JP2022181398A - Submersible pump with air tube, and its equipment - Google Patents

Abstract

To make it possible to maintain an operation at a rated speed and inhibit repeated starts and stops of a pump even if the suction port side water level is equal to or less than a lowest water level allowing an all-volume pumping-out operation.SOLUTION: A horizontal-shaft submersible mixed flow pump 1 has a discharge port 65 disposed to face an impeller 32, and inspired air is supplied from the discharge port 65 formed in a suction cover 5. When the water level decreases, air is supplied from the discharge port 65 at a time right before entry to an air-water mixing discharge operation. Water in a casing 2 of the submersible mixed flow pump 1 instantaneously drops so that the impeller 32 stops causing discharge of water, and thus the intra-pump pressure drops and a flap valve 4 is closed by its own weight and the external water pressure, so as to start an aerial stand-by operation in which the impeller 32 is exposed into air (a motor 3 maintains a rotary drive state at a rated speed). The oscillation is small and the burden on the motor 3 is small. If the water level increases during the aerial stand-by operation, then the air from the discharge port 65 is blocked to cause an instantaneous transition to an all-volume pumping-out operation.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a submersible pump with an air tube and equipment therefor. More specifically, for example, in a submersible pump that is fixed to the gate of a water gate installed across a river, even if the water level on the suction port side is below the minimum water level that allows full discharge operation, the rated rotation speed The present invention relates to a submersible pump with an air tube and its equipment that can maintain operation and suppress repetition of starting and stopping of the pump.

In a submersible pump, when the water level on the suction port side drops below a certain water level, air is sucked into the pump casing from the suction port, causing air-water mixed operation. Therefore, when the water level on the suction port side drops below a certain water level, the operation of the pump is temporarily stopped, and then when the inflow increases and the water level on the suction port side rises, the pump is restarted. If the pump is repeatedly turned on and off in response to the water level on the suction port side in this way, the operation management becomes complicated, the frequency of starting and stopping the pump becomes complicated, and the burden on the submersible motor and the starter. is not preferable because it becomes large.

In the vertical shaft pump described in Patent Document 1, in order to avoid the air-water mixing operation, a float that moves up and down according to the water level is arranged on the water intake side, and when the water level drops below the minimum water level, the air valve is opened to release air. It sucks in and drops the water in the bell mouth to operate in the air. The preceding standby operation pump described in Patent Document 2 is provided with a compressed air supply passage in the main shaft of the pump, which is a vertical shaft, in order to prevent abnormal vibration and noise when switching from the drain operation to the holding operation. This compressed air supply passage discharges compressed air from the inlet side of the impeller and quickly drops the remaining water in the discharge pipe into the water supply well, thereby shortening the holding operation that allows full speed operation regardless of the water level of the pump well. Time is what you do. Furthermore, the submersible pump described in Patent Document 3, when the water level on the suction port side is low, sucks air from a notch provided in the suction cover or the suction pipe, and performs air-water mixing operation to reduce the amount of drainage. Even if the water level on the suction port side is lower than the water level during the full discharge operation, the operation is maintained at the rated rotation speed and the repetition of turning on and off of the pump is suppressed.

Japanese Utility Model Laid-Open No. 2-3095 JP-A-8-312580 WO2016/178387

However, the pump described in Patent Document 1 is a fixed vertical shaft pump in which the pump body is fixed to a structure such as a slab, and has a horizontal or oblique shaft tilted at a predetermined angle from the horizontal. It does not apply to submersible pumps. Therefore, a movable type horizontal shaft submersible such as a gate pump (trademark registration No. 2585973, general name is "pump gate") in which a submersible pump is mounted on the gate of a water gate or a sluice gate and integrated with both Not applicable to pumps. Similarly, the preceding standby operation pump described in Patent Document 2 is also a fixed vertical shaft pump in which the pump body is fixed to a structure such as a slab, and is not intended for a horizontal or inclined shaft submersible pump. It cannot be applied to gate pumps, which are movable submersible pumps. The submersible pump applied to the pump gate described in Patent Document 3 is a horizontal submersible pump that introduces air when the water level drops below a certain level. Drainage is also reduced. In addition, when the water level drops further, if the operation is performed at the rated rotation speed while the amount of water discharged is lost, the air-water mixed operation will shift to the air standby operation. Better not.
The present invention was invented against the above background, and achieves the following objects.

