JP2915600B2 - Spiral mixed flow 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 swirl mixed flow pump, such as a rainwater drainage pump or a sewage drainage pump, which is required to operate at all water levels and at full speed.

[0002]

2. Description of the Related Art Spiral mixed-flow pumps are usually used for rainwater drainage pumps and sewage drainage pumps, and the spiral mixed-flow pumps are required to operate at all water levels and at full speed. FIG.
FIG. 1 is a cross-sectional view showing a spiral mixed flow pump that has been conventionally and generally used. This spiral mixed flow pump has an impeller 2 housed in a casing 1, and a lower portion thereof serves as an impeller suction section 3. The impeller suction section 3 is connected via a connection pipe 6 and the like to a suction pipe 5 whose distal end projects into the water intake tank 4.

[0003] The impeller suction section 3 is provided with several intake holes 7 for intake just before the entrance of the impeller 2 in the circumferential direction, and each of the intake holes 7 is a ring-shaped ring. It is connected to a tube 8. The ring pipe 8 is connected to an intake pipe 9, and the intake pipe 9 extends in the vertical direction, and its tip is opened at a position higher than the maximum water level HWL of the spiral mixed flow pump. Therefore, such a spiral mixed flow pump is called an open-air spiral mixed flow pump. The impeller 2 is connected to a rotating shaft 10 that is driven to rotate by a drive source (not shown), and pressurizes a fluid such as sewage flowing into the suction pipe 5 by the rotation of the impeller 2 to the spiral chamber 11. It is sent out and discharged.

[0004]

As described above, the conventional open-air swirl mixed-flow pump according to the related art releases the intake air from the relationship between the water level of the water intake tank 4 and the loss from the suction pipe 5 to the impeller suction section 3. Inhale air from a higher water level than you do not need,
There has been a problem that extra reduction in pump performance is caused.

[0005] Such a problem is caused by the drawing in which the same reference numerals are given to the same parts as in FIG. 2 instead of the intake pipe 9 which extends in the vertical direction and has a tip open at a position higher than the highest water intake level HWL. As shown in FIG. 3, an intake pipe 9a is extended from the ring pipe 8 in the horizontal direction, and the water level of the water intake tank 4 which needs intake is set .
That is, the problem can be solved by a so-called tank-directed spiral mixed flow pump connected to the position of the required intake water level LWL. That is, FIG. 4 shows the efficiency change and the flow rate change of the open-air type spiral mixed-flow pump and the tank-directed spiral mixed-flow pump. As shown by the solid line, the intake pipe 9a is removed from the water tank.
It can be seen that the swirl mixed-flow pump directly connected to the tank directly connected to the position of the required intake water level LWL of No. 4 exhibits better characteristics than the open-air swirl mixed-flow pump shown by the broken line. In FIG. 4, the horizontal axis represents the suction pipe 5 with respect to the diameter D of the suction pipe 5.
Is the ratio of the height Hs from the center to the water level.

Incidentally, various foreign substances flow into the water intake tank 4 . In the tank directly coupled spiral diagonal flow pump, since the water flows into the intake pipe 9a when high water level, the intake
Mixed even foreign matter into the tube 9a, thereby clogged intake pipe 9a, there is a problem that clogged the intake hole 7.
The present invention has been made in order to solve such a problem, and it is possible to prevent a decrease in pump performance due to suction of air from a water level higher than a water level that does not require suction, and to prevent a suction pipe or a suction hole due to foreign matter. The purpose is to prevent clogging.

[0007]

SUMMARY OF THE INVENTION In order to achieve this object,
According to the present invention, there is provided an impeller for pressurizing a fluid flowing into a suction pipe and sending the fluid to a swirl chamber, and an impeller suction section connected to the suction pipe and having an intake hole for intake immediately before an entrance of the impeller. The spiral mixed flow pump having: a first branch pipe connected horizontally in the middle of the suction pipe and rising in the vertical direction; and a vertical pipe part of the first branch pipe.
To the inlet valve of the impeller suction section.
The position corresponding to the required intake water level above the main valve
A second branch extending in a horizontal direction from the vertical tube portion.
A branch pipe, which is connected to the upper end of the vertical pipe portion, and an intake pipe extending in the vertical direction so that the distal end is positioned higher than the intake high water is opened, the second branch pipe, said first
Slows flow and prevents foreign matter clogging compared to branch pipes
It is formed to have a diameter sufficient to perform the operation.

[0008]

[Operation] According to the swirl mixed flow pump having the above configuration, the intake hole of the impeller suction portion is provided with the water level required for intake,
In other words , since it is indirectly communicated with the position corresponding to the required intake water level , it is possible to operate while taking advantage of the advantages of the tank-directed swirl mixed flow pump and to eliminate the inflow of foreign matter at that time. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a spiral mixed flow pump according to the present invention will be described below in detail with reference to FIG. In FIG. 1, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, and a description thereof will be omitted.

In the spiral mixed flow pump according to the present invention, a first branch pipe 21 is connected in a horizontal direction in the middle of the suction pipe 5 protruding into the water intake tank 4. The first branch pipe 21 is raised in the vertical direction, and the main valve 22 is connected to the vertical pipe portion 23 . And the main valve 2
2, that is, on the downstream side with respect to the main valve 22,
The second branch pipe 24 is connected to. Second branch pipe 2
The branch point 4 is located at a position corresponding to the required intake water level LWL , and the branch pipe 24 extends horizontally from this branch point so as to connect to the ring pipe 8 communicating with the intake hole 7 of the impeller suction section 3. It is growing. Further, the upper end of the vertical pipe portion 23 is connected to an intake pipe 25 extending in the vertical direction. The tip of the intake pipe 25 is open at a position higher than the maximum water level HWL.

