JP5312600B2 - Slurry pump and slurry pump operating method - Google Patents

Description

  The present invention relates to a slurry pump for pumping slurry (suspension) containing sludge, semi-solid or suspended solids such as crystals stored in a tank or a water tank, and a method for operating the slurry pump.

  In recent years, liquid crystal display panels have been widely used as display units for home appliances such as computers and televisions. In general, a liquid crystal display panel has a configuration in which a pair of glass substrates, each composed of a thin film transistor (TFT) array substrate and a color filter (CF) substrate, are arranged opposite to each other in parallel at a predetermined interval, and liquid crystal is filled between the substrates. I am doing.

  A plurality of pixel electrodes are formed in a matrix on the TFT array substrate, and a common electrode is formed on almost the entire surface of the CF substrate, and the orientation of the liquid crystal can be controlled by changing the voltage applied between these electrodes. Can be done.

  In the manufacturing process of such a liquid crystal display panel, those that do not satisfy the predetermined quality standards required for the TFT array substrate and the CF substrate cannot be used for the liquid crystal display panel and are discarded.

  Therefore, various thin films and the like formed on the glass substrate are removed from the discarded materials and recycled, and reused as a glass substrate for a TFT array substrate or a CF substrate. .

  As a method of removing the film formed on the surface of such a glass substrate, there is a method of removing by polishing. Conventionally, as a device for polishing the surface of such a glass substrate, a substrate polishing machine 30 as shown in FIG. 4 has been used. 4A is a side view of the main part of the substrate polishing machine 30, and FIG. 4B is a top view thereof.

  As shown in the drawing, the substrate polishing machine 30 includes upper surface plates 31 and 31 and a lower surface plate 32 that are arranged to face each other in the vertical direction. A polishing cloth 34 is attached to the lower surface of the upper surface plate 31 having a circular shape via a double-sided adhesive sheet, and the abrasive liquid S supplied from the nozzle 35 disposed on the upper surface of the upper surface plate 31 is supplied. The inside of the upper surface plate 31 flows down and is supplied to the polishing pad 34.

  The lower surface plate 32 is a member made of porous ceramic having a rectangular shape substantially the same size as the glass substrate W, and the glass substrate is evacuated by a vacuum pump (not shown) connected to the lower portion of the lower surface plate 32. W can be adsorbed and fixed on the surface of the lower surface plate 32.

  Then, the upper surface plate 31 is pressurized, the glass substrate W is sandwiched between the polishing cloth 34 and the lower surface plate 32 of the upper surface plate 31, and the abrasive liquid S is supplied to the polishing cloth 34, while the upper surface plate 31 is pressed. Polishing is performed by repeatedly moving in the direction indicated by arrow 36 while rotating 31 and lower surface plate 32.

  In this case, as the polishing abrasive liquid S supplied from the nozzle 35, a suspension (slurry) in which abrasive grains (abrasive material) made of powdered alumina, cerium oxide or the like is dispersed in, for example, an alkaline solution or water. Is used.

  FIG. 5 shows an abrasive liquid supply device for supplying the abrasive liquid S to the substrate polishing machine 30 described above. As illustrated, the abrasive liquid supply device 40 includes an abrasive liquid storage tank 41 in which the abrasive liquid S is stored, and a slurry pump 42 that sucks up the abrasive liquid S in the abrasive liquid storage tank 41 and supplies it to the substrate polishing machine 30. It has.

  The slurry pump 42 is a so-called centrifugal vertical shaft pump, and a hollow suspension pipe 4 is fixed to a base plate 9 attached to an upper wall of an abrasive liquid storage tank 41 as a pedestal for installing the pump. Yes. An impeller casing 5 is attached to the lower end of the suspension pipe 4.

  The impeller casing 5 has an abrasive liquid suction port 5a that opens downward and an abrasive liquid discharge port 5b that opens upward, and a centrifugal impeller (rotation with blades for applying pressure to the fluid) inside the impeller casing 5 Body) 6 is disposed. The impeller 6 is disposed in the impeller casing 5 such that the suction portion 6a faces the abrasive liquid suction port 5a and the discharge blade 6b faces the abrasive liquid discharge port 5b, and rotates in a horizontal plane. .

