JP4772968B2 - Air suction device for vertical axis pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air suction device installed in a plurality of stages for sucking air from the atmosphere in a water suction pipe provided below an impeller in a vertical axis pump.
[0002]
[Prior art]
In the conventional air suction devices in many vertical pumps, for example, as shown in Japanese Patent Laid-Open No. 7-145793 and shown in FIG. 4, a preliminary standby operation is performed from a water level below the minimum water level (LLWL). The pump impeller 1 is disposed below the minimum water level (LLWL), and an air pipe 7 opened to the other end of the water suction pipe 2 below the impeller 1 is provided. The air pipe 7 is provided with a control valve 9 in the upper part from the pump water tank.
[0003]
Since the air pipe 7 is connected to the water absorption pipe 2 provided below the impeller 1 as described above, the water pipe is provided below the impeller 1 when the water level is below the lowest level (LLWL). Then, air is sucked into the intake pipe 2 from the atmosphere, and the operation is automatically switched to the air / water mixing operation and the air operation.
[0004]
In addition, when the water level drops below the minimum water level (LLWL), the air is sucked from the atmosphere through the air holes into the water suction pipe by the negative pressure generated at the impeller inlet, and the pumping operation starts. In addition, stable operation is possible without sudden stoppage.
[0005]
However, the prior art has a problem in that air bubbles sucked from the air pipe are not uniformly dispersed in the pump casing.
[0006]
Therefore, for example, a plurality of air holes are provided in the inner wall of the water absorption pipe facing the air pipe to introduce necessary air uniformly and quickly, or a plurality of air holes having a small diameter to introduce fine bubble-like air uniformly. Means are used.
Further, in the water absorption pipe, a vortex is generated around the axis due to the rotation of the impeller. For this reason, surging occurs, noise is generated, and operation may be disabled.
[0007]
Therefore, as a vertical axis pump that not only prevents the generation of eddy currents during operation but also enables air-water mixing operation by uniformly introducing air into the water absorption pipe, one disclosed in JP-A-8-105400 is disclosed. Are known.
[0008]
As shown in FIG. 5, the vertical axis pump presented in this publication is a cylindrical air chamber 3 having a large number of air holes on the inner wall disposed along the inner periphery of the water absorption pipe 2, A plurality of vortex-preventing plates 4 extending in the vertical direction are provided on the inner surface of the inner wall so as to protrude from each other at a predetermined interval and have air holes communicating with the air chamber 3 at the tip.
[0009]
However, the vertical axis pump presented in the above-mentioned JP-A-8-105400 has a plurality of air holes provided in the inner wall arranged along the inner circumference of the water absorption pipe, and a plurality of the vicinity of the inner circumference of the water absorption pipe. Air is only introduced into the central portion of the water absorption pipe from the tip of the eddy current prevention plate.
[0010]
Therefore, there is a problem in that air is not sufficiently introduced into the portion between the inner periphery of the water absorption pipe and the central portion, and uniform air introduction cannot be achieved throughout the water absorption pipe.
[0011]
Therefore, as filed in Japanese Patent Application No. 11-341958, there is provided an air suction device for a vertical axis pump that not only prevents the occurrence of surging but also enables uniform introduction of air into the water suction pipe. .
[0012]
The vertical axis pump filed in the Japanese Patent Application No. 11-341958 is an annular air chamber that is arranged along the inner or outer peripheral surface of the water absorption pipe and has a number of air holes communicating with the water absorption pipe. A plurality of eddy current preventing plates extending in the vertical direction having a plurality of air holes communicating with the air chamber on the upper end surface and projecting at predetermined intervals on the inner peripheral surface of the water absorption pipe; An air pipe that communicates with the atmosphere from the air chamber disposed in the water absorption pipe.
[0013]
According to Japanese Patent Application No. 11-341958, a plurality of eddy current preventing plates extending in the vertical direction eliminate eddy currents to prevent surging and are provided on the inner wall arranged along the inner periphery of the water absorption pipe. By introducing air from the air holes and air holes formed in the upper end surfaces of the plurality of vortex flow prevention plates, uniform air can be introduced into the water absorption pipe.
[0014]
[Problems to be solved by the invention]
However, each of the prior arts consists of a single-stage air suction device that is composed of an air tube, an air chamber, and a vortex prevention plate provided with air holes.
Therefore, in the above prior art, in a wide range of operating flow rates, air bubbles sucked through the air pipe are more uniformly generated with respect to the impeller, and the operation performance of the vertical pump with less vibration and the like is more stable. There is a problem that it is difficult to obtain.
