JPH04159492A - All-water level operation pump - Google Patents

Abstract

PURPOSE:To control an air suction amount and further to adjust a delivery amount in accordance with a water level so as to contrive an efficient drainage and reduction of vibration by providing a water level meter, suction air pipe, adjusting valve and a controller as an intake air amount control device. CONSTITUTION:One end of a suction air pipe 4 is mounted to a suction bell 1 below an impeller further to provide a control valve 8 in the other end. On the other hand, a water level meter 6 is provided in a suction water tank to always feed a signal of detected water level to a controller 7. A relation between the water level and a suction air amount is input to the controller 7 thus to indicate an optimum opening of the control valve 8 in accordance with the water level. In this way, an effective drainage and reduction of vibration are attained by changing resistance of the suction air pipe to control a suction air amount and by adjusting a delivery amount in accordance with the water level. In a region of unstable suction air amount in the vicinity of starting suction of air, the control valve 8 is throttled so as to prevent a large amount of air from being sucked, and the reduction of vibration in the vicinity of the water level in starting air suction is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake air amount control device for a pump operating at full water level.

[Conventional technology]

In the full water level operation pump, a type of pump that adjusts the discharge amount by intake air is, for example, disclosed in Japanese Utility Model Application No. 63-15009.
It is described in Publication No. 7.

In this type, when the water level in the water absorption tank decreases, air is sucked in through the opening and air-water mixing operation is possible, but no consideration is given to stable intake and adjustment of the amount of intake air.

[Problem to be solved by the invention]

Although the above conventional technology allows air and water temperature matching operation, it does not take into consideration the stable control of the intake air amount based on the water level, and in particular, near the intake start water level, a large amount of air is generated at the same time as the intake starts. There was a problem that the pump was sucked into the pump, causing a sudden change in the pump discharge amount and an increase in vibration.

An object of the present invention is to efficiently drain water and reduce vibration by controlling the amount of intake air depending on the water level and adjusting the amount of discharge.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an intake air amount control device that includes a water level gauge, an intake pipe, a regulating valve, and a controller.

[Effect]

In air/water mixing operation, simply opening the intake pipe attached to the suction bell below the impeller to the atmosphere allows air/water temperature mixing operation, but the intake air amount is unstable and the discharge amount fluctuates and vibrations occur. I found out that it does.

It was also found that the device is particularly unstable near the start of intake, and a large amount of air is sucked in at the same time as intake starts, resulting in a low discharge amount and large vibrations.

In the present invention, a regulating valve is provided at the other end of the intake pipe attached to the suction bell below the impeller, and the opening degree of the regulating valve is changed according to the water level, and the resistance of the intake pipe is changed to control the intake air amount. Because there are
A pump with stable intake air volume and low vibration can be realized. Particularly near the intake start water level, it is effective to reduce vibration by closing the regulating valve to prevent a large amount of air from being sucked in.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.6 FIG. 8 shows a diagram of a conventional spindle pump.

With conventional spindle pumps, when the water level in the water suction tank decreases,
Vibrations and noise are generated by swirling vortices from the water surface. To prevent this, it is necessary to have a depth of wood that is commensurate with the discharge amount. In order to be able to operate the pump at full water level even at low water levels, at low water levels below the depth of submerged trees where vortices are not sucked in from the water surface, the pump operates in air/water temperature mode to reduce the discharge amount.

FIG. 9 shows a performance curve when the engine is operated with air intake and air/water temperature. As the intake amount increases, the discharge amount decreases. If the discharge amount is reduced, the flow velocity of the suction bell 1 will also be reduced, so
It becomes difficult to suck in eddies from the water surface, and as a result, operation at low water levels is possible.

In this way, a pump operating at full water level can be operated at a low water level by operating the pump at the same temperature as the air and water.

Conventionally, since the amount of intake air was not controlled, there were problems in that a large amount of air was sucked into the pump at the same time as the intake started, resulting in a significant decrease in the amount of discharge and increased vibration.

By controlling the amount of intake air and adjusting the amount of discharge according to the depth of the fallen tree as shown in FIG. 10, efficient drainage and vibration reduction can be achieved.

Figure 1 shows an example of how to achieve this, with an intake pipe 4
One end is attached to the suction bell 1 below the impeller, and a control valve 8 is provided at the other end. The water absorption tank has a water level gauge 6, which constantly sends a water level signal to the controller 7. The controller 7 receives the relationship between the water level and the intake air amount as shown in FIG. 10, and can instruct the optimum opening degree of the control valve according to the water level. As described above, according to the present invention, the resistance of the intake pipe can be changed according to the water level, the amount of intake air can be controlled, and the amount of discharge can be adjusted, so that effective drainage and vibration reduction can be achieved.