  A motor 7 is mounted on the base plate 9, and a main shaft 8 whose upper end is connected to a rotating shaft 7 a of the motor 7 via a shaft coupling 10 is disposed inside the suspension pipe 4. The lower end of the main shaft 8 is connected to the impeller 6 in the impeller casing 5.

  FIG. 2 shows a view when the impeller casing 5 with the bottom plate 5c removed is viewed from below. In the impeller casing 5, there are formed a spiral chamber 5d, which is a space in which the impeller 6 is disposed, and a discharge passage 5e extending laterally from the spiral chamber 5d. The abrasive fluid suction port 5a opened in the bottom plate 5c communicates with the center of the spiral chamber 5d. A polishing liquid discharge port 5b communicates with the tip of the discharge passage 5e, and a discharge pipe 12 is connected to the polishing liquid discharge port 5b.

  When the impeller 6 is rotated by driving the motor 7 in the impeller casing 5 having such a shape, the pressure in the central portion is lowered by the centrifugal force in the spiral chamber 5d, and accordingly the abrasive suction port 5a of the bottom plate 5c. Abrasive fluid S is sucked in. The suctioned abrasive liquid S is boosted in the spiral chamber 5d of the impeller casing 5 by the rotation of the impeller 6 having a plurality of discharge blades 6b, guided to the discharge passage 5e, and discharged from the abrasive liquid discharge port 5b to the discharge pipe 12. To be sent out. In addition, the following patent document is mentioned as a prior art document relevant to this invention.

JP 58-160592 A

  However, while the slurry pump 42 having such a configuration is not operated, the abrasive liquid S in the impeller casing 5 is solidified due to retention, and is fixed to the impeller 6, thereby restricting the rotation of the impeller 6. Had occurred. For example, when the abrasive liquid concentration (slurry concentration) is about 10 percent by weight, such sticking occurs only by stopping the slurry pump 42 for about one hour.

  When the slurry pump 42 is operated in such a state, a protection circuit provided to prevent the motor 7 called so-called thermal trip from being overheated and damaged by overheating is activated.

  In such a case, the operator inserts a jig such as a flat-blade screwdriver into the motor casing 11 and manually rotates the rotating shaft 7a of the motor 7 to rotate the impeller 6 in the impeller casing 5 and solidify the abrasive. The operation of operating the slurry pump 42 is necessary after loosening the liquid S and releasing the restraint of the impeller 6 and resetting the activated thermal trip, which is complicated and problematic.

  Therefore, the problem to be solved by the present invention is a slurry pump and a slurry pump capable of preventing the abrasive liquid in the impeller casing from solidifying and restraining the rotation of the impeller while the slurry pump is not operated. It is to provide a method for operating a slurry pump.

  In order to solve the above-described problems, the present invention provides a slurry pump for pumping a stored slurry, which is connected to a suspension pipe immersed in the slurry, a lower end of the suspension pipe, and a slurry suction port and a slurry discharge port. An impeller casing having an outlet; an impeller disposed inside the impeller casing; and a main shaft having an upper end connected to a rotating shaft of a motor and penetrating the suspension pipe and having a lower end connected to the impeller. And an air pipe is connected to a discharge pipe connected to the slurry discharge port, and air is supplied into the impeller casing through the discharge pipe to discharge internal slurry. To do.

  In this case, an air vent valve is preferably provided in the air pipe connected to the discharge pipe. Further, it is preferable that an air pipe is connected to the suspension pipe so that air is supplied into the suspension pipe. Furthermore, it is preferable that the air piping connected to the suspension pipe is provided with an air vent valve.

  To solve the above problems, the present invention provides a suspension pipe immersed in the stored slurry, an impeller casing connected to the lower end of the suspension pipe and having a slurry suction port and a slurry discharge port, The impeller disposed inside the impeller casing, the upper end of which is connected to the rotating shaft of the motor and penetrates the suspension pipe, and the lower end of the impeller is connected to the impeller, and is connected to the abrasive discharge port. A slurry pump having an air pipe connected to the discharge pipe so that air is supplied into the impeller casing via the discharge pipe, and the impeller is stopped rotating. The gist of the invention is that air is supplied into the impeller casing through the air pipe and the discharge pipe to discharge the slurry inside.

  In this case, the air piping connected to the discharge pipe may be provided with an air bleeding valve, and the air bleeding valve may be opened before the impeller starts rotating.

