JP2018204518A - Pump and brine circulation device - Google Patents

Abstract

To provide a pump for circulating brine with good pump efficiency.SOLUTION: A pump 10 for circulating brine for adjusting temperature of an external device 50 is provided. The pump comprises a pump main shaft fitted with an impeller, a pump casing 11 internally housing the pump main shaft, and a motor 100 provided on the side opposite to a discharge pipe of the pump casing in an axial direction of the pump main shaft to rotate the pump main shaft. The motor comprises a rotor and a stator. The rotor is provided in an internal space of the motor in which liquid can be enclosed. The stator is provided in a closed space of the motor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pump and a brine circulation device.

  In order to cool or adjust the temperature of an external device such as a semiconductor manufacturing device or an injection device, a pump is used to pump the brine stored in the brine tank to the heat exchange section of the external device. As such a pump, for example, a vertical multistage submersible pump is known (for example, see Patent Document 1).

JP-A-2005-330901

  Such a vertical multi-stage pump has a long main shaft extending from the motor to the inside of the tank because the impeller disposed inside the tank is driven by a motor installed above the brine tank. It is desirable that the suction port and the impeller of the pump be positioned as low as possible in the tank so that the brine can be sucked even when a small amount of brine is stored in the tank. For this reason, in the conventional vertical multistage pump, a plurality of intermediate casings are provided to adjust the position of the impeller. However, as the number of intermediate casings increases, the discharge flow path of the impeller becomes more complicated, and there is a problem that pressure loss increases and pump efficiency deteriorates.

  Further, as disclosed in Patent Document 1, in the vertical multistage pump, a mechanical seal is provided between the pump main shaft and the motor casing so that the brine does not leak from the inside of the pump to the outside of the tank. It is done. In such a pump, a ball bearing is used as a bearing for the main shaft of the pump. However, since the mechanical seal and the ball bearing are consumed due to wear, periodic replacement work is required. Further, since the motor of the vertical multistage pump is arranged outside the tank, it has a cooling fan to cool the motor. For this reason, there exists a problem that the noise of a motor and a fan especially at the time of high speed rotation is large.

  The output of the motor is proportional to the motor torque and the motor speed. For this reason, in order to increase the output of the motor, it is necessary to increase the motor torque or the rotational speed of the motor. However, as described above, when the rotation speed of the motor is increased, the noise of the motor and the fan increases, and there is a possibility that the replacement frequency of the mechanical seal and the ball bearing is increased due to the increase in the rotation speed. For this reason, in a conventional vertical multistage pump, in order to obtain a certain level of motor output, the motor torque must be increased, that is, the size of the motor itself must be increased. Therefore, there is a tendency that a space for arranging the motor outside the tank becomes large.

  The present invention has been made in view of the above problems, and one of its purposes is to provide a pump for circulating brine having good pump efficiency.

According to one aspect of the present invention, a pump for circulating brine for adjusting the temperature of an external device is provided. The pump includes a pump main shaft to which an impeller is attached, a pump casing that houses the pump main shaft, and a pump casing that is provided on a side opposite to a discharge pipe of the pump casing in an axial direction of the pump main shaft. And a motor for rotating the main shaft. The motor includes a rotor and a stator, and the rotor is provided in an internal space of the motor that can enclose liquid, and the stator is provided in a sealed space of the motor.

It is the schematic of the brine circulating apparatus using the pump which concerns on this embodiment. It is a partial expanded sectional view of the pump shown in FIG. It is sectional drawing of the motor shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a schematic view of a brine circulating apparatus using a pump according to the present embodiment. FIG. 1 shows a brine circulation device 30 and an external device 50 such as a semiconductor manufacturing device or an injection device. The brine circulation device 30 is configured to circulate the temperature-adjusted brine between the external device and the brine circulation device 30 in order to adjust the temperature of the external device. Specifically, the brine circulation device cools, for example, a susceptor that supports a semiconductor wafer when the external device is a semiconductor manufacturing device, and preheats a mold, for example, when the external device is an injection device. Composed. The brine in the present specification refers to a heat medium such as water, aqueous propylene glycol solution, oil, and Fluorinert (registered trademark).

