JP2998779B2 - Operation control method of vacuum pump attached to mixed flow pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of a vacuum pump attached to a mixed flow pump such as a horizontal mixed flow pump or a mixed flow swirl pump.

[0002]

2. Description of the Related Art Conventionally, in a pump flow path system as shown in FIG. 2, a suction pipe 2 is connected to a suction side of a horizontal-axis mixed flow pump 1, and a discharge pipe built-in heat exchanger 3 is provided at a discharge side. The discharge pipe 5 is connected via the valve 4. The heat exchanger 3 with a built-in discharge pipe cools the refrigerant water of the pump driver 6, has a discharge flow path for a discharge fluid inside, and has a heat transfer pipe arranged around the discharge flow path. . The heat transfer tube of the heat exchanger 3 with a built-in discharge pipe communicates with the heat transfer tube of the cooling jacket of the pump driver 6 via the cooling water circulation tube 7.

The impeller 1a of the horizontal mixed flow pump 1 is connected to a pump drive 6 via a main shaft 8, and the main shaft 8 penetrates the pipe wall of the suction pipe 2 at a main shaft penetration portion 9. The suction pipe 2 has a vacuum suction pipe 10 near the horizontal-axis mixed flow pump 1.
Are connected to each other, and a vacuum pump 11 is connected to the vacuum suction pipe 10.

[0004]

In the above configuration, during normal operation, the horizontal-axis mixed-flow pump 1 is driven by the pump driving device 6 via the main shaft 7 so that the fluid sucked through the suction pipe 2 is discharged into the discharge pipe. The heat is discharged from the discharge pipe 5 through the heat exchanger 3 and the discharge valve 4. At this time, during the operation of the pump, the pressure upstream of the impeller is always negative, and air flows in from the main shaft through portion 9. However, the amount of inflow of this air is small, and in the operation in a state where the discharge valve 4 is fully opened, the flow rate in the pump is high, and the inflow air is discharged from the discharge port together with water, which is a problem. Never.

On the other hand, during a standby operation or a small water amount management operation, the air in the suction pipe 2 is sucked out by the vacuum pump 11 through the vacuum suction pipe 10, and the horizontal-axis mixed flow pump 1 and the suction pipe 2 are sucked.
The interior is set to a negative pressure, and the state where water is sucked into the suction pipe 2 is maintained.

At this time, the vacuum pump 11 is in continuous operation, and when it is full, the vacuum pump 11 sucks out water in the suction pipe 2, so that the vacuum pump 11 continuously sucks water. This causes the vacuum pump to fail. In addition, in the method of providing a full-water detector and the like to detect a full state and stop the vacuum pump by this detection, a sensor device for measuring the amount of air in the pump flow path and restarting the vacuum pump is separately provided. Was needed.

An object of the present invention is to provide a method for controlling the operation of a vacuum pump attached to a mixed flow pump for preventing an excessive operation of a vacuum pump in a full state.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for controlling the operation of a vacuum pump attached to a mixed flow pump according to the present invention comprises the steps of: At the time of discharge by the accompanying vacuum pump, a full state in the pump flow path is detected by a full state detection device provided at the top of the casing of the mixed flow pump, and a full state signal for informing the control unit of the full state is input from the full state detection device. When the controller receives the full signal, the operation of the vacuum pump is stopped by the controller, and the variable timer circuit built in the controller is started, and after a fixed time set by the variable timer circuit, the full signal is controlled from the full detector. The operation of the vacuum pump is restarted by the control device under conditions that are not input to the device.

[0009]

In the above construction, since air flows into the pump flow path from the main shaft penetration of the mixed flow pump, there is no flow velocity in the pump flow path, especially during standby operation or small flow control operation. In a slow or slow state, the air in the pump flow path is sucked out by a vacuum pump, and the water level is maintained at a certain level or higher.

At this time, since the vacuum pump is stopped when the inside of the pump flow path is full, an excessive operation of the vacuum pump in a full state, that is, an operation of sucking water in the pump flow path is prevented. Therefore, the failure of the vacuum pump can be avoided, and the vacuum pump operates intermittently, so that the running cost can be reduced.
Further, by adjusting the set time in the variable timer circuit, the operation water level at which the operation of the vacuum pump is resumed can be set arbitrarily, so that it is possible to easily cope with a change in the amount of air inflow due to wear of the main shaft penetration. .

[0011]

An embodiment of the present invention will be described below with reference to the drawings. The basic configuration in this embodiment is the same as that described above with reference to FIG. 2, and members performing the same operations are denoted by the same reference numerals and description thereof is omitted.

In FIG. 1, a full-water detecting device 21 is provided at the top of the horizontal-axis mixed flow pump 1, and the full-water detecting device 21 detects a full state of the pump flow path. The fullness detecting device 21 is connected to a control device 22, and the control device 22 controls start / stop of the operation of the vacuum pump 11. The control device 22 has a variable timer circuit 23.

With the above configuration, when the horizontal-axis mixed flow pump 1 is driven, air flows from the main shaft through portion 9 into the suction pipe 2 forming the pump flow path and into the casing of the horizontal-axis mixed flow pump 1. For this reason, in a state where there is no flow velocity in the pump flow path or a slow state such as a standby operation or a management operation of a small flow rate, the air in the pump flow path is sucked by the vacuum pump 11 and the water level is maintained at a certain level or higher. It is necessary to.

When the air in the pump flow path is discharged by the vacuum pump 11, the water level rises with the discharge of the air, and the water becomes full. A full state in the pump flow path is detected by the full state detecting device 21, and a full state signal for informing the control unit 22 of the full state is input from the full state detecting device 21 to the control device 22. The control device 22 that has received the full signal stops the operation of the vacuum pump 11 and starts the variable timer circuit 23 built in the control device 22. The control device 22 restarts the operation of the vacuum pump 11 under a condition that the full-water detection device 21 has not input the full-water signal to the control device 22 after a fixed time set in the variable timer circuit 23.

In this embodiment, the pump flow path constituted by the horizontal-axis mixed flow pump 1 is shown, but the present invention can be applied to a pump flow path constituted by a mixed flow spiral pump.

[0016]

As described above, according to the present invention, the vacuum pump is stopped when the inside of the pump flow path becomes full, thereby eliminating the excessive operation of the vacuum pump and the failure of the vacuum pump. And running cost can be reduced by intermittent operation of the vacuum pump. Further, by adjusting the set time in the variable timer circuit, it is possible to arbitrarily set the operation water level at which the operation of the vacuum pump is restarted.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a pump channel system according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a conventional pump channel system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal-axis mixed flow pump 2 Suction pipe 21 Fullness detection device 22 Control device 23 Variable timer circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F04D 11/00 101 F04D 9/04 F04D 15/00

Claims (1)

(57) [Claims] When the air in a pump flow path of a mixed flow pump is discharged by a vacuum pump attached to the mixed flow pump, a full state of the pump flow path is detected by detecting a full state provided at the top of a casing of the mixed flow pump. Detected by the device, a full signal is sent from the full detector to the controller to notify the controller of the full state, and the controller that receives the full signal stops the operation of the vacuum pump and starts the variable timer circuit built in the controller. After a certain time set by the variable timer circuit, the vacuum pump is restarted by the control device under the condition that the full water signal is not input to the control device from the full water detection device. Operation control method of the vacuum pump.