafts 12 on the opposite side of the motor 20 is connected to a pair of timing gears 30 that mesh with each other. The pair of rotating shafts 12 are synchronously rotated in opposite directions by the timing gear 30. When one rotating shaft 12 is rotated by the motor 20, the other rotating shaft 12 rotates synchronously in opposite directions, and in each pump chamber 10, the two rotors 13 rotate in opposite directions. As a result, the gas is compressed and exhausted in each pump chamber 10. A motor 20 may be connected to each rotating shaft 12 so that each rotating shaft 12 is rotated by the motor 20. Further, although the case where the rotating shaft 12 of the roots rotor 11 is connected to the drive shaft of the motor 20 has been described here, the rotating shaft 12 of the roots rotor 11 may be integrated with the drive shaft of the motor 20.

When the motor 20 is driven, the pair of roots rotors 11 rotate in a non-contact manner while a slight gap is maintained between the wall surface of the pump chamber 10 and the rotors 13. As the pair of roots rotors 11 rotate, the gas on the intake side is confined in the space formed between the rotor 13 and the wall surface of the pump chamber 10 and transferred to the exhaust side. The gas introduced from the intake port 1121 is compressed and transferred by the five-stage rotor 13 and discharged from the exhaust port 1122, and the gas of the device 400 is exhausted by continuously performing this transfer.

The vacuum pump 100 further includes a cooling water flow path 115. As shown in FIG. 2, the cooling water flow path 115 has flow paths 115a to 115e. In FIG. 1, the flow path 115e is omitted. The flow path 115a fluidly connects an external water source (reservoir) and the inlet of the flow path 1021 of the motor housing 102. The flow path 115b fluidly connects the outlet of the flow path 1021 of the motor frame 102 and the inlet of the flow path 1031 of the gear case 103. The flow path 115c fluidly connects the outlet of the flow path 1031 of the gear case 103 and the inlet 1211 of the cooling device 120 of the exhaust pipe 113, which will be described later. The flow path 115d is connected to the outlet 1212 of the cooling device 120 of the exhaust pipe 113 to return the cooling water to the reservoir. The flow path 115e bypasses the cooling device 120 of the exhaust pipe 113 and fluidly connects the flow path 115c and the flow path 115d. The flow path 115c is provided with a valve 151 that controls the inflow of cooling water into the cooling device 120. The flow path 115e is provided with a valve 152 that controls the flow of the flow path 115e.
As long as there is no excess or deficiency in the cooling water flowing through the cooling water flow path 115, the connection with the reservoir may be cut off and the cooling water may be circulated from the flow path 115a through a closed loop of the flow path 115d. In this case, the solenoid valve, flow path 115a, which opens and closes the connection between the cooling water flow path 115 and the reservoir.
An additional pump may be provided to pump the cooling water that has returned to the water.

FIG. 4 is a detailed view of the exhaust pipe. FIG. 4A is an enlarged cross-sectional view of the center ring. FIG. 5 is an enlarged view of an example of a connection structure between the first exhaust pipe portion and the second exhaust pipe portion. FIG. 6 is an enlarged view of another example of the connection structure between the first exhaust pipe portion and the second exhaust pipe portion.

As shown in FIGS. 2 and 4, the exhaust pipe 113 has a first exhaust pipe portion 1131 and a second exhaust pipe portion 1132. The first end of the first exhaust pipe portion 1131 is connected to the exhaust port 1122 of the pump chamber 10, and the second end is connected to the first end of the second exhaust pipe portion 1132 via the heat insulating member 114. It is connected. A flange 1131a is provided at the first end of the first exhaust pipe portion 1131, and the first exhaust pipe portion 1131 is fixed to the pump casing 101 at the flange 1131a. A cooling device 120 is attached around the second exhaust pipe portion 1132. As shown in FIG. 1, the second end portion of the second exhaust pipe portion 1132 is connected to the capture device 200 via the pipe 130. In the present embodiment, the case where the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132 are respectively composed of an integral exhaust pipe will be described, but the first exhaust pipe portion 1131 and the second exhaust pipe are described. At least one of the portions 1132 may be configured by connecting a plurality of exhaust pipes.

As shown in FIGS. 4 and 5, the heat insulating member 114 has a center ring 1141 and a clamp 1142. As shown in FIG. 4A, the center ring 1141 includes an annular member 1141a made of a resin having heat insulating properties, an inner ring 1141b, and an outer ring 1141c. The cross-sectional shape of the resin annular member 1141a is circular or elliptical. The annular member 1141a is, for example, an O-ring. In this example, the resin annular member 1141a is sandwiched and fixed between the inner ring 1141b and the outer ring 1141c, but the outer ring 1141c may be omitted. In other embodiments, both the inner ring 1141b and the outer ring 1141c may be omitted. The inner ring 1141b and the outer ring 1141c are made of, for example, stainless steel having a lower thermal conductivity than iron. The inner ring 1141b and the outer ring 1141c may be made of resin. The clamp 1142 can be made of, for example, stainless steel or resin. However, by making the clamp 1142 made of resin, the heat insulating property between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132 can be further improved.