  As shown in FIG. 1, the brine circulation device 30 includes a pump 10, a discharge pipe 12, a tank 31, a brine pipe 32, a refrigerator 33, and a return pipe 34. The discharge pipe 12 is connected to the pump 10 and supplies the brine pipe 32 with the brine pumped by the pump 10. The tank 31 stores a brine for adjusting the temperature of the external device. The pump 10 is configured so that at least a part of the pump 10 is accommodated in the tank 31 and the brine in the tank 31 is pumped to the brine pipe 32 via the discharge pipe 12. One end of the brine pipe 32 is connected to the discharge pipe 12, passes through the external device 50, and the other end is connected to the return pipe 34. That is, the brine pipe 32 is configured to supply the brine pumped from the pump 10 to the external device 50 and return the brine to the tank 31. The refrigerator 33 is an example of a temperature adjusting device for adjusting the temperature of the brine passing through the brine pipe 32. Specifically, the refrigerator 33 is configured to cool the brine that passes through the brine pipe 32. In the present embodiment, the refrigerator 33 is provided as an example of a temperature adjustment device in order to cool the external device 50. However, the present invention is not limited to this. A device can be employed. The return pipe 34 is configured to return the brine from the brine pipe 32 into the tank 31.

  As shown in the figure, the pump 10 is a vertical immersion pump that is supported in a suspended manner in a tank 31 and is partially immersed in brine. Specifically, the pump 10 includes a pump casing 11 and a motor 100. The discharge pipe 12 may constitute a part of the pump 10. The pump casing 11 houses an impeller and a pump main shaft (see FIG. 2), which will be described later, and constitutes a brine flow path that is pumped by the pump 10. The discharge pipe 12 is connected to the upper end of the pump casing 11 and extends upward, and is configured to discharge the brine passing through the pump casing 11 to the brine pipe 32. The motor 100 is configured to rotate a pump main shaft (see FIG. 2), and is provided in a pump casing 11 opposite to the discharge pipe 12 in the axial direction (vertical direction in the drawing) of the pump main shaft as shown in the figure. It is done. That is, the motor 100 is arranged such that the motor shaft extends upward. The motor 100 is a submerged motor that can be used by being immersed in a brine.

  The tank 31 has an opening 31a. The opening 31 a is closed by the tank lid 35. The tank lid 35 is fixed to the tank 31 with a bolt or the like, for example. The discharge pipe 12 penetrates the tank lid 35 and is fixed to the tank lid 35 by welding or the like. The pump 10 is suspended and supported by the tank lid 35 by connecting the pump casing 11 to the discharge pipe 12. Further, a lead wire (lead wire) 36 passes through the tank lid 35, and the hole is sealed with a rubber packing 37. The lead wire 36 electrically connects the motor 100 and an AC power source 39 provided outside the tank 31 via a connector 41. Further, the brine circulation device 30 has an inverter 38. The inverter 38 is configured to control the rotation speed of the motor 100 by changing the frequency of the AC power supply 39. A safety valve 40 is provided on the wall surface of the tank 31. The safety valve 40 is configured to release the pressure in the tank 31 to the outside when the pressure in the tank 31 becomes too high due to a rise in brine temperature or the like. The safety valve 40 may be provided on the wall surface of the tank 31 as shown in FIG. 1 or may be provided on the tank lid 35.

  Next, the structure of the pump 10 shown in FIG. 1 will be described in detail. FIG. 2 is a partial enlarged cross-sectional view of the pump 10 shown in FIG. As shown in FIG. 2, the pump casing 11 of the pump 10 includes a discharge casing 11a, an upper casing 11b, an intermediate casing 11c, and a suction casing 11d. A suction port 13 for sucking brine is provided between the intermediate casing 11c of the pump casing 11 and the suction casing 11d. The discharge casing 11a is connected to the discharge pipe 12 shown in FIG.

  A pump main shaft 14 coupled to a motor shaft (see FIG. 3) of the motor 100 via a coupling or the like extends inside the pump casing 11. A plurality of impellers 15 are attached to the pump main shaft 14. The plurality of impellers 15 rotate along with the rotation of the pump main shaft 14, pressurize the brine by centrifugal force, and pump the brine toward the discharge casing 11a. The vicinity of the end of the pump main shaft 14 opposite to the motor 100 is supported by a slide bearing 16.

