JPH0592490U - Vertical pump - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevent water from remaining in the discharge pipe 7 after pumping off, avoid abnormal vibration, reduce power consumption during air operation, and increase temperature of residual water. Avoid adverse effects on the pump components caused by. [Structure] A discharge passage 7 is provided in a discharge pipe 7 connected to a discharge side of an impeller chamber 3 of a vertical shaft pump 2 so that water in the discharge pipe 7 is discharged when pumping is stopped and water W remains in the discharge pipe 7. I try not to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vertical shaft pump for preceding standby operation, and more particularly to a vertical shaft pump capable of avoiding the occurrence of abnormal vibration after a pumping cutoff.

[0002]

[Prior Art]

 In order to carry out the operation method of the vertical shaft pump that performs the preceding standby operation, it is composed of the open air intake pipe 4B in which the intake valve 4A is provided in the suction pipe 11 of the vertical shaft centrifugal pump 2 installed in the water intake well 1 shown in FIG. The intake system 4 is connected, the water level signal detected by the water level detecting means 5 is input to the controller 6, and the controller 6 outputs an open / close signal to the intake valve 4A based on the input water level signal. There is a vertical pump.

A conventional operation example using the vertical shaft pump thus configured will be described. When the water level of the intake well 1 (hereinafter simply referred to as the water level) rises. A-. Until the water level exceeds the pumping cutoff water level SWL shown in FIGS. 6 and 7 and reaches the pumping start water level RWL, the intake valve 4A is fully opened to perform the air operation (0 → p1 in FIG. 7). A-. When the pumping start water level RWL is reached, the intake valve 4A is fully closed and switched to the normal drainage operation (100% Q) with a predetermined discharge amount (p1 → p2 in FIG. 7). At the water level, regular drainage operation is continued (p2 → ph in FIG. 7). When the water level of suction well 1 drops. B-. From the position where the water level exceeds the pumping start water level RWL to the pumping cutoff water level SWL after passing through the pumping start water level RWL, the regular drainage operation is continued (ph → p3 in Fig. 7). B-. When the pumping cutoff water level SWL is reached, the intake valve 4A is fully opened to switch to the air operation (p3 → p4 in FIG. 7), and the air operation is continued at the water level below the pumping cutoff water level SWL (see FIG. 7). p4 → 0).

By the way, in the conventional vertical centrifugal pump 2, when the normal drainage operation is switched to the air operation by the pump cutoff in the B-, the inside of the discharge pipe 7 connected to the discharge side of the impeller chamber 3 is changed. A state occurs in which the water W remaining in the above is stirred by the impeller 8. That is, in the air operation, the impeller 8 continues to stir the residual water W in the discharge pipe 7. As a result, in FIG. 8, as compared with the vibration A during normal drainage operation shown in the area T1, a much larger abnormal vibration B occurs during the air operation as shown in the area T2, and Have various adverse effects on. On the other hand, since the stirring load of the residual water W is applied to the impeller 8 even during the air operation, the motor input value is larger than that in the complete air operation (the state where there is no residual water W) in FIG. As the region T2 becomes larger, the characteristics are changed, which hinders reduction of power consumption during air operation and increases running cost. In addition, the residual water W is agitated, which causes an abnormal rise in the water temperature, which adversely affects the pump constituent members.

[0005]

[Problems to be solved by the device]

 The problem to be solved is that in the conventional vertical axis pump, water remains in the discharge pipe even if the pumping operation is switched from the pumping operation to the aerial operation by shutting off the pumping. This is an obstacle to reducing power consumption and raising the temperature of residual water.

[0006]

[Means for Solving the Problems]

 According to a first aspect of the present invention, in a vertical pump in which an intake pipe communicating with the atmosphere is connected to a suction pipe below the impeller, the discharge pipe connected to the discharge side of the vertical pump from the impeller chamber is connected to the discharge pipe. The feature is that there is an escape passage for discharging the discharged liquid, and during the air operation, the liquid (water) is not left in the discharge pipe to avoid the occurrence of abnormal vibration and to operate in the air. In addition to reducing power consumption during operation, the purpose of avoiding adverse effects on the pump components caused by the rise in the temperature of the residual water was achieved.

The invention of claim 2 is characterized in that a relief valve is provided in the relief passage, and the relief valve is opened in synchronization with the pumping cutoff, so that liquid is discharged into the discharge pipe during air operation. I tried not to survive.

The invention of claim 3 is characterized in that the relief valve is controlled to open and close in conjunction with an intake valve provided in the intake pipe, and is synchronized with opening of the intake valve when pumping is cut off. By opening the relief valve, liquid was prevented from remaining in the discharge pipe during air operation.

[0009]

[Action]

 According to the invention of claim 1, since the liquid in the discharge pipe can be discharged from the escape passage, the liquid does not remain in the discharge pipe after the pumping is cut off.

According to the second aspect of the invention, the liquid in the discharge pipe can be discharged from the escape passage by opening the escape valve in synchronization with the pumping cutoff.

