KR20220157893A - Submersible pump with air tube and its equipment - Google Patents

Abstract

The present invention relates to a submersible pump with an air tube, which can suppress the repetition of a start and a stop of a pump while maintaining an operation at rated revolutions even when a water level on a suction port side is equal to or less than a minimum water level at which a drainage operation for the entire amount can be performed. According to the present invention, a submersible diagonal flow pump (1) of a horizontal shaft has a discharge port (65) arranged to face an impeller (32), and has sucked air to be supplied from the discharge port (65) provided in a suction cover (5). When a water level is lowered, air is supplied from the discharge port (65) at the timing just before entering a steam mixing operation. Also, water in a casing (2) of the submersible diagonal flow pump (1) instantaneously falls to allow the impeller (32) not to discharge the water so as to lower the pressure in a pump, such that a flap valve (4) is closed by the self-weight and the pressure of external water, and the impeller (32) becomes an air standby operation (a motor (3) is continued in a rotation driving state at rated revolutions) exposed to air. Accordingly, vibration is less, such that the load on the motor (3) is less. In addition, when the water level rises during the air standby operation, air from the discharge port (65) is blocked, such that a drainage operation for the entire amount is instantaneously performed.

Description

Submersible pump with air tube and its equipment

The present invention relates to a submersible pump with an air pipe and equipment therefor. More specifically, in a submersible pump fixed and disposed on the gate body of a water gate installed across a river, etc., even when the water level at the inlet side is below the lowest water level capable of draining the entire amount, the operation of the rated rotation speed is maintained, , It relates to a submersible pump with an air pipe that makes it possible to suppress the repetition of starting and stopping the pump and its equipment.

In a submersible pump, when the water level at the suction port side is lower than a certain water level, air is sucked into the pump casing from the suction port, resulting in brackish water mixing operation. Therefore, when the water level on the suction port side is lower than a certain level, the operation of the pump is temporarily stopped, and then, when the inflow amount increases and the water level on the suction port side rises, the pump is restarted. In this case, if the pump is frequently turned on and off according to the water level at the inlet side, operation management becomes complicated, the frequency of starting and stopping the pump becomes complicated, and the load on the submersible motor and starter increases, which is not preferable.

The pump gate described in Patent Literature 1 suppresses the generation of air intake vortices and underwater vortices by providing a suction cover having a rectifying effect on the upper part of the suction port of the pump, so that it can be operated to a lower water level. In the prior standby operation pump described in Patent Literature 2, a compressed air supply passage is provided in the main shaft of the pump, which is a vertical shaft, in order to prevent abnormal vibration or noise when switching from drain operation to holding operation. This compressed air supply passage discharges compressed air from the inlet side of the impeller, quickly pours the remaining water in the discharge pipe into the water supply well, and performs a holding operation that can operate at full speed regardless of the water level of the pump well in a short time. will be. Furthermore, in the submersible pump described in Patent Document 3, when the water level on the inlet side decreases, air is sucked in from a notch provided in the inlet cover or the intake pipe, and the water mixing operation is performed to reduce the displacement, thereby reducing the water level in the inlet side. Even below the water level at the time of draining the entire amount, the operation at the rated speed is maintained and the repetition of the pump on and off is suppressed.

Patent Document 1: Japanese Unexamined Patent Publication No. 2003-3450 Patent Document 2: Japanese Unexamined Patent Publication No. 8-312580 Patent Document 3: WO2016/178387

However, the pump described in Patent Literature 1 prevents the generation of continuous air intake vortices to prevent vibration and noise generated when air is sucked in, and the pump is repeatedly turned on and off according to the water level on the suction port side, and the lowest water level Even in the following, operation at the rated rotation speed is not possible. In the preceding atmospheric operation pump described in Patent Literature 2, the driving shaft of the impeller is a vertical shaft pump, and neither a horizontal shaft nor an inclined shaft is assumed. The submersible pump described in Patent Literature 3 has a transverse axis and introduces air when the water level falls below a certain level, but during the water mixing operation, vibration and noise increase and the amount of displacement decreases. Further, when the water level is further lowered, if the operation is performed at the rated rotation speed with no displacement, the jockey mixing operation is shifted to the air-standby operation.