  And an air pipe connected to the suspension pipe so that air is supplied into the suspension pipe, and the rotation of the impeller is stopped when the impeller is stopped. It is preferable to adopt a configuration in which air is supplied.

  Furthermore, it is preferable that an air vent valve is provided in the air pipe connected to the suspension pipe, and the air vent valve is opened before the impeller starts rotating.

  According to the slurry pump and the method of operating the slurry pump according to the present invention, the air pipe is connected to the discharge pipe connected to the slurry discharge port while the slurry pump is not operated, that is, while the impeller in the impeller casing does not rotate. Since air is supplied into the impeller casing through the discharge pipe, slurry such as abrasive liquid that normally solidifies by staying in the impeller casing is bubbled by the air supplied into the impeller casing. Will be discharged or stirred. Therefore, since the solidification of the slurry is suppressed by the discharge or stirring by such air bubbling, it is possible to prevent the impeller from being restricted from rotating.

  In this case, if an air vent valve is provided in the air pipe connected to the discharge pipe, the air inside the impeller casing that has been air bubbled can be removed before the slurry pump starts operating. In addition, it is possible to prevent poor pumping of the slurry (defective discharge) due to air contamination.

  Further, if an air pipe is connected to the suspension pipe so that air is supplied into the suspension pipe, the suspension pipe is suspended by the influence of bubbling due to the air supplied from the discharge pipe to the inside of the impeller casing. Since the slurry rising inside the pipe is suppressed by the pressure of the air supplied to the inside of the suspension pipe, for example, the bearing portion that supports the rotation shaft of the motor provided inside the suspension pipe is made of the slurry. Inundation is prevented.

  Furthermore, if the air piping connected to the suspension pipe is provided with an air vent valve, the air inside the impeller casing that has been air bubbled can be removed before the slurry pump starts operating. In addition, it is possible to prevent poor pumping of the slurry (defective discharge) due to air contamination.

It is the figure which showed schematic structure of the abrasive fluid supply apparatus provided with the slurry pump which concerns on one Embodiment of this invention. It is a figure when the bottom plate of the impeller casing with which the slurry pump is provided is viewed from below. It is the figure which showed the state by which the inside of the impeller casing of FIG. 1 is bubbled with air. The schematic structure of the substrate polishing machine which grind | polishes the substrate surface used conventionally is shown, (a) is a side view, (b) is the top view. It is the figure which showed schematic structure of the abrasive fluid supply apparatus provided with the slurry pump used conventionally.

  Embodiments of a slurry pump and a method for operating the slurry pump according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an abrasive liquid supply device provided with a slurry pump. As shown in the figure, the abrasive liquid supply device 1 includes an abrasive liquid storage tank 2 in which an abrasive liquid S, which is a suspension (slurry) supplied to the substrate polishing machine 30 described in FIG. A slurry pump 3 for sucking and discharging the abrasive liquid S in the liquid storage tank 2 is provided.

  The abrasive liquid storage tank 2 is provided with a liquid level sensor (not shown) for detecting the liquid level of the stored abrasive liquid S, and when the liquid level is lowered to a predetermined position by the discharge of the slurry pump 3. Similarly, the abrasive liquid S is replenished by a pump (not shown).

  The slurry pump 3 has a centrifugal vertical shaft pump structure, and is attached to the upper surface of the abrasive liquid storage tank 2.

  The slurry pump 3 includes a hollow suspension pipe 4, an impeller casing 5 connected to the lower end of the suspension pipe 4, an impeller 6 disposed inside the impeller casing 5, and an upper end of the motor 7. A main shaft 8 that is connected to the rotary shaft 7 a and penetrates the suspension pipe 4 and has a lower end connected to the impeller 6 is provided.

  The suspension pipe 4 is fixed to a base plate 9 attached to the upper wall 2a of the abrasive liquid storage tank 2 as a pedestal for installing the pump.

  A motor 7 is mounted on the base plate 9, and a main shaft 8 whose upper end is connected to a rotating shaft 7 a of the motor 7 via a shaft coupling 10 is disposed inside the suspension pipe 4. The lower end of the main shaft 8 is connected to the impeller 6 in the impeller casing 5. The motor 7 is accommodated in a motor casing 11, and the motor casing 11 is fixed on the base plate 9.

