JPH09209968A - Pre-standby operation pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a load given the residual water in the pump up passage to an impeller at the pump up interception time and discharge a water remained in a pump up passage after pump up interception to the outside of the pump up passage as soon as possible, in a pre-standby operation pump. SOLUTION: A check valve mechansim 10 is installed in the pump up passage 11 of the downstream side of an impeller 2 in a pre-standby operation pump. A water escape passage 41 interposed by a valve mechanism in the downstream side of the check valve mechanism 10 is communicated. The check valve mechanism 10 is supported two flappers 13, 13 rotatably by supports 14, 14 and opened by the water stream force at the pump up operation time and closed by its own weight and water pressure after pump up interception.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preparatory standby operation pump, and more particularly to a preparatory standby operation pump for reducing vibration, noise and power consumption during pumping cutoff operation.

[0002]

2. Description of the Related Art Conventionally, the pump illustrated in FIG. 5 has been known as a preceding standby operation pump. In the preceding standby operation pump, the suction cover 5 is connected to the suction port 31 of the casing 3 accommodating the impeller 2 fixed to the main shaft 1, and the pumping pipe 4 is connected to the discharge port 32 of the casing 3. The operation is performed by rotating the main shaft 1 by a prime mover (not shown). A steam / water switching pipe 6 is connected to the upstream side of the impeller 2. A steam switching valve 61 is interposed in the steam switching pipe 6. The steam / water switching valve 61 is controlled to be opened / closed by a signal output from the controller 8 based on the water level signal detected by the water level detection means 7.

An operation example of the preceding standby operation pump configured as described above will be described.

A. When the water level of the suction well 9 rises (1) The water / water switching valve 61 is opened until the water level exceeds the pumping cutoff water level LWL and reaches the pumping start water level HWL. As a result, air is introduced into the impeller inlet 21 through the water / water switching pipe 6, so that air operation is performed. (2) When the water level reaches the pumping start water level HWL, the steam switching valve 61 is closed. As a result, the introduction of air to the impeller inlet 21 is stopped, and the pumping operation is performed. Pumping operation is continued at a water level higher than the pumping start water level HWL.

B. When the water level drops (1) The water / water switching valve 61 is closed from the position where the water level exceeds the pumping start water level HWL to the pumping cutoff water level LWL through the pumping start water level HWL. As a result, the pumping operation continues. (2) The steam switching valve 61 is opened when the water level drops to the pumping cutoff water level LWL. As a result, the pumping operation is cut off (pumping cutoff operation) to prepare for future rise in water level.

[0006]

By the way, in the conventional preceding standby operation pump, even if the operating state is switched from the pumping operation to the pumping cutoff operation by the pumping cutoff described in the above B (2), the pumping pipe 4 is used. Since the water W that has been pumped up to then remains, a state occurs in which the water is agitated by the impeller 2. For this reason, vibration and noise may occur, which may have various adverse effects on the pump equipment. The vibrations and noises are larger than the vibrations and noises that occur during the pumping operation, and become significant when the head is high. Further, since this state consumes relatively large amount of power, if it is continued for a long time, that much energy is wasted.

The present invention has been made in view of the above circumstances, and the pumping passage on the downstream side of the impeller is opened by utilizing the water flow at that time during the pumping operation and remains in the pumping passage after the pumping interruption. By using the weight (water pressure) of the stored water to close the pumping passage, the load on the impeller is reduced to suppress vibration and noise during pumping cutoff operation, and power consumption during pumping cutoff operation. It is an object of the present invention to provide a preceding standby operation pump capable of reducing the above-mentioned.

The present invention also provides a preceding standby operation pump capable of reducing vibration and noise in a short time by draining the water remaining in the pumping passage after the pumping is cut off to the outside of the pumping passage as quickly as possible. The purpose is to provide.

[0009]

In the preceding standby operation pump of the invention according to claim 1, a suction cover and a pumping pipe are connected to a suction port and a discharge port of a casing accommodating the impeller, respectively, and the casing is connected to the casing. On the upstream side of the stored impeller,
An air / water switching pipe that allows the internal passage to be switched between an open state and a shutoff state with respect to the atmosphere by a water / water switching valve is communicated, and the pumping passage on the downstream side of the impeller has a The check valve mechanism is provided with a valve body that is in a standing posture that opens the pumping passage and that is in a laid posture that closes the pumping passage when the pumping water is cut off.