SUMMARY OF THE INVENTION An object of the present invention is to provide a submersible pump with a horizontal or oblique shaft type air pipe, and its equipment, by using a mechanical air on-off valve that can be opened and closed by a float, without mixing air and water. be.
Another object of the present invention is to maintain the operation at the rated rotation speed even when the water level on the suction port side is lower than the minimum water level at which the full discharge operation is possible, and to suppress the repetition of starting and stopping of the pump. To provide a submersible pump with an axial or oblique axis air pipe and equipment therefor.

In order to solve the above problems, the present invention employs the following means.
That is, the submersible pump with an air tube of the first invention is
a casing having an inlet on one side and an outlet on the other;
an electric motor fixed within the casing for rotational driving;
an impeller arranged in a lateral direction in which the axis of the output shaft of the electric motor is horizontal or with the axis inclined at a predetermined angle from the horizontal and connected to the output shaft and driven to rotate;
a suction cover fixed to the casing and formed with an opening for sucking fluid,
an air pipe for sucking air into the submersible pump from a discharge port arranged upstream of the impeller and within the submersible pump;
It is characterized by comprising an air opening/closing valve control mechanism for supplying or shutting off air to the air pipe.

A submersible pump with an air tube according to a second aspect of the present invention is the submersible pump with an air tube according to the first aspect, wherein the flow path of the fluid driven by the impeller is inclined with respect to the axis. or a submersible axial flow pump in which the flow path of the fluid extends in the axial direction.
A submersible pump with an air tube according to a third aspect of the present invention is the submersible pump with an air tube according to the first or second aspect of the present invention, wherein the air on-off valve control mechanism is an air on-off valve for supplying or shutting off air to the air tube. , a float that moves up and down by buoyancy according to the water level on the suction port side, and a lever mechanism that transmits the vertical movement of the float to the air on/off valve to control the opening and closing of the air on/off valve. and
A submersible pump with an air pipe according to a fourth aspect of the present invention is the submersible pump with an air pipe according to any one of the first to third aspects of the invention, wherein the air on-off valve control mechanism controls the timing of the water level when the air on-off valve is opened and closed so that the water level rises. It is characterized in that it is different between time and when the water level falls.

A submersible pump with an air tube according to a fifth aspect of the present invention is the submersible pump with an air tube according to the third aspect, wherein the lever mechanism has one end fixed to the float and the other end provided with the air on-off valve serving as a lid that opens and closes. It is characterized by swinging about a swing axis.
A submersible pump with an air tube according to a sixth aspect of the present invention is the submersible pump with an air tube according to the fourth aspect of the present invention, wherein the air on-off valve control mechanism is selectively set at two different positions when the water level rises and when the water level falls. It is characterized by having a float wobble prevention mechanism having a locking position.
A submersible pump with an air pipe according to a seventh aspect of the invention is the submersible pump with an air pipe according to the sixth aspect of the invention, wherein the float wobble prevention mechanism comprises a first locking portion that locks at a position when the water level rises; and a second locking portion that locks at a lowered position.

A submersible pump with an air pipe according to an eighth aspect of the invention is characterized in that, in the submersible pump with an air pipe according to any one of the first to seventh aspects, the central axis of the outlet is arranged parallel to the axis. do.
A submersible pump with an air pipe according to a ninth aspect of the present invention is characterized in that, in the submersible pump with an air pipe according to any one of the first to eighth aspects of the present invention, the discharge port is arranged facing the impeller.

A submersible pump with an air tube according to a tenth aspect of the present invention is characterized in that, in any one of the submersible pumps with an air tube according to any one of aspects 1 to 9, the air tube is connected to the suction cover or the casing.
A submersible pump facility with an air tube according to the eleventh aspect of the present invention is a submersible pump facility using the submersible pump with an air tube according to any one of the first to tenth aspects of the present invention, wherein the submersible pump with an air tube is a water gate that crosses a river or a waterway, or It is characterized by being mounted on a sluice.

The submersible pump with an air pipe of the present invention and its equipment control the air valve by a mechanical float type automatic air opening and closing valve control mechanism that can open and close the air valve with a float, and the air valve is controlled from full drainage operation to air standby operation or air Instantaneous shift from medium standby operation to total drainage operation. Specifically, when the water level on the side of the suction port drops below the minimum water level at which the full discharge operation is possible, air is supplied from the air pipe, so that the full discharge operation can be instantaneously switched to the air standby operation. If the water level on the suction port side rises during the air standby operation, the air can be cut off and the air standby operation can be instantaneously shifted to the total discharge operation. Therefore, since the air-water mixing operation is finished in a short time or without it, it is possible to maintain the operation at the rated rotation speed while reducing the vibration, and to suppress the repetition of starting and stopping of the pump. . Furthermore, since the float-type automatic air on-off valve control mechanism for controlling the opening and closing of the air valve is provided with a float fluctuation prevention mechanism, the air valve can be reliably and stably opened and closed.