The center ring 1141 is formed between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132, more specifically, the flange 1131b at the second end of the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132. It is arranged between the first end portion and the flange 1132a, and insulates between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132. The clamp 1142 is arranged around both flanges 1131b and 1132a in a state where the flange 1131b of the first exhaust pipe portion 1131 and the flange 1132a of the second exhaust pipe portion 1132 are combined, and the first exhaust pipe portion 1131 and the first clamp 1142 are arranged. 2 Connect with the exhaust pipe portion 1132. The clamp 1142 is, for example, a two-divided type, in which two semicircular arc-shaped members are connected by a hinge or the like, can be opened and closed, and can be fixed in a closed state. The clamp 1142 is placed around the flanges 1131b and 1132a in an open state, and the flanges 1131b and 1132a are fixed so as to be tightened radially inward by closing the clamp 1142.

As shown in FIG. 4, the cooling device 120 includes a hollow cylindrical cooling jacket 121. The cooling jacket 121 is made of stainless steel, for example, and is fixed to the outer peripheral surface of the second exhaust pipe portion 1132 by welding or the like. The cooling jacket 121 has an inlet 1211 and an outlet 1212. The inlet 1211 is fluidly connected to the flow path 115c and the outlet 1212 is fluidly connected to the flow path 115d. As shown by the arrow in FIG. 4, the cooling water introduced from the inlet 1211 comes into contact with the outer peripheral surface of the second exhaust pipe portion 1132 and flows while being cooled, and is led out from the outlet 1212. As a result, the second exhaust pipe portion 1132 is cooled by the cooling water, and the gas flowing through the second exhaust pipe portion 1132 is cooled accordingly.

Further, in the internal space of the cooling jacket 121, a plurality of partition plates 1213 are arranged side by side in the axial direction. When the cross section of the internal space of the cooling jacket 121 is circular or elliptical, the partition plate 123 is, for example, a C-shaped plate-shaped member, and an opening 1213a is provided in a part of the circular or elliptical plate-shaped member. Have. The opening 1213a is composed of, for example, a notch from which a part of the outer circumference of the plate-shaped member is removed. The plurality of partition plates 1213 are arranged so that the positions of the openings 1213a of the adjacent partition plates 1213 do not match. For example, the plurality of partition plates 1213 are arranged so that the positions of the openings 1213a of the adjacent partition plates 1213 are staggered. In FIG. 4, the positions of the openings 1213a of the adjacent partition plates 1213 are arranged so as to be above and below the second exhaust pipe portion 1132. The partition plate 1213 arranged in this way makes it possible to uniformly bring the cooling water flowing into the internal space of the cooling jacket 121 closer to each other and uniformly cool the second exhaust pipe portion 1132.

The partition plate 1213 may be one or a plurality of spiral members extending spirally between the inner wall of the cooling jacket 121 and the outer surface of the second exhaust pipe portion 1132. A single spiral member extending continuously in a spiral direction along the axial direction of the cooling jacket 121 may be provided, or a plurality of spiral members may be arranged side by side. When the cross section of the internal space of the cooling jacket 121 has a shape other than a circular shape or an elliptical shape, the outer shape of the partition plate (plate-shaped member, spiral member) may be created according to the cross-sectional shape of the internal space.

According to this configuration, the second exhaust pipe portion 1132 with the cooling device 120 can be easily attached and detached, and the cooling device 120 and the second exhaust pipe portion 1132 can be easily replaced. Further, when the cooling device 120 and the second exhaust pipe portion 1132 are replaced, a part or all of the heat insulating member 114 may be replaced together.

A temperature sensor 122 that detects the temperature of the second exhaust pipe portion 1132 (exhaust pipe temperature) is attached to the wall surface of the second exhaust pipe portion 1132. The temperature sensor 122 is connected to the control device 140 by wire or wirelessly, and the output of the temperature sensor 122 is supplied to the control device 140. The temperature sensor 122 may be provided at another portion as long as the correlation with the temperature of the exhaust gas can be confirmed.

In the example of FIG. 6, the heat insulating member 114 includes a center ring 1141, a clamp 1142, and a heat insulating pipe 1143. The heat insulating pipe 1143 is a pipe made of a heat insulating resin. The heat insulating pipe 1143 has a flange 1143a provided at the first end portion and a flange 1143b provided at the second end portion. The heat insulating pipe 1143 is arranged between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132, and insulates between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132. Further, a center ring 1141 is arranged between the first exhaust pipe portion 1131 and the heat insulating pipe 1143, and between the second exhaust pipe portion 1132 and the heat insulating pipe 1143, respectively. Therefore, the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132 are insulated by the heat insulating pipe 1143, and are provided by the center rings 1141 and the clamps 1142 (particularly when the clamps are made of resin) on both sides of the heat insulating pipe 1143. The connection structure of FIG. 6 has higher heat insulation performance than the connection structure of FIG.