Furthermore, in a region where the amount of intake air is unstable near the start of intake, the control valve is throttled to prevent a large amount of air from being sucked in, which is very effective in reducing vibrations near the intake start water level.

FIG. 2 is based on the same concept, and one end of the intake pipe is branched into a plurality of parts and a switching valve 9 is provided.

The intake volume can be controlled by changing the number of switching valves that are opened depending on the water level, and the discharge volume can be adjusted. Also, when fine adjustment is required, use the switching valve 9.
This can be adjusted by providing an orifice 11 or the like in the.

At this time as well, by inserting the orifice 11 and opening the throttled intake pipe, it is possible to reduce vibrations caused by unstable phenomena near the intake start water level.

FIG. 3 shows another embodiment.

One end of the intake pipe 4 is attached to the intake bell 1 by branching it below the impeller.

As the water level decreases, air intake starts in the order of 4a, 4b, and 4c, and the amount of air intake gradually increases. By adjusting the mounting level of the branch pipe 4 and the size of the intake holes 4a, 4b, and 4c, it is possible to obtain the relationship between the water level and the intake air amount as shown in Figure 10, which allows efficient drainage according to the water level. , vibration reduction is possible.

In addition, in this embodiment, it is possible to provide an air pipe that communicates with the atmosphere above the drainage stop water level, so a width can be maintained between the drainage start water level and the drainage stop water level, which prevents hunting during drainage operation and idling operation. It is possible.

Furthermore, by making the diameter of the intake pipe smaller as it gets closer to the impeller, it is possible to reduce vibrations caused by unstable phenomena near the intake start water level.

A similar idea is shown in FIG. 4, where the intake bell 1 has multiple intake holes 13.
a, 13b, and 13c are provided.

As the water level decreases, air is taken in in the order of 13a, 13b, and 13c, and the air intake hole 13a is opened in the same manner as in the previous embodiment.

By adjusting the level and size of 13b and 13c, it is possible to efficiently drain water according to the water level and reduce vibration.

FIG. 5 shows another embodiment.

An adjustment plate 15 is attached to the intake pipe 4, and a float 14
It is designed to be linked with Now, when the water level decreases, the opening of the intake pipe increases as shown by the broken line, and as resistance decreases, the amount of intake air increases. By appropriately selecting the shape and size of the adjustment plate 15, the relationship shown in FIG. 10 can be obtained, and efficient drainage and vibration reduction can be achieved depending on the water level.

In FIG. 6, a bellows 16 is provided in the intake pipe 4, making use of changes in the pressure difference within the intake pipe due to changes in water level.

As the water level decreases, the differential pressure inside the intake pipe 4 increases, so the bellows 16 deforms as shown by the broken line, and the opening d□ becomes d.
2, the resistance decreases and the amount of intake air increases.

FIG. 7 shows another embodiment in which an intake hole 17 is provided below the attachment portion of the intake pipe 4 for the intake bell 1.

The other end of the intake pipe 4 may be attached to any one of the embodiments of the present invention, and the intake pipe 4 can be adjusted by adjusting the intake air amount of the intake pipe 4 and dividing the function such as air and water separation at the intake hole 17. It is possible to make it compact.

〔Effect of the invention〕

According to the present invention, since the intake air amount can be controlled and the discharge amount can be adjusted based on the water level, efficient drainage and vibration reduction are possible.

[Brief explanation of drawings]

1 and 2 are side views of different embodiments of the present invention, FIGS. 3 to 7 are sectional views of different embodiments of the present invention, and FIG. 8 is a conventional chamber shaft pump. FIG. 9 is an explanatory diagram of changes in pump performance due to intake air, and FIG. 10 is an ideal characteristic diagram of immersion depth and intake air amount. ■...Suction bell, 2...Casing liner, 3...
・Casing, 4...Intake pipe, 5...Support, 6
...Water level gauge, 7.. Controller, 8.. Control valve, 9.. Switching valve, 10.. Branch pipe, 11.. Orifice, 12.. Impeller. 13...Intake hole, 14...Float, 15...Adjustment plate, Figure 8

Claims (1)

[Claims] 1. A full water level operation pump characterized by being equipped with a water level gauge, an intake pipe, a regulating valve, and a controller as an intake air amount control device.