JPH01315692A - Method of operating rotary pump for high purity liquid - Google Patents

Abstract

PURPOSE:To prevent worn impurity from passing through a gap in a shaft piercing section into a pump chamber by feeding under pressure liquid to be handled by a pump at a predetermined flow rate into the shaft piercing section from the pump chamber always during the rotation of the pump but for a predetermined time after stop of the pump. CONSTITUTION:During rotation of a geared motor pump 20A, a discharge pump 38 is operated always, and accordingly, liquid to be handled by a pump in a suction tank 42 is fed under pressure into a discharge tank 41 by the suction force of the discharge pump 38 and the discharge pressure of an impeller in the geared motor pump 20A. That is, the liquid to be handled by a pump is fed successively through a shaft piercing section gap 27, a front bearing 28, a can gap 31 and a rear bearing 34 from a pump chamber 25, and then is feed successively through a discharge passage 37a, the discharge pump 38, a flow regulating valve 39 and a flow sensor 40 from a discharge port 36. Further, the operation of the discharge pump 38 is continued until at least a predetermined time elapses after stop of the motor pump 20 so as to similarly feed the liquid to be handled by a pump.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a method of operating a high-purity liquid rotary pump, and relates to a method for operating a high-purity liquid rotary pump. In rotary pumps used for pumping pure liquids, in which the impeller installed in the pump chamber rotates without contact, wear impurities occur in rotating sliding parts such as mechanical seals and bearings as the rotary pump rotates. The present invention relates to an operating method that prevents the liquid from entering the pump chamber from the rotating sliding portion side through the shaft recessed portion gap and mixing with the pump discharge liquid.

(Prior art) High-purity liquids are used as cleaning liquids and etching liquids in the semiconductor manufacturing process to prevent impurities from adhering to semiconductors and increase product yield. For example, ultrapure water or fluorocarbons are used as cleaning liquids. , concentrated sulfuric acid is used as an etching solution.

Conventionally, the rotary pumps used to pump this high-purity liquid were general-purpose motor-driven pumps that adopted mechanical seal shaft seals, which required disassembly and inspection after operation for less than -2 years, but in recent years, Canned motor pumps are preferred because they have a completely leak-free structure with no shaft seals, do not require overhauling for several years, and have extremely low noise and vibration, making them ideal for indoor pumps.

(Problems to be Solved by the Invention) By the way, as shown in FIG. Although the disposed impeller 5 is rotated without contact, abrasion impurities are generated due to the rotation and sliding of the shaft seal section 2, which is a rotating and sliding section, and some of these abrasion impurities are transferred to the pump chamber 4 and the shaft seal section 2. Due to the pressure pulsations that occur in the shaft recessed part gap 6 between the shaft recessed part 6 and the diffusion phenomenon that occurs because the abrasion impurities are ultrafine particles, they enter the pump chamber 4 side through the shaft recessed part gap 6, and the pump discharge liquid It will be mixed in.

Furthermore, as shown in FIG. 8, in a canned motor-driven rotary pump, that is, a canned motor pump IB,
Due to the pressure difference between the pump discharge lower side and the pump suction port 8 side, a part of the liquid handled by the pump is guided from the pump discharge lower side through the circulation pipe 9 to the canned motor rear side chamber 10, which lubricates the rear bearing 11 and cools the stator. After cooling the stator 15 and rotor 16 through the can gap 14 between the can 12 and the rotor can 13 and lubricating the front bearing 17,
Circulation route 1 that circulates from the pump back to the pump suction port 8 side
9, and the impeller 5 disposed in the pump chamber 4 is rotated without contact, but abrasion impurities are generated due to the rotation and sliding of the front bearing 17 and rear bearing 11, which are rotating and sliding parts. Most of these abrasion impurities are carried by the pump handling liquid flowing through the circulation path 19, enter the pump chamber 4 side, and are mixed into the pump discharge liquid.

Therefore, in order to minimize the amount of these abrasion impurities generated, the material of the rotating and sliding parts is selected. For example, in the above-mentioned canned motor pump IB, the bearings I+ and +7 are filled with tetrafluoroethylene resin and their sliding partners are Stellite is used as a material for pumping ultrapure water for cleaning in the semiconductor manufacturing process of up to 4 megabit DRAM, but in order to further improve the semiconductor product yield, the abrasion of the pump discharge liquid is reduced. It is desired to further reduce the amount of impurities mixed in, and when manufacturing semiconductors with a high degree of integration compared to general ones, it is necessary to further reduce the amount of the abrasion impurities mixed into the pump discharge fluid by one order of magnitude or more.

In addition to the above-mentioned rotary pump driven by a general-purpose motor 3 and the above-mentioned canned motor pump IB having a shaft sealing part 2 such as a mechanical seal or gland packing, the same applies to high-purity liquid rotary pumps such as magnetic coupling pumps. There was a problem.

