JPH02283896A - Operating method of vertical shaft pump driven by engine - Google Patents

Abstract

PURPOSE:To eliminate bad influence upon an engine by discharging the air in a vertical shaft pump while in no-load running or stopping, raising the water level in the vertical shaft pump up to the level where the pump can raise water by itself, letting it perform no-discharge operation applying actual loads on it, and then stopping the engine. CONSTITUTION:The following no-discharge operation is performed by a vertical shaft pump after continuous air-flow operation, that is, no-load operation in the state of water level A where the suction port of a suction cylinder 2 stays underwater. That is, first of all, a delivery valve 6 is completely closed, and a suction valve 10 and discharge valve 11 are also fully opened to operate the vacuum pump 9 installed between the valves 10 and 11. In addition, the air between the water face of a water level A and the delivery valve 6 is discharged out of the vertical shaft pump through a discharge pipe 8 to raise the water level. As a result, when the water level B reaches the specified level 1a of a pump casing 1, water is made to enter the discharge pipe 8, and a flow sensor 12 detects. In the next step, the vacuum pump 9 is made to stop, and then an engine is made to stop after no-discharge operation with the pump loaded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of operating a vertical shaft pump that is used in a rainwater drainage pump or the like, and whose drive source is mainly an engine such as a diesel engine.

[Prior Art] Recently, in order to cope with the sudden inflow of rainwater, etc. into the pump water intake well, it has been proposed to operate the pump without load in advance, as disclosed in, for example, Japanese Patent Application Laid-open No. 134897/1983. There is a growing demand for advanced standby operation pumps or air management operation pumps.

Conventionally, in such advance standby operation pumps and air management operation pumps, the driving source has been repeatedly stopped after quite a long period of no-load or load operation.

In addition, even in the case of a general vertical shaft pump that is not a standby operation pump as mentioned above, if actual load operation cannot be performed due to the water level, management operation may be performed at no load for a relatively short period of time. The drive source was sometimes repeatedly stopped after load operation.

[Problems to be Solved by the Invention] However, when an engine such as a diesel engine is used as a drive source, stopping the engine after no-load operation as described above can lead to: Due to the accumulation of carbon in the combustion chamber and exhaust system of the engine due to complete combustion, there is a risk of a reduction in output and generation of raw combustion gas from the exhaust pipe.

■ There is a risk that the engine's exhaust valve seat will be corroded by the gas, causing compression leaks.

■ There is a risk that surging may occur due to dirt on the exhaust gas turbine.

■ Contamination of lubricating oil due to deposited carbon.

There is a risk that it may promote poor performance.

There was a problem that the engine was adversely affected.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vertical shaft pump in which the engine is stopped after actual load operation, thereby eliminating the adverse effects on the engine.

[Means for Solving yAm] In order to achieve the above object, the method of operating a vertical shaft pump using an engine as a driving source according to the present invention, during no-load operation or after stopping, releases the air inside the pump by leaving the discharge valve open. is discharged to the outside of the pump using a vacuum pump, thereby raising the water level inside the pump to at least the water level at which the pump can self-pump, and then shutting down the engine under actual load and then stopping the engine. It is characterized by

[Sakukawa] According to the above method, the shut-off operation is always performed under the actual load, so even if the engine is stopped after the shut-off operation, there will be no adverse effect on the engine.

[Example] Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic diagram of a vertical shaft pump for carrying out the method of this invention. This vertical shaft pump includes a pump casing 1 containing an impeller (not shown), a suction cylinder 2 connected to the upstream side of the pump casing 1, a lift pipe 3 connected to the downstream side of the pump gauging 1, and this lift pipe. An elbow pipe 4 connected to the downstream side of 3 and bent on the floor F of the water absorption well, this elbow pipe 4
A discharge pipe 5 connected to the downstream side of the discharge pipe 5 and having a discharge valve 6 interposed therein
It is equipped with Further, a diesel engine 7 serving as a driving source is connected to the main shaft 15 of the impeller passing through the elbow pipe 4.

This vertical shaft pump constructed as described above has exhaust piping 8.
is connected. That is, this exhaust pipe 8 is connected to a predetermined part 1a in the pump casing l, which is a part corresponding to water (iB) that can be self-pumped by this vertical pump. 8 is interposed with a vacuum pump 9. Also, an intake valve 10 and an exhaust valve 11 are installed before and after the vacuum pump 9, respectively.

Further, a known flow detector 12 is disposed on the primary side of the intake valve 10, that is, on the side of the pump casing 1, for detecting that liquid has entered this portion. A detection signal from the flow detector 12 is used to control the operation of the engine 7 and vacuum pump 9.

The vertical shaft pump using the engine as a driving source as described above can be further configured as a pre-standby operation pump as disclosed in the above-mentioned Japanese Patent Laid-Open No. 63-134897, so that it can be used for long periods of time such as standby operation. It is possible to perform aerial driving. After the submerged operation, that is, the no-load operation, continues at a water level that submerges the suction port of the suction cylinder 2, such as the water level A shown in FIG. 1, the shut-off operation is performed as follows.

First, when a command for shut-off operation is issued after no-load operation, the discharge valve 6 is first fully closed.

Next, the intake valve 10 and exhaust valve 11 before and after the vacuum pump 9 are opened, and then the vacuum pump 9 is operated.

When the vacuum pump 9 is operated in this way.

Air between the water surface at water level A and the discharge valve 6 is discharged to the outside of this vertical pump via the exhaust pipe 8. Then, by discharging this air, the pressure inside the vertical shaft pump decreases, and therefore the water level inside this vertical shaft pump rises.

In this way, the water level inside the vertical pump rises and when it reaches the predetermined position 1a of the pump casing 1, the rising water (liquid) enters the exhaust pipe 8 and the intake valve 10.
It is detected by the flow detector 12 in the front.

Next, if the diesel engine 7 is stopped based on the detection signal of the flow detector 12, the diesel engine 7 is restarted, and
The operation of the vacuum pump 9 is stopped.

In this way, the water level B corresponding to the predetermined portion 1a
is the water level at which this vertical pump can self-pump water, so the water (
(liquid) is sucked up by the rotation of the impeller, and the vertical shaft pump performs shut-off operation under the actual load.

After performing the shut-off operation under the actual load in this manner, the diesel engine 7 is stopped.

When the shut-off operation is performed as described above, the diesel engine 7 can completely burn the fuel, and there is no possibility that carbon will be deposited in the combustion chamber or the exhaust system.

In addition to the flow detector shown in the embodiment, other means such as a full water detector may be used as a means for detecting that the water level in the vertical shaft pump has reached a water level at which self-pumping is possible.

[Effects of the Invention] As is clear from the above explanation, according to the method of operating a vertical shaft pump using an engine as a drive source according to the present invention, shut-off operation under actual load can be performed even after no-load operation. Therefore, unlike when the engine is repeatedly stopped during no-load operation, carbon does not accumulate in the combustion chamber or exhaust system, and there is no adverse effect on the engine.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a vertical shaft pump that implements the method of operating a vertical shaft pump using an engine as a driving source according to the present invention. 6...Discharge valve 7...Diesel engine (engine) 9...Vacuum pump B...Water level capable of self-pumping Patent applicant Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] (1) During no-load operation or after stopping, close the discharge valve and discharge the air inside the pump to the outside of the pump using a vacuum pump, thereby raising the water level inside the pump at least to the water level at which this pump can self-pump, A method for operating a vertical shaft pump using an engine as a driving source, characterized in that the engine is stopped after a shut-off operation under an actual load is performed.