JPS58133496A - Immersed motor pump - Google Patents

Abstract

PURPOSE:To increase the allowance even when the water level is dropped, by providing a circular suction port wall at the suction port of a casing thus eliminating the suction eddy flow. CONSTITUTION:A circular suction port wall 11 having the maximum height same with the lower eye point is provided at the suction port 6 of a casing 3. In such a structure, when the liquid is reduced to lower the water level below the lower eye point P to level P', the suction port 6 will not reach to the liquid thereby the liquid can not be pumped even if the runner 4 continues the rotation resulting in the increase of allowance for the water level drop.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of transferring liquid by immersing only the pump part in liquid.
This invention relates to the shape of the casing suction port of a submerged weir electric pump that circulates 1lt.

The prior art will be explained using FIG. 1, FIG. 2, and FIG. 3.

A pump casing 3 is attached to the electric motor 1,
A runner 4 is attached to the leading end of the shaft 2 of the electric motor 1. The cover 5 has a structure that is assembled so as to wrap around the runner 4, and constitutes a so-called pump chamber.

This pump is an immersed type electric bong with the pump chamber immersed in liquid, and is used to transfer liquid.

The cycle looks like this:

2 attached to the tip of shaft 2 by the operation of electric motor 1.
The roller 4 performs a rotational movement. Due to this rotational movement of the runner 4, the blades 4a formed integrally with the runner 4 apply centrifugal force to the liquid, and the liquid moves in the rotational direction and also moves in the outer diameter direction of the runner 4, causing the runner 4 to move. Go out.

On the other hand, the pressure in the area where the liquid has moved becomes low, and the area sucks in new liquid and repeats the same operation, allowing it to function as a pump. That is, as the runner 4 rotates, the liquid is sucked through the suction port 6 of the casing 3, passes through the discharge channel 7, is pushed up, and is discharged to the discharge port 8.

In such a structure, when looking at the suction state of the liquid at the suction port 6, the liquid level generally decreases concentratedly at the center of the suction port 6t, as shown in FIG. This is because due to the rotational movement of the runner 4, rotational force is also applied to the sucked liquid, causing the liquid to be sucked into the suction port 6 while causing a swirling phenomenon. For this reason, if the liquid level drops extremely, air will be sucked in at the same time as liquid is sucked in, leading to a dramatic drop in pump performance, so the depth of the cypress