JPH08312570A - Pre-standby operation pump - Google Patents

Abstract

PURPOSE: To dissolve the inconvenience such as the generation of abnormal vibration and noise and the waste of a motive power at the retention operation time in a short time by shortening a retention operation time. CONSTITUTION: When a water level drops upto a water pumping interception water level SWL, this water level is detected by a water level detection means 7 and a detected water level signal is inputted to a controller 8 and a valve open signal is outputted from the controller 8 to an air water switch valve 6A based on the inputted water level signal and the air water switch valve 6A is opened and also the switch signal is inputted from the controller 8 to the switch valve 13C and a compressed air is supplied to the lower room of a cylinder 13A and an outer peripheral impeller 21 is raised. Thereby, a torque intermittent mechanism 12 is intercepted and the rotation of the outer peripheral impeller 21 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-standby operation pump, and more particularly to a pump suitable for high-head advance operation.

[0002]

2. Description of the Related Art Conventionally, a pump shown in FIG. 4 has been known as a preceding standby operation pump. In this preceding standby operation pump, an impeller 2 fixed to a main shaft 1 is rotatably loaded into an impeller chamber 3, a discharge pipe 4 is connected to a discharge side of the impeller chamber 3, and suction of the impeller chamber 3 is performed. The suction pipe 5 is connected to the side, the suction pipe 5 is communicated with the steam / water switching pipe 6 having a steam / water switching valve 6A, and a water level signal detected by the water level detecting means 7 including, for example, a water level gauge is supplied to the controller 8 The controller 8 is configured to output an opening / closing signal to the steam / water switching valve 6A based on the input water level signal and installed in the water intake well 9. On the other hand, the main shaft 1 penetrates the discharge elbow 10 in a watertight and rotatably manner, extends to the outside, and is connected to a prime mover (not shown).

A conventional operation example of the preceding standby operation pump configured as described above will be described. When the water level of the water intake well 9 (hereinafter, simply referred to as the water level) rises. A-. Until the water level exceeds the pumping cutoff water level SWL and reaches the pumping start water level RWL, the air-water switching valve 6A is fully opened to perform the air operation. A-. When the pumping start water level RWL is reached, the steam switching valve 6A is fully closed to switch to drainage operation with a predetermined discharge amount, and drainage operation is continued at a water level above the pumping start water level RWL. When the water level of the suction well 9 drops. B-. From the area where the water level exceeds the pumping start water level RWL,
The drainage operation is continued until the pumping start water level RWL is reached and the pumping cutoff water level SWL is lowered. B-. When the water level drops to the pumping cutoff water level SWL, the steam switching valve 6A is fully opened, and air is introduced into the suction pipe 5,
Pumping is cut off by vacuum breaking and switched to holding operation, holding operation is performed at a water level below the pumping cutoff water level SWL, and residual water in the discharge pipe 4 is dropped over time to perform air operation.

In the conventional preceding standby operation pump, the B-
When the drainage operation is switched to the holding operation by shutting off the pumping at 2, the state in which the water remaining in the discharge pipe 4 connected to the discharge side of the impeller chamber 3 is supported by the impeller 2 and stirred occurs. That is, in the holding operation, a large pressure of residual water is applied to the discharge side (pressure surface) of the impeller 2 and the suction side is open to the atmosphere, so the load pressure is small, that is, the outlet side and the inlet side of the impeller 2. The pressure difference on the side becomes large, and vibrations and noises larger than those during drainage operation are generated, which has various adverse effects on pump equipment and
Since the residual water in the discharge pipe 4 is supported by the impeller 2 and agitated, inconvenience such as wasting power is generated.

