JP2641807B2 - Vertical pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical shaft pump installed in a water absorption tank, and more particularly to a pump for pumping operation even when the water level in the water absorption tank is low. The present invention relates to a vertical shaft pump that is suitable for performing a preparatory standby operation to be performed and that facilitates a pump management operation in normal times.

[0002]

2. Description of the Related Art A conventional vertical pump of this type is disclosed in
As described in JP-A-3-150097, the impeller is located at a position lower than the water level of the water absorption tank, and a through-hole communicating with the outside is provided near the entrance of the impeller, and the through-hole is connected to a pipe. It is known that the other end of the pipe is provided with an opening in the water absorption tank near the level where the impeller is submerged. According to this means, when the water level of the water absorption tank is lower than the level of the opening, air is sucked from the opening, and the pumping action of the pump is gradually reduced as the water level decreases.
Pumping operation is possible at a low water level, and there is a feature that transition to an idling state does not suddenly occur. Seems to be a suitable means for the pump to perform.

[0003]

In the above prior art, it is necessary to provide a rectifying plate on the suction side of the pump, such as in the case of not only the vertical mixed flow pump but also the vertical axial flow pump or the case where the shape of the water absorption tank is bad. In such a case, there is a problem that the intake means is not specified, and application to such a case is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. For example, when the pump is an axial flow pump or when the shape of the water absorption tank is poor, a flow straightening plate is provided on the suction side of the pump. Also in the case of providing, it is possible to control the flow rate of the pump by the intake, pressure adjustment of the intake section,
Adjustment of intake volume and adjustment of water level to start intake
It is another object of the present invention to provide a preparatory standby operation pump having a wider range of application.

[0005]

In order to achieve the above object, a first aspect of the invention relates to a vertical pump according to the present invention, wherein the water level during the operation of the pump is lower than the water level at the suction bell mouth of the pump casing. The impeller is positioned below the position corresponding to the lowest water level where the water is sucked, and the intake pipe opened to the atmosphere at a level higher than the highest water level of the pump suction tank is placed in the pump casing upstream of this impeller. In a vertical shaft pump connected and provided with a plurality of rectifying plates on a pump suction side, the plurality of rectifying plates have a boss portion,
Providing multiple air intake holes in the boss of the current plate,
Drill the air introduction hole, and connect the intake pipe to this air introduction hole.
And the air introduction hole and the intake hole are
The communication is made at the boss of the current plate .

In order to achieve the above object, a second aspect of the invention relates to a vertical pump according to the present invention, on the same premise as that of the first aspect, wherein the side surfaces or upper and lower surfaces of the plurality of current plates are provided. any, a plurality of suction holes provided in the radial direction, the air inlet holes drilled into the plurality of rectifying plates, thereby connecting the intake pipe to the air introducing hole, and the air inlet holes and said suction holes Are communicated within the current plate.

Furthermore, in order to achieve the above object, the configuration of the third invention according to the standing shaft pump according to the present invention, in the first aspect and the same assumptions, the plurality of rectifying plates boss
Has, the boss of the current plate , the spherical convex surface portion faces the upstream side,
Impeller side is formed in a hollow open configuration, perforated air inlet holes into the plurality of rectifying plates, thereby connecting the intake pipe to the air inlet holes, the air inlet holes into the hollow boss inner surface of the rectifying plate boss It is open.

[0008]

The operation of the representative first invention among the above technical means will be described. That is, a plurality of intake holes are provided in the boss portion of the current plate installed on the pump suction side, and
Drill an air introduction hole, and insert one of the intake pipes into this air introduction hole.
While connecting the ends, the air introduction hole and the intake hole
At the boss portion of the current plate, and the other end of the intake pipe was opened to the atmosphere at a level higher than the maximum water level of the pump water absorption tank.

By providing an intake hole in the boss portion, the intake
Holes are inclined with respect to the flow direction,
Can be easily provided in multiple directions in the radial direction
Become. This makes the air supply to the pump uniform
Can reduce the load imbalance that occurs on the impeller
it can. Also, pressure adjustment at the intake opening becomes easy,
Adjustment of intake air volume when used as a preceding standby operation pump
It is possible to adjust the water level at which the air intake starts.