According to this configuration, the second exhaust pipe portion 1132 with the cooling device 120 can be easily attached and detached, and the cooling device 120 and the second exhaust pipe portion 1132 can be easily replaced. Further, when replacing the cooling device 120 and the second exhaust pipe portion 1132, a part or all of the heat insulating member 114 (center ring 1141, clamp 1142, heat insulating pipe 1143) may be replaced together.

The connection between the first exhaust pipe portion 1131 and the second exhaust pipe portion 1132 is performed as follows. With the center ring 1141 arranged between the flange 1131b of the first exhaust pipe portion 1131 and the flange 1143a of the heat insulating pipe 1143, the flanges 1131b and 1143a are fixed by the clamp 1142. With the center ring 1141 arranged between the flange 1132a of the second exhaust pipe portion 1132 and the flange 1143b of the heat insulating pipe 1143, the flanges 1132a and 1143b are fixed by the clamp 1142. The first exhaust pipe portion 1131 and the heat insulating pipe 1143 may be attached first, and the second exhaust pipe portion 1132 and the heat insulating pipe 1143 may be attached in any order, or the attachment work may be performed at the same time.

FIG. 7 is a block diagram of a fluid circuit for cooling the exhaust pipe.
As shown in FIGS. 2 and 7, the flow path 115c is provided with a valve 151 that controls the inflow of cooling water into the cooling device 120. The flow path 115e, which is a bypass flow path, is provided with a valve 152 that controls the flow of the flow path 115e. The valve 151 and the valve 152 are, for example, solenoid valves. The valve 151 and the valve 152 may be an on-off valve that takes two states of opening and closing, or may be a flow rate control valve whose opening degree can be adjusted. A flow rate sensor 153 may be provided in the flow path 115c on the downstream side of the valve 151 to detect the amount of cooling water flowing into the cooling device 120.

The control device 140 is electrically connected to the motor 20, the valves 151 and 152, and the temperature sensor 122. When the flow rate sensor 153 is provided, the control device 140 is further connected to the flow rate sensor 153. The control device 140 has a control unit including a microprocessor or the like, and is a program (a program for controlling a motor for driving a roots rotor, a fluid) stored in a memory (not shown) provided inside or outside the control device 140. Various controls are executed by executing a program that controls the circuit, etc.) in the control unit.

FIG. 8 shows a control flow of a fluid circuit when an on-off valve is used. This control flow is repeatedly executed by the control device 140 at a predetermined control cycle. The following control flow may be executed by a control device different from the control device 140.

In step S11, the control device 140 acquires the temperature (exhaust pipe temperature) of the second exhaust pipe portion 1132 from the temperature sensor 122.

In step S12, the control device 140 determines whether or not the exhaust pipe temperature T is lower than the preset lower limit value Ta. The lower limit value Ta is a preset value, and is a lower limit temperature capable of preventing solidification of the generated gas in the exhaust pipe 113.
If the exhaust pipe temperature T is equal to or higher than the lower limit value Ta in step S12, the process proceeds to step S13.

In step S13, the control device 140 determines whether or not the exhaust pipe temperature T is higher than the preset upper limit value Tb. The upper limit value Tb is a preset value, and is set within a temperature range in which the capture process of the subsequent capture device 200 can be performed satisfactorily.
If the exhaust pipe temperature T is equal to or lower than the upper limit value Tb in step S13, the process returns to step S11 and the process from step S11 is repeated.

On the other hand, if the exhaust pipe temperature T is lower than the lower limit value Ta in step S12, the process proceeds to step S14.
In step S14, the valve 151 is closed and the valve 152 is opened in order to raise the exhaust pipe temperature T. As a result, all of the cooling water in the flow path 115c is bypassed to the flow path 115d through the flow path 115e, and the cooling water is not supplied from the flow path 115c to the cooling device 120 of the second exhaust pipe portion 1132. As a result, the temperature of the second exhaust pipe portion 1132 rises, and the second exhaust pipe portion 11
The temperature of the gas in 32 also rises.

If the exhaust pipe temperature T is higher than the upper limit value Tb in step S13, the process proceeds to step S15.
In step S15, the valve 151 is opened and the valve 152 is closed in order to lower the exhaust pipe temperature T. As a result, all of the cooling water in the flow path 115c flows into the cooling device 120 through the valve 151 and does not flow into the flow path 115e. As a result, the temperature of the exhaust pipe drops, and the temperature of the gas in the second exhaust pipe portion 1132 also drops.

According to the control of this fluid circuit, the exhaust pipe temperature T in the second exhaust pipe portion 1132 can be controlled in a range between the lower limit value Ta and the upper limit value Tb. Therefore, it is possible to prevent the temperature of the gas supplied from the second exhaust pipe portion 1132 to the capture device 200 from rising, and the capture device 200 can efficiently perform the capture process.