The present invention has been made in view of the above-mentioned problems, and the abrasion impurities generated in the rotating sliding part as the rotary pump rotates without contact with the impeller disposed in the pump chamber are removed from the rotating sliding part. By preventing ultrapure water for cleaning in the semiconductor manufacturing process, etching liquid, etc. from entering the pump discharge liquid from the moving part side through the shaft recessed part gap and entering the pump chamber side and mixing with the pump discharge liquid. The object of the present invention is to provide a method of operating a rotary pump for high-purity liquids, which is suitable for transporting high-purity liquids in which dust contamination is strictly restricted.

[Structure of the invention]

(Means for Solving the Problems) A method of operating a rotary pump for high purity liquid according to the present invention is a rotary pump in which an impeller disposed in a pump chamber rotates without contact. At all times during the rotation of the rotary pump, and at least a predetermined amount after the rotary pump is stopped, so as to prevent the generated wear impurities from entering the pump chamber from the rotary sliding portion through the narrow shaft penetration gap. The pump handling liquid is passed from the pump chamber to the shaft penetrating part gap at a predetermined flow rate until time elapses.

Further, in the invention according to claim 2, during the rotation of the rotary pump, a predetermined flow rate is pumped by at least one of the discharge pressure of the main impeller of the rotary pump and the pressure of an auxiliary impeller disposed coaxially with the main impeller. It is characterized in that a part or all of the pressure source necessary for passing the handling liquid into the shaft-penetrating part gap is obtained.

Further, while the rotary pump is stopped, the forced liquid head at the rotary pump suction port serves as a pressure source necessary for passing a predetermined flow rate of the pump handling liquid into the shaft penetrating part gap. It is characterized by obtaining part or all of the

The invention according to claim 4 provides that, while the rotary pump is stopped, the pump operates at a predetermined flow rate by the suction force of a discharge pump connected to a discharge port for discharging the pump handling liquid that has passed through the shaft penetrating part gap to the outside of the rotary pump. The present invention is characterized in that a part or front part of the pressure source necessary for passing the handling liquid into the shaft-penetrating part gap is provided.

(Function) The operating method of the rotary pump for high-purity liquids of the present invention is based on the discharge pressure of the main impeller of the rotary pump, the pressure from the auxiliary impeller disposed coaxially with the main impeller, or the pressure at the pump suction port of the rotary pump. By a pressure source such as the liquid head, the suction force of a discharge pump connected to the discharge port of the rotary pump, or a combination thereof, the pump is constantly pumped while the rotary pump is rotating, and until at least a predetermined period of time has elapsed after the rotary pump has stopped. After the pump handling liquid of a predetermined flow rate flows from the pump chamber through the narrow shaft passage gap or further passes through the rotating sliding part, it is discharged to the outside of the rotary pump from the outlet or rotated via the filter device. It is returned to the pump suction port side of the pump.

The flow of the pump handling liquid at a predetermined flow rate into the shaft-penetrating part gap prevents wear impurities generated in the rotating sliding part from entering the pump chamber side through the shaft-penetrating part gap. and the wear impurities are discharged from the outlet to the outside of the rotary pump along with the pump handling fluid;
Alternatively, the abrasion impurities discharged together with the pump handling liquid are filtered and deposited by the filter device, so that the abrasion impurities are not mixed into the pump discharge liquid while the rotary pump is rotating, and the abrasion impurities are not mixed in the pump discharge liquid after the rotary pump is stopped. There is no possibility that the liquid will enter the pump chamber and be mixed into the pump discharge liquid when the rotary pump is restarted.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a canned motor pump device to which the operating method of the present invention is applied.

2OA is constructed by integrally connecting a pump section 21 and a canned motor section 22 via a front bearing housing 23, and a pump casing 24 of the pump section 21.
This is a rotary pump, that is, a canned motor pump, in which a main impeller 26 that rotates without contact is arranged in a pump chamber 25 formed by a front bearing housing 23 and a front bearing housing 23. lubricates the front bearing 28 through the narrow shaft penetration gap 27 formed between the front bearing housing 23 and the boss portion 26a of the main impeller 26, and lubricates the front bearing 28 between the stator can 29 and the rotor can 30. After cooling the stator 32 and rotor 33 through the can gap 31 between the canned motor pump 2O and lubricating the rear bearing 34, the canned motor pump 2O is
It forms a discharge path 37a to be discharged to the outside of A.
The above configuration is the same as that of a conventional canned motor pump called reverse circulation type.

