JPS6067798A - Flow pattern controller in water tank - Google Patents

Abstract

PURPOSE:To prevent occurrence of vortex without sacrifice of pump performance while to control the pump performance in accordance to load variation, by providing means for producing spiral flow on the wall face of water tank. CONSTITUTION:A recess 9 is formed at the lower portion of both side walls 1b located near to the suction port 2a of suction tube 2 where rotary member 6 is contained in each recess 9 while a motor 7 for driving a rotary member 6 is provided. Said rotary member 6 will rotate in the direction reverse from the rotary direction of vortex T1 to be produced through suction of suction pipe 2 to weaken the strength of vortex T1 thus to control the flow and to prevent vortex and air suction vortex. When locating the rotary member 6 immediately below the suction pipe 2a to regulate the strength of pre-spiral flow of suction port 2a, the pump performance can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow pattern control device for preventing vortices generated in a pump suction tank and for controlling the strength of pre-swirling of the flow at the suction port.

As is well known, various vortices are generated in a pump suction water tank in which a pump suction pipe is installed, causing problems in pump operation.

The form of these vortices is as shown in FIGS. 1(A) and 1(B). There are three submerged vortices that connect the side walls 1b and 1b of the aquarium 1, an air suction tfMl r 2 that connects the suction port 2a and the free surface 1d. MIA observed the flow inside the submerged vortex.The strong downward flow induced by the underwater vortex is added to the wake vortex near the free surface, usually created by the suction pipe, and the wake vortex becomes a depression vortex. It is clear that the air suction vortex [2] grows from the air suction vortex [2].The air suction vortex [2] also has an adverse effect on the upper layer of pump operation.J3.1C is the rear wall of water tank 1, 1d is the water is the free surface of

In order to prevent the generation of these various types of vortices, conventional vortex generation prevention devices have been known. For example, Figure 2 shows the suction pipe 2.
The plate 3 is installed vertically on the upstream side of the suction pipe 2 (the plate 3 is placed vertically below the free surface 1d). Board 4 is installed.

Furthermore, in the one shown in FIG. 4, a splitter 5 is installed on the center line directly below the suction pipe 2. Further, various other forms are described, for example, in Japanese Patent Publication No. 57-50941 filed by the present applicant.

However, although all of these known techniques are effective in preventing the generation of vortices, they do not require a vortex prevention device such as a plate, a rod, or a splitter to be provided close to the suction port 2a of the suction pipe 2. As a result, the flow toward the suction port 2a becomes non-uniform, resulting in a reduction in pump performance.

Therefore, an object of the present invention is to prevent the generation of vortices without installing a vortex prevention device such as a plate that degrades pump performance, and to adjust the head of the pump and 1lII according to fluctuations in the load.
The object of the present invention is to provide a 71''-pattern control device for a pump suction water tank that can adjust the moving horn to an appropriate value.

According to the present invention, swirling flow generating means for generating swirling flow is provided on the wall surface of the water tank near the pump suction port.

Therefore, in terms of vortex prevention, even if a vortex is to be generated, a flow in the opposite direction is generated by the rotating flow generating means, so that the generation of a vortex is prevented. Furthermore, the rotating flow generating means can be provided within the wall of the water tank, and even if it is located slightly within the water channel, it does not substantially block the flow within the water tank, so that the pump performance will not be degraded.

In addition, by giving a pre-swirl to the flow toward the suction port, it is possible to adjust the pump head and shaft J force to appropriate values in accordance with load fluctuations.

In carrying out the present invention, a swirling flow generating means (,), a rotating body, and a driving means for driving the rotating body can be used. When controlling the strength of the pre-swivel toward the pump suction port, it is preferable to install the rotating body on the bottom wall of the water tank directly below the suction port.

Further, when carrying out the present invention, it is preferable to install a rotating body on the bottom wall or on the side wall near the bottom wall to stir the flow near the bottom wall. By applying this J: sea urchin, it is possible to prevent sand and solid matter from accumulating on the bottom wall.

In carrying out the present invention, an electric motor can be used as the driving means for driving the rotating body. However, it can be rotated fluidically by a jet from a nozzle. The jet flow from the nozzle may be generated by using the discharge flow of a pump, or by using another pump or a liquid supply source such as water passage.

Further, in carrying out the present invention, a nozzle can be used as the swirling flow generating means. In guiding the jet stream injected from the nozzle to a circular recess or a volute-shaped recess J: 6
Two flows are obtained. Furthermore, a swirling flow can be generated by providing a plurality of nozzles in the tangential direction.

The present invention will be described in detail below with reference to FIGS. 5(a) and 5(b) to FIG. 12.

In the embodiment shown in FIGS. 5(a) and 5(b), four parts 9 are formed at the lower part of both side walls 1b adjacent to the suction port 2a of the suction pipe 2, and each of the four parts 9 is provided with a rotating body 6. It also houses an electric motor 7 that rotates these rotating bodies 6.

In general, as shown in Fig. 1, a desirable suction vortex "2" is an underwater vortex created by the suction action of the suction pipe 2. A strong downward flow induced by the blind joins the wake vortex and grows. It is something to do.

Therefore, by providing a rotating body 6 that rotates in the opposite direction to the rotation direction of the underwater vortex [+], the strength of the underwater vortex "1" can be appropriately weakened, thereby controlling its flow. In this way, the occurrence of underwater vortices "1" and "2" can be prevented.