By the way, in the spiral mixed flow pump of the present invention shown in FIG. 1, the pressure P ₁ at the first branch point, the pressure P _{2 at} the second branch point, and the pressure P _{3 at} the impeller suction section ₃ are respectively expressed by the following equations. 1, 2, and 3 . _{P 1 / γ = H-ζ} 1 · V 1 2 / 2g ··· (1) P 2 / γ = (H-H 2) - (ζ 1 · V 1 2 / 2g + ζ 2 · V 2 2 / 2g) _{··· (2) P 3 / γ} = (H-H 2) - (ζ 1 · V 1 2 / 2g + ζ 3 · V 3 2 / 2g) ··· (3) In addition, formula 1, formula 2 and formula In FIG. 3 , γ is the specific weight of the liquid, H is the height from the center of the suction pipe 5 to the maximum intake water level HWL, and H ₂ is the required intake water level LW from the center of the suction pipe 5.
L, ζ ₁ is a loss coefficient from the inlet of the suction pipe 5 to the first branch point, ζ ₂ is a loss coefficient from the first branch point to the second branch point, ζ ₃ is The loss coefficient from the first branch point to the impeller suction section 3, V ₁ is the main flow velocity at the first branch point in the suction pipe 5, and V ₂ is the second branch pipe 23
Velocity of the fluid in the inner, V ₃ is the mainstream velocity at the impeller inlet portion 3.

When the water level is high, the main flow flowing through the impeller suction section ₃ is a differential pressure (P ₁ -P ₃ ) between the pressure P _{1 at} the first branch point and the pressure P 3 at the impeller suction section 3. Based on
Zui flows, the speed is _{V 3.} The pressure P _{2 at} the second branch point and the impeller suction section 3 are also directed to the branch pipe 24.
The water flows based on the pressure difference (P ₂ −P ₃ ) from the pressure P _{3 at} . In this case, as compared with the mainstream loss factor zeta _3, since towards the branch pipe 24 of small diameter has a large loss factor including the intake hole 7, the amount of water flowing through the branch pipe 24 is small.

Here, consider the case where foreign matter is flowing. The first branch pipe 21 branches off from the suction pipe 5 in the horizontal direction , and the inside of the first branch pipe 21 is divided into a pressure P1 at a _first branch point and a pressure P2 at a _second branch point. Water flows based on the pressure difference (P ₁ −P ₂ ) , and the flow velocity is relatively small as V ₂ . Therefore, it is difficult for foreign matter to flow into the first branch pipe 21, and even if it flows, the flow velocity V
₂ is a vertical tube section 23 which is small and rises vertically
, Sludge will settle. In the case where foreign matter is clogged, maintenance can be easily performed by closing the main valve 22.

[0014] On the other hand, regarding the intake air, it is as follows.
That is, the intake air occurs when the pressure _{P 2} in the second branch point becomes negative pressure, the conditions of Equation _{2, (H-H 2)} <(ζ 1 · V 1 2 / 2g + ζ 2 · V 2 ² / 2g) (4) . Then, when the air is sucked, the two terms on the right side of Equation 4 become zero, so the relationship between the water level to be sucked and the flow rate Q is: H ₂ = H−ζ ₁ / 2g (Q / A ₁ ) ² (5) Can be determined as Incidentally, _{A 1} in Formula 5 is the cross-sectional area of the suction pipe 5.

[0015]

As described above in detail, according to the present invention, it is possible to communicate with the middle of the suction pipe 5 and to set the maximum water level HWL of the water intake.
Since the suction hole 7 of the impeller suction part 3 is communicated with the suction pipe 25 whose tip is opened at a higher position, the operation of the spiral mixed flow pump utilizing the advantages of the tank direct-connected spiral mixed flow pump is possible. Becomes Therefore, unlike the open-air swirl mixed flow pump, the pump performance is not reduced by sucking air from a water level higher than a water level that does not require suction, and foreign matter is hardly mixed into the suction hole 7 and the like. Thus, a swirl mixed flow pump having a large effect is provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a spiral mixed flow pump according to the present invention.

FIG. 2 is a cross-sectional view showing a conventional open-type spiral mixed flow pump.

FIG. 3 is a cross-sectional view showing a conventional tank-directed spiral mixed flow pump.

FIG. 4 is a characteristic diagram comparing characteristics of a conventional spiral mixed flow pump.

[Explanation of symbols]

2 impeller, 3 impeller suction portion, 5 suction pipe, 7 suction hole, 11 spiral chamber, 21 first branch pipe, 22 main valve,
23 vertical section of the first branch pipe , 24 second branch
Pipe , 25 ... intake pipe, LWL ... intake required water level, HWL ...
Water highest water level .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F04D 11/00 101 F04D 5/00 F04D 13/00 F04D 15/00

Claims (1)

(57) [Claims] 1. An impeller for pressurizing a fluid flowing into a suction pipe and sending the pressurized fluid to a swirl chamber, and an impeller suction part connected to the suction pipe and having an intake hole for intake immediately before an entrance of the impeller. A first branch pipe connected horizontally in the middle of the suction pipe and rising vertically, and provided in a vertical pipe portion of the first branch pipe.
To the inlet valve of the impeller suction section.
The position corresponding to the required intake water level above the main valve
A second branch extending in a horizontal direction from the vertical tube portion.
A branch pipe, which is connected to the upper end of the vertical pipe portion, and an intake pipe extending in the vertical direction so that the distal end is positioned higher than the intake high water is opened, the second branch pipe, said first
Slows flow and prevents foreign matter clogging compared to branch pipes
A swirl mixed flow pump that is formed with a diameter large enough to be used .