With this configuration, during the pumping operation, the valve body of the check valve mechanism is in the upright posture to open the pumping passage by the force of the water flow at that time, so that the pumping operation can be continued. When the pumping operation is switched to the pumping interruption operation, there is no water flow in the pumping passage, so that the valve body of the check valve mechanism is in the laid posture and the pumping passage is closed. For this reason,
The weight (water pressure) of the water remaining on the downstream side of the valve body will be received by the valve body, and the load applied to the impeller located on the upstream side of the valve body will be greatly reduced. Therefore, the vibration generated during the pumping cutoff operation becomes slight.

In the preceding standby operation pump described above,
As in the invention according to claim 2, the pumping passage on the downstream side of the installation location of the check valve mechanism is closed during the pumping operation, and is opened when the operating state is switched from the pumping operation to the pumping cutoff operation. It is possible to adopt a configuration in which the water escape passages in which the valve mechanism is interposed are communicated.

According to the preceding standby operation pump configured as described above, the water remaining in the pumping passage downstream of the valve body of the check valve mechanism after the pumping cutoff passes through the water escape passage after the pumping cutoff and the pumping passage. Will be drained out of the room in a short time.

In the above-described preceding standby operation pump, as in the invention according to claim 3, the check valve mechanism is a valve body composed of two or more flappers arranged side by side in the circumferential direction of the pumping passage, and these. It is said that each flapper is provided with a support shaft that supports each flapper at a position eccentric from its center of gravity, and each flapper is swingable around the axis of the support shaft between a standing posture and a lying posture. A configuration can be adopted.

If this construction is adopted, the valve body of the check valve mechanism is pushed up by the force of the water flow at that time during the pumping operation and swings around the axis of the support shaft, and becomes a standing posture to open the pumping passage. To do. When the pumping operation is switched to the pumping cutoff operation, the flow of water in the pumping passage disappears, and the valve body is pushed down due to the weight of the water (water pressure) remaining in the pumping passage and the valve body's own weight pushing down the valve body. The posture is reached and the pumping passage is closed.

In the preceding standby operation pump described above, as in the invention according to claim 4, the valve mechanism interposed in the water escape passage includes a valve body and a valve shaft, and at least one flapper is fixed to the support shaft. When the flapper is rotated from the upright posture to the upright posture, the valve shaft is rotated by the rotation of the support shaft, the valve body of the valve mechanism closes the water escape passage, and the flapper is changed from the upright posture to the upright posture. It is possible to adopt a configuration in which the valve shaft is rotated by the rotation of the support so that the valve body opens the water escape passage.

With this configuration, the valve mechanism of the water escape passage is controlled to be opened / closed by utilizing the movement of the valve body or the support shaft, so that a special control device is not required to perform the opening / closing control of the valve mechanism. .

[0017]

1 is a schematic vertical sectional front view showing a preceding standby operation pump according to an embodiment of the present invention, and FIG. 2 is a schematic vertical sectional side view showing a main part of the preceding standby operation pump shown in FIG.
FIG. 3 is a schematic cross-sectional view at a position on the downstream side of the check valve mechanism 10.

In this preceding standby operation pump, the check valve mechanism 10 is arranged in the pumping passage 11 at a position close to the impeller 2 on the downstream side of the impeller 2. In the illustrated example, the pumping passage 11 on the downstream side of the impeller 2 is formed by an internal passage of the casing 3 that houses the impeller 2 and the pumping pipe 4.

The check valve mechanism 10 comprises two semicircular flappers 13, 1 arranged side by side in the circumferential direction of the pumping passage 11.
3 and the flaps 13 and 13 supporting the flappers 13 and 13 at positions decentered from their center of gravity, specifically, at the roots of the flappers 13 and 13.
And the support shafts 14, 14 are supported by bearing mechanisms 15, 15 provided at the lower end of the pumping pipe 4.
The flappers 13 and 13 are swingable about the axes of the support shafts 14 and 14 between the standing posture shown by the phantom line in FIG. 1 and the fall posture shown by the solid line in FIG. hand,
When the flappers 13, 13 are in the laid posture, the flappers 13, 13 come into contact with the valve seats 16, 16 provided on the pumping pipe 4 side. FIG.
As shown in the description above, each flapper 13, 1
Recesses 17 and 17 are provided on the upper surface of 3, and when the flappers 13 and 13 stand up to a forward tilted posture in a state of being nearly vertical, the protection pipe 18 surrounding the main shaft 1 in the recesses 17 and 17 is provided. Is designed to fit in. By doing so, it is possible to minimize the flow resistance of the flappers 13, 13 during the pumping operation. Further, these flappers 13, 13 are in a standing posture in which the pumping passage 11 is opened by the force of the water flow during the pumping operation, and when the pumping is cut off, the weight of the water remaining in the pumping passage 11 and its own weight cause the pumping passage 1 to move. Close to prone position. It is desirable that the flapper 13 be in an upright posture such that the upper surface thereof is slightly inclined forward. If this is done, the flapper 13 will be easily pushed down by water pressure after the pumping interruption, and the flapper 13 after the pumping interruption will become easier. The closing of the water is quickly performed by using the water pressure.