  The impeller casing 5 has an abrasive liquid suction port 5a that opens downward and an abrasive liquid discharge port 5b that opens upward, and a centrifugal impeller (rotation with blades for applying pressure to the fluid) inside the impeller casing 5 Body) 6 is disposed.

  As shown in FIG. 2, the impeller 6 includes a surface opposite to the suction portion 6 a, that is, a circular main plate 6 c, and a plurality of sheets radially provided around the main shaft 8 on the lower surface of the main plate 6 c. And a discharge blade 6b. In this case, in the impeller casing 5, the suction part 6a faces the abrasive liquid suction port 5a and the discharge blade 6b faces the abrasive liquid discharge port 5b, and rotates in a horizontal plane.

  In the impeller casing 5, there are formed a spiral chamber 5d, which is a space in which the impeller 6 is disposed, and a discharge passage 5e extending laterally from the spiral chamber 5d. In this case, the abrasive fluid suction port 5a opened in the bottom plate 5c communicates with the center of the spiral chamber 5d.

  A polishing liquid discharge port 5b communicates with the tip of the discharge passage 5e, and a discharge pipe 12 is connected to the polishing liquid discharge port 5b. A draining portion 5f is formed in a connection portion between the spiral chamber 5d and the discharge passage 5e, that is, a portion from the start of winding of the spiral chamber 5d to the discharge passage 5e.

  When the impeller 6 is rotated by driving the motor 7 in the impeller casing 5 as described above, the pressure in the central portion is lowered by the centrifugal force in the spiral chamber 5d, and accordingly the abrasive liquid is supplied from the abrasive liquid suction port 5a of the bottom plate 5c. S is inhaled. The suctioned abrasive liquid S is boosted by the rotation of the impeller 6 in the spiral chamber 5d of the impeller casing 5, guided to the discharge passage 5e, and sent out from the abrasive liquid discharge port 5b to the discharge pipe 12.

  In the middle of the discharge pipe 12, a discharge electromagnetic valve 15 capable of closing / opening operation is provided. By opening the discharge electromagnetic valve 15 and operating the slurry pump 3, the discharge pipe 12 is opened. The polishing liquid S is supplied to the nozzle 35 of the substrate polishing machine 30 shown in FIG.

  An air pipe 16 is connected to an intermediate portion of the discharge pipe 12 between the abrasive liquid discharge port 5 b of the impeller casing 5 and the discharge electromagnetic valve 15, and compressed air can be supplied into the discharge pipe 12. It is like that. The air pipe 16 is connected to a compressed air supply source 23 via an air supply electromagnetic valve 17 that can be opened and closed. Further, an air venting electromagnetic valve 18 capable of opening and closing is provided in the middle of the air pipe 16 between the air supply solenoid valve 17 and the connection portion of the discharge pipe 12.

  Further, a liquid intrusion prevention electromagnetic valve 19 that can be opened and closed is provided at the connection portion between the discharge pipe 12 and the air pipe 16 so that the abrasive liquid S does not enter the air pipe 16 from the discharge pipe 12. Thus, it is possible to prevent the abrasive fluid S from entering the air pipe 16 and solidifying the air pipe 16 to clog the air pipe 16 so that the air cannot be supplied.

  A bearing portion 13 such as a ball bearing is provided below the shaft coupling 10 in the suspension pipe 4, and the main shaft 8 is rotatably supported. Further, a sealing seal portion 14 serving as a shaft sealing mechanism such as a gland packing and a mechanical seal is provided below the bearing portion 13, and the airtightness inside the suspension tube 4 below the sealing seal portion 14 is provided. Is to be maintained.

  By providing such a sealing seal portion 14, the air supplied from the air pipe 20 connected to a position below the sealing seal portion 14 flows downward in the suspension pipe 4. It has become.

  In this case, the lower end of the suspension pipe 4 is formed with an opening 4 a that opens laterally so that the abrasive liquid S can be discharged. Therefore, the suspension pipe is inserted through the opening 5 g on the upper surface of the impeller casing 5. 4, the abrasive liquid S rises and the sealing seal portion 14 and the bearing portion 13 are prevented from being immersed in the abrasive liquid S.