Further, since the first exhaust pipe portion 1131 is insulated from the second exhaust pipe portion 1132 by the heat insulating member 114, it is not easily affected even if the second exhaust pipe portion 1132 is cooled, and the first exhaust pipe portion is not affected. It is possible to suppress or prevent a decrease in the temperature of 1131. As a result, it is possible to suppress or prevent a decrease in the temperature of the gas in the first exhaust pipe portion 1131 and the pump chamber 10 due to the cooling of the second exhaust pipe portion 1132. Therefore, it is possible to suppress or prevent the product from adhering to the pump chamber 10, the roots rotor 11, and the first exhaust pipe portion 1131.

FIG. 9 is a time chart of the control of the fluid circuit when the on-off valve is used.

When the exhaust pipe temperature T becomes lower than the lower limit value Ta at time t1, the valve 151 is closed and the valve 152 is opened (step S14 in FIG. 8). As a result, all of the cooling water in the flow path 115c is bypassed to the flow path 115d through the flow path 115e, and the cooling water in the flow path 115c does not flow to the cooling device 120 in the second exhaust pipe portion 1132. As a result, the exhaust pipe temperature T rises and exceeds the lower limit value Ta and is controlled to the target temperature range (Ta or more and Tb or less).

When the exhaust pipe temperature T becomes higher than the upper limit value Tb at time t2, the valve 151 is opened and the valve 152 is closed. As a result, all of the cooling water in the flow path 115c flows into the cooling device 120 through the valve 151 and does not flow into the flow path 115e. As a result, the exhaust pipe temperature T drops, falls below the upper limit value Tb, and is controlled within the target temperature range (Ta or more and Tb or less).

After that, at time t3, the exhaust pipe temperature T falls below the lower limit value Ta again, so the same processing as the processing at time t1 is executed so that the exhaust pipe temperature T is returned to the target temperature range (Ta or more and Tb or less). Control.

The above processing is repeatedly executed, the exhaust pipe temperature T is maintained in the target temperature range, and the gas temperature is also maintained in the target temperature range.

FIG. 10 shows a control flow of a fluid circuit when a flow rate control valve is used. This control flow is repeatedly executed by the control device 140 at a predetermined control cycle. The following control flow may be executed by a control device different from the control device 140.

In step S 21, the control unit 140 acquires the temperature sensor 122 of the second exhaust pipe portion 1132 temperature (exhaust pipe temperature).

In step S22, the control device 140 determines whether or not the exhaust pipe temperature T is lower than the preset lower limit value Ta.
If the exhaust pipe temperature T is equal to or higher than the lower limit value Ta in step S22, the process proceeds to step S23.

In step S23, the control device 140 determines whether or not the exhaust pipe temperature T is higher than the preset upper limit value Tb.
If the exhaust pipe temperature T is equal to or lower than the upper limit value Tb in step S23, the process returns to step S21 and the process from step S21 is repeated.

On the other hand, if the exhaust pipe temperature T is lower than the lower limit value Ta in step S22, the process proceeds to step S24.
In S24, in order to raise the exhaust pipe temperature T, the opening degree of the valve 151 is decreased and the opening degree of the valve 152 is increased. As a result, the flow rate of the cooling water flowing from the flow path 115c to the cooling device 120 of the second exhaust pipe portion 1132 decreases, and the flow rate of the cooling water bypassing from the flow path 115c through the flow path 115e to the flow path 115d increases. .. As a result, the exhaust pipe temperature T rises, and the temperature of the gas in the second exhaust pipe portion 1132 also rises. When the flow rate sensor 153 is provided, the opening degree of the valve 151 and / or the valve 152 may be adjusted so that the flow rate of the flow path 115c becomes a desired value based on the detected value of the flow rate sensor 153. Good.

If the exhaust pipe temperature T is higher than the upper limit value Tb in step S23, the process proceeds to step S25.
In step S25, in order to lower the exhaust pipe temperature T, the opening degree of the valve 151 is increased and the opening degree of the valve 152 is decreased. As a result, the flow rate of the cooling water flowing from the flow path 115c to the cooling device 120 of the second exhaust pipe portion 1132 increases, and the flow rate of the cooling water bypassing the flow path 115c through the flow path 115e to the flow path 115d decreases. .. As a result, the exhaust pipe temperature T drops, and the temperature of the gas in the second exhaust pipe portion 1132 also drops. When the flow rate sensor 153 is provided, the opening degree of the valve 151 and / or the valve 152 may be adjusted so that the flow rate of the flow path 115c becomes a desired value based on the detected value of the flow rate sensor 153. Good.

The opening degree of the valve 151 and the valve 152 may be changed at a predetermined increasing speed or decreasing speed when the exhaust pipe temperature T is lower than the lower limit value Ta and when the exhaust pipe temperature T is higher than the upper limit value Tb. However, it may be changed at a non-linear speed.

When the flow control valve is used, the same effect as when the on-off valve is used can be obtained. Further, when the flow control valve is used, it is possible to supply necessary and sufficient cooling water according to the temperature of the second exhaust pipe portion 1132, and the cooling of the second exhaust pipe portion 1132 is controlled more accurately. be able to.