As shown in FIG. 2, at a position close to the check valve mechanism 10, a pumping passage 11 downstream of the check valve mechanism 10 is provided.
A water escape passage 41 is communicated with. This water escape passage 41 plays a role of letting the water in the pumping pipe 4 escape to the water intake well 9, and is closed at a midway point during the pumping operation and accompanying the switching of the operating state from the pumping operation to the pumping cutoff operation. A valve mechanism 42 that is opened by the valve is interposed.

Other matters are the same as in the case of the conventional preceding standby operation pump described with reference to FIG.
In FIG. 3, parts that are the same as or correspond to those in FIG.

The operation of the preceding standby operation pump configured as described above will be described.

A. When the water level of the suction well 9 rises (1) The water / water switching valve 61 is opened until the water level exceeds the pumping cutoff water level LWL and reaches the pumping start water level HWL. As a result, air is introduced into the impeller inlet by the water / water switching pipe 6, so that air operation is performed. (2) When the water level reaches the pumping start water level HWL, the steam switching valve 61 is closed. As a result, the introduction of air to the inlet of the impeller is stopped, and the pumping operation is performed. Pumping start water level H
Pumping operation is continued at a water level higher than WL. The valve mechanism 42 is closed during the pumping operation.

B. When the water level of the water intake well 9 drops (1) The water / water switching valve 61 and the valve mechanism 42 are closed from the position where the water level exceeds the pumping start water level HWL to the pumping start water level HWL and decreases to the pumping cutoff water level LWL. Keep it. As a result, the pumping operation continues. (2) The steam switching valve 61 is opened when the water level drops to the pumping cutoff water level LWL. As a result, pumping cutoff operation is started,
Prepare for future rising water levels. Further, the valve mechanism 42 is opened together with the steam switching valve 61.

During the pumping operation described in A (2) and B (1), the water sucked from the suction cover 5 by the rotation of the impeller 2 flows through the pumping passage 11 and is pumped. Therefore, the flapper 13, 13 of the check valve mechanism 10 is pushed up by the force of the water flow of the pumping passage 11 and swings around the axis of the support shafts 14, 14 to be in a standing posture to open the pumping passage 11. . The standing postures of the flappers 13, 13 are maintained during the pumping operation.

When the operating state is switched from the pumping operation to the pumping interruption operation by the pumping interruption described in B (2) above, the water flow in the pumping passage 11 disappears, so that the flappers 13, 13 of the check valve mechanism are replaced by the pumping passages. The flapper 13, 13 is pushed down by the weight (water pressure) of the water remaining in 11 and the weight of the valve body, and the pumping passage 11 is closed. Therefore, the weight (water pressure) of the water remaining on the downstream side of the flappers 13, 13 is determined by the flappers 13, 1.
3, the load applied to the impeller 2 located upstream of the flappers 13, 13 is significantly reduced, so that the vibration generated during the pumping cutoff operation becomes extremely small.

Moreover, when the pumping water is cut off, the valve mechanism 42 is opened, and the water remaining in the pumping passage 11 is drained into the water intake well 9 through the water escape passage 41 in a short time. Decay.

In the above description, the water exiting the water escape passage 41 provided with the valve mechanism 42 is drained into the water intake well 9, but this point is that the water escape passage 41 is located upstream of the impeller 2. For example, it may be connected to the suction cover 5, and in this case, the water that has exited the water escape passage 41 is drained into the suction cover 5.

As shown in FIG. 1, the method for controlling the opening / closing of the valve mechanism 42 interposed in the water escape passage 41 is based on the water level signal detected by the water level detecting means 7 for detecting the water level of the water intake well 9. It is possible to employ a method of controlling the opening and closing by a signal output from the controller 8 according to the above. Further, it may be configured as shown in FIG.
That is, the valve mechanism 42 shown in FIG. 3 includes the valve body 43 and the valve shaft 44, and the valve shaft 44 is rotated by the rotation of the support shaft 14 to which one flapper 13 is fixed. There is. Here, the valve shaft 44 may be used also as the support shaft 14, or may be jointed to the support shaft 14, or the rotation of the support shaft 14 may be transmitted to the valve shaft 44 via a gear. It may be. By doing so, the valve shaft 44 rotates due to the rotation of the support shaft 14 when the flapper 13 changes from the standing posture to the lying posture, the valve body 43 opens the water escape passage 41, and the flapper 13 moves from the lying posture. The valve shaft 44 is rotated by the rotation of the support shaft 14 in the standing posture.
Rotates and the valve element 43 closes the passage for releasing water.

