JPS60164695A - Method and device for management operation of vertical pump - Google Patents

Abstract

PURPOSE:To reduce power necessary for management operation of a pump and to prevent biting of foreign matter by feeding compressed air into the interior of vertical pump under management operation and mixing foam air into water in pump even under shutt-off operation. CONSTITUTION:At first, the delivery valve (not shown) located in the downstream of a column pipe 5 is fully closed. Then compressed air is fed from a compressed air source 12 through a pressure feed pipe 11 into the interior of vertical pump 2 to lower the water level in the vertical pump 2 until the lower portion of an impeller 8 is submerged. Upon rotation of the impeller 8 under this state, water and air are agitated to produce two phase flow of gas and liquid where foam air is mixed in water. Consequently, apparent density of fluid in the vertical pump 2 will lower to reduce driving force even when shut-off operation is continued while biting of foreign matter between the impeller 8 and casing 6 is prevented through lubrication of water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for the controlled operation of a pump and a device for implementing this method.

Generally, pumps at drainage pump stations installed to drain water from waterways during floods are operated under controlled conditions. This control operation refers to a trial run that is performed to check the operation of the pump and prime mover, in addition to regular operation during floods and floods, in view of the importance of the reliability of this type of pump and its infrequent operation. . Therefore, since the pump is operated when the amount of water is low, the discharge valve downstream of the pump is fully closed to perform shut-off operation.

Drainage pump stations where this kind of management operation is carried out are
As shown in the figure, the spindle pump 2 is placed inside the bit l,
The prime mover 3 of this spindle pump 2 is installed on one floor, and water is drained through a pumping pipe 5 in which a discharge valve 4 is interposed.

By the way, a conventional management and operation device for such a spindle pump 2 is as follows. In other words, the water level in the pump 1 is lowered so that the lower half of the impeller of the spindle pump 2 is submerged in water, and then the shut-off operation is performed. this is,
The shaft power required for shut-off operation at a normal water level becomes excessive, and on the other hand, when the vertical shaft pump 2 is exposed above the water surface and idles, foreign objects may become trapped between the impeller and the casing 6. Since there is a risk that a serious accident may occur, the air inside the shaft pump 2 is mixed into the water in the form of bubbles to reduce the apparent density of the water and reduce the shaft power required for shut-off operation. This is to prevent foreign objects from getting caught.

However, in such a conventional method, the above-mentioned effects can only be obtained at the beginning of the controlled operation, and when the controlled operation continues, the air inside the spindle pump 2 is damaged by the water that is about to flow into the bell mouth 7. There was an inconsistency in that the water was discharged to the outside and the result was the same as shut-off operation at a normal water level.

This mismatch occurs because the apparent density of the water in the spindle pump 2 cannot be controlled to a density suitable for the controlled operation during the controlled operation.

The technical problem to be solved by the present invention is to control the apparent density of trees inside the ring pump during controlled operation to a density suitable for controlled operation. IFM
The technical measures to be taken to solve this problem are as follows: First, the method for managing and operating a type-driven pump is to close the discharge pt installed in the lift pipe of the type-driven pump in advance, and then close this discharge valve and the bell mouth. In this state, compressed air is supplied between the pump and the pump is operated in a closed state.On the other hand, the control operation device for the vertical shaft pump is connected to the discharge valve and bell mouth installed in the lift pipe of the pump. A pressure pipe that supplies compressed air to the inside was connected between the two.

As a result, compressed air is supplied between the discharge valve of the mold-driven pump and the bell mouth during controlled operation, and even if shut-off operation continues, air bubbles remain in the water inside the mold-driven pump. This reduces the power required for the controlled operation of the type-driven pump and prevents foreign matter from getting caught.

Therefore, with the said technical means, the apparent density of water in the ring pump during controlled operation can be controlled to a density suitable for controlled operation.

In the present invention, compressed air is supplied inside the mold pump, so the water level inside the mold pump can be lowered by the pressure of the compressed air regardless of the water level in the pit. Adjustment can be omitted.

Hereinafter, one embodiment of the present invention will be described with reference to FIG.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same or equivalent parts.

An impeller 8 is pivotally supported within the casing 6 in FIG. 2 by a bearing 9, and a guide vane 10 is formed above the impeller 8. A bell mouth 7 is fixed to the lower end of the casing 6, and a water pump 5 is connected to the upper end of the casing 6. A discharge valve 4 (see FIG. 1) is interposed on the downstream side of the lift pipe 5. One end of a pressure sending pipe 11 is connected to the lifting pipe 5 in the vicinity of the casing 6 of the lifting pipe 5, and the other end of the pressure sending pipe 11 is connected to a compressed air source 12. Further, an on-off valve 13 is interposed in the middle of the pressure feed pipe 11, and the management operation method for such a type-driven pump 2 is executed according to the following steps (f) to (*). That is, the discharge valve 4 is fully closed.

2.- Compressed air is supplied from the compressed air source 12 to the inside of the movable pump 2 through the pressure pipe 11, and the water level inside the shaft pump 2 is lowered to such an extent that the F part of the impeller 8 is submerged.

+31 In this state, the movable pump 2 is operated in a closed state, and an amount of compressed air corresponding to the air layer discharged to the outside from the bell mouth 7 is supplied from the compressed air source 12.

Hereinafter, the operation of this embodiment will be explained. When the impeller 8 is rotated with the water level inside the spindle pump z lowered to such an extent that the lower part of the impeller 8 is submerged in water, water and air are agitated. Air bubbles were mixed into the water. This is a so-called gas-liquid two-phase flow.

In this way, when the inside of the spindle pump 2 is in a gas-liquid two-phase flow, the apparent noise of the fluid inside the spindle pump 2 is decreasing. - Even if the slow rotation of the embroidery cut is continued, the necessary shaft power will not increase, and excessive load will be prevented from being applied to the prime mover of the type wheel pump 2. In addition, the lubrication effect of water will prevent the impeller from being overloaded. Foreign matter is also prevented from getting caught between 8 and the casing 6.

It should be noted that the present invention is not limited to the above-described embodiments.For example, the timing for starting the shut-off operation of the mold ring pump 2 may be determined by lowering the water level in the mold ring pump 2 before starting the shut-off operation. However, the shut-off operation may be started at the time when compressed air starts to be supplied into the ring pump 2.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a conventional example, and FIG. 2 is a vertical sectional view showing an embodiment of the present invention. 2... Type wheel pump 4... Discharge valve 5... Lifting pipe 7... Bell mouth 8... Impeller 11... Pressure pipe Fig. 1

Claims (2)

[Claims] (1) Close the discharge valve installed in the lift pipe of the spindle pump in advance, supply compressed air between the discharge valve and the bell mouth, and operate the spindle pump in a closed state. A management operation method for a spindle pump characterized by: (2) A control and operation device for a spindle pump, characterized in that a pressure feed pipe for supplying compressed air to the inside is connected to a portion between a discharge valve installed in a lift pipe of the spindle pump and a bell mouth. .