The present invention was invented against the above background, and achieves the following objects.

An object of the present invention is to provide a submersible pump with an air pipe and equipment therefor using an air on-off valve and no air mixing operation.

Another object of the present invention is a submersible pump with an air pipe that can maintain operation at the rated speed even when the water level at the inlet side is below the lowest water level capable of draining the entire amount and suppresses repetition of starting and stopping the pump, and the same. in providing facilities.

In order to solve the above problems, the present invention adopts the following means.

That is, the submersible pump with an air pipe of the present invention 1,

A casing having an inlet on one side and an outlet on the other,

An electric motor fixed in the casing and driven to rotate;

An impeller connected to and driven to rotate in a horizontal direction in which the shaft center of the output shaft of the motor is horizontal, or to the output shaft in which the shaft center is disposed inclined at a predetermined angle from the horizontal;

In the submersible pump having a suction cover fixed to the casing and having an opening for sucking fluid,

an air pipe for sucking air into the submersible pump from a discharge port located upstream of the impeller and disposed in the submersible pump;

It is characterized in that an air opening/closing valve for supplying or shutting off air to the air pipe is provided.

In the submersible pump with an air tube according to the present invention 2, in the submersible pump with an air tube according to the first aspect of the present invention, the submersible pump with an air tube is a submersible mixed-flow pump in which a flow path of a fluid driven by the impeller is inclined with respect to the shaft center, or It is characterized in that the flow path of the submersible axial flow pump in the direction of the shaft center.

In the submersible pump with an air pipe according to the present invention 3, in the submersible pump with an air pipe according to the present invention 1 or 2, a water level gauge for detecting the water level at the suction port side, and opening and closing of the air on-off valve are controlled by the water level detection value of the water level gauge. It is characterized in that it is provided with an on-off valve control means.

In the submersible pump with an air pipe according to the fourth aspect of the present invention, in the submersible pump with an air tube according to the third aspect of the present invention, the opening/closing valve control means controls the water level when opening and closing the air opening/closing valve when the water level rises and when the water level falls. It is characterized in that it performs other control on.

In the submersible pump with an air tube according to the present invention 5, in the submersible pump with an air tube according to the present inventions 1 to 4, the discharge port is characterized in that the central axis of the discharge port is arranged parallel to the shaft center.

The submersible pump with an air pipe according to the sixth aspect of the present invention is characterized in that, in the submersible pump with an air tube according to the present inventions 1 to 5, the discharge port is disposed to face the impeller.

The submersible pump with an air tube according to the seventh aspect of the present invention is characterized in that in the submersible pump with an air tube according to the first to sixth aspects of the present invention, the air tube is connected to the suction cover or the casing.

The submersible pump facility with an air pipe according to the present invention 8 is a submersible pump facility using the submersible pump with an air pipe according to the present inventions 1 to 7, wherein the submersible pump with an air pipe is a water gate or sluiceway crossing a river or waterway. ) is characterized in that it is mounted on.

The submersible pump with an air pipe and its equipment according to the present invention supplies air from the air pipe when the water level on the inlet side becomes lower than the minimum water level capable of draining the entire amount, so that the full amount draining operation can be switched to the air standby operation in an instant. . If the water level on the inlet side rises during the air standby operation, the air is cut off, so that the air standby operation can be switched from the air standby operation to the total amount drain operation in an instant. Therefore, since the rider mixing operation is terminated in a short period of time or eliminated, it is possible to reduce vibration, maintain operation at the rated rotational speed, and suppress repeated starting and stopping of the pump.

Fig. 1 is a longitudinal sectional view showing a submersible mixed flow pump 1 provided with an air supply circuit 60 according to a first embodiment of the present invention.
Fig. 2 is an explanatory diagram showing an outline of an air supply circuit 60 for supplying or shutting off air to the submersible mixed flow pump 1 of the first embodiment of the present invention.
3 is a flowchart showing an example of an operation of an electric valve control circuit 71 for supplying or shutting off air to the submersible mixed flow pump 1 of the first embodiment of the present invention.
Fig. 4 is a graph showing the current and vibration of the submersible mixed flow pump 1 of the first embodiment of the present invention when the water level on the inlet side is raised/lowered.
Fig. 5 is a graph showing current and vibration of a conventional submersible mixed flow pump when the water level on the inlet side is raised/lowered.
Fig. 6 is a longitudinal sectional view showing a submersible axial flow pump 10 provided with an air supply circuit 60 according to a second embodiment of the present invention.