In the conventional reverse circulation type canned motor pump, the discharge port 36 is connected to the pH zone of the suction tank via a reverse pipe, but in this canned motor pump device,
A discharge pump 38 driven separately from the canned motor pump 2OA is connected to the discharge port 36, and a flow rate control valve 39 is connected to the discharge port 36.
And, if necessary, it is connected to a discharge tank 41 via a flow rate sensor 40.

42 is a suction tank connected to the pump suction port 43 via a suction pipe, and 59 is a motor that drives the discharge pump 38.

Next, an embodiment of the operating method of the present invention in the canned motor pump device configured as described above will be described.

First, while the canned motor pump 2OA is rotating, the discharge pump 38 is always operated, and the suction force of the discharge pump 38 and the discharge pressure of the main impeller 26 of the canned motor pump 20^ cause a narrow shaft penetration from the pump chamber 25. Retraction gap 2
7 to lubricate the front bearing 28 and the can gap 3
1, cools the stator 32 and rotor 33, lubricates the rear bearing 34, and flows through the discharge path 37a from the discharge port 36 to the outside of the canned motor pump 2OA, and the discharge pump 38, the flow rate control valve 39, and The flow rate of the pump handling liquid discharged to the discharge tank 41 via the flow rate sensor 40 is
The opening degree of the flow rate control valve 39 or the driving speed of the discharge pump 38 is adjusted so that a predetermined flow rate is achieved.

The predetermined flow rate in this case is the canned motor pump 20^
Wear impurities generated by the rotation and sliding of the front bearing 28 and rear bearing 34, which are the rotating and sliding parts of the
The minimum amount that can prevent the intrusion into the pump chamber 25 side through the shaft recessed part gap 27 due to pressure pulsations occurring in the shaft recessed part gap 27 and the diffusion phenomenon that occurs because these wear impurities are ultrafine particles. The flow rate is higher than the flow rate and is higher than the minimum flow rate required for cooling the stator 32 and rotor 33 of the canned motor section 22.

Next, after the canned motor pump 2OA is stopped, the discharge pump 38 is continuously operated until at least a predetermined period of time has elapsed, and the narrow shaft recess gap 27 is removed from the pump chamber 25 by the suction force of the discharge pump 38. A discharge path 37 passes through the canned motor section 22 and from the discharge port 36 to the outside of the canned motor pump 20! The opening degree of the flow rate control valve 39 or the discharge pump 38 is adjusted so that the flow rate of the pump handling liquid that flows through the discharge pump 38, the flow rate control valve 39, and the flow rate sensor 40 and is discharged to the discharge tank 41 becomes a predetermined flow rate. Adjust drive speed.

In this case, the predetermined flow rate is the canned motor pump 2OA.
The wear impurities generated in the rotating sliding part during the rotation of the
Due to the diffusion phenomenon that occurs because these abrasion impurities are ultrafine particles, it is possible to prevent them from entering the pump chamber 25 from the canned motor section 22 side through the shaft recessed part gap 27 while the canned motor pump 20^ is stopped. The flow rate is higher than the minimum flow rate that can be prevented, and the predetermined time period is such that after the canned motor pump 2OA is stopped, the abrasion impurities remaining in the canned motor section 22 are discharged from the discharge port 36 to the outside of the canned motor pump 20A. This is the time required to complete the process.

As described above, according to the above embodiment, the pump handling liquid at a predetermined flow rate is pumped from the pump chamber 25 at all times while the 20 canned motor pumps are rotating, and until at least a predetermined time has elapsed after the canned motor pump 2OA is stopped. Since the liquid passes through the shaft recessed part gap 27 and is discharged to the outside of the canned motor pump 20^ from the discharge port 36, the rotational sliding of the front bearing 28 and the rear bearing 34 is caused by the flow of the pump handling liquid at each predetermined flow rate. Abrasion impurities generated in the moving parts are prevented from entering the pump chamber 25 side through the shaft recessed part gap 27, and the abrasion impurities are prevented from entering the pump chamber 25 side from the discharge port 36 to the outside of the canned motor pump 2OA. It is discharged together with the liquid.

Therefore, while the canned motor pump 20^ is rotating, the abrasion impurities are not mixed into the pump discharge liquid, and after a certain period of time has elapsed after the canned motor pump 20A is stopped, the abrasion impurities in the canned motor section 22 are swept away. When the canned motor pump device is stopped, the abrasion impurities do not enter the pump chamber 25 side due to a diffusion phenomenon or the like and are not mixed into the pump discharge liquid when the canned motor pump device is restarted.