By the way, even if such an inconvenience occurs, in the case of a preceding standby operation pump having a lift of about 5 m to 10 m, the air (atmosphere) introduced from the steam / water switching pipe 6 to the suction pipe 5 is relatively short. The remaining water is dropped in time and the operation is switched to air operation. That is, the above-mentioned inconvenience is eliminated in a relatively short time. However, in a high lift (actual head is about 30 m to 40 m) preceding standby operation pump that tends to be used frequently in recent years, since the impeller 2 having a large centrifugal force component and a high pumping capacity is used, the residual water holding power is also high. growing. Therefore, since the holding operation time becomes long, the aforementioned inconvenience continues for a relatively long time.

[0006]

The problem to be solved by the invention is that in a pump with a high head leading standby operation, there are various vibrations in the pump equipment due to abnormal vibration and noise when switching from drainage operation to holding operation due to pumping interruption. The disadvantage is that it has a bad influence and wastes power for a relatively long time.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an impeller fixed to a main shaft, an impeller chamber into which the impeller is rotatably inserted, and a suction connected to the upstream side of the impeller chamber. With a tube,
In a preceding standby operation pump provided with a discharge pipe connected to a downstream side of an impeller chamber, an inner peripheral impeller in which the impeller is fixed to a main shaft, and an inner peripheral part which is fitted to the main shaft so as to be relatively rotatable. A holding operation, characterized in that it is provided on an outer peripheral portion of the impeller and is provided with an outer peripheral impeller connected through a rotational force interrupting mechanism, and an operating means for operating the rotational force interrupting mechanism intermittently is provided. By shortening the time, the purpose of solving the above-mentioned inconvenience in a short time was achieved.

[0008]

According to the present invention, when the water level drops to the pumping cutoff water level, the rotating force interrupting mechanism is cut off by operating the operating means, and the outer peripheral impeller performing pumping work with a large centrifugal force component. By stopping the rotation, the pumping work of the impeller is positively hindered, the residual water in the discharge pipe is quickly dropped into the suction well, and the holding operation time can be shortened.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of the present invention. It should be noted that the same or corresponding parts as those in the conventional example of FIG.

In FIG. 1 and FIG. 2, the high-lift head standby operation pump is provided with an inner peripheral impeller 20 fixed to a main shaft 1 via a key 11 and an outer peripheral rotatably movable axially with respect to the main shaft 1. And an outer peripheral impeller 21 located on the outer peripheral portion of the inner peripheral impeller 20.
For example, they are connected to each other via a rotating force connecting / disconnecting mechanism 12 formed of a dog clutch. The rotating force connecting / disconnecting mechanism 12 is configured to be operated intermittently by the operating means 13. That is, the operating means 13 moves (raises) the outer peripheral impeller 21 in the axial direction to move the rotational force interrupting mechanism 1.
2 for shutting off or for moving the outer peripheral impeller 21 in the axial direction in the reverse direction (downward) to connect the rotational force interrupting mechanism 12, and accommodates the flange 21a formed on the boss portion 21A of the outer peripheral impeller 21. At the same time, the cylinder 13A, which is axially movably and airtightly inserted through the boss portion 21A, the air compressor 13B that alternately supplies high-pressure fluid (for example, compressed air) to the upper chamber and the lower chamber of the cylinder 13A, and the switching valve 13C, air compressor 13B, and switching valve 13C
The secondary side passages 13E and 13E connecting the primary side passage 13D connecting the primary side port of the cylinder 13A and the secondary side port of the switching valve 13C to the upper chamber and the lower chamber of the cylinder 13A. A switching signal is input from the controller 8 to the switching valve 13C.