[0015]
[Means for Solving the Problems]
Accordingly, in order to solve the above problems, the present invention provides an air suction device for sucking air from the atmosphere into a water suction pipe provided below an impeller in a vertical axis pump, and an outer peripheral surface of the water suction pipe Alternatively, a plurality of air chambers arranged along the inner peripheral surface and having a large number of air holes communicating with the water absorption pipe, and a plurality of air chambers protruding at predetermined intervals on the inner peripheral surface of the water absorption pipe And a plurality of eddy current preventing plates extending in the vertical direction having a plurality of air holes, and a plurality of air pipes communicating with the atmosphere from the air chambers arranged in the water absorption pipe.
[0016]
By providing the vortex prevention plates in a plurality of stages, the size of the air chambers in the upper and lower tiers and the diameter of the air holes provided in the vortex prevention plates are changed, and the upper and lower stages are provided according to the water level of the pump tank. By properly using the air bubbles, the air bubbles ejected from the air holes can be made more uniform, and the vertical pump can be operated more stably and efficiently corresponding to a wider pumping flow rate region.
[0017]
That is, as the water level of the pump tank decreases from the pumping operation, air is sucked from the air hole, and the operation shifts to the air-water mixing operation, and the air is sucked only from the upper air suction device from the initial stage to the middle stage of the transition operation, Highly efficient operation with as much pumped water as possible with a small amount of air. From mid-term, flexible operation control can be performed in a wide range of operation of the vertical pump by simultaneously using the lower-stage air suction device or the upper-lower air suction device that can inhale with a larger amount of air than the upper stage. It becomes.
[0018]
A side surface of the eddy current preventing plate is constituted by a side plate, and the side plate provided with a plurality of air holes having different diameters is replaceable.
[0019]
As described above, the side surface of the vortex-preventing plate is constituted by a side plate, and it is different in consideration of operating conditions such as pumping amount and operating time, operating time such as standby time, pump vibration value and noise value, etc. The side plate having a plurality of air holes having a diameter can be replaced, and in the present invention, the number of side plates that can be replaced is increased by having a plurality of vortex prevention plates, and the operation status is further increased as compared with the prior art. Etc. can be handled flexibly.
[0020]
It is an air suction device installed in a plurality of stages of the vertical axis pump, wherein each of the plurality of stages of eddy current preventing plates is arranged to be shifted.
[0021]
A control valve is provided at each of the inlet portions of the plurality of air pipes, and on / off control and flow rate control are performed on the intake air amount of each air pipe.
[0022]
The control valve is used as an on / off valve for opening and closing the plurality of air pipes, and as a control valve for controlling an air amount while monitoring an operation state such as a vibration value and a noise value of the pump. By controlling the suction device in accordance with the operation status of the pump, etc., it is possible to generate extremely uniform air bubbles in the water absorption pipe in a wide range of operation of the pump, improving the operational efficiency and stability of the vertical axis pump. High pump operation performance can be obtained.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described.
[0024]
FIG. 1 shows a general view of a main body of a vertical axis pump and a cross-sectional detail of a main part when an air suction device having two upper and lower stages in an example of an embodiment of the present invention is provided in a water suction pipe under an impeller. is there.
[0025]
Hereinafter, it demonstrates in detail based on FIG.
A two-stage air suction device for a vertical axis pump according to the present embodiment, which is annularly arranged along the outer peripheral surface of a water suction pipe 2 provided below the impeller 1, and is arranged on the inner wall of the water suction pipe 2. At the time of suction, the air chambers 3a and 3b having two upper and lower air holes 3a and 3b and the inner peripheral surface of the water absorption pipe 2 are projected to extend in the longitudinal direction and the central direction with a predetermined distance from each other. Four vortex prevention plates 4a, 4b, 4c, 4d and 5a, 5b, 5c, 5d each comprising two upper and lower stages for preventing the vortex of the inflowing water, and the water absorption pipe 2 from the atmosphere outside the pump water tank This is an embodiment provided with upper and lower stage air pipes 7 and 8 for sucking air and upper and lower stage control valves 9 and 10 installed at the inlets of the upper and lower stage air pipes 7 and 8.
[0026]
In particular, the upper and lower eddy current preventing plates 4a, 4b, 4c and 4d and the upper end surfaces and the side surfaces of the upper and lower eddy current preventing plates 4a, 4b, 4c and 4d are connected to the upper and lower air chambers 3a and 3b. Each hole is provided.
[0027]
In addition, by providing different diameters and number of air holes in the upper and lower stages, it is possible to change the amount of air and the density of air bubbles, etc., and flexible operation control is possible in a wide range of operation of the vertical pump. is there.