[Submersible Mixed Flow Pump 1 of First Embodiment]

EMBODIMENT OF THE INVENTION Hereinafter, the 1st embodiment of this invention is described based on drawing. 1 is a longitudinal sectional view showing a submersible mixed flow pump 1 according to a first embodiment of the present invention. As shown in FIG. 1, the submersible mixed-flow pump 1 of the first embodiment of the present invention is installed across a river, waterway, sewage, etc. It is fixed with bolts or the like through. In addition, the flange portion of the casing 2 of the submersible mixed flow pump 1 may be of a structure in which the flange portion is directly fixed to the gate body 100 of the sluice gate or passage gate. These structures are integrated with a submersible pump mounted on a water gate (gate), and are called gate pumps (Japanese Trademark Registration No. 2585973, common name is "pump gate").

The submersible mixed flow pump 1 of the present embodiment is called a mixed flow pump in which the flow of fluid discharged from the impeller 32 sends the fluid in an oblique direction from the center line of the output shaft 31 . The submersible mixed flow pump 1 has a casing 2 having a suction port 21 (left side in Fig. 1) on one side and a discharge port 22 on the other side (right side in Fig. 1). Inside the casing 2, an electric motor 3 for rotationally driving the impeller 32 is fixed. In the electric motor 3 of the submersible mixed flow pump 1, an output shaft 31 is mounted on the suction port 21 side, an impeller 32 is fixed to the output shaft 31, and the rotational torque of the electric motor 3 is applied to the impeller ( 32) is passed on. Adjacent to the downstream side of the impeller 32, a guide vane 33 is fixed between the inner circumference of the casing 2 and the outer circumference of the oil room 34. The guide vane 33 guides the water raised by the impeller 32 .

On the discharge port 22 side of the casing 2, a flap valve 4 supported so as to be able to open and close is disposed. The flap valve 4 is mounted at a position 4a disposed above the casing 2 so that it can swing freely. When the discharge pressure of the water from the discharge port 22 is low, the flap valve 4 is closed by its own weight, and when the discharge pressure of water becomes high, the flap valve 4 is opened centering on the fulcrum 4a at the top, thereby releasing the valve from the discharge port 22. allows for the discharge of water. A suction cover 5 for smoothly guiding water to the suction port 21 is fixed to the suction port 21 of the casing 2 . The opening 53 at the end of the suction cover 5 is inclined downward from the horizontal (angle of attack θ), and river water on the upstream side is sucked in from this opening 53.

As shown in FIG. 1 , in the submersible mixed flow pump 1, the shaft center 311 of the output shaft 31 is horizontally arranged. The height from the bottom surface 102 of the waterway to the upper edge of the opening 53 of the suction cover 5 (the lower surface of the suction guide plate 511) 531 is Y1, and the impeller from the bottom surface 102 of the waterway If the height to the lower end of 32) is Y3, Y1 is arranged at a higher position than Y3. Moreover, the upper edge 531 of the opening part 53 of the suction cover 5 is arrange|positioned lower than the shaft center 311 of the output shaft 31 of the electric motor 3. The lower edge 532 of the opening 53 is at a height of Y2 from the bottom surface 102 of the waterway. When the water level is lower than the water level Y2 of the lower edge 532 of the opening 53, it is lower than the height Y3 of the lower end of the impeller 32, so the submersible mixed flow pump 1 does not suck river water. . The water level shown on the left side of FIG. 1 is the water level at which the entire amount of draining operation is possible when the water level decreases or when the water level rises in operation of the submersible mixed flow pump 1 of the first embodiment of the present invention, and the water level at standby operation (air standby). driving).