The operation of the standby operation pump configured as described above will be described. When the water level in the suction well 9 rises. A-. Until the water level exceeds the pumping cutoff water level SWL and reaches the pumping start water level RWL, the water / water switching valve 6A is fully opened to perform the air operation. A-. When the pumping start water level RWL is reached, the steam / water switching valve 6A is fully closed and the controller 8 switches the switching valve 13C.
A switching signal is input, compressed air is supplied to the upper chamber of the cylinder 13A, and the pumping operation (draining operation) is performed while the inner peripheral impeller 20 and the outer peripheral impeller 21 are rotated, and the pumping start water level RWL or higher. This drainage operation is continued at the water level. When the water level of the suction well 9 drops. B-. From the area where the water level exceeds the pumping start water level RWL,
The drainage operation is continued until the pumping start water level RWL is reached and the pumping cutoff water level SWL is lowered. B-. When the water level drops to the pumping cutoff water level SWL, this water level is detected by the water level detecting means 7, the detected water level signal is input to the controller 8, and the controller 8 sends the water / water switching valve 6A based on the input water level signal. A valve opening signal is output to open the steam / water switching valve 6A, and a switching signal is input from the controller 8 to the switching valve 13C to supply compressed air to the lower chamber of the cylinder 13A and to rotate the outer peripheral impeller. 21 is lifted to shut off the rotational force interrupting mechanism 12, and the outer peripheral impeller 2
Stop the rotation of 1.

As described above, when the steam / water switching valve 6A is opened, air is introduced from the steam / water switching pipe 6 to the upstream side of the impeller 2 and the rotational force connecting / disconnecting mechanism 12 is shut off, whereby the centrifugal force is reduced. Peripheral impeller 21 that performs pumping work with a large force component
Will stop the rotation of. With this, the impeller 2
Since the pumping work of the above is positively hindered, even if the pump has a high lift preceding standby operation with a large retention capacity of the residual water, the residual water in the discharge pipe 4 is promptly dropped into the water absorption well 9 to maintain the retention operation time. Can be shortened. As a result, due to abnormal vibration and noise when switching from drainage operation to holding operation,
It is possible to eliminate inconveniences such as various adverse effects on pump equipment and waste of power in a short time. The remaining water in the discharge pipe 4 is quickly dropped into the water intake well 9 only by stopping the rotation of the outer peripheral impeller 21 by omitting the opening of the steam / water switching valve 6A, and the holding operation time is maintained. Can be shortened.

In the above embodiment, the one-stage impeller 2 is constructed by combining the inner peripheral impeller 20 and the outer peripheral impeller 21.
However, in the present invention, as shown in FIG. 3, a configuration using a two-stage impeller 2 configured by a combination of an inner peripheral impeller 20 and an outer peripheral impeller 21 or 3 is used. It can also be applied to a configuration (not shown) using a multi-stage impeller 2 having more than two stages. Further, the rotational force connecting / disconnecting mechanism 12 may be constituted by an electromagnetic clutch instead of the dog clutch described in the above embodiment.

[0014]

As described above, according to the present invention,
When the water level drops to the pumping cutoff water level, the rotating force interrupting mechanism is shut off by operating the operating means, and the rotation of the outer peripheral impeller that is performing pumping work with a large centrifugal force component is stopped to pump the impeller. Since it actively hinders work, even with a high-lift preceding standby operation pump that has a large retention capacity of residual water,
Residual water in the discharge pipe can be quickly dropped into the suction well to shorten the holding operation time. As a result, it is possible to eliminate inconveniences such as abnormal vibration and noise when switching from the drainage operation to the holding operation, various adverse effects on the pump equipment, and wasted power.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is an enlarged configuration diagram of a main part.

FIG. 3 is a front view showing another embodiment of the present invention.

FIG. 4 is a front view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 main shaft 2 impeller 3 impeller chamber 4 discharge pipe 5 suction pipe 12 rotational force interrupting mechanism 13 operation means 20 inner peripheral impeller 21 outer peripheral impeller

Claims (1)

[Claims] 1. An impeller fixed to a main shaft, an impeller chamber into which the impeller is rotatably inserted, a suction pipe connected to an upstream side of the impeller chamber, and a downstream of the impeller chamber. In a preceding standby operation pump having a discharge pipe connected to a side, an inner peripheral impeller in which the impeller is fixed to a main shaft, and an outer peripheral portion of the inner peripheral impeller fitted to the main shaft so as to be relatively rotatable. And a peripheral impeller connected via a rotational force interrupting mechanism, and an operating means for performing an intermittent operation of the rotational force interrupting mechanism is provided.