  The sealing seal portion 14 also has a function of preventing the steam and moisture of the polishing liquid S that has reached the inside of the suspension tube 4 from reaching the bearing portion 13. This prevents the bearing portion 13 from being corroded or prematurely deteriorating the lubricant such as grease.

  The air pipe 20 is connected so that compressed air can be supplied into the suspension pipe 4. In this case, the air pipe 20 is connected to an intermediate portion between the sealing seal portion 14 provided inside the suspension pipe 4 and the opening 4 a at the lower end of the suspension pipe 4.

  The air pipe 20 is connected to a compressed air supply source 23 via an air supply electromagnetic valve 21 that can be opened and closed. Further, an air venting solenoid valve 22 that can be similarly opened and closed is provided at an intermediate portion of the air pipe 20 between the air supply solenoid valve 21 and the connection portion of the suspension pipe 4. .

  Such an abrasive fluid supply device 1 includes a control unit 24, and controls the rotation / stop operation of the motor 7 and the opening / closing operation of the solenoid valves 15, 17, 18, 19, 21, 22 as described above. It is possible to do.

  Next, the operation procedure of the slurry pump 3 provided in such an abrasive liquid supply device 1 will be described.

  First, when the abrasive liquid S in the abrasive liquid storage tank 2 is supplied to the substrate polisher 30, the control unit 24 opens the discharge electromagnetic valve 15 and rotates the motor 7 as shown in FIG. To drive. When the impeller 6 in the impeller casing 5 is rotated by the rotation drive of the motor 7, the abrasive liquid S is sucked into the spiral chamber 5d from the abrasive liquid suction port 5a, and discharged from the abrasive liquid discharge port 5b through the discharge passage 5e. And supplied to the substrate polishing machine 30 to be used for polishing the glass substrate W.

  At this time, the control unit 24 controls the air supply solenoid valve 17 provided in the air pipe 16, the air release solenoid valve 18, the liquid intrusion prevention solenoid valve 19, and the air supply solenoid valve 21 provided in the air pipe 20. Then, the air vent solenoid valve 22 is controlled to be closed.

  Next, when the supply of the polishing liquid S to the substrate polishing machine 30 is stopped, the control unit 24 stops the rotation of the motor 7 and closes the discharge electromagnetic valve 15 as shown in FIG. The control unit 24 opens the air supply solenoid valve 17 and the liquid intrusion prevention solenoid valve 19 while the air release solenoid valve 18 of the air pipe 16 is closed, and the air release solenoid of the air pipe 20 is opened. The valve 22 opens the air supply solenoid valve 21 in a closed state.

  When the air supply solenoid valve 17 and the liquid intrusion prevention solenoid valve 19 of the air pipe 16 are opened, air is supplied into the discharge pipe 12. Since the discharge solenoid valve 15 is closed, the air supplied to the inside of the discharge pipe 12 does not flow upward but flows downward in the discharge pipe 12 and enters the impeller casing 5 through the abrasive liquid discharge port 5b. It is sent.

  The air sent into the impeller casing 5 from the abrasive liquid discharge port 5b becomes bubble-like (foam-like) in the abrasive liquid S staying inside the impeller casing 5, and the bubble-shaped air is The impeller 6 is moved around the connecting portion of the impeller 6 to the main shaft 8, the main plate 6c, and the discharge blade 6b, overflows and is discharged from the abrasive fluid suction port 5a, and passes through the opening 5g at the lower end of the suspension pipe 4. It overflows from the opening 4a and is discharged.

  The air supplied into the discharge pipe 12 in this way is sent into the impeller casing 5, so that the supplied air is bubbled (bubbles) in the abrasive liquid S staying inside the impeller casing 5. And move around the impeller 6. Since the abrasive liquid S is discharged or agitated by the movement of the bubble-like air at this time, the stay of the abrasive liquid S around the impeller 6 is suppressed, and as a result, the abrasive liquid S is solidified and fixed to the impeller 6. It is prevented.

  As a result, the abrasive liquid S in the impeller casing 5 is solidified due to retention while the slurry pump 3 is not operated, and is prevented from being fixed to the impeller 6 and restricting the rotation of the impeller 6. Become.

  Further, when the air supply solenoid valve 21 of the air pipe 20 is opened, air is supplied into the suspension pipe 4. The air supplied to the inside of the suspension tube 4 does not flow upward because of the sealing seal portion 14, but flows downward in the suspension tube 4.