1 to 3, the check valve mechanism 10 has been described as having the valve body 12 consisting of two flappers 13 and 13, but the number of flappers constituting the valve body 12 is two. Not limited. That is, the valve body 12 may be composed of three or more flappers. FIG. 4 shows an example in which the valve body 12 is composed of six flappers 13. In the valve body 12, the support shafts 14 that support the individual flappers 13 are rotatably supported by bearing mechanisms 15 that are provided at six positions at equal angles on the inner surface side of the pumping pipe 4. Also in this case, any one of the support shafts 14 can penetrate the pumping pipe 4 in a watertight state and extend to the outside thereof, and the support shaft 14 can be connected to the valve shaft 44 of the valve mechanism 42 in advance. Is. In FIG. 4, parts that are the same as or correspond to those in FIG. 3 are assigned the same reference numerals and detailed explanations thereof are omitted.

[0031]

EFFECTS OF THE INVENTION According to the preceding standby operation pump of the present invention, the load applied to the impeller after the pumping operation is switched to the pumping cutoff operation is significantly reduced as compared with the conventional preceding standby operation pump. The vibration during the cutoff operation and the noise caused by the vibration are reduced, and the power consumption during the pumping cutoff operation is significantly reduced. Providing the water escape passage has an advantageous effect that residual water in the pumping pipe can be drained in a short time.

Further, the valve body of the check valve mechanism, which is useful for reducing the load applied to the impeller after the pumping is cut off, is controlled without opening and closing by the force of the water flow during the pumping operation, the water pressure after the pumping off, and the own weight. The effect is that it will be.

Further, the effect that the water remaining in the pumping passage after the pumping off is drained in a short time to reduce the vibration and noise in a short time, and the valve body or the support valve of the check valve mechanism is provided. There is also an effect that the valve mechanism of the water escape passage can be controlled to be opened and closed by using the movement of the shaft without power.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional front view showing a preceding standby operation pump according to an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional side view showing a main part of the preceding standby operation pump of FIG.

FIG. 3 is a schematic cross-sectional view at a position on the downstream side of the check valve mechanism in the preceding standby operation pump of FIG.

FIG. 4 is a schematic cross-sectional view corresponding to FIG. 3 showing a modification of the check valve mechanism.

FIG. 5 is a schematic vertical sectional front view of a conventional preceding standby operation pump.

[Explanation of symbols]

 2 Impeller 3 Casing 4 Pumping pipe 5 Suction cover 6 Steam switching pipe 10 Check valve mechanism 11 Inside pumping passageway 12 Valve body 13 Flapper 14 Spindle 21 Impeller inlet 31 Casing inlet 32 Casing outlet 41 Water Release passage 42 Valve mechanism 43 Valve body 44 Valve shaft 61 Steam switching valve

Claims (4)

[Claims] 1. A suction cover and a pumping pipe are connected to a suction port and a discharge port of a casing for accommodating an impeller, respectively.
On the upstream side of the impeller housed in the casing, there is communicated a steam switching pipe whose internal passage is switched between an open state and a shut-off state for the atmosphere by a steam switching valve, and the downstream side of the impeller. In the pumping passage on the side, a check valve mechanism is provided with a valve body that is in a standing posture that opens the pumping passage by the flow of water during the pumping operation and closes the pumping passage when the pumping is cut off. A preceding standby operation pump characterized by the above. 2. A valve mechanism, which is closed during the pumping operation and is opened when the operating state is switched from the pumping operation to the pumping cutoff operation, in the pumping passage downstream of the installation location of the check valve mechanism. The preceding standby operation pump according to claim 1, wherein the water escape passage is in communication with each other. 3. A check valve mechanism comprising a valve body composed of two or more flappers arranged side by side in the circumferential direction of a pumping passage, and a spindle for supporting each of these flappers at a position eccentric from its center of gravity. 3. The preceding standby operation pump according to claim 1, wherein each flapper is swingable around the axis of its support shaft between an upright posture and a fallen posture. 4. A valve mechanism interposed in a water escape passage comprises a valve body and a valve shaft, at least one flapper is fixed to a support shaft, and the flapper supports when the fallen posture is changed to the standing posture. The rotation of the shaft causes the valve shaft to rotate and the valve body of the valve mechanism to close the water escape passage. The preceding standby operation pump according to claim 3, wherein the escape passage is opened.