Air supply circuit (60)

FIG. 2 is a block diagram showing an outline of an air supply circuit 60 for supplying or shutting off air to the submersible mixed flow pump 1. As shown in FIG. The air supply circuit 60 consists of a water level gauge 70, an electric valve control circuit 71, an electric air valve 63, an air pipe 64, a discharge port 65, and the like. Atmospheric air passes through the electric air valve 63 and the air pipe 64 and is sucked into the casing 2 from the discharge port 65 by the suction force (negative pressure) during operation of the submersible four-flow pump 1. The discharge port 65 is piped to an air pipe 64 attached to the suction cover 5. The electric air valve 63 is housed in a storage chamber 66 sealed watertightly so as not to get wet (see Fig. 1). The central axis of the discharge port 65, which is a pipe, is arranged parallel to the axis 311 of the output shaft 31 of the submersible mixed flow pump 1. More precisely, the central axis of the discharge port 65 is disposed at a position lower than the axis 311 of the output shaft 31 . That is, the discharge port 65 is disposed at a position lower than the shaft center 311 opposite the impeller 32 .

For this reason, the air sucked in from the discharge port 65 is sucked in substantially uniformly in the center direction of the impeller 32 and up and down the impeller 32 while slightly upward due to the buoyancy of the air. The timing of opening and closing of the motorized air valve 63 is controlled by the motorized valve control circuit 71 . The water level gauge 70 always measures the water level of the upstream river, and measures the water level by water pressure or the like. This structure and function are well-known techniques, and their descriptions are omitted. The motorized valve control circuit 71 controls opening and closing of the motorized air valve 63 while observing the water level in the water level gauge 70 when the submersible mixed flow pump 1 is operating. Opening and closing control of the electric air valve 63 is performed according to the water level detected by the water level gauge 70. In Fig. 1, the leftmost part shows the water level at which the electric air valve 63 is opened when switching from the entire water drain operation when the water level drops to the air standby operation. The right side shows the water level at which the electric air valve 63 is closed at the time of switching from air standby operation to total amount drain operation when the water level rises.

The reason why the water level position of opening/closing of the electric air valve 63 differs between when the water level falls and when the water level rises is as follows. That is, when the water level rises and falls, in order to avoid the air mixing operation, "when the water level drops, if the water level is up to the vicinity of the upper edge 531 of the opening 53 of the suction cover 5, the inside of the casing 2 When the water level is lower than the upper edge 531, air is sucked in from the suction cover 5. The electric air valve 63 is opened at the "air valve opening water level" (a water level higher than the upper edge 531 by about 10 mm in this embodiment), which is the water level near the upper edge 531, and the air from the air pipe 64 is sucked into the casing 2, and the water in the casing 2 is dripped at once, and the entire quantity draining operation is instantly transferred to the air standby operation.” Also, “When the water level rises, the water level is 60% of the impeller 32. When the above height is reached, the impeller 32 can discharge the water in the casing 2 by itself. At the water level in this vicinity when the water level rises, in order to avoid the air mixing operation reliably, the "air valve closing water level" becomes a water level slightly lower than that water level (in this embodiment, the water level of about 55% of the impeller 32) closes the electric air valve 63, shuts off the air from the air pipe 64, and when the water level reaches the water level at which all water drain operation is possible (approximately 60% of the water level of the impeller 32), the whole amount water drain operation from the air standby operation For the above reasons, the water level positions of opening and closing of the electric air valve 63 are different between when the water level is lowered and when the water level is raised.

Operation of air supply circuit 60

3 is a flowchart showing an operation example of the electric valve control circuit 71 of the air supply circuit 60. As shown in FIG. This flowchart is a control example in the case where the "air valve opening level" and "air valve closing level" of the electric air valve 63 are set at the positions shown in FIG. 1 . The electric motor 3 (FIG. 1) is turned on (S1). The timer counter for setting the operating time of the electric motor 3 is set to zero, and the valve of the electric air valve 63, which is in a state of blocking air, is closed (S2, S3). At the start of the operation of this control device, the control phase is in a full amount drainage operation state. Next, the water level on the water intake side is measured by the water level gauge 70 to obtain water level data (S4). It is determined whether or not this water level data is "above the air valve closing water level" (see Fig. 1) (S5).