In the above description, the case where the opening degree of the valve 151 and the valve 152 is controlled at the same time has been described, but the opening degree of the valve 152 of the flow path 115e on the bypass side may be fixed at a constant opening degree. Further, the valve 152 of the flow path 115e on the bypass side may be omitted.

FIG. 11 shows the configuration of a vacuum exhaust system connected to the device to be exhausted.
The exhaust side of the device 400 and the intake pipe 111 of the vacuum pump 100 are fluidly connected by a pipe 410. Further, the control unit (not shown) of the device 400 and the control device 140 of the vacuum pump 100 are connected by a cable 420, and data is transmitted and received between the two. Although the case where data is transmitted / received via the cable 420 is shown here, data may be transmitted / received via wireless communication.

FIG. 12 shows a flow of processing for setting a target set temperature of the exhaust pipe temperature. This control flow is performed by the control device 140 executing a program stored in the memory inside or outside the control device 140. Further, in the memory, data in which the combination of process gases and the produced gas (product) are associated with each other is stored together with the data of the reaction ratio. In addition, the vapor pressure data of the generated gas is stored in the memory.

In step S31, the control device 140 of the vacuum pump 100 acquires the process gas and the process gas flow rate information from the device 400 side to be exhausted by wire or wirelessly.
For example, when the device 400 is a semiconductor manufacturing device and the process gases are "gas A" and "gas B" and each flow rate is 1 slm, the control device 140 receives gas A (flow rate 1 slm) from the device 400 side. ), Gas B (flow rate 1 slm) is acquired. The unit "slm" is a unit in which the flow rate per minute at 1 atm and 0 ° C. is expressed in liters. 1 [slm] = 1 * 10 ^-3 [m ³ / min] = (1/60) * 10 ^-3 [m ³ / s].

In step S32, the control device 140 determines the generated gas based on the information on the type of process gas and the gas flow rate. This is done by referring to the data in which the combination of process gas and the product gas (product) are associated with each other and the data of the reaction ratio stored in the memory.
In the case of the above example, this data has contents such as gas A (flow rate 1 slm) + gas B (flow rate 1 slm) → gas C (1 slm). The control device 140 determines the generated gas as gas C (1 slm) based on the acquired information (gas A (flow rate 1 slm), gas B (flow rate 1 slm)).

In step S33, the control device 140 determines the concentration of the produced gas.
In the case of the above example, since the gas A and the gas B all react to form the gas C, the flow rate of the gas C is 1 slm, and the ratio / concentration is determined to be 100%.

In step S34, the temperature (sublimation temperature) at which the product (produced gas) becomes a gas is calculated from the gas ratio / concentration and vapor pressure data.
The vapor pressure data is stored in the memory in advance. For example, the vapor pressure data of gas C is stored in the following table format.
(Gas pressure) 1 Torr 10 Torr 100 Torr 760 Torr
(Sublimation temperature) 10 ℃ 20 ℃ 40 ℃ 60 ℃

Since the pressure in the second exhaust pipe portion 1132 is atmospheric pressure 760 Torr and the ratio / concentration of gas C in the second exhaust pipe portion 1132 is 100%, the pressure of gas C is 760 Torr. From the above vapor pressure data, the temperature at which the produced gas C becomes a gas can be determined to be 60 ° C.

If the ratio / concentration of gas C is less than 100%, the pressure in the second exhaust pipe portion 1132 (here, atmospheric pressure 760 Torr) is multiplied by the ratio / concentration of gas C to divide the pressure of gas C. Will be determined and the vapor pressure data will be referenced based on the partial pressure.

In step S35, the temperature obtained by adding the first predetermined value α to the “temperature at which the generated gas becomes a gas” Tsbl is set as the exhaust pipe set temperature Ts. In consideration of control stability, the temperatures obtained by adding and subtracting the second predetermined value β to the exhaust pipe set temperature Ts are set to the upper limit value Tb and the lower limit value Ta (Tb = Tsbl + α + β, Ta = Tsbl + α-β, respectively). ). Then, the exhaust pipe temperature T is controlled so as to be within the target temperature range from the lower limit value Ta to the upper limit value Tb.

The exhaust pipe set temperature Ts is a temperature obtained by adding a first predetermined value α to the “temperature at which the generated gas becomes a gas” Tsbl in order to surely prevent the generated gas from solidifying and adhering in the exhaust pipe 113. And. The first predetermined value α is obtained in advance by an experiment or the like. The second predetermined value β is a width for ensuring the stability of the cooling control by the cooling device 120 and the fluid circuit, and is set in advance according to the characteristics of the cooling device 120 and the fluid circuit. The second predetermined value β is a value smaller than the first predetermined value α so that the lower limit value Ta does not become lower than the “temperature at which the produced gas becomes a gas” Tsbl. Further, the second predetermined value β is a value at which the upper limit value Tb is a temperature within a range in which the capture process by the capture device 200 can be performed satisfactorily.