[0028]
As described above, the upper and lower eddy current preventing plates 4a, 4b, 4c, 4d and 5a, 5b, 5c, 5d, which are composed of upper and lower two stages having a plurality of air holes communicating with the upper and lower air qualities 3a, 3b, are moved up and down. By providing two stages, it is possible to deal with a wide range of operation of the vertical pump, and appropriately observe the inner wall of the upper and lower two-stage water absorption pipe 2 and the vortex prevention plate 4 while observing the vibration value and noise value of the pump during pump operation. , 5 is adjusted by the control valves 9, 10 provided for the upper and lower stages, so that more flexible operation can be performed.
[0029]
In the above embodiment, the number, width, length, etc. of the air holes provided in the air chambers 3a, 3b and the vortex prevention plates 4, 5 comprising the upper and lower stages are determined by the shape, size, etc. of the water absorption pipe 2. Furthermore, the presence / absence of the air hole may be appropriately determined in consideration of the application status of the vertical axis pump.
[0030]
Further, the size and shape of the upper and lower eddy current preventing plates 4 and 5, the number of installations, the mounting position, the mounting method, the mounting angle, and the intake pipe attached to the upper end surface 41 of the upper and lower eddy current preventing plates 4 and 5. The mounting and the like may be determined as appropriate according to the purpose of use of the vertical pump in consideration of the application situation of the vertical pump.
[0031]
The upper and lower stage air chambers 3 and 3b are connected to upper and lower stage air pipes 7 and 8 communicating with the atmosphere outside the pump water tank, and the upper and lower stage control valves 9 and 10 for adjusting the amount of air to the water absorption pipe 2 are pumps. It can be turned on and off in conjunction with the level gauge in the water tank.
[0032]
When interlocking with the level gauge of the pump water tank as described above, the control valve opens when the liquid level falls below the minimum water level, and closes when the liquid level recovers above the minimum water level. Further, the amount of air can be controlled as the water level fluctuates.
[0033]
According to the present embodiment, when the impeller 1 rotates and the inside of the water suction pipe 2 is in the suction state, if the upper and lower air pipes 7 and 8 are in the open state, the outside air is sucked in by the negative pressure, A number of air holes provided in the side wall of the water absorption pipe 2 from the upper and lower air chambers 3a and 3b, and a plurality of air holes provided in the upper and lower vortex prevention plates 4a, 4b, 4c and 4d and 5a, 5b, 5c and 5d Air is introduced into the water absorption pipe 2. However, it is possible to cope with a wide range of pump operation controls by controlling the flow rate of the air amount with the upper and lower control valves 9 and 10 in accordance with the use state and operation state of the pump.
[0034]
Therefore, for example, when the water level falls below the minimum water level, air is automatically sucked into the water suction pipe 2 from the atmosphere through the upper and lower air pipes 7 and 8 and the upper and lower air chambers 3a and 3b. Switching to air / water mixing operation prevents vortex inhalation and the occurrence of breathing phenomena, allowing stable vertical pump operation.
Further, when the water level is lowered, air is sucked into the water suction pipe 2 from the atmosphere, and by appropriately adjusting the air suction amount from the upper and lower air pipes 7 and 8, the pumping is not started and stopped suddenly. Stable operation is possible.
[0035]
From the pumping operation as described above to the air-water mixing operation, and further from the air-water mixing operation to the air-operating operation, or vice versa, from the air-operating operation to the air-water mixing operation, and further from the air-water mixing operation to the pumping operation. By shifting the flow rate using the upper and lower stage control valves 9 and 10 at the time of shifting to, it is possible to secure stable operation performance in a wider range of pump operation than in the past.
[0036]
In particular, in the present embodiment, in addition to means for introducing air from a large number of air holes provided in the side walls of the upper and lower air chambers 3a and 3b of the water absorption pipe 2, the upper and lower vortex preventing plates 4a, 4b, By introducing air from the plurality of air holes provided in 4c, 4d and 5a, 5b, 5c, 5d, air can be introduced uniformly over the entire plane of the water absorption pipe 2, and thus more stable air-water mixing Driving is possible.
[0037]
In the present embodiment, the eight upper and lower two eddy current preventing plates 4a, 4b, 4c and 4d and 5a, 5b, 5c and 5d center the shaft center by the rotation of the impeller 1. As a result, the eddy current generated is buffered, so that no surging or noise occurs or the operation becomes impossible.
[0038]
By providing the two-stage air intake device at the top and bottom as described above, the operation performance of the pump is greatly improved or the operation control is easily optimized and the operation efficiency is optimized as compared with the case of the air intake device of only the upper stage. I can plan.