[0010]

Next, embodiments of the present invention will be described with reference to FIGS. First, a vertical lift pump to which the present invention is applied will be described with reference to FIG. FIG. 1 is a side view showing the entire configuration of a general vertical shaft pump. In FIG. 1, a pump casing 4 equipped with an impeller 1 is provided.
A suction bell mouth 3 forming a part of the pump casing is connected to a lower part of the casing liner 2, and a pumping pipe 5 and a discharge elbow 6 forming a part of the pump casing are connected to the upper side. , Constituting a vertical pump. A discharge pipe 7 and a discharge valve 8 are provided on the discharge side of the discharge elbow 6.
Are arranged. Slightly below the impeller 1, a plurality (for example, 4
), And an intake pipe 10 is provided in connection with the intake hole 9. The intake port 12 of the intake pipe 10 is installed at a position higher than the highest water level (HWL) in the water absorption tank 20. These constitute a flow control device.

The intake hole 9 has a conventional minimum water level,
That is, at the lowest water level (WL1) at which the air is sucked from the suction bell mouth 3 below this water level, the air is not sucked from the suction hole 9.
Now, when this pump is operated at a water level WL4 higher than WL1, and when the pump starts intake from the intake hole 9 when the water level drops to WL1, when the water level decreases, the intake air amount increases and the certain water level WL3 In, the pump cannot be pumped, and the impeller 1 runs idle. Then, when the water level rises again and the water level reaches WL2,
The pump again performs the suction operation, and when the inflow amount is larger than the pumping amount, the water level continues to rise, stops the suction when it reaches WL1, and shifts to the normal pumping operation.

Next, an embodiment related to the present invention will be described with reference to FIG. FIG. 2 is a sectional view showing a suction portion of a vertical shaft pump developed in connection with the present invention. In the present pump, a rectifying plate 15 and a rectifying plate boss 14 are provided on the downstream side of the suction bell mouth 3. A part of the rectifying plate 15 is provided with an intake hole 9, and an intake pipe 10 is provided in the intake hole 9. The other end of the intake pipe 10 is connected to the atmosphere. With such a configuration, an axial flow pump can be applied to the pump,
Even when a flow straightening plate needs to be installed, such as when the shape of the water absorption tank is bad, the air introduction portion can be provided with a simple shape.

Further, by adjusting the positional relationship between the intake hole 9 and the rectifying plate boss 14, the pressure at the portion of the intake hole 9 can be adjusted. That is, when the center of the intake hole 9 shown in FIG. 2 is taken on the line (A) on the upstream side of the tip 14a of the spherical convex portion of the rectifying plate boss 14, the flow velocity near the intake hole 9 is V
a, the flow velocity near the intake hole 9 when taking the line (B)
b, the flow velocity near the intake hole 9 when taken along the line (C) is Vc
In other words, since Va <Vb <Vc, when the flow rate is constant, the pressure near the intake hole 9 in each case is Pa>Pb> Pc, and the intake hole 9 and the rectifying plate boss 1
By changing the relative position with respect to the pressure 4, the pressure in the intake hole 9 can be adjusted. This makes it possible to adjust the amount of intake air when used as a preceding standby operation pump, and to adjust the water level at which intake is started.

Embodiment 1 Next, an embodiment of the first invention will be described with reference to FIG. 3 and FIG. FIG. 3 is a cross-sectional view showing a suction portion of the vertical shaft pump according to one embodiment of the present invention, and FIG. 4 is a detailed cross-sectional view showing a portion R in FIG. Here, FIG. 3A is a longitudinal sectional view, and FIG.
(B) is a plan view seen from the upstream side. The flow of water and the flow of air are indicated by arrows. Rectifier plate boss 14A
Has a hollow shape, and a plurality of (four in the figure) intake holes 9 are pierced radially from the center. On the other hand, a plurality of (four in the figure) straightening plates 15 are provided with air introduction holes 16.
Are perforated. The intake pipe 10 is connected to the air introduction hole 16 to constitute an air supply device.