According to the third aspect of the invention, the liquid in the discharge pipe can be discharged from the escape passage by opening the relief valve in synchronization with the opening of the intake valve when the pumping water is cut off.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of a vertical centrifugal pump according to the present invention. In a vertical centrifugal pump 2 installed in an intake well 1, a discharge pipe 7 connected to a discharge side of an impeller chamber 3 of the vertical centrifugal pump 2 is shown. The escape passage 9 is provided at a low position, and the passage cross-sectional area of the escape passage 9 is set to be relatively small.

With such a configuration, the water level is lowered to the pumping cutoff water level SWL by the operation of the vertical volute pump 2, and the pumping is cut off. The water W remaining in the discharge pipe 7 at this point is discharged to the water absorption well 1 through the escape passage 9, and therefore does not remain in the discharge pipe 7. As a result, in FIG. 2, as compared with the vibration A during normal drainage operation shown in the area T1, the vibration B is significantly reduced during the air operation as shown in the area T2, and various adverse effects are exerted on the pump equipment. Inconvenience can be avoided. Moreover, since the stirring load of the water W on the impeller 8 disappears during the air operation, the motor input value shows a greatly reduced stability characteristic as shown by the region T2 in FIG. Power consumption is reduced and running costs are reduced. Of course, it does not cause an abnormal rise in water temperature. Even during the normal drainage operation, the water W is discharged through the escape passage 9, but it can be ignored because the passage cross-sectional area of the escape passage 9 is set to be relatively small.

According to the present invention, as shown in FIG. 4, a relief valve 10 is provided in the relief passage 9, and the relief valve 10 is opened in synchronization with the fact that the water level is lowered to the pumping cutoff water level SWL and pumping is blocked. It may be configured as follows. Further, as shown in FIG. 5, the suction pipe 11 is connected to the intake system 4 constituted by an atmosphere open intake pipe 4B provided with an intake valve 4A, and the pumping cutoff water level SWL detected by the water level detecting means 5 is sent to the controller 6. The intake valve 4A is opened by the control signal output from the controller 6 based on the input water level signal, and the relief valve 10 is opened by the control signal output from the controller 6. Good. Further, the opening timing of the relief valve 10 is slightly delayed to detect vibrations caused by water remaining in the discharge pipe 7, abnormal input values of characteristics such as the motor input value and water temperature in the discharge pipe 7, and the like. The relief valve 10 may be opened based on this detected value.

[0015]

[Effect of the device]

 As described above, according to the first aspect of the invention, since the liquid in the discharge pipe can be discharged from the escape passage, the liquid does not remain in the discharge pipe after the pumping is cut off. Therefore, it is possible to avoid the occurrence of abnormal vibration during the air operation, reduce the power consumption during the air operation, and surely avoid the adverse effect on the pump component caused by the temperature rise of the residual water.

Further, according to the invention of claim 2, the liquid in the discharge pipe is discharged from the escape passage by opening the relief valve in synchronization with the cutoff of pumping water, thereby avoiding occurrence of abnormal vibration during air operation. The power consumption during air operation can be reduced, and the adverse effect on the pump components caused by the temperature rise of the residual water can be reliably avoided.

Further, according to the invention of claim 3, the liquid in the discharge pipe is discharged by discharging the liquid in the discharge pipe from the discharge passage by opening the relief valve in synchronization with the opening of the intake valve when the pumping is cut off. Discharge from the escape passage to avoid abnormal vibration during air operation, reduce power consumption during air operation, and surely avoid adverse effects on pump components caused by temperature rise of residual water be able to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a vertical shaft pump according to the present invention.

FIG. 2 is a graph showing the relationship between the operating state and vibration of the present invention.

FIG. 3 is a graph showing a relationship between an operating state and a motor input value according to the present invention.

FIG. 4 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing a conventional example.

FIG. 7 is a graph showing operating characteristics of a conventional example.

FIG. 8 is a graph showing a relationship between a driving state and vibration in a conventional example.

FIG. 9 is a graph showing a relationship between an operating state and a motor input value in a conventional example.

[Explanation of symbols]

 2 Vertical shaft centrifugal pump (vertical shaft pump) 3 Impeller chamber 4 Intake system 4A Intake valve 4B Intake pipe 7 Discharge pipe 9 Escape passage 10 Escape valve 11 Suction pipe SWL Pumping water cutoff water RWL Pumping start water level

Front page continuation (72) Inventor Masahide Konishi 1-1-1 Nakanomiya Oike, Hirakata City, Osaka Prefecture Kubota Hirakata Manufacturing Company

Claims (3)

[Scope of utility model registration request] 1. In a vertical shaft pump having an intake pipe communicating with the atmosphere connected to a suction pipe below the impeller, a discharge pipe connected to a discharge side of the vertical shaft pump discharges the impeller chamber. A vertical shaft pump having a relief passage for discharging the liquid. 2. The vertical pump according to claim 1, wherein a relief valve is provided in the relief passage. 3. The vertical pump according to claim 2, wherein the relief valve is controlled to open and close in conjunction with an intake valve provided in the intake pipe.