In S3, the electric air valve 63 is closed, and in this S5, if the water level is "above the air valve closing level" (YES), that is, this water level is not the air standby operation, but the water level in the entire amount drain operation area ( see Figure 1). In this case (YES), it is determined whether "electrically operated air valve 63: closed?" (S12). When the electric air valve 63 is closed (YES), the total amount draining operation is possible, the timer counter is set to zero (S14), and the return to "water level measurement" (S4) continues the total amount draining operation. When the electric air valve 63 is not closed (NO), the electric air valve 63 closes (S13), sets the timer counter to zero (S14), and returns to "water level measurement" (S4) to drain the entire amount. continue driving

In S5, if the water level is not "Above the air valve closing level?" (NO), it is judged again whether the water level is "below the air valve opening level?" (S6). In this S6, when the water level is "below the air valve opening level" (YES), the water level at this time means that it is in the air standby operation area regardless of "when the water level falls" or "when the water level rises" (Fig. 1). If it is judged that this air standby operation region (YES), the electric air valve 63 needs to be open, so the process proceeds to the next step S7 for confirmation, and it is checked whether "electric air valve 63: open?" It is judged (S7). If the electric air valve 63 is already open (YES), it proceeds to step S9. When the air-powered air valve 63 is closed (NO), since the air-powered air valve 63 is opened and the air-powered air valve 63 is closed (NO), the operating time for the air-powered air valve 63 is set (S8, S9). Setting of this operation time is a region where the water level is low, and since it is not necessary to continue the air standby operation more than necessary, the operation time of the electric motor 3 is set. In S10, it is determined whether or not the time shifted to the air standby operation is "more than operating time?".

When the operating time of the electric motor 3 is not equal to or longer than the set time (NO), the process returns to step S4, that is, the standby operation is continued. When the electric motor 3 exceeds the operating time (YES), the power of the electric motor 3 is turned off (step S11). That is, since the set operating time of the submersible mixed flow pump 1 has reached the set time, the operation is stopped. On the other hand, in S6, if the water level is not "lower than the air valve opening level?" (NO), the process proceeds to S15. Since the water level at this time is neither "Above the air valve closing level?" (S5) nor "Are you below the air valve opening level?" (S6), the water level at this time is the "air valve opening level" and "air valve opening level" It means the intermediate water level between the "valve closing water level" (see Fig. 1). In this intermediate water level, it is a setting area in which the electric air valve 63 is opened when the water level rises and the electric air valve 63 is closed when the water level falls.

In this S15 "Electric air valve 63: open?", when the electric air valve 63 is open (YES), it means that it is in the state of "at the time of water level rise". In “when the water level rises”, the water level region that is the intermediate water level is the air standby operation region. The electric air valve 63 is left open as it is, and the process proceeds to S9 to continue the air standby operation until the set time. That is, that the electric air valve 63 is already open at this intermediate water level usually means that the water level is rising, and at this water level, it means the air standby operation water level. For this reason, the electric air valve 63 remains open. And it progresses to S4, and the operation of the electric motor 3 continues. In step S15 "Is the electric air valve 63 open?", the case where the electric air valve 63 is not opened (NO) means that the water level is in a falling state. Continue driving with the electric air valve 63 closed. That is, at this intermediate water level, that the air-powered air valve 63 is not open means "at the time of the water level drop" when the water level is falling, which is the entire drain operation area, and the air-powered valve 63 is closed. In this state, the timer counter is set to zero (S16), and the process returns to "water level measurement" (S4), and the entire draining operation is continued.

If the above operation is summarized, the control becomes as follows. For example, when the driver turns on the switch (not shown) of the electric motor 3 of the submersible mixed flow pump 1 and turns it ON, the electric motor 3 starts to rotate, and the river water on the upstream side is pumped up and sent to the downstream side. . The motorized valve control circuit 71 determines the current water level according to the water level signal from the water level gauge 70, controls opening and closing of the motorized air valve 63, and selects whether the entire amount is drained or the air standby operation is performed. . And the timing of opening and closing of the electric air valve 63 is changed according to whether the water level is rising or falling. Even if the water level at the inlet side is lowered while the water level is falling or during the total drain operation, as shown in FIG. 1 , if the water level at the inlet side is higher than the "air valve opening water level", air is not sucked in from the opening 53, so the intake cover (5) and the casing (2) are filled with water. Therefore, the submersible mixed-flow pump 1 continues to drain the entire amount at the rated rotational speed. Then, when the water level drops from the water level in the total amount drain operation, the motorized valve control circuit 71 opens the motorized air valve 63 when it reaches the position of the “air valve opening water level” and blows air through the air pipe 64. Through this, it is supplied to the submersible mixed flow pump (1). With this supply of air, the submersible mixed flow pump 1 enters the air standby operation mode at once.