In the illustrated example, the rotating bodies 6 are provided on both side walls 1b and 4t, respectively, but depending on the situation, the purpose can be sufficiently achieved with only one rotating body. Further, it is preferable that this rotating body 6 is located at a place where the underwater vortex [1 reaches the side wall 11]. The position at which this underwater vortex reaches side q 11) varies slightly depending on the shape and dimensions of the tank 1, but in a standard tank it is around a = 0.2D and +3 = 0.3D. Here, D is the diameter of the suction pipe, il is the distance 1 from the center of the suction pipe to the rear wall, and l+ is the distance from the lower end of the suction pipe to the bottom wall.

Furthermore, the rotating body 6 does not necessarily need to be accommodated in the recess 9;
It should not be installed protruding from the wall.

FIG. 6 shows an example in which a rotating body 6 is provided at the lower part of the rear wall 1C and driven by an electric motor 7, which is effective in preventing underwater vortices and controlling pump performance. In this embodiment, generation of an underwater vortex 1-tB connecting the suction port 2a and the rear wall 1C can be prevented.

FIG. 7 shows an example in which the rotating body 6 is provided on the bottom wall 1a of the water tank directly below the suction port 12a. In this embodiment, it is possible to prevent the generation of an underwater vortex "0" connecting the suction port 2a and the bottom wall 1a.To prevent the vortex, the rotating body 6 is rotated in the opposite direction to the underwater vortex "0" by the electric 1FIJ machine 7. Of course.

In addition, by positioning the rotating body G directly below the suction port 2aU) and adjusting the strength of the pre-swirling of the flow at the suction port, the pump performance can be improved. J- can do it.

FIG. 8 shows an example of the relationship between the pre-swirling direction of the suction flow and pump performance. When the suction flow is rotated in the opposite direction to the pump's rotational direction, Jj is shown in curve a. Niage Pi! At t-1, the shaft power decreases. The curved line shows the performance without pre-turn. Utilizing this relationship between the direction of pre-swivel and pump performance, it is possible to control the rotational speed of the rotating body 6 according to demand to achieve an appropriate pre-swivel, thereby saving pump power. .

9(a) and 9(b) are examples in which a jet stream is used as the driving means for the rotating body 6. FIG. In the illustrated example, a recess 9 for accommodating the rotating body 6 is provided in the bottom wall 1a directly below the suction port 2a, and the nozzle 8 applies the jet stream 3 toward the inner circumferential direction of the rotating body 6 to move the rotating body 6. Rotate J: It turns into a sea urchin. This nose'
A water supply pipe 11 is connected to the pipe 8, and this water supply pipe 11 is connected to an outlet 12 of the pump discharge 1]2.

Figure 10 shows a nozzle and a Voriko 1- as a swirling flow generating means.
This is an example in which the shape of the recess 10 is combined. The jet flow J from the nozzle 8 is caused by the recess 10 to generate an n:'j-circulation flow W. In this example, a recess 10 is provided in the polygon 1 in place of the recess 9 that accommodates the rotating body 9 shown in FIG. 9.

Further, FIG. 11 shows an example in which a recess 10 similar to that in FIG. 10 is provided at the position shown in FIG. 5 (b).

FIG. 12 shows an example in which a nozzle 8 facing tangentially is installed in an annular water supply pipe 13 to generate a swirling flow.

As described above, according to the present invention, the swirling flow generating means for generating swirling flow is provided on the wall surface of the water tank to control the flow pattern in the water tank, so that generation of vortices can be prevented without deteriorating pump performance. Pump performance can be controlled from 1 to 1 in accordance with load fluctuations. Further, the effect of preventing sand trapping can be reduced by 9-3.

[Brief explanation of drawings]

Figure 1 shows the forms of various vortices generated in the pump gravel tank, (a) is a front view, (b) is a side view, and (b) is a side view.
Figures 3 and 4 are side views showing a conventionally commonly used vortex prevention device, respectively, and Figure 5 shows an embodiment of the present invention. ) is a side view thereof, FIG. 6 is a side view showing another embodiment of the present invention, FIG. 7 is a side view showing still another embodiment, and FIG. 8 is a direction of pre-swivel of the pump suction port. FIG. 9 is a diagram showing still another embodiment, and (a) is a side view thereof;
(B) is a plan view taken along line A-A in (A), FIG. 10 is a plan view showing an embodiment of the present invention that uses a jet stream instead of a rotating body, and FIG. The flow generation means is shown in Figure 5 (
FIG. 12 is a plan view showing another example of the swirling flow generating means. 1...Pump suction water tank 1a...Iceberg bottom wall 1b.
...Aquarium side wall 1C...Aquarium rear wall 1d...Free surface 2...+f, Inlet pipe 2a...Suction port 6...Rotating body 7...Electric motor 8...Nozzle J...・Jet flow 9...Circular depression W...Swirling flow 10...Volume 1~Shape depression 13...Annular water supply pipe Fig. 1 1CL Fig. 4 - Fig. 5 Fig. 6 Figure 7 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] In a flow pattern control device for controlling the flow near the pump suction port of a pump suction water tank, at least one swirl flow generation means for giving a swirl to the flow is provided on the wall surface of the water tank near the pump suction port, The flow in the aquarium can be controlled by the flow, preventing vortices, and
) is a flow pattern control device that rolls the strength of the pre-turn to control 1.