Note that during the rotation of the canned motor pump 20^, the abrasion impurities are transferred from the canned motor part 22 to the shaft penetrating part gap 2.
The minimum flow rate of the pump handling liquid that can prevent it from entering the pump chamber 25 side through 7 is determined by the dimensions of the shaft penetrating part gap 27, the rotational speed of the canned motor pump 20, the specific gravity viscosity of the pump handling liquid, etc. Although different, the flow rate is generally extremely small compared to the minimum flow rate required to cool the stator 32 and rotor 33 of the canned motor section 22, and therefore, the shaft penetration gap 27 is reduced during the rotation of the canned motor pump 20^. The predetermined flow rate of the pump handling liquid that flows through the canned motor section 22 only needs to be at least the minimum flow rate necessary for cooling the canned motor section 22, and in most cases, this flow rate can be sufficiently obtained using only the discharge pressure of the main impeller 26 as a pressure source. , the discharge pump 38 may be stopped while the canned motor pump 20A is rotating.

Also, depending on whether the canned motor pump 2OA is rotating or stopped, the drive speed of the discharge pump 38 or the flow rate control valve 3
In addition to switching the opening degree of the discharge pump 38 and the opening degree of the flow rate control valve 39, the drive speed of the discharge pump 38 and the opening degree of the flow rate control valve 39 are controlled within a range that allows a predetermined flow rate of the pump handling liquid to pass through the shaft penetration gap 27 during rotation and during stoppage. or the flow control valve 39
A fixed orifice may be adopted instead of, in which case,
Usually, when the canned motor pump 20^ is rotating or stopped, the flow rate of the pump handling liquid passing through the shaft penetration gap 27 becomes more than necessary, reducing the operating efficiency of the canned motor pump system as a whole. However, the canned motor pump device is inexpensive because a control device for switching the drive speed of the discharge pump 38 and the opening degree of the flow control valve 39 is not required.

In addition, as shown in FIG.
There is a forced liquid head in and a canned motor pump 2
If the forced liquid head required for passing the pump handling liquid at a predetermined flow rate into the shaft penetrating part gap 27 can be maintained until the predetermined time elapses after the OA is stopped, this forced liquid head can be maintained as described above. It can be used as a pressure source in place of the discharge pump 38,
If the forced liquid head is low, this forced liquid head and the drain pump 38
It may be used in combination with the suction power of

In addition, the pump handling liquid discharged from the canned motor pump 2OA from the discharge port 36 to the outside 1 of the canned motor pump 2OA flows into the discharge tank 41, and as shown by the broken line in FIG.
After pressurizing at step 8, the abrasion impurities may be filtered through a filter device 46 consisting of a filter 44 and a valve 45, and then refluxed to the pump suction port 43 side.

In addition, when the discharge pressure of the main impeller 26 is low, a predetermined flow rate of the pump handling liquid cannot be passed through the shaft penetration gap 27 while the canned motor pump 2OA is rotating. As in the canned motor pump 2OB shown in FIG. Alternatively, by using this in combination with the suction force of the drain pump 38, a predetermined flow rate of the pump handling liquid is passed through the shaft penetration gap 27, and the discharge path 37
It is sufficient to obtain a pressure source necessary for the flow to flow through the shaft through the shaft gap 27, and a balance hole (not shown) is provided in the main impeller 26 so that the discharge pressure of the main impeller 2f+ is not applied to the shaft penetration gap 27. If the auxiliary impeller 4
The necessary pressure source may be obtained only by the pressure 7 or by the suction force of the discharge pump 38.

Next, FIG. 3 shows another canned motor pump device to which the operating method of the present invention is applied, and the explanation of the same parts as the canned motor pump device shown in FIG. 1 will be omitted.

20C is configured by integrally connecting a pump section 21 and a canned motor section 22 via an adapter 48 that also serves as a front bearing housing, and is formed by the pump casing 24 of the pump section 21 and the adapter 48. This is a canned motor pump in which a main impeller 26 that rotates without contact is disposed in a pump chamber 25 that rotates without contact. Due to the pumping action of the impeller 49, the canned motor is sucked from the rear chamber 50 through the shaft passage 51, and is energized by the auxiliary impeller 49.
A part of it lubricates the rear bearing 34 and returns to the canned motor rear chamber 50, and the rest passes through the can gap 31 to cool the stator 32 and rotor 33, and the remaining part lubricates the rear bearing 34 and returns to the canned motor rear chamber 50.
from the canned motor front chamber 52 to the adapter 48.
The heat exchanger 54 is reached through the through hole 53 of the heat exchanger 5.
After being cooled in step 4, a canned motor circulation path 55 is formed in which the canned motor is circulated back to the rear side chamber 50, and the above configuration is the same as that of a conventional canned motor pump called an independent circulation type. It is.