FIG. 1 is a vertical cross-sectional view showing a horizontal submersible mixed flow pump 1 having a float type automatic air on-off valve control mechanism 80 according to a first embodiment of the present invention. FIG. 2 is an enlarged sectional view of the float type automatic air on/off valve control mechanism 80. As shown in FIG. FIG. 3 is a graph showing current and vibration of the submersible mixed flow pump 1 according to the first embodiment of the present invention when the water level on the suction port side is raised and lowered. FIG. 4 is a graph showing the current and vibration of a conventional submersible mixed flow pump when the water level on the suction port side is raised and lowered. FIG. 5 is a longitudinal sectional view showing the float fluctuation prevention mechanism 200 of the float type automatic air on-off valve control mechanism 90 in the submersible mixed flow pump 1 of the second embodiment of the present invention. FIG. 6 is a longitudinal sectional view showing a submersible axial flow pump 10 with a horizontal axis provided with a float type automatic air on-off valve control mechanism 90 according to a third embodiment of the present invention.

[Submersible Mixed Flow Pump 1 of First Embodiment]
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a submersible mixed flow pump 1 with a horizontal axis according to a first embodiment of the present invention. As shown in FIG. 1, a horizontal shaft submersible mixed flow pump 1 according to the first embodiment of the present invention is attached to a gate 100 of a water gate or a sluice gate provided across a river, a waterway, a sewer, or the like. , and are fixed with bolts or the like via brackets 101 and the like. In addition, the structure which fixes the flange part of the casing 2 of the submersible mixed flow pump 1 directly to the door 100 of a water gate or a sluice gate may be used. As mentioned above, these structures are integrated with a submersible pump mounted on a water gate (gate), and are called a gate pump (trademark registration No. 2585973, general name is "pump gate"). It is what is

The submersible mixed flow pump 1 of this embodiment is called a mixed flow pump in which the flow of fluid discharged from the impeller sends the fluid obliquely from the center line of the output shaft 31 . The submersible mixed flow pump 1 has a casing 2 having a suction port 21 on one side (left side in FIG. 1) and a discharge port 22 on the other side (right side in FIG. 1). An electric motor 3 for rotationally driving an impeller 32 is fixed inside the casing 2 . An output shaft 31 is attached to the electric motor 3 of the submersible mixed flow pump 1 on the suction port 21 side. Adjacent to the downstream side of the impeller 32 , a guide vane 33 is fixed between the inner peripheral surface of the casing 2 and the outer peripheral surface of the oil chamber 34 . The guide vane 33 guides the water pumped up by the impeller 32 .

A flap valve 4 supported to be openable and closable is arranged on the discharge port 22 side of the casing 2 . The flap valve 4 is attached to a fulcrum 4a arranged on the upper part of the casing 2 so as to be swingable. The flap valve 4 closes by its own weight when the water discharge pressure from the discharge port 22 is low, and opens around the upper fulcrum 4a when the water discharge pressure increases, thereby discharging the water from the discharge port 22. enable A suction cover 5 for smoothly guiding water to the suction port 21 is fixed to the suction port 21 of the casing 2 on the opposite side of the discharge port 22 . An opening 53 at the tip of the suction cover 5 faces obliquely downward from the horizontal (attack angle θ), and the upstream river water (or channel water) is sucked through this opening 53 .

As shown in FIG. 1, in the submersible mixed flow pump 1 of the present embodiment, the shaft center 311 of the output shaft 31 is arranged substantially horizontally. Let Y1 be the height from the bottom surface 102 of the water channel to the upper edge of the opening 53 of the suction cover 5 (the lower surface of the suction guide plate 511) 531, and Y3 be the height from the bottom surface 102 of the water channel to the lower end of the impeller 32. , Y1 are positioned higher than Y3. An upper edge 531 of the opening 53 of the suction cover 5 is arranged at a position lower than the axial center 311 of the output shaft 31 . A lower edge 532 of the opening 53 is at a height of Y2 from the bottom surface 102 of the channel. When the water level is lower than the water level Y2 of the lower edge 532 of the opening 53, the submersible mixed flow pump 1 sucks river water (or channel water) because it is lower than the height Y3 to the lower end of the impeller 32. no. Here, the "air valve open/close water level" shown on the left side of FIG. 1 will be described. The water level rises during the air standby operation, and when the water level reaches 60% or more of the height of the impeller 32, the impeller 32 can discharge the water in the casing 2 by itself, and the total amount draining operation becomes possible. Since the impeller 32 does not discharge water by itself until the water level reaches around this level when the water level rises, the air standby operation is performed. When the water level reaches 60% of the impeller 32, the air valve 89 is closed to cut off the air to the submersible mixed flow pump 1 through the air pipe 64, so even if the impeller 32 discharges water, no air is supplied. Therefore, it is possible to instantly shift from air standby operation to full discharge operation. Therefore, the "air valve opening/closing water level" shown on the left side of FIG. switch.