  Next, the structure of the motor 100 shown in FIG. 1 will be described in detail. FIG. 3 is a cross-sectional view of the motor 100 shown in FIG. The motor 100 is a submerged motor that is used by being immersed in a brine, and is a liquid ring motor that contains liquid inside the motor. As shown in FIG. 3, the motor 100 includes a casing 101. The casing 101 includes a cylindrical frame 102, a first frame side plate 120, and a second frame side plate 130. The motor 100 includes a stator (stator) 104 fixed in the frame 102, a rotor (rotor) 107 provided inside the stator 104, and a motor main shaft 110 attached to the rotor 107. Further, the motor 100 includes a cylindrical can 111 interposed between the stator 104 and the rotor 107.

  Stator 104 has a stator core 105 formed by laminating electromagnetic steel plates, and a stator coil 106 wound around stator core 105. A cable connector 112 for energizing the stator coil 106 is connected to the stator coil 106. Rotor 107 includes laminated electromagnetic steel sheets and secondary conductor 109. Although the motor 100 of this embodiment is an induction motor, it may be a so-called permanent magnet motor in which a permanent magnet is disposed on a rotor. Since a permanent magnet motor does not require an excitation circuit, it can be more efficient than an induction motor and can be designed to have a shorter length in the longitudinal direction. When the motor pump is installed in the finite-length tank 31 as in this embodiment, a permanent magnet motor is preferable. In the motor 100, the rotor 107 is rotated in the frame 102 by the rotating magnetic field generated by energizing the stator coil 106, and the motor main shaft 110 is also rotated with the rotation of the rotor 107.

  The first frame side plate 120 is provided so as to cover the end portion on the side to which the pump 10 is not connected (end portion on the anti-load side). Specifically, the first frame side plate 120 is fixed to the anti-load side bracket 122 by bolts 184. On the other hand, the second frame side plate 130 is provided so as to cover the end (load side end) on the side to which the pump 10 is connected. Specifically, the second frame side plate 130 is fixed to the load side bracket 131 by bolts 194.

  The can 111 includes an outer stator chamber (corresponding to an example of a sealed space) in which the stator 104 is disposed, and an inner rotor chamber (corresponding to an example of an internal space) in which the rotor 107 is disposed. Isolate. An insulating cooling oil 115 is enclosed in the stator chamber in order to cool the heat generated from the stator 104 and the like. In addition, a sealing liquid 114 is sealed in the rotor chamber in order to cool the heat generated from the rotor 107 and the like and improve the slidability of the motor main shaft 110. The can 111 isolates the stator chamber and the rotor chamber so that the sealing liquid 114 and the cooling oil 115 are not mixed with each other. As described above, the stator chamber and the rotor chamber are separated by the can 111, so that the cooling oil 115 is prevented from being discharged to the outside of the motor 100, and the stator 104 is cooled by the insulating cooling oil 115. be able to.

  In the present embodiment, paraffin oil or the like that is insulating oil is used as the cooling oil 115. Further, as the sealing liquid 114, for example, water, an aqueous propylene glycol solution, oil, Fluorinert (registered trademark), or the like is used. As will be described later, the sealing liquid 114 sealed in the rotor chamber is preferably the same liquid as the brine pumped by the pump 10. Thereby, even if the sealing liquid 114 in the rotor chamber leaks into the tank 31, the brine is not affected.

  A diaphragm 182 that absorbs pressure fluctuations in the rotor chamber is provided on the non-load side of the motor 100. The diaphragm 182 absorbs the pressure fluctuation between the rotor chamber and the external pressure of the motor 100 by displacing the film in accordance with the pressure fluctuation in the rotor chamber. The diaphragm 182 has a predetermined volume (pressure difference) in consideration of the rating of the motor 100, the depth and temperature of the brine in which the motor 100 is installed (for example, −20 ° C. to 80 ° C., etc.), the margin, and the like. What can be absorbed may be used.

  On the non-load side of the motor 100, a radial bearing 188 and a thrust bearing 190 for supporting the motor main shaft 110 are provided. On the other hand, on the load side of the motor 100, an O-ring 196 that seals between the second frame side plate 130 and the load-side bracket 131 and a radial bearing 198 for supporting the motor main shaft 110 are provided.