The upper limit value Tb and the lower limit value Ta may be calculated by adding and subtracting different values β1 and β2 to the exhaust pipe set temperature Ts (Tb = Tsbl + α + β1, Ta = Tsbl + α-β2).

Further, the lower limit value Ta is determined based on the "temperature at which the produced gas becomes a gas" Tsbl as described above, and the upper limit value Tb captures the product separately from the "temperature at which the produced gas becomes a gas" Tsbl. It may be determined as an upper limit value of the temperature that can be captured by the device 200.

Further, in step S35, the lower limit value Ta may be set by adding the first predetermined value α to the “temperature at which the produced gas becomes a gas” Tsbl. In this case, the upper limit value Tb is calculated by adding the third predetermined value γ to the lower limit value Ta (= exhaust pipe set temperature Ts). The third predetermined value γ is a value for ensuring the stability of control. The upper limit value Tb may be determined as the upper limit value of the temperature at which the product can be captured by the capture device 200, separately from the “temperature at which the product gas becomes a gas” Tsbl.

According to the process flow for setting the target temperature range of the exhaust pipe temperature described above, information on the type and flow rate of the process gas is acquired from the device 400 to be exhausted, and the type, ratio / concentration of the produced gas (product) is determined. By determining and calculating the sublimation temperature from the vapor pressure data, the temperature of the gas is controlled to a temperature within a range in which no product adheres to the vacuum pump 100 and the capture process can be efficiently performed by the capture device 200. Can be done.

Further, since the data in which the combination of the process gas and the produced gas (product) are associated with each other is stored in the memory together with the data of the reaction ratio, the generated gas can be used even when the type of the process gas is changed. The type, ratio / concentration can be determined in the vacuum pump.
If the vacuum pump is configured to acquire information on the type and flow rate of the process gas from the host system such as the device to be exhausted, the type, ratio / concentration of the generated gas can be obtained even if the type of the process gas is changed. It can be determined automatically in the vacuum pump.
Even when the input of the process gas type and flow rate information is received from the user (vacuum pump manufacturer, maintainer, user or other person), the type, ratio / concentration of the generated gas is determined by the vacuum pump. be able to. In this case, a user interface such as a keyboard, a touch panel, and buttons connected to the control device 140 is provided in the vacuum pump 100 to receive input of information from the user.
Further, since the vapor pressure data of the produced gas is stored in the memory of the vacuum pump 100, the sublimation temperature of the produced gas can be accurately calculated based on the type and ratio / concentration of the produced gas.

FIG. 13 is a block diagram of a vacuum exhaust system including a vacuum pump according to another embodiment.
In the above embodiment, the case where the second exhaust pipe portion 1132 and the cooling device 120 are arranged in the housing 16 of the vacuum pump 100 has been described, but as shown in FIG. 13, the second exhaust pipe portion 1132 and the cooling device 120 are cooled. The device 120 may be arranged outside the housing 16 of the vacuum pump 100.
In this case, since the second exhaust pipe portion 1132 and the cooling device 120 are outside the vacuum pump 100, the cooling device 120 can be removed and replaced, or the cooling device 120 can be removed and replaced together with the second exhaust pipe portion 1132. It will be easier. On the other hand, when the second exhaust pipe portion 1132 and the cooling device 120 are arranged in the housing 16 as shown in FIG. 1, since the cooling device 120 is installed in the vacuum pump 100, the cooling device 120 is installed at the time of connecting the pipes. Does not require the work of installing separately. Further, it is not necessary to change the length of the pipe connected to the catching device 200 on the exhaust side.

Although the embodiments of the present invention have been described above based on some examples, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and do not limit the present invention. .. The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes an equivalent thereof. In addition, any combination or omission of the claims and the components described in the specification is possible within the range in which at least a part of the above-mentioned problems can be solved, or in the range in which at least a part of the effect is exhibited. Is.

10 ... Pump chamber 11 ... Roots rotor 12 ... Rotating shaft 13 ... Rotor 14 ... Gas passage 16 ... Housing 20 ... Motor 30 ... Timing gear 100 ... Vacuum pump 101 ... Pump casing 102 ... Motor flange 103 ... Gear case 111 ... Intake pipe 113 ... Exhaust pipe 114 ... Insulation member 115 ... Cooling water flow path 116 ... Housing 120 ... Cooling device 121 ... Cooling jacket 122 ... Temperature sensor 130 ... Piping 140 ... Control device 151 ... Valve 152 ... Valve 153 ... Flow sensor 200 ... Capture device 210 ... Piping 300 ... Abatement device 400 ... Equipment 410 ... Piping 420 ... Cable 1021 ... Flow path 1031 ... Flow path 1121 ... Intake port 1121 ... Exhaust port 1122 ... Exhaust port 1131 ... First exhaust pipe part 1132 ... Second exhaust pipe Part 1141 ... Center ring 1142 ... Clamp 1143 ... Insulation piping 115a ... Flow path 115b ... Flow path 115c ... Flow path 115d ... Flow path 115e ... Flow path 1131b ... Flange 1132a ... Flange 1141a ... Ring member 1141b ... Inner ring 1141c ... Outer ring 1143a ... Flange 1143b ... Flange 1211 ... Inlet 1212 ... Outlet 1213 ... Partition plate 1213a ... Opening