In this canned motor pump device, part of the liquid handled by the pump flows from the pump discharge side of the pump chamber 25.
After flowing into the pump rear side chamber 58 through the through hole 56 of the adapter (8), a part of it flows into the pump chamber through the narrow shaft penetration gap 27 formed between the boss portion 26! of the main impeller 26 and the adapter 48. 25, and the remainder flows back to the pump rear chamber 58.
The canned motor pump passes through the narrow shaft penetration gap 60 formed between the adapter 48 and the rotating shaft 57 between the canned motor pump front chamber 52 and the canned motor pump front chamber 52, passes through the inside of the canned motor section 22, and passes through the canned motor pump front chamber 52. A discharge path 3 that discharges from the rear chamber 50 to the discharge port 36 to the outside of the canned motor pump 20C? As in the case of the canned motor pump device shown in FIG. It is connected to the discharge tank 41 or to the pump suction port 43 side via the filter device 46.

The operating method of the present invention in the canned motor pump device configured as described above is similar to the case of the canned motor pump device shown in FIG. The pressure of an auxiliary impeller provided separately from the auxiliary impeller 49 of 55, for example, the auxiliary impeller coaxial with the main impeller 26 provided between the main impeller 26 and the shaft penetration gap 60, or the pump suction port 43 of the canned motor pump 20C.
Forced liquid head or canned motor pump 2
The suction force of the discharge pump 38 connected to the 0C discharge port 36,
Alternatively, a pressure source such as a combination of these may be used to control the pump operation at a predetermined flow rate from the pump chamber 25 at all times while the canned motor pump 2 [IC is rotating, and until at least a predetermined period of time has elapsed after the canned motor pump 20C has stopped. The liquid is passed through the shaft penetration gap 60, passed through the canned motor section 22, and discharged from the discharge port 36 to the discharge tank 4I to the outside of the canned motor pump 20C, or via the filter device 46, to the pump suction port 43 side. All you have to do is reflux it.

According to the canned motor pump device shown in FIG. 3, the stator 32 and rotor 33 of the canned motor pump section 22 are cooled by the circulating flow of the pump handling liquid flowing through the canned motor circulation path 55. , during the rotation of the canned motor pump 20c, the shaft penetration part gap 6
The predetermined flow rate of the pump handling liquid that flows through the shaft opening may be any flow rate higher than the minimum flow rate that can prevent the abrasion impurities from entering the pump chamber 25 side through the shaft penetration gap 60.
The flow rate is extremely small compared to the flow rate in consideration of cooling of the canned motor section 22 as in the case of the canned motor pump device shown in FIG. It is economical because the discharge tank 41 is small and small, and even when the liquid handled by the pump is recirculated to the pump suction port 43 side through the filter device 46, the filter device 46 and the like are extremely small and inexpensive.

In the canned motor pump device shown in FIG. 3, the discharge port 36 is provided facing the canned motor rear chamber 50, and is also provided facing the canned motor front chamber 52 as shown by the broken line in the figure. It may be provided on the canned motor section 22 side with respect to the shaft penetration gap 60, such as on the heat exchanger 54.

Next, FIG. 4 shows a magnetic coupling pump device to which the operating method of the present invention is applied.

200 is the pump part 21 and the magnetic cup link part 7
0 and a general-purpose motor 71 are integrally coupled, and the pump casing 24 of the pump section 21 and the casing side plate 74
This is a rotary pump in which a main impeller 26 that rotates without contact is arranged in a pump chamber 25 formed by the above, that is, a magnetic coupling pump. A through hole 79 is provided in the installed rotor 76, passing through the rotor 76 in the axial direction, and opening at both ends on the inner diameter side of the front thrust force member 77 and the rear thrust force member 78 attached to the rotor 76, A passage groove 82 is provided in the bottom wall of the partition body 73 on which the rear bearing 34 is mounted, and a communication groove 82 is provided to communicate the rear side chamber 80 of the magnetic coupling and the rear rotor chamber 81. The front bearing 28 is lubricated through the narrow shaft penetration gap 27 formed between the side plate 74 and the boss portion 26a of the main impeller 26.
The remaining portion passes through the rotating sliding gap between the front bearing 28 and the front thrust force member 77 to reach the front rotor chamber 83, and the remaining portion passes through the through hole 79 of the rotor 76 to lubricate the rear bearing 34. , a part of it passes through the rotating sliding gap between the rear bearing 34 and the rear thrust collar 78, and the rest passes from the rear side chamber 80 of the magnetic coupling. They pass through R82 to the rear rotor chamber 81, pass through the gap 84 between the rotor 76 and the partition wall 73, cool the partition wall 73, and reach the front rotor chamber 83. A discharge path 37d is formed in which the liquid is discharged from 83 to the outside through the discharge port 36 provided in the casing side plate 72.

Further, the discharge port 36 may be connected to a discharge pump 38 as necessary.
, the flow rate control valve 39 and the flow rate sensor 40 are connected to the discharge tank 41, or to the pump inlet 43 side via the filter device 46.