Due to the pressure difference between the intake hole 9 and the atmosphere, the air flows through the intake pipe 10 and the air introduction hole 16 to the rectifying plate boss 1.
4A, and the air is guided into the water flow Q through the intake hole 9. At this time, the intake hole 9 is
If the pump is provided symmetrically (radially to the center) with respect to the water flow Q as shown in (b), the supply of air to the pump can be made uniform, and the imbalance of the load generated on the impeller can be reduced. can do. In addition, the perforation position of the intake hole 9 is
As shown in FIGS. 4 (K), 4 (L), and 4 (M), the rectifying plate boss 14A is selectively provided on the spherical convex portion (commonly referred to as a shell portion) of the rectifying plate boss 14A, thereby explaining the embodiment shown in FIG. The pressure in the vicinity of the intake hole 9 can be adjusted by the same principle as described above. If the pump was used as a preliminary standby operation pump,
It is possible to adjust the intake air volume when
is there.

Embodiment 2 Next, an embodiment of the second invention will be described with reference to FIG.
FIG. 5 is a sectional view showing a suction portion of a vertical shaft pump according to another embodiment of the present invention. In FIG. 5, the outer surface of the current plate 15 is shown on the right side of the current plate boss 14, and the longitudinal section of the current plate 15 is shown on the left side. In the embodiment of FIG. 5, a plurality of (n) intake holes 9A are radially provided on the side surface of each of the plurality of current plate 15s.
Are perforated. On the other hand, an air introduction hole 16 is perforated in each of the plurality of straightening plates 15, and the air introducing holes 16 and the intake holes 9 </ b> A communicate with each other in the straightening plate 15. Thus, similarly to the embodiment of FIG.
Are connected to the intake pipe 10 to form an air supply device.

Since the flow regulating plate 15 is usually provided so as to be axially symmetric with respect to the center of the pump, each intake hole 9A is symmetric with respect to the flow Q of water. Further, by distributing n intake holes 9A in the radial direction, the supply of air in the radial direction can be made uniform, and the imbalance of the load generated on the impeller can be further reduced. Further, in the case of the embodiment of FIG. 5, similarly to the examples of FIGS. 2 and 4, if the intake holes 9A are provided in the cross section including the spherical convex portion of the rectifying plate boss 14, the pressure near the intake holes 9A is reduced. It is possible to adjust. In addition, in the example of FIG. 5, the intake hole 9 </ b> A is provided on the side surface of the current plate 15. However, the same effect can be expected even if the intake hole is provided on the upper surface or the lower surface of the current plate.

Embodiment 3 Next, an embodiment of the third invention will be described with reference to FIGS. FIG. 6 is a sectional view showing a suction portion of a vertical axial flow pump according to still another embodiment of the present invention, and FIG. 7 is a detailed sectional view of a portion S in FIG. In the figure, components having the same reference numerals as those in FIG. 3 are the same as those in the previous embodiment, and the description thereof will be omitted. In FIG. 6, reference numeral 1A denotes an impeller of an axial flow pump, and a straightening plate boss 1 is provided below the impeller 1A, that is, on the pump suction side.
4B and a current plate 15 are provided. The rectifying plate boss 14B has a spherical convex surface facing the upstream side, and the impeller 1A side is formed in a hollow open shape. Plural straightening plates 15
Is connected to the intake pipe 10 to constitute an air supply device.

The air supplied to the inside of the rectifying plate boss 14B through the intake pipe 10 and the air introduction hole 16 is collected near the center by the swirling flow generated inside the rectifying plate 14B by the impeller 1A as shown in the figure. The impeller 1A then rises, and is then discharged to the periphery along the lower surface of the impeller 1A. For this reason, the supply of air becomes uniform, and the imbalance of the load generated on the impeller 1A can be reduced. Also,
As shown in FIG. 7, the S portion shown in FIG.
By providing a dimensional difference between the diameter (d ₁ ) of B and the boss diameter (d ₂ ) of the impeller 1A and forming a stepped portion with respect to the flow of water, the pressure in this portion can be adjusted. That is, when d ₁ <d ₂ (FIG. 7), the flow of water is
The boss of A shuts down, and the pressure in this portion increases as compared with the case where d ₁ = d ₂ . On the other hand, when d ₁ > d ₂ , the flow separates at the trailing edge of the rectifier plate boss 14B,
The pressure is lower than when d ₁ = d ₂ . Thus, by appropriately determining d ₁ and d ₂ , the pressure in this portion can be adjusted.