When the water level rises from the air standby operation, the electric valve control circuit 71 closes the electric air valve 63 when it reaches the "air valve closing water level" position, and the submersible mixed flow pump 1 by the air pipe 64 ) to block the air. Due to this air blocking, in the present embodiment, when the water level reaches 60% or more of the impeller 32, the impeller 32 is in a state where it can discharge the water in the casing 2 by itself, so the submersible mixed flow pump ( 1) changes from the air standby operation mode to the entire quantity drainage operation mode at once. In addition, even if the water level on the suction port side is lowered while the water level is rising or during total drain operation, as shown in FIG. If it is higher than that, since air is not sucked in from the opening 53, the inside of the suction cover 5 and the inside of the casing 2 are filled with water. Therefore, the submersible mixed-flow pump 1 continues to drain the entire amount at the rated rotational speed. Since the “air valve opening water level” and the “air valve closing water level” are different from the natural conditions in which the pump (submersible mixed-flow pump (1)) is installed, exactly the field conditions, operation is performed in the river where the pump (submersible mixed flow pump (1)) is installed, and the result It is good to determine the optimal water level with

When the water level on the suction port side is lower than the “air valve opening water level” in FIG. 1 , air is sucked in from the opening 53 . Before air is sucked in from this opening 53, the motorized air valve 63 opens, and air is supplied through the air pipe 64. As a result, the water inside the suction cover 5 and the casing 2 of the submersible mixed flow pump 1 drips down in an instant, and the impeller 32 stops discharging water, so the pressure inside the pump decreases and the flap valve Since (4) is closed by its own weight and the pressure of external water, and the impeller 32 is exposed to the air, the air standby operation (the motor 3 continues to rotate at the rated rotation speed), so the vibration is small, and the motor ( 3) is less burdensome. Even if the water level on the suction port side is further lowered, if it is within a set time (for example, set by a timer not shown), air standby operation is continued. Therefore, the submersible mixed flow pump 1 of the first embodiment of the present invention has little vibration because there is no brackish water mixing operation. In the submersible mixed flow pump 1 of the present embodiment, when the water level on the inlet side becomes equal to or lower than the minimum water level at which the total amount drain operation is possible, the entire amount drain operation is instantly transferred to the air standby operation, and the water level on the inlet side rises during the air standby operation, and the entire amount is drained. When the water level at which the draining operation is possible (about 60% of the water level of the impeller 32) is reached, the air standby operation is shifted to the entire amount draining operation in an instant. As a result, there is no jockey mixing operation, vibration is reduced, and operation at the rated rotational speed can be maintained.

When the water level is below the water level Y2 of the lower edge 532 of the opening 53 of the suction cover 5, the river water cannot be physically sucked in, so the casing 2 is removed from the outlet 65 of the air pipe 64. Air is not required to be sucked inside, but at the water level of the air standby operation (see Fig. 1), the air standby operation is performed within a set time (set by a timer not shown) with the electric air valve 63 open. Continue. By this control, it becomes possible to suppress repetition of starting and stopping of the submersible mixed flow pump 1. 4 is a current (A) and vibration (note: synthesized vibration in the X, Y, and Z directions) of the electric motor 3 of the submersible mixed-flow pump (pump diameter is 300 mm) 1 of this embodiment of the present invention ( It is a graph showing μm). In Fig. 4, the water level on the inlet side is raised from 200 mm to 600 mm and then lowered to 200 mm. As shown in FIG. 4 , when the water level rises, the transfer from the air standby operation to the full amount drain operation is instantaneous, and when the water level decreases, the entire amount drain operation is shifted from the air standby operation to the air standby operation, and the mixed water operation is performed. Since this does not occur, fluctuations in the current A and fluctuations in the oscillations (μm) are reduced.