[0039]
In FIG. 2, when the eddy current preventing plates 4a, 4b, 4c, 4d and the eddy current preventing plates 5a, 5b, 5c, 5d are installed, the upper eddy current preventing plates 4a, 4b, 4c, 4d are Corresponding lower eddy current preventing plates 5a, 5b, 5c, 5d are installed by being shifted by 45 degrees.
[0040]
Of course, there is a method in which the upper and lower eddy current preventing plates 4a, 4b, 4c, 4d and the eddy current preventing plates installed by shifting 45a by 5 degrees, 5b, 5c, 5d are installed at the same angle. Thus, by installing 45 degrees apart, a more uniform air bubble in the water absorption pipe 2 is obtained, and at the same time, the surging prevention effect is improved, and a more stable operation is possible.
[0041]
FIG. 3 is an embodiment of the upper and lower eddy current preventing plates 4a, 4b, 4c and 4d and 5a, 5b, 5c and 5d, and side plates 45 on both sides of the upper and lower eddy current preventing plates 4 and 5 are provided. The side plate 45 having a plurality of air holes with different diameters can be exchanged according to the operating conditions and the operating performance, and is attached to the vortex preventing plate body with mounting bolts 24. It is possible to handle the operation of the vertical axis pump.
[0042]
【The invention's effect】
As described above, the present invention provides an air chamber having a large number of air holes provided on the inner wall of the water absorption pipe, and a plurality of eddy current preventing plates having a large number of air holes extending in the vertical direction along the inner wall of the water absorption pipe. An air suction device comprising an air pipe communicating with the atmosphere outside the pump water tank for supplying air to the air chamber is provided in a plurality of stages in the water suction pipe, and these are used properly according to the water level of the pump water tank. Rapid, uniform and fine bubble-like air is introduced over the entire plane, and stable and efficient operability can be obtained in a wider operating range of the vertical pump than ever before.
[Brief description of the drawings]
FIG. 1 is a front view of a vertical axis pump provided with a vortex prevention plate in a two-stage air suction device and a cross-sectional view showing details of a main part.
FIG. 2 is a plan view of a two-stage vortex prevention plate.
FIG. 3 is an enlarged view showing details of a swirl prevention plate having a replaceable side surface.
FIG. 4 is a front view showing a vertical axis pump provided with a single-stage air suction device according to an embodiment of a conventional example.
FIG. 5 is a front view showing a vertical axis pump provided with an air chamber and a vortex prevention plate in the single-stage air suction device in the embodiment of the conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Impeller 2 Water absorption pipe 3 Air chamber 3a Upper air chamber 3b Lower air chamber 4 Upper vortex prevention plate 4a Upper vortex prevention plate 4b Upper vortex prevention plate 4c Upper vortex prevention plate 4d Upper vortex prevention plate 5 Lower vortex prevention plate 5a Lower vortex flow Preventing plate 5b Lower vortex preventing plate 5c Lower vortex preventing plate 5d Lower vortex preventing plate 7 Upper air tube 8 Lower air tube 9 Upper control valve 10 Lower control valve 24 Mounting bolt 41 Upper end surface 42 Side surface 43 Air hole 45 side Face plate

Claims (4)

An air suction device for sucking air from the atmosphere into a water absorption pipe provided below an impeller in a vertical axis pump, which is arranged along an outer peripheral surface or an inner peripheral surface of the water absorption pipe and communicates with the water absorption pipe A plurality of stages of air chambers having a plurality of air holes and a plurality of stages of eddy currents that protrude in the inner peripheral surface of the water absorption pipe with a predetermined interval and extend in the longitudinal direction have a plurality of air holes. In the air suction device of the vertical pump composed of a plate and a plurality of air pipes communicating with the atmosphere from each air chamber arranged in the water suction pipe, the side surface of the vortex prevention plate is constituted by a side plate, and the different diameters An air suction device for a longitudinal pump, wherein the side plates each having a plurality of air holes are replaceable .  2. The air suction of the vertical axis pump according to claim 1, wherein the air holes provided in the plurality of stages of air chambers and the vortex prevention plate are provided with different diameters and number of installations for each stage. apparatus.  3. The air suction device of the vertical axis pump according to claim 1, wherein the air suction devices are installed in the plurality of stages, and the plurality of stages of the eddy current preventing plates are arranged so as to be shifted from each other.  The longitudinal direction according to claim 1, 2, or 3, wherein a control valve is provided at each of the inlet portions of the plurality of air pipes, and on / off control and flow rate control are performed on the intake air amount of each air pipe. Air suction device for shaft pump.

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