[0020]

As described above in detail, according to the present invention, when a flow straightening plate is provided on the suction side of a pump, such as when the pump is an axial flow pump or when the shape of a water absorption tank is poor. In addition, it is possible to control the flow rate of the pump by intake air,
It is possible to adjust the water level at which the air is started, and to provide a preparatory standby operation pump having a wider range of application.

[Brief description of the drawings]

FIG. 1 is a side view showing an entire configuration of a general vertical shaft pump.

FIG. 2 is a sectional view showing a suction portion of a vertical shaft pump developed in connection with the present invention.

FIG. 3 is a sectional view showing a suction portion of the vertical shaft pump according to one embodiment of the present invention.

FIG. 4 is a detailed sectional view showing an R portion in FIG. 3;

FIG. 5 is a sectional view showing a suction portion of a vertical shaft pump according to another embodiment of the present invention.

FIG. 6 is a sectional view showing a suction portion of a vertical axial flow pump according to still another embodiment of the present invention.

FIG. 7 is a detailed sectional view of a portion S in FIG. 6;

[Explanation of symbols]

1, 1A impeller, 3 suction bell mouth, 43 pump casing, 9, 9A intake hole, 10 intake pipe, 14,
14A, 14B: current plate boss, 15: current plate, 16: air introduction hole.

Claims (5)

(57) [Claims] An impeller is positioned below a position corresponding to a minimum water level at which a water level during operation of the pump is below which air is sucked from a suction bell mouth of a pump casing, and an upstream side of the impeller. in the pump casing, to connect the intake pipe that is open to the atmosphere at higher than the highest water level in the pump water tank level, a plurality of rectifying plates to the pump suction side
In the vertical shaft pump comprising: the plurality of rectifying plates have a boss portion, and the rectifying plate has a boss portion.
Providing multiple air intake holes and drilling air inlet holes in multiple current plates
Then, while connecting the intake pipe to the air introduction hole, the air introduction hole and the intake hole are connected to the boss portion of the rectifying plate.
Vertical shaft pump for causing communicate Oite communication. Wherein a plurality of air intake holes, the spherical convex surface portions of the rectifying plate boss, vertical-shaft pump according to claim 1, wherein the multiple levels of the flow direction of the water so as to selectively provided. 3. An impeller is positioned below a position corresponding to a minimum water level at which the water level during operation of the pump is below which air is sucked from the suction bell mouth of the pump casing. in the pump casing, to connect the intake pipe that is open to the atmosphere at higher than the highest water level in the pump water tank level, a plurality of rectifying plates to the pump suction side
In standing axis pump comprising wherein the side surface or the upper surface of the plurality of rectifier plates, to one of the lower surface, a plurality of suction holes provided in the radial direction, and piercing the air inlet holes into the plurality of rectifying plates, the air A vertical shaft pump, wherein the intake pipe is connected to an introduction hole, and the air introduction hole and the intake hole communicate with each other in the rectifying plate. 4. An impeller is located below a position corresponding to a minimum water level at which a water level during operation of the pump is below which air is sucked from a suction bell mouth of a pump casing, and an upstream side of the impeller. in the pump casing, to connect the intake pipe that is open to the atmosphere at higher than the highest water level in the pump water tank level, a plurality of rectifying plates to the pump suction side
In the vertical pump comprising: the plurality of straightening plates have a boss portion, the boss of the straightening plate ,
Spherical convex portion faces the upstream side, the impeller side is formed in a hollow open configuration, perforated air inlet holes into the plurality of rectifying plates, thereby connecting the intake pipe to the air inlet holes, the air inlet holes A vertical shaft pump having an opening on the inner surface of the hollow boss of the straightening plate boss. And the diameter of 5. A rectifying plate boss, the size difference in the diameter of the impeller boss facing the current plate boss provided, according to claim 4, characterized in that the formation of the stepped portion to the water flow Vertical shaft pump.