The operating method of the present invention in the magnetic coupling pump device configured as described above is based on the discharge pressure of the main impeller 26, the forced liquid head at the pump suction port 43, the suction force of the discharge pump 38 connected to the discharge port 36, or By means of a pressure source such as a combination of these, a predetermined flow rate of the pump handling liquid is pumped from the pump chamber 25 at all times while the magnetic coupling pump 20D is rotating and until at least a predetermined period of time has elapsed after the magnetic coupling pump 20D has stopped. The liquid is passed through the penetration part gap 27 and passed through the magnetic coupling part 70 from the discharge port 36 to the discharge tank 41- and the magnetic coupling pump 20.
D is discharged to the outside, or is returned to the pump suction port 43 side via the filter device 46.

Note that the predetermined flow rate while the magnetic coupling pump 20D is rotating is
The flow rate is higher than the minimum flow rate that can prevent abrasion impurities generated by the rotation and sliding of the front bearing 28 and rear bearing 34, which are the rotational and sliding parts of 0D, from entering the pump chamber 25 side through the shaft penetration gap 27. At the flow rate, and the partition body 73
is a flow rate that is greater than or equal to the minimum flow rate necessary for cooling the partition wall body 73 when the partition wall body 73 is made of a metal material that generates heat due to a rotating magnetic field, and the predetermined flow rate after the magnetic coupling pump 200 is stopped is
This prevents the abrasion impurities generated in the rotating sliding part during the rotation of 00 from entering the pump chamber 25 side from the magnetic coupling part 70 side through the shaft penetration part gap 27 while the magnetic coupling pump 20D is stopped. The flow rate is equal to or higher than the minimum flow rate that can be prevented, and the predetermined period of time means that after the magnetic coupling pump 200 is stopped, the worn impurities remaining in the magnetic coupling part 70 are removed from the discharge port 36 of the magnetic coupling pump 20D. This is the time required to complete evacuation to the outside.

Therefore, according to this embodiment, as in the case of the canned motor pump device, while the magnetic coupling pump 200 is in operation, at least until a predetermined period of time has elapsed after the magnetic coupling pump 200 is stopped,
Each predetermined flow rate of the pump handling liquid is passed from the pump chamber 25 to the narrow shaft penetration gap 27 and discharged to the outside of the magnetic coupling pump 200, so that the front bearing 28 and the rear bearing 34 are prevented from entering the pump chamber 25 side through the shaft penetration gap 27, and the abrasion impurities are prevented from entering the pump chamber 25 side through the shaft penetration gap 27.
The liquid is discharged from the magnetic coupling pump 200 to the outside of the magnetic coupling pump 200 together with the pump handling liquid.

By the way, when a large-diameter or thick-walled partition body 73 is adopted in order to increase the size or high pressure resistance of the magnetic coupling pump 20p, the amount of heat generated by the partition body 73 due to the rotating magnetic field increases, and this partition wall Since the flow rate of the pump handling liquid required to cool the body 73 is extremely large compared to the minimum flow rate of the pump handling liquid that can prevent the abrasion impurities from entering the pump chamber 25 side, the candling shown in FIG. Like motor pump device, magnetic coupling pump 2Q
D may be configured as an independent circulation type.

That is, as in the magnetic coupling pump 2GE shown in FIG. Through holes 86 and 8 provided
By disposing the heat exchanger 54 between the front rotary chamber 83 and the magnetic coupling front side chamber 88 via the auxiliary impeller 85, the pump handling liquid in the magnetic coupling part 70 is transferred to the auxiliary impeller by the pumping action of the auxiliary impeller 85. 85 and reaches the rear rotor chamber 81, and after lubricating the rear bearing 34 through the rotating sliding gap between the rear bearing 34 and the rear thrust collar 78, the shaft is energized from the rear side chamber 80 of the magnetic coupling. The water flows back through the inner passage 89 to the suction port side of the auxiliary impeller 85, and the rest passes through the gap 84 between the rotor 76 and the partition wall 73 to cool the partition wall 73, and flows from the front rotor chamber 83 to the casing side plate. It reaches the heat exchanger 54 through the through hole 86 of the casing side plate 72, and after being cooled by the heat exchanger 54, it reaches the magnetic coupling front chamber 88 through the through hole 87 of the casing side plate 72, and lubricates the front bearing 28. A part of it passes through the gap between the rotating sliding part between the front bearing 28 and the front thrust collar 77 and enters the front rotor chamber 83.
The remainder passes through the through hole 79 of the rotor 76 and returns to the auxiliary impeller 85 to form a magnetic coupling circulation path 90 in which the remaining liquid is circulated from the pump discharge side of the pump chamber 25 to the pump handling liquid. After a part of it flows into the pump rear side chamber 58 through the through hole 91 provided in the casing side plate 72, a part of it flows from the pump rear side chamber 58 into the pump chamber 25.
The flow returns to the pump chamber 25 through the narrow shaft penetration gap 93 formed between the side rotating shaft 92 and the casing side plate 72, and the remainder flows from the pump rear chamber 58 to the rotating shaft 92 on the magnetic coupling front chamber 88 side. It passes through the narrow shaft penetration gap 94 formed between the casing side plate 72 and the magnetic coupling front chamber 88, and then flows through the magnetic coupling circulation path 90 and reaches the discharge port 3 from the middle thereof.
6, a discharge path 37e that is discharged to the outside of the magnetic coupling pump 2 (IE) may be formed.