Claims (29)

It is a 2-axis capacitance type dry vacuum pump.
A pump casing with a suction port and a discharge port,
A gear case provided with a pair of timing gears connected to each rotation shaft of the pair of rotors arranged in the pump casing, and a gear case.
A cooling medium flow path having a flow path for flowing the cooling medium in the gear case, and a cooling medium flow path.
An exhaust pipe connected to the discharge port, which guides the exhaust gas from the pump casing to the outside of the vacuum pump.
A cooling device for cooling the exhaust pipe and
With
The exhaust pipe has a first exhaust pipe portion and a second exhaust pipe portion.
The first exhaust pipe portion is connected to the exhaust port of the pump casing, and the second exhaust pipe portion is located farther from the exhaust port of the pump casing than the first exhaust pipe portion.
The cooling device is arranged in the second exhaust pipe portion, and the cooling device is arranged.
The exhaust pipe is used by being fluidly connected to a trapping device for capturing the product in the exhaust.
The cooling medium fluid flow path further comprises a flow path of the gear case, a first cooling medium flow path and the second is disposed in the exhaust pipe portion the cooling device fluidly connecting,
Vacuum pump. The vacuum pump according to claim 1, further comprising a heat insulating member interposed between the first exhaust pipe portion and the second exhaust pipe portion. In the vacuum pump according to claim 2.
The heat insulating member is made of a resin that connects an annular ring made of resin interposed between the first exhaust pipe portion and the second exhaust pipe portion, and the first exhaust pipe portion and the second exhaust pipe portion. With a clamp and a vacuum pump. In the vacuum pump according to claim 2.
The heat insulating member is a vacuum pump having a third exhaust pipe portion made of resin interposed between the first exhaust pipe portion and the second exhaust pipe portion. In the vacuum pump according to any one of claims 1 to 4.
The cooling device is a vacuum pump mounted around the second exhaust pipe portion and having a cooling jacket through which a cooling medium is circulated. In the vacuum pump according to claim 5,
The cooling device is a vacuum pump in which one or a plurality of partition plates are provided inside the cooling jacket. In the vacuum pump according to claim 6,
The partition plate is one or a plurality of plate-shaped members extending in a direction crossing the direction in which the second exhaust pipe portion extends and having an opening, or a spiral between the inner wall of the cooling jacket and the second exhaust pipe portion. A vacuum pump, which is one or more spiral members extending in a shape. In the vacuum pump according to claim 7.
The partition plate is a vacuum pump having a plurality of the plate-shaped members, and the plate-shaped members are arranged so that the openings do not overlap in the adjacent plate-shaped members. In the vacuum pump according to any one of claims 1 to 8.
Further comprising at least a part of the exhaust pipe and a housing for accommodating the pump casing.
The cooling device is a vacuum pump arranged in the housing. In the vacuum pump according to any one of claims 1 to 8.
Further comprising at least a part of the exhaust pipe and a housing for accommodating the pump casing.
The cooling device is a vacuum pump arranged outside the housing. In the vacuum pump according to any one of claims 1 to 10.
A vacuum pump that is arranged in the first cooling medium flow path and further has a first valve that controls the supply of the cooling medium to the second exhaust pipe portion. In the vacuum pump according to claim 11,
A second cooling medium flow path that bypasses the second exhaust pipe portion,
A vacuum pump further comprising a second valve arranged in the second cooling medium flow path and controlling the flow of the cooling medium in the second cooling medium flow path. In the vacuum pump according to claim 11 or 12.
The first valve is a vacuum pump, which is a flow control valve capable of continuously or in a plurality of steps to adjust the flow rate of the cooling medium supplied to the second exhaust pipe portion. In the vacuum pump according to claim 12, or claim 13, which is subordinate to claim 12.
The second valve is a vacuum pump, which is a flow control valve capable of continuously or in a plurality of steps to adjust the flow rate of the cooling medium supplied to the second exhaust pipe portion. In the vacuum pump according to any one of claims 11 to 14.
A vacuum pump provided in the exhaust pipe and further provided with a temperature sensor for detecting the temperature of the second exhaust pipe portion. In the vacuum pump according to any one of claims 11 to 15.
A vacuum pump further including a flow rate sensor that detects the amount of inflow of the cooling medium into the cooling device. In the vacuum pump according to any one of claims 1 to 16.
A control device for controlling the cooling of the second exhaust pipe portion by the cooling device is further provided.
The control device is a vacuum pump that controls cooling of the second exhaust pipe portion by the cooling device according to the type of gas flowing into the vacuum pump. In the vacuum pump according to claim 17,
The control device is a vacuum pump that acquires the type of gas by receiving an input from a host system or a user. In the vacuum pump according to claim 18,