Float type automatic air on/off valve control mechanism 80
The submersible mixed flow pump 1 of the first embodiment controls the supply and cutoff of air into the submersible mixed flow pump 1 with a float type automatic air opening/closing valve control mechanism 80 mounted on the submersible mixed flow pump 1. It is a thing. FIG. 2 is an enlarged sectional view of the float type automatic air on/off valve control mechanism 80. As shown in FIG. The float type automatic air opening/closing valve control mechanism 80 is a mechanical opening/closing mechanism in which the float 84 moves up and down according to the water level, and the air valve is automatically opened/closed by this up/down movement. A box-shaped dust-repellent cover 81 having a space inside surrounded by an upper plate and a side plate is fixed to the upper part of the suction cover 5 . The dust protection cover 81 is not essential for the basic function of the float type automatic air on/off valve control mechanism 80, but it protects the air valve 89 and the like from the flow of dust and the like. A plurality of through air holes 83 are formed in the upper part of the side plate 82 of the dust cover 81 . Therefore, when the water level drops, outside air can freely enter into the dust cover 81 from the outside. A through hole (not shown) is formed in the dust cover 81 so that water from the river (or channel) on the water intake side can enter freely. The water level inside the dust cover 81 is the same as the water level of the river (or waterway).

The float 84 is a metal sphere with a hollow inside, and moves up and down according to the water level of the river (or channel). One end of a rod 85 directed radially is fixed to the sphere of the float 84 . The other end of the rod 85 is attached to a flange 87 by a swing shaft 86 so as to be swingable. The flange 87 is fixed to a mounting pipe 88, which is an air pipe. The lower end of the mounting pipe 88 is connected to the upper end of the L-shaped air pipe 64 . This air pipe 64 is fixed to the suction cover 5 . The upper end of the mounting pipe 88 is open, and an air valve 89 is arranged to cover this opening. One end of the air valve 89 is fixed to the end of the rod 85 described above. Therefore, when the float 84 moves up and down according to the water level of the river (or waterway), the air valve 89 opens or closes the opening at the upper end of the mounting pipe 88 according to this up or down. The lower end of the attachment pipe 88 is connected to the upper end of the air pipe 64, and the air communicates with each other. The other end of the air pipe 64 is fixed to one end of a discharge port 65 which is a pipe. The central axis of the discharge port 65 is arranged parallel to the axial direction of the output shaft 31 . Also, the discharge port 65 is arranged to face the impeller 32 .

Air passes through the mounting pipe 88 and the air pipe 64 and is sucked into the casing 2 from the tip of the discharge port 65 . This float type automatic air on/off valve control mechanism 80 uses the float 84 which is moved up and down by the buoyancy of water. has the advantage that the air valve 89 can be opened and closed. Air, which is the atmosphere, passes through the attachment pipe 88 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 mixed flow pump 1 . That is, the discharge port 65 is connected to an air pipe 64 attached to the suction cover 5 . As shown in 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. As shown in FIG. More precisely, the center axis of the discharge port 65 is arranged at a position lower than the axis 311 of the output shaft 31 . That is, the discharge port 65 is arranged at a position lower than the axis 311 so as to face the impeller 32 . As a result, the air sucked from the discharge port 65 is expected to be sucked almost evenly vertically in the direction toward the center of the impeller 32 while moving slightly upward due to the buoyancy of the air.

The operation of the float type automatic air on-off valve control mechanism 80 and above can be summarized as follows. For example, when an operator turns on a switch (not shown) of the electric motor 3 of the submersible mixed flow pump 1 to turn it on, the electric motor 3 starts rotating, pumps up river water (or channel water) on the upstream side, and flow to For example, when the water level is falling and the total amount of water is being drained, the float 84 in the dust cover 81 is positioned at the top of the water due to its buoyancy, so the air valve 89 is closed. Therefore, even if the water level on the suction port side drops, as shown in FIG. Since air is not sucked in and 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 full discharge operation at the rated rotation speed. Then, when the water level reaches the "air valve open/close water level" position below the water level for "full discharge operation", the float 84 is lowered, the air valve 89 is opened, and air is supplied to the submersible mixed flow pump 1 through the air pipe 64. supply to This supply of air causes the submersible mixed flow pump 1 to enter the air standby operation mode at once. As a result, the water in the suction cover 5 of the submersible mixed flow pump 1 and the water in the casing 2 drops instantaneously, preventing the impeller 32 from discharging water. The impeller 32 is closed by the pressure of the outside water, and the impeller 32 is exposed to the air (the electric motor 3 continues to rotate at the rated speed), so vibration is small and the load on the electric motor 3 is small. Driving continues.