According to the magnetic coupling device configured in this manner, since the partition wall body 73 is cooled by the circulating flow of the pump handling liquid flowing through the magnetic coupling circulation path 90, the shaft penetrating portion is cooled while the magnetic coupling pump 20E is rotating. The predetermined flow rate of the pump handling liquid flowing into the gap 94 means that the abrasion impurities are absorbed into the shaft penetrating part gap 94, as in the case of the canned motor pump device shown in FIG.
It is sufficient that the flow rate is at least the minimum flow rate that can prevent the liquid from entering the pump chamber 25 side through the flow, and an extremely small flow rate is sufficient.

Next, FIG. 6 shows a general-purpose motor-driven rotary pump device having a shaft seal to which the operating method of the present invention is applied.

20F is a rotary pump driven by a general-purpose motor 7I having a shaft sealing part 95 such as a mechanical seal or gland packing, and a boss part 26 of the main impeller 26! and a discharge port 36 that communicates with the pump suction port 58 between the narrow shaft penetration gap 27 formed between the shaft sealing portion 95 and the casing side plate 72.
is provided in the casing side plate 72, and a part of the liquid handled by the pump from the pump chamber 25 flows into the pump rear side chamber 58 through the narrow shaft penetration gap 27, and is discharged from the discharge port 36 to the outside of the rotary pump 20F. 371, and the discharge port 36 is connected to a discharge pump 38 and a flow control valve 39 as necessary.
and a flow rate sensor 40 connected to the discharge tank 41 or via a filter device 46 to the pump suction port 4
Connect to side 3.

The operating method of the present invention in the rotary pump device configured as described above is based on the discharge pressure of the main impeller 26, the forced liquid head at the pump suction port 43, the suction force of the discharge pump 38 connected to the discharge port 36, or the suction force of the discharge pump 38 connected to the discharge port 36, or By means of a pressure source such as a combination, a predetermined flow rate of the pump handling liquid is passed from the pump chamber 25 to the shaft penetration gap 27 at all times while the rotary pump 20F is rotating and until at least a predetermined period of time has elapsed after the rotary pump 20F has stopped. The liquid is drained to the outside of the rotary pump 20F from the discharge port 36 to the discharge tank 41 through the pump rear side chamber 58, or to the outside of the rotary pump 20F.
It is made to flow back to the pump suction port 43 side via G.

Note that the predetermined flow rate during rotation of the rotary pump 20F means that abrasion impurities generated by the rotation and sliding of the shaft sealing portion 95, which is a rotating and sliding portion of the rotary pump 20F, flow through the shaft penetrating portion gap 27.
The flow rate is the minimum flow rate that can be prevented from entering the pump chamber 25 side through The wear impurities are removed from the rotary pump 2Ql'
The flow rate is at least the minimum flow rate that can prevent the rotary pump 20 from entering the pump chamber 25 side through the shaft penetration gap 27 from the pump rear side chamber 58 while the rotary pump 20 is stopped.
This is the time required to completely discharge the worn impurities remaining in the pump rear side chamber 58 from the discharge port 36 to the outside of the rotary pump 20F after the pump F is stopped.

Therefore, according to this embodiment, as in the case of the canned motor pump device and the magnetic coupling pump device, when the rotary pump 20F is in operation, at all times, and after the rotary pump 20F is stopped, at least until a predetermined period of time has elapsed. , each pump handling liquid at a predetermined flow rate is pumped into the pump chamber 25.
The liquid passes through the narrow shaft penetration gap 27 from the rotary pump 20F.
Therefore, due to the flow of the pump handling liquid at each predetermined flow rate, abrasion impurities generated at the rotating sliding part of the shaft sealing part 95 pass through the shaft penetrating part gap 27 and into the pump chamber 2.
5 side is prevented, and the abrasion impurities are discharged from the discharge port 36 to the outside of the rotary pump 20F together with the pump handling liquid.