5 shows the current (A) and vibration (note: synthesized vibration in the X, Y, and Z directions) (μm) of the electric motor 3 of a conventional submersible mixed-flow pump (pump diameter is 300 mm) without an air pipe. It is a graph that represents As shown in FIG. 5, since the conventional submersible mixed-flow pump sucks air from the upper edge 531 of the opening 53 and the mixing operation occurs, switching from air standby operation to total drain operation, and total drain Switching from operation to standby operation takes time, and vibration is large. On the other hand, in the submersible mixed flow pump 1 of the first embodiment of the present invention, as shown in FIG. 4 , since the air mixing operation does not occur, switching from the air standby operation to the total amount drainage operation and the total amount drainage operation to the air discharge operation are performed. Switching to standby operation is performed instantaneously, and vibration is small.

[Submersible axial flow pump 10 of the second embodiment]

The submersible axial flow pump 10 of the second embodiment shown in FIG. 6 has a structure different from that of the first embodiment described above. The submersible axial flow pump 10 is a pump that sends fluid in the direction of the shaft center 311 of the output shaft 31, and has a suction port 21 on one side (left side in FIG. 6) and an outlet port 22 on the other side (right side in FIG. 6). ) with a casing (2). Inside the casing 2, an electric motor 3 for driving rotation is fixed. In the motor 3, an output shaft 31 is mounted on the outlet 22 side, an impeller 32 is fixed to the output shaft 31, and rotation of the electric motor 3 is transmitted to the impeller 32. A guide vane 33 is fixed between the inner circumference of the casing 2 and the outer circumference of the oil room 34 on the suction port 21 side (upstream side) of the impeller 32 . The guide vane 33 guides the water raised by the impeller 32 .

The casing 2 is equipped with a flap valve 4 supported on the discharge port 22 side so as to be able to open and close. When the discharge pressure of the water from the discharge port 22 is low, the flap valve 4 is closed by its own weight, and when the discharge pressure of water becomes high, it is opened centering on the upper point 4a, thereby reducing the discharge from the discharge port 22. allow water to drain. A suction cover 5 for smoothly guiding water to the suction port 21 is fixed to the suction port 21 of the casing 2 . As shown in Fig. 6, the suction cover 5 is formed of a top plate, a side plate, or the like from one or more plate materials. In the submersible axial flow pump 10 of the second embodiment, an air supply circuit 60 that operates on the same principle as that of the first embodiment described above is disposed. It consists of a water level gauge 70, an electric valve control circuit 71, an electric air valve 63, an air pipe 64, a discharge port 65, and the like.

Atmospheric air, due to the suction force during operation of the submersible axial flow pump 10, the air pipe 64 connected to the electric air valve 63 is branched into two, and each of the two outlets 65 is discharged from the branch pipe (not shown). is sucked into the casing 2 from the The two discharge ports 65 are disposed in the suction cover 5 with the left and right sides of the outer periphery of the electric motor 3, that is, both sides of the electric motor 3 interposed therebetween. This discharge port 65 is piped to an air pipe 64 fixed to the suction cover 5. The central axis of the outlet 65 is arranged parallel to the axis 311 of the output shaft 31 of the submersible axial flow pump 10 . To be precise, the central axis of the discharge port 65 is disposed at a position slightly lower than the axis 311 of the output shaft 31 . That is, the discharge port 65 is arranged at a position lower than the shaft center 311 so as to face the front of the impeller 32 . Level gauges, control circuits, etc. for operating the electric air valve 63 of the submersible axial flow pump 10 of the second embodiment are substantially the same as those of the submersible mixed flow pump 1 of the first embodiment, and description thereof is omitted. do. Moreover, as shown in the far left part of FIG. 6, the reason why the water level position of opening and closing of the electric air valve 63 differs between when the water level falls and when the water level rises is as follows. That is, when the water level rises and falls, in order to avoid the air mixing operation, "when the water level drops, if the water level is up to the vicinity of the upper edge 531 of the opening 53 of the suction cover 5, the inside of the casing 2 When the water level is lower than the upper edge 531, air is sucked in from the suction cover 5.