In addition, when the water level is rising and in the water level region of "air standby operation", the air valve 89 is open and the water level has not reached the level at which the impeller 32 can discharge water, so the air standby operation is continued. . When the water level rises further and the water level on the suction port side reaches the "air valve open/close water level" (see FIG. 1), the air valve 89 is closed to cut off air to the submersible mixed flow pump 1 through the air pipe 64. do. As a result, air is not supplied to the submerged mixed flow pump 1 even if the impeller 32 discharges water, so the submerged mixed flow pump 1 shifts from the air standby operation to the full discharge operation at the rated rotation speed. FIG. 3 shows the current (A) and vibration (note: composite vibration in the X, Y and Z directions) of the electric motor 3 of the submersible mixed flow pump (pump diameter: 300 mm) 1 according to the present embodiment of the present invention. μm). In FIG. 3, the suction port side water level is raised from 200 mm to 600 mm and then lowered to 200 mm. As shown in Fig. 3, when the water level rises, the air standby operation immediately shifts to full-drain operation. Since the water mixing operation does not occur or is for a short period of time, fluctuations in current (A) and fluctuations in vibration (μm) are reduced.

Fig. 4 shows the current (A) and vibration (note: composite vibration in the X, Y and Z directions) (μm) of the electric motor 3 of a conventional submersible mixed flow pump (pump diameter: 300 mm) without an air pipe. is a graph showing As shown in FIG. 4, the conventional submersible mixed flow pump sucks air from the upper edge 531 of the opening 53 to cause air-water mixing operation. It takes time to switch from operation to air standby operation, and the vibration is large. On the other hand, in the submersible mixed flow pump 1 according to the first embodiment of the present invention, as shown in FIG. , and the switching from full discharge operation to air standby operation are instantaneous, and vibration is small.

[Submersible Mixed Flow Pump 1 of Second Embodiment]
FIG. 5 shows a submersible mixed flow pump 1 of a second embodiment. The submersible mixed flow pump 1 (not shown) of the second embodiment has the same structure as that of the first embodiment, except that only the structure of the float type automatic air on/off valve control mechanism 90 is changed. is. FIG. 5 is an enlarged sectional view of the float type automatic air on-off valve control mechanism 90. As shown in FIG. In the float type automatic air on/off valve control mechanism 80 (FIG. 2) of the first embodiment, when the water level fluctuates up and down without being stable near the water level at which the air valve 89 opens and closes, the air valve 89 frequently opens and closes. It may become unstable due to The float-type automatic air on-off valve control mechanism 90 has a "float fluctuation prevention mechanism 200" for reliably and stably opening and closing the air valve 89. As shown in FIG.

[Float fluctuation prevention mechanism 200]
The float wobble prevention mechanism 200 is locked in one of two positions: the "air valve closed water level" position where the air valve 89 is closed depending on the water level, or the "air valve open water level" position where the air valve 89 is opened (a kind of temporarily fixed). With this float fluctuation prevention mechanism 200, the water level (timing) at which the air valve 89 is opened and closed can be made different between when the water level rises and when the water level falls. The float fluctuation prevention mechanism 200 will be described below. In the first pattern (a type in which both the rod 85 and the spring case 205 oscillate), the cam plate 201 constituting the float fluctuation prevention mechanism 200 is fixed to the flange 87 (see FIG. 2), the dust cover 81 and the like. It is fixedly arranged by a member (not shown). The cam plate 201 is formed with an arcuate surface centered on the pivot shaft 86 of the rod 85 . An upper recessed portion 202a and a lower recessed portion 202b, which are two hemispherical recesses, are formed on the arcuate surface.