  At this time, the polishing liquid S rises in the suspension pipe 4 due to the bubbling caused by the air supplied from the discharge pipe 12 to the impeller casing 5 due to the pressure of the air supplied to the suspension pipe 4. Since it is suppressed, it is prevented that the sealing seal part 14 and the bearing part 13 provided in the suspension pipe 4 are flooded by the rising abrasive liquid S.

  In addition, by supplying air into the suspension pipe 4 in this way, steam and moisture of the polishing liquid S that rises inside the suspension pipe 4 do not reach the sealing seal portion 14 and the bearing portion 13. Therefore, it is possible to prevent the sealing seal portion 14 and the bearing portion 13 from being corroded or prematurely deteriorating the lubricant such as grease due to such steam or moisture.

  Next, a case where the operation of the slurry pump 3 is started from the state of FIG. 3 will be described. First, the control unit 24 closes the air supply electromagnetic valve 17 whose air pipe 16 is opened, and closes the air supply electromagnetic valve 21 whose air pipe 20 is opened.

  Thereby, supply of the air into the impeller casing 5 via the discharge pipe 12 is stopped, and bubbling by the air inside the impeller casing 5 is stopped. In addition, the supply of air to the suspension pipe 4 for preventing the polishing liquid S from rising inside the suspension pipe 4 due to the influence of bubbling by the air supplied from the discharge pipe 12 to the impeller casing 5 is also stopped. .

  Next, the air vent solenoid valve 18 that is plugged in the air pipe 16 is opened, and the air vent solenoid valve 22 that is plugged in the air pipe 20 is opened. When the air release solenoid valve 18 of the air pipe 16 is opened, the inside of the air pipe 16 and the inside of the discharge pipe 12 are released to the atmosphere. Further, when the air venting solenoid valve 22 of the air pipe 20 is opened, the air pipe 20 and the suspension pipe 4 are released into the atmosphere. As the air in the discharge pipe 12 and the suspension pipe 4 is released into the atmosphere, the air in the impeller casing 5 passes through the discharge pipe 12 and the air piping 16 to the outside through the air piping 16. Further, the air is discharged (air vented) from the air vent solenoid valve 22 through the air pipe 20 through the inside of the suspension pipe 4.

  When the air inside the impeller casing 5 is discharged, the control unit 24 sets the air release solenoid valve 18 of the air pipe 16 and the liquid entry prevention solenoid valve 19 and the air release solenoid valve 22 of the air pipe 20 respectively. Close it. Thereafter, when the discharge solenoid valve 15 of the closed discharge pipe 12 is opened and the motor 7 is driven to rotate, the supply of the abrasive fluid S by the slurry pump 3 is started as shown in FIG. Become.

  According to the slurry pump 3 described above, the air pipe 16 is connected to the discharge pipe 12 connected to the abrasive liquid discharge port 5b while the slurry pump is not operated, that is, while the impeller 6 in the impeller casing 5 does not rotate. In addition, since air is supplied into the impeller casing 5 via the discharge pipe 12, the abrasive liquid S that normally solidifies by staying in the impeller casing 5 is supplied to the impeller casing 5. It will be discharged or stirred by bubbling. Therefore, since the solidification of the abrasive liquid S is suppressed by the discharge or stirring by such air bubbling, the rotation of the impeller 6 is prevented from being restricted.

  In this case, since the air vent valve 18 is provided in the air pipe 16 connected to the discharge pipe 12, the air inside the impeller casing 5 that has been air bubbled can be removed before the slurry pump 3 is started. Therefore, it is possible to prevent the pumping failure (discharge failure) of the abrasive liquid S due to air scooping.

  Further, since the air pipe 20 is connected to the suspension pipe 4 and air is supplied into the suspension pipe 4, the suspension pipe 4 is suspended by the influence of bubbling by the air supplied from the discharge pipe 12 into the impeller casing 5. Since the rise of the polishing liquid S inside the tube 4 is suppressed by the pressure of the air supplied into the suspension tube 4, the sealing seal portion 14 and the bearing portion provided inside the suspension tube 4. 13 is prevented from being immersed in the abrasive liquid S. In addition, by supplying air into the suspension pipe 4 in this way, steam and moisture of the polishing liquid S that rises inside the suspension pipe 4 do not reach the sealing seal portion 14 and the bearing portion 13. Therefore, it is possible to prevent the sealing seal portion 14 and the bearing portion 13 from being corroded or prematurely deteriorating the lubricant such as grease due to such steam or moisture.