〔Effect of the invention〕

According to the method of operating a rotary pump for high-purity liquid of the present invention, the discharge pressure of the main impeller of the rotary pump, the pressure by the auxiliary impeller disposed coaxially with this main impeller, or the forced liquid at the pump suction port of the rotary pump Suction power of the discharge pump connected to the head or the discharge port of the rotary pump,
Or, due to pressure sources such as a combination of these, abrasion impurities generated in the rotating sliding part of the rotary pump are kept in the gap between the shaft penetrating parts at all times while the rotary pump is rotating and until at least a predetermined period of time has elapsed after the rotary pump has stopped. Since a predetermined flow rate of the pump handling liquid that can be prevented from entering the pump chamber through the pump chamber is passed from the pump chamber to the shaft penetration gap, the abrasion impurities are prevented from entering the pump discharge liquid during rotation of the rotary pump. The abrasion impurities will not enter the pump chamber after the rotary pump is stopped and will not be mixed into the pump discharge liquid when the rotary pump is restarted. The semiconductor product yield can be improved or it can be applied to the production of highly integrated semiconductors.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a canned motor pump device to which an operating method according to an embodiment of the present invention is applied, and FIGS. 2 and 3 are longitudinal sectional views of another canned motor pump device, respectively. FIG. 4 is a longitudinal sectional view of a magnetic coupling pump device to which the operating method of another embodiment of the present invention is applied, FIG. 5 is a longitudinal sectional view of another magnetic coupling pump device same as the above, and FIG. FIG. 7 is a vertical cross-sectional view of a general-purpose motor-driven rotary pump having a shaft seal to which the operating method of still another embodiment of the invention is applied; FIG. FIG. 8 shows a longitudinal sectional view of a conventional canned motor pump. 20^, 208, 2θC...canned motor pump, 2QD, 20E...magnetic coupling pump, 20F...general-purpose motor-driven rotary pump with shaft seal section, 21...pump section, 22φ.canned motor section, 25 ... Pump room, 26 ... Main impeller, 27
...Shaft penetration gap, 28...Front bearing, 31...
Can gap, 32... Stator, 33... Rotor, 34...
・Rear bearing, 36...Discharge port, 37a, 3
7b, 37c. 31d, 37e...Discharge path, 38...Discharge pump, 39...Flow rate control valve, 40...Flow rate sensor, 41...
- Discharge tank, 42... Suction tank, 43... Pump suction port, 46... Filter device, 47.49... Auxiliary impeller, 53, 56... Adapter hole, 54... Heat exchanger, 55...・Canned motor circulation path, 57...Rotating shaft, 58...Pump rear side chamber, 60...Shaft penetration gap, 7o
...Magnetic coupling part, 71...General-purpose motor,
73.. Partition body, 76.. Rotor, 77.. Front thrust collar, 78.. Rear thrust collar, 79.. Rotor through hole, 82.. Passing groove, 84.. Gap, 85. Auxiliary impeller. 86. ' 87.91...through hole in casing side plate,
90...Magnetic coupling circulation path, 92...Rotating shaft, 94...Shaft penetration gap, 95...Shaft sealing part.

Claims (4)

[Claims] (1) In a rotary pump in which an impeller disposed in a pump chamber rotates without contact, abrasion impurities generated in the rotary sliding part of the rotary pump pass from the rotary sliding part through the narrow shaft-penetrating part gap to the rotary pump. In order to prevent liquid from entering the pump chamber, a predetermined flow rate of pump handling liquid is pumped from the pump chamber into the shaft at all times while the rotary pump is rotating and until at least a predetermined period of time has elapsed after the rotary pump has stopped. A method of operating a rotary pump for high-purity liquid, which is characterized by passing liquid through a gap between penetration parts. (2) While the rotary pump is rotating, a predetermined flow rate of pump liquid is supplied to the shaft penetrating part by at least one of the discharge pressure of the main impeller of the rotary pump and the pressure of the auxiliary impeller disposed coaxially with the main impeller. 2. The method of operating a rotary pump for high-purity liquid according to claim 1, characterized in that part or all of the pressure source necessary for passing liquid through the gap is obtained. (3) While the rotary pump is stopped, part or all of the pressure source necessary to pass a predetermined flow rate of pump handling liquid into the shaft penetration gap is obtained by the forced liquid head at the pump suction port of this rotary pump. 3. The method of operating a rotary pump for high purity liquid according to claim 2. (4) While the rotary pump is stopped, a predetermined flow rate of the pump handling liquid is pumped into the shaft by the suction force of the discharge pump connected to the discharge port that discharges the pump handling liquid that has passed through the shaft penetration gap to the outside of the rotary pump. Claim 1, characterized in that part or all of the pressure source necessary for passing liquid through the gap of the penetration part is obtained.
3. A method of operating a rotary pump for high purity liquid according to 2 or 3.