The electric air valve 63 is opened at the "air valve opening level" which is the water level near the upper edge 531 (in this embodiment, the water level is higher than the upper edge 531 by about 10 mm), and air is blown from the air pipe 64. Suction is sucked into the casing 2, and the water in the casing 2 is dripped at once, and the entire amount draining operation is instantly transferred to the air standby operation.” Also, “When the water level rises, the water level is 60% or more of the impeller 32 or more. When the height is reached, the impeller 32 can discharge the water in the casing 2 by itself. At the water level in this vicinity when the water level rises, in order to avoid the air mixing operation reliably, the "air valve closing water level" becomes a water level slightly lower than that water level (in this embodiment, the water level of about 55% of the impeller 32) closes the electric air valve 63, shuts off the air from the air pipe 64, and when the water level reaches the water level at which all water drain operation is possible (approximately 60% of the water level of the impeller 32), the whole amount water drain operation from the air standby operation For the above reasons, the water level positions of opening and closing of the electric air valve 63 are different between when the water level is lowered and when the water level is raised.

[Other embodiments]

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment. For example, although the electric air valve 63 of the above-described embodiment is a valve driven by an actuator using a motor, it may be a solenoid valve using a solenoid electromagnet. In addition, in the aforementioned submersible mixed-flow pump 1 and submerged axial-flow pump 10, the output shaft 31 of the electric motor 3 and the shaft center of the impeller 32 connected thereto are disposed in a horizontal transverse direction. There is. However, the axis may be tilted from the horizontal. In addition, although the air supplied to the air pipe is atmospheric air to avoid the air mixing operation, pressurized air from a blower or a compressor may be supplied to actively drip water in the pump casing. Further, the shapes of the suction cover 5 of the submersible mixed flow pump 1 and the submersible axial flow pump 10 described above differ depending on the structure of the submersible pump. Therefore, the suction cover 5 according to the present invention is a concept including a body portion, not limited to a cover on the suction side of the pump body.

One… submersible mixed flow pump
10... submersible axial flow pump
100... literary style
101... Brackets
102... bottom of waterway
2… casing
21... intake
22... outlet
3... electric motor
31... output shaft
311... axis
32... impeller
33... guide wing
34... oil room
4… flap valve
5... suction cover
60... air supply circuit
63... motorized air valve

Claims (8)

A casing having an inlet on one side and an outlet on the other,
An electric motor fixed in the casing and driven to rotate;
An impeller connected to and driven to rotate in a horizontal direction in which the shaft center of the output shaft of the motor is horizontal, or to the output shaft in which the shaft center is disposed inclined at a predetermined angle from the horizontal;
In the submersible pump having a suction cover fixed to the casing and having an opening for sucking fluid,
an air pipe for sucking air into the submersible pump from a discharge port located upstream of the impeller and disposed in the submersible pump;
A submersible pump with an air pipe characterized by comprising an air opening/closing valve for supplying or shutting off air to the air pipe. The method of claim 1,
The submersible pump with an air tube is a submersible mixed-flow pump in which a flow path of fluid driven by the impeller is inclined with respect to the shaft center, or a submersible axial flow pump in which the flow path of the fluid is in the direction of the shaft center. According to claim 1 or claim 2,
a water level gauge for detecting a water level on the suction port side;
The submersible pump with an air pipe characterized by comprising an on/off valve control means for controlling opening and closing of the air on/off valve based on a water level detection value of the water level gauge. The method of claim 3,
The on-off valve control means performs different controls on the water level when the air on-off valve is opened and closed when the water level rises and when the water level falls. According to claim 1 or claim 2,
In the discharge port, a central axis of the discharge port is disposed parallel to the axis of the air pipe submersible pump. According to claim 1 or claim 2,
The air pipe submersible pump characterized in that the discharge port is arranged to face the impeller. According to claim 1 or claim 2,
The air pipe is connected to the suction cover or the casing. As a submersible pump facility using the submersible pump with an air pipe according to claim 1 or 2,
The submersible pump with air tube is mounted on a water gate or sluiceway crossing a river or waterway.

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