  Further, since the air vent valve 22 is provided in the air pipe 20 connected to the suspension pipe 4, the air inside the impeller casing 5 that has been air bubbled can be removed before the slurry pump 3 is started. Therefore, it is possible to prevent a failure in pumping (discharge failure) of the slurry due to air contamination.

  As mentioned above, although one embodiment of the slurry pump and the slurry pump handling method according to the present invention has been described, the present invention is not limited to such embodiment, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the following manner.

  For example, in the above-described embodiment, the impeller casing provided with the abrasive liquid suction port on the lower surface and the abrasive liquid discharge port on the upper surface has been described, but the abrasive liquid suction port is provided on one side surface and the abrasive liquid discharge port is provided on the other side surface. The present invention can also be applied to an impeller casing having various shapes such as a configuration of an impeller casing provided and an impeller casing having a polishing liquid suction port on a lower surface and a polishing liquid discharge port on a side surface. There is no limitation to the above-described embodiment.

  The solenoid valve for air supply and the solenoid valve for air release provided in the air pipe may be solenoid valves capable of switching between air supply and atmospheric release at the same time. Without limitation, various valves can be used.

  Further, in the above-described embodiment, the configuration of the slurry pump 3 that supplies the polishing liquid S to the substrate polishing machine 30 has been described. However, various suspensions such as an agricultural water pump that pumps up sludge accumulated in the bottom of the tank or the water tank. The present invention is applicable to a pump that pumps up a turbid liquid (slurry), and is not limited to the above-described embodiment.

  For example, even when the suspension (slurry) is sludge, there is a problem that the impeller 6 is solidified by staying in the impeller casing and fixed to the impeller while the pump is not operated, and the rotation of the impeller 6 is restricted. Therefore, such a problem can be solved by applying the slurry pump according to the present invention to a pump that pumps up such sludge.

Claims (8)

  A slurry pump for pumping a stored slurry, a suspension pipe immersed in the slurry, an impeller casing connected to a lower end of the suspension pipe and having a slurry suction port and a slurry discharge port, and the impeller casing An impeller disposed inside and a main shaft connected to the rotating shaft of the motor and penetrating through the suspension pipe and having a lower end connected to the impeller are connected to the slurry discharge port. A slurry pump, wherein an air pipe is connected to the discharge pipe, and air is supplied into the impeller casing through the discharge pipe to discharge the internal slurry.   The slurry pump according to claim 1, wherein an air vent valve is provided in an air pipe connected to the discharge pipe.   The slurry pump according to claim 1 or 2, wherein an air pipe is connected to the suspension pipe so that air is supplied into the suspension pipe.   The slurry pump according to claim 3, wherein an air vent valve is provided in an air pipe connected to the suspension pipe.   A suspension pipe immersed in the stored slurry, an impeller casing connected to a lower end of the suspension pipe and having a slurry suction port and a slurry discharge port, and an impeller disposed inside the impeller casing; The upper end of the impeller casing is connected to the rotating shaft of the motor and passes through the suspension pipe, and the lower end of the main shaft is connected to the impeller, and the discharge pipe connected to the abrasive liquid discharge port is disposed inside the impeller casing. An operation method of a slurry pump including an air pipe connected to the discharge pipe so that air is supplied, and when the impeller stops rotating, the air pipe and the discharge pipe pass through the air pipe and the discharge pipe. A method for operating a slurry pump, characterized in that air is supplied to the inside of the impeller casing and the slurry in the interior is discharged.   6. The air vent valve is provided in an air pipe connected to the discharge pipe, and the air vent valve is opened before the impeller starts rotating. The operation method of the slurry pump as described.   An air pipe connected to the suspension pipe is provided so that air is supplied into the suspension pipe, and when the impeller stops rotating, the air is introduced into the suspension pipe via the air pipe. The method for operating a slurry pump according to claim 5 or 6, characterized in that is supplied.   8. An air vent valve is provided in an air pipe connected to the suspension pipe, and the air vent valve is opened before the impeller starts to rotate. The operation method of the slurry pump described in 1.

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