The diameter of the upper recessed portion 202a and the lower recessed portion 202b is substantially the same as the diameter of the steel ball (or roller) 203, and the steel ball (or roller) 203 is selectively fitted into the upper recessed portion 202a or the lower recessed portion 202b. . A steel ball (or roller) 203 is biased toward the cam plate 201 by a coil spring 204 . A coil spring 204 is housed in a hole of a spring case 205 which is open at one end. The spring pressure of the coil spring 204 can be adjusted by an adjusting bolt 206 screwed into the other end of the spring case 205 . The spring case 205 is fixed to a rod 85 that swings together with the float 84 . Therefore, the spring case 205 also swings together with the rod body 85 . It should be noted that this mechanism is not limited to the second pattern (a type in which both the rod 85 and the cam plate 201 swing). It is fixed to a rod 85 that swings together with the float 84 . Therefore, the cam plate 201 also swings together with the rod body 85 .

The cam plate 201 is formed with an arcuate surface centered on the pivot shaft 86 of the rod 85 . An upper recessed portion 202a and a lower recessed portion 202b, which are two hemispherical recesses, are formed on the arcuate surface. The diameter of the upper recessed portion 202a and the lower recessed portion 202b is substantially the same as the diameter of the steel ball (or roller) 203, and the steel ball (or roller) 203 is selectively fitted into the upper recessed portion 202a or the lower recessed portion 202b. . A steel ball (or roller) 203 is biased toward the cam plate 201 by a coil spring 204 . A coil spring 204 is housed in a hole of a spring case 205 which is open at one end. The spring pressure of the coil spring 204 can be adjusted by an adjusting bolt 206 screwed into the other end of the spring case 205 . In the mechanism of the second pattern, the spring case 205 is fixed to the flange 87 (see FIG. 2), the dust cover 81 and the like by fixing members (not shown). Further, the third pattern has the same basic structure as the above two patterns, but two spring cases 205 and two cam plates 201 are installed for the upper part and the lower part. Specifically, the upper cam plate 201a has an upper recessed portion 202a, which is a single hemispherical recess, on the arc surface, and the lower cam plate 201b has a lower recessed portion 202b, which is a single hemispherical recess on the arc surface. It is Corresponding to this, the upper spring case 205a and the lower spring case 205b are used to set the air valve 89 to the "air valve closed water level" position where the air valve 89 is closed depending on the water level, or to open the air valve 89. The two positions of the "water level" position are locked (a kind of temporary fixation). With this configuration, it is possible to adjust the respective positions of the "air valve closing water level" and the "air valve closing water level". Therefore, the structure is such that the float fluctuation prevention mechanism 200 can be easily adjusted at the place where the pump (submersible mixed flow pump 1) is installed, that is, at the site.

In the structure of the first to third patterns above the operation of the float fluctuation prevention mechanism 200 , the operation of the float 84, the rod 85, the air valve 89, the cam plate 201 (201a, 201b), and the spring case 205 (205a, 205b) are basically the same, the operation will be explained in the case of the first pattern. When the water level on the suction port side drops from the water level of the "full discharge operation" to below the "air valve opening water level" (see FIG. 5), the air valve 89 must be opened to avoid air-water mixing operation. At this time, even if the water level slightly moves up and down and the float 84 moves up and down accordingly, the steel ball (or roller) 203 is fitted in the upper concave portion 202a of the float fluctuation prevention mechanism 200. , the steel ball (or roller) 203 does not escape from the upper concave portion 202a. However, when the float 84 further descends and the buoyancy becomes smaller, the condition of "the resistance force (friction force, tilt angle) of the anti-sway mechanism <(|buoyancy of the float−the weight of the float 84|)" is established, and the weight of the float 84 is satisfied. As a result, the steel ball (or roller) 203 escapes from the upper concave portion 202a and the air valve 89 opens. That is, even if the water level fluctuates to some extent, the air valve 89 is not opened until the "air valve open water level", so that the air-water mixing operation will not be unstable. This "air valve opening water level" is set for stable operation when the water level drops, and is the water level at which the submersible mixed flow pump 1 is switched from full discharge operation to air standby operation. Therefore, this "air valve opening water level" is preset according to the structure and function of the submersible pump.

Conversely, if the water level rises during the air standby operation and exceeds the "air valve closed water level", the air valve 89 must be closed to avoid air-water mixed operation. At this time, even if the water level moves up and down slightly and the float 84 moves up and down to follow it, the steel balls (or rollers) 203 will not move in the lower concave portion 202b of the float fluctuation prevention mechanism 200. , the steel ball (or roller) 203 does not escape from the lower recess 202b. However, when the buoyancy of the float 84 further increases and the condition of "the resistance force (friction force, tilt angle) of the anti-sway mechanism <(│buoyancy of the float−weight of the float 84│)" is established, the buoyancy of the float 84 The steel ball (or roller) 203 escapes from the lower recess 202b and closes the air valve 89. That is, even if the water level before and after the opening and closing of the air valve 89 fluctuates to some extent, the air valve 89 cannot be closed until the "air valve closing water level". Middle standby operation can be performed. This "air valve closed water level" is set for stable operation when the water level rises, and is the water level at which the submersible mixed flow pump 1 is switched from air standby operation to full discharge operation. Therefore, this "air valve closed water level" is preset according to the structure and function of the submersible pump.