  A through-hole 132 through which the motor main shaft 110 can pass is formed at the center of the second frame side plate 130 so that the tip of the motor main shaft 110 protrudes to the outside of the motor 100. The motor main shaft 110 protrudes to the outside of the motor 100 through the through hole 132 and is connected to the pump main shaft 14 of the pump 10.

  In the present embodiment, the through-hole 132 is provided with a shaft sealing mechanism 150 that prevents the sealing liquid 114 from leaking to the outside and the brine in the tank 31 from entering the motor 100. In this embodiment, the shaft sealing mechanism 150 can have, for example, an oil seal or a mechanical seal. In addition, when the sealing liquid 114 may be mixed with brine, the shaft sealing mechanism 150 can be omitted. The motor 100 also has an inlet 160 for supplying the sealing liquid 114 into the rotor chamber.

  The operation and effect of the brine circulation device 30 described above will be described. First, as described with reference to FIG. 1, in the pump 10 of the brine circulation device 30, the motor 100 is provided on the opposite side of the pump casing 11 from the discharge pipe 12 in the axial direction of the pump main shaft 14. Thereby, when the pump 10 is arrange | positioned in the tank 31, the motor 100 can be immersed in a brine. Therefore, the motor 100 is cooled by the brine during driving. For this reason, since it is not necessary to provide the motor 100 with a cooling fan that is necessary when the motor 100 is disposed outside the tank 31, it is possible to prevent noise from being generated by the cooling fan when the motor 100 is driven. In addition, since the motor 100 is immersed in the brine, electromagnetic noise due to the driving of the motor 100 is absorbed by the brine, and noise to the outside of the tank can be reduced.

  Further, since the motor 100 is immersed in the brine, even if the sealing liquid 114 of the motor 100 leaks out of the rotor chamber, it can be prevented from flowing out of the tank 31. Since there is no possibility that the filled liquid 114 flows out of the tank 31, the shaft seal mechanism 150 used in the motor 100 is omitted, or an oil seal having a simple structure as compared with a mechanical seal is adopted as the shaft seal mechanism 150. can do. In addition, since the motor 100 is a liquid ring motor, a liquid film can be formed around the motor main shaft 110, so that radial bearings 188 and 198 can be employed as the bearing of the motor main shaft 110. Therefore, the motor 100 according to the present embodiment does not need to use a mechanical seal and a ball bearing that are frequently exchanged as in the prior art, so that maintenance costs can be reduced. In the case where an oil seal is employed as the shaft seal mechanism 150, the oil seal need not be replaced if there is no problem even if the sealing liquid 114 is mixed with brine. That is, in this case, even if the oil seal reaches the replacement time, it can be left without replacing the oil seal.

  As described above, according to the present embodiment, noise caused by the motor 100 is reduced. For this reason, even if the motor 100 is rotated at a higher speed, the magnitude of noise caused by the motor 100 can be suppressed as compared with the related art. In addition, since the motor 100 does not need to have a mechanical seal that is easily consumed by high-speed rotation and a ball bearing that is not suitable for high-speed rotation, the motor 100 can be rotated at high speed. As described above, the output of the motor 100 is proportional to the motor torque and the rotational speed of the motor 100. For this reason, by increasing the rotation speed of the motor 100, the motor torque required to obtain a predetermined motor output can be reduced. As a result, the size of the motor 100 can be reduced, so that the space in the tank 31 necessary for arranging the motor 100 can be reduced. Further, when a permanent magnet motor is used as the motor 100 as in this embodiment, the motor can be further reduced in size. In addition, as the motor 100 of this embodiment, you may employ | adopt not only a permanent magnet motor but an induction motor.

  Further, as shown in FIGS. 1 and 2, the motor 100 is provided below the pump 10. Thereby, compared with the case where the motor 100 is arrange | positioned outside the tank 31, the length of the intermediate casing 11c of the pump 10 can be shortened. As a result, the pressure loss resulting from the length of the intermediate casing 11c can be reduced, and the pump efficiency can be improved.

  In the brine circulation device 30 according to this embodiment, the pump 10 can be replaced by removing the pump 10 from the discharge pipe 12 during maintenance. When the pump 10 is removed from the discharge pipe 12, the liquid in the discharge pipe 12 and the pump 10 falls into the tank 31, so that the possibility that brine will flow out of the tank 31 is very low even during maintenance.