The vacuum pump holds vapor pressure data including data on the temperature at which the product contained in the gas flowing into the vacuum pump becomes a gas, and the product is obtained from the type and flow rate of the gas flowing into the vacuum pump. A vacuum pump that determines the type and concentration, and determines the target set temperature of the second exhaust pipe portion from the type and concentration of the product and the vapor pressure data of the product. In the vacuum pump according to any one of claims 1 to 19.
The cooling device is set so that the temperature inside the exhaust pipe is at least the lower limit temperature at which the product in the exhaust does not adhere to the exhaust pipe and at least the upper limit temperature at which the product can be captured by the capture device. Controlled, vacuum pump. It is a cooling device for a 2-axis capacitance type dry vacuum pump.
It is provided with an exhaust pipe portion with a cooling device that can be interchangeably connected to the exhaust pipe of the vacuum pump.
The exhaust pipe and the exhaust pipe portion is intended to be used is fluidly connected to the capture device for capturing the product in exhaust, the cooling device may cool the gear case of the vacuum pump A first cooling medium flow path that is fluidly connected to the flow path through which the cooling medium flows.
Cooling system. In the cooling device according to claim 21,
A cooling device further comprising a heat insulating member that can be arranged between the exhaust pipe of the vacuum pump and the exhaust pipe portion with the cooling device. In the cooling device according to claim 21 or 22
The exhaust pipe portion with a cooling device
An exhaust pipe portion that can communicate with the exhaust pipe of the vacuum pump,
A cooling jacket attached around the exhaust pipe portion and
Cooling device with. It is a cooling method for a two-shaft capacitive dry vacuum pump.
From the pump casing of the first exhaust pipe portion and the second exhaust pipe portion of the exhaust pipe of the vacuum pump used by being fluidly connected to a capture device for capturing the product in the exhaust of the vacuum pump. A cooling method in which the distant second exhaust pipe portion is cooled by a cooling medium supplied from a flow path through which a cooling medium for cooling the gear case of the vacuum pump flows. In the cooling method according to claim 24,
A cooling method in which the second exhaust pipe portion far from the pump casing is cooled while the first exhaust pipe portion is insulated from the second exhaust pipe portion. It ’s a vacuum exhaust system,
2-axis capacitive dry vacuum pump and
A catching device connected to the exhaust side of the vacuum pump is provided.
The vacuum pump
A pump casing with a suction port and a discharge port,
A gear case provided with a pair of timing gears connected to each rotation shaft of the pair of rotors arranged in the pump casing, and a gear case.
A cooling medium flow path having a flow path for flowing the cooling medium in the gear case, and a cooling medium flow path.
An exhaust pipe connected to the discharge port, which guides the exhaust gas from the pump casing to the outside of the vacuum pump.
A cooling device for cooling the exhaust pipe and
With
The exhaust pipe has a first exhaust pipe portion and a second exhaust pipe portion.
The first exhaust pipe portion is connected to the exhaust port of the pump casing, and the second exhaust pipe portion is located farther from the exhaust port of the pump casing than the first exhaust pipe portion.
The cooling device is arranged in the second exhaust pipe portion, and the cooling device is arranged.
The cooling medium fluid flow path further comprises a flow path of the gear case, a first cooling medium flow path and the second is disposed in the exhaust pipe portion the cooling device fluidly connecting,
Vacuum exhaust system. A recording medium containing a program for causing a computer to execute a control method of a twin-screw capacitive dry vacuum pump provided with an exhaust pipe fluidly connected to a trapping device for capturing products in the exhaust.
Obtain information on the type of gas used in the device connected to the vacuum pump and the flow rate of gas,
The type of produced gas and the concentration of the produced gas are determined from the acquired information, and the temperature at which the produced gas becomes a gas is determined based on the determined type and concentration of the produced gas and the vapor pressure data of the produced gas. And
The target set temperature of the first exhaust pipe portion and the second exhaust pipe portion of the exhaust pipe, which is far from the vacuum pump, is set to the temperature at which the produced gas becomes a gas, or the produced gas becomes a gas. To set the temperature by adding a predetermined temperature to the temperature
The second exhaust pipe portion is cooled by the cooling medium supplied from the flow path through which the cooling medium for cooling the gear case of the vacuum pump flows, and the temperature of the second exhaust pipe portion is set based on the target set temperature. Control within the specified temperature range set by
A storage medium that contains a program that allows a computer to execute a program. A method for maintaining a vacuum pump according to any one of claims 1 to 20, wherein the vacuum pump is maintained.
A maintenance method in which the second exhaust pipe portion is removable from the first exhaust pipe portion, and the second exhaust pipe portion is removed from the first exhaust pipe portion and replaced. In the maintenance method according to claim 28, in the exhaust pipe, a heat insulating member is arranged between the first exhaust pipe portion and the second exhaust pipe portion, and the heat insulating member is arranged together with the second exhaust pipe portion. A maintenance method that replaces parts.

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