As can be understood from the above description, the float fluctuation prevention mechanism 200 allows the water level (timing) at which the air valve 89 is opened and closed to differ between when the water level rises and when the water level falls. and 2 can be controlled, and a wide range of pump drainage operation (full discharge operation and air standby operation) that avoids air-water mixed operation and the effect of suppressing repetition of starting and stopping of the pump can be expected.
1. When the water level drops, the water level in the "full discharge operation" is lower than the air valve open/close water level (approximately 60% water level of the impeller 32) in the first embodiment. (In the present embodiment, the water level is about 10 mm higher than the upper edge 531), and by supplying air at the "air valve open water level", the total amount of water can be discharged instantaneously. can be controlled to shift from to air standby operation.
2. When the water level rises, it is conceivable that the air-water mixed operation cannot be reliably avoided at the air valve open/close water level (approximately 60% water level of the impeller 32) of the first embodiment. Therefore, by shutting off the air by closing the air valve at a water level lower than this, the "air valve closed water level" (in this embodiment, the water level of about 55% of the impeller 32) can reliably avoid the air-water mixed operation. ). As a result, compared to the air valve open/close water level (approximately 60% water level of the impeller 32) in the first embodiment, the "full amount water level" (approximately 60% water level of the impeller 32) in FIG. By shutting off the air at the "air valve closed water level", it is possible to control the transition from the air standby operation to the full drainage operation instantaneously.

[Submersible axial flow pump 10 of the third embodiment]
FIG. 6 shows a submersible axial flow pump 10 of a third embodiment. The submersible axial flow pump 10 has a structure different from that of the first and second embodiments described above. The submersible axial flow pump 10 is a pump that feeds fluid in the direction of the axis 311 of the output shaft 31, and has a suction port 21 on one side (left side in FIG. 6) and a discharge port 22 on the other side (right side in FIG. 6). It has a casing 2 . An electric motor 3 is fixed inside the casing 2 for rotational driving. An output shaft 31 is attached to the electric motor 3 on the side of the outlet 22 , an impeller 32 is fixed to the output shaft 31 , and the rotation of the electric motor 3 is transmitted to the impeller 32 . A guide vane 33 is fixed between the inner periphery of the casing 2 and the outer periphery of the oil chamber 34 on the suction port 21 side (upstream side) of the impeller 32 . The guide vanes 33 guide the water pumped up by the impeller 32 .

A flap valve 4 is attached to the casing 2 so as to be openable and closable on the discharge port 22 side. The flap valve 4 closes by its own weight when the water discharge pressure from the discharge port 22 is low, and opens around the upper fulcrum 4a when the water discharge pressure increases, thereby preventing water from being discharged from the discharge port 22. to enable. 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 one or more plates including an upper plate and side plates. A submersible axial flow pump 10 of the third embodiment is provided with a float-type automatic air on-off valve control mechanism 90 that operates on the same principle as that of the second embodiment. It consists of a float 84, a rod 85, a swing shaft 86, an air valve 89, a float fluctuation prevention mechanism 200, an air pipe 64, a discharge port 65, and the like.

Air, which is atmospheric air, is branched into two by the air pipe 64 connected to the mounting pipe 88 due to the suction force during operation of the submersible axial flow pump 10, and two discharge ports 65 are provided from each of the branch pipes (not shown). is sucked into the casing 2 from the The two outlets 65 are arranged inside the suction cover 5 on both sides of the outer periphery of the electric motor 3, that is, on both sides of the electric motor 3. As shown in FIG. This discharge port 65 is connected to an air pipe 64 fixed to the suction cover 5 . The central axis of the discharge port 65 is arranged parallel to the axis 311 of the output shaft 31 of the submersible axial flow pump 10 . More precisely, the center axis of the discharge port 65 is arranged at a position lower than the axis 311 of the output shaft 31 . That is, the discharge port 65 is arranged at a position lower than the axis 311 so as to face the front of the impeller 32 . The operation of the float-type automatic air on-off valve control mechanism 90 of the submersible axial pump 10 of the third embodiment and the full discharge operation and the air standby operation of the submersible axial pump 10 interlocked therewith are substantially the second embodiment. Since it is the same as the submersible mixed flow pump 1 of the embodiment, the description thereof is omitted.