  As described above, it is preferable to use the same liquid as the brine as the sealing liquid 114 of the motor 100. When the external device 50 is a semiconductor manufacturing device, an insulating fluid such as Fluorinert (registered trademark) can be used as the brine. In this case, when propylene glycol is used as the sealing liquid 114 of the motor 100 and the sealing liquid 114 and fluorinate are mixed, harmful hydrogen fluoride is generated. On the other hand, when the same liquid as the brine is used as the sealing liquid 114, such a problem is solved. Further, when the sealing liquid 114 and the brine are the same, even if they are mixed, there is no influence on the brine circulating device 30. Therefore, in such a case, the shaft seal mechanism 150 of the pump 10 can be omitted.

Some of the forms disclosed in this specification will be described below.
According to the 1st form, the pump which circulates the brine for adjusting the temperature of an external apparatus is provided. The pump includes a pump main shaft to which an impeller is attached, a pump casing that houses the pump main shaft, and a pump casing that is provided on a side opposite to a discharge pipe of the pump casing in an axial direction of the pump main shaft. And a motor for rotating the main shaft. The motor includes a rotor and a stator, and the rotor is provided in an internal space of the motor that can enclose liquid, and the stator is provided in a sealed space of the motor.

  According to the second form, in the pump of the first form, the same liquid as the brine is sealed in the internal space of the motor.

  According to the 3rd form, in the pump of the 1st or 2nd form, the motor is a permanent magnet motor.

  According to the fourth aspect, in the pump of any one of the first to third aspects, the motor has a motor main shaft coupled to the rotor, and the motor main shaft is directed from the inner space toward the pump main shaft. The pump includes an oil seal for sealing between the internal space and the motor main shaft, and a slide bearing that receives a load in the radial direction of the motor main shaft.

  According to the fifth embodiment, a brine circulation device is provided. The brine circulation device includes a pump according to any one of the first to fourth embodiments, a tank in which at least the motor and the suction port of the pump are accommodated, a discharge pipe connected to the pump casing, and one end of the discharge A brine pipe connected to a pipe for supplying the brine to the external device and returning the brine to the tank; and a temperature adjusting device for adjusting the temperature of the brine.

  According to a sixth aspect, in the brine circulator of the fifth aspect, the discharge pipe is fixed to the lid of the tank, and the pump is connected to the discharge pipe so that the pump casing is connected to the discharge pipe. Suspended by.

  As mentioned above, although embodiment of this invention was described, embodiment of the invention mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect can be achieved. is there.

DESCRIPTION OF SYMBOLS 10 ... Pump 11 ... Pump casing 14 ... Pump main shaft 15 ... Impeller 30 ... Brine circulation apparatus 31 ... Tank 32 ... Brine piping 33 ... Refrigerator 100 ... Motor 110 ... Motor main shaft 114 ... Filling liquid

Claims (6)

A pump that circulates brine for adjusting the temperature of an external device,
A pump spindle with an impeller attached;
A pump casing for accommodating the pump main shaft therein;
A motor for rotating the pump main shaft, provided on the opposite side of the discharge pipe of the pump casing in the axial direction of the pump main shaft,
The motor includes a rotor and a stator, the rotor is provided in an internal space of the motor capable of enclosing a liquid, and the stator is provided in a sealed space of the motor. The pump according to claim 1, wherein
The pump, wherein the same liquid as the brine is sealed in the internal space of the motor. The pump according to claim 1 or 2,
The motor is a pump, which is a permanent magnet motor. The pump according to any one of claims 1 to 3,
The motor has a motor spindle coupled to the rotor;
The motor spindle extends from the internal space toward the pump spindle,
The pump includes an oil seal for sealing between the internal space and the motor main shaft, and a slide bearing that receives a load in a radial direction of the motor main shaft. A pump according to any one of claims 1 to 4;
A tank that accommodates at least the motor and the suction port of the pump;
A discharge pipe connected to the pump casing;
A brine pipe having one end connected to the discharge pipe for supplying the brine to the external device and returning the brine to the tank;
A brine circulator having a temperature regulator for regulating the temperature of the brine. The brine circulator according to claim 5,
The discharge pipe is fixed to the lid of the tank;
The pump is a brine circulation device in which the pump is suspended in the tank by connecting the pump casing to the discharge pipe.

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