[Other embodiments]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in both the submerged mixed flow pump 1 and the submerged axial flow pump 10 described above, the output shaft 31 of the electric motor 3 and the axial center of the impeller 32 connected thereto are arranged in a horizontal direction. There is. However, this axis may be tilted from the horizontal. Further, the shape of the suction cover 5 of the submersible mixed flow pump 1 and submersible axial flow pump 10 described above differs depending on the structure of the submersible pump. Therefore, the suction cover 5 in the present invention is a concept including not only the cover on the suction side of the pump main body but also the main body portion. Furthermore, in the above-described embodiment, the vertical motion of the float 84 is directly driven by the rod 85 to the air valve 89 . However, the up-and-down movement of the float 84 may be performed by opening and closing the air valve 89 via a link mechanism instead of the rod 85 . For example, a link mechanism having a plurality of fulcrums, points of force, and points of action, known as a double ball tap, may be used.

Reference Signs List 1 Submersible mixed flow pump 10 Submersible axial flow pump 100 Door body 101 Bracket 102 Bottom surface of water channel 2 Casing 21 Suction port 22 Discharge port 3 Electric motor 31 Output shaft 311 Axis 32 Impeller 33 Guide vane 34 Oil chamber 4 Flap valve 5 Suction cover 64 Air pipe 65 Discharge port 80, 90 Float type automatic air opening/closing valve control mechanism 84 Float 85 Rod 89 Air valve 200 Float Anti-sway mechanism

Claims (11)

a casing having an inlet on one side and an outlet on the other;
an electric motor fixed within the casing for rotational driving;
an impeller arranged in a lateral direction in which the axis of the output shaft of the electric motor is horizontal or with the axis inclined at a predetermined angle from the horizontal and connected to the output shaft and driven to rotate;
a suction cover fixed to the casing and formed with an opening for sucking fluid,
an air pipe for sucking air into the submersible pump from a discharge port arranged upstream of the impeller and within the submersible pump;
and an air opening/closing valve control mechanism for supplying or shutting off air to the air pipe. In the submersible pump with air tube according to claim 1,
The submersible pump with an air tube is a submersible mixed flow pump in which the flow path of the fluid driven by the impeller is inclined with respect to the axis, or a submersible shaft in which the flow path of the fluid is in the axial direction. A submersible pump with an air tube, characterized in that it is a flow pump. In the submersible pump with an air tube according to claim 1 or 2,
The air on-off valve control mechanism includes an air on-off valve for supplying or blocking air to the air pipe,
a float that moves up and down by buoyancy according to the water level on the suction port side;
A submersible pump with an air pipe, comprising: a lever mechanism for transmitting vertical movement of the float to the air on-off valve to control opening and closing of the air on-off valve. In the submersible pump with an air tube according to claim 1 selected from claims 1 to 3,
The submersible pump with an air pipe, wherein the air on-off valve control mechanism has different timings of the water level when opening and closing the air on-off valve, depending on whether the water level is rising or when the water level is falling. In the submersible pump with air tube according to claim 3,
A submersible pump with an air pipe, wherein the lever mechanism has one end fixed to the float and the other end provided with the air opening/closing valve serving as a lid portion that opens and closes, and swings around a swing shaft. In the submersible pump with air tube according to claim 4,
The air on-off valve control mechanism has a float wobble prevention mechanism that selectively locks at two different positions when the water level rises and when the water level falls. submersible pump. In the submersible pump with air tube according to claim 6,
The float fluctuation prevention mechanism is
a first locking portion that locks at a position when the water level rises;
a second locking portion that locks at a position when the water level is lowered;
A submersible pump with an air tube, characterized in that it has two sets of engaging portions consisting of: The submersible pump with an air tube according to claim 1 selected from claims 1 to 7,
A submersible pump with an air tube, wherein a central axis of the discharge port is arranged parallel to the axis. The submersible pump with an air tube according to claim 1 selected from claims 1 to 8,
A submersible pump with an air tube, wherein the discharge port is arranged so as to face the impeller. In the submersible pump with an air tube according to claim 1 selected from claims 1 to 9,
A submersible pump with an air tube, wherein the air tube is connected to the suction cover or the casing. Submersible pump equipment using the submersible pump with an air tube according to claim 1 selected from claims 1 to 10,
A submersible pump facility with an air pipe, wherein the submersible pump with an air pipe is mounted on a water gate or a sluice gate that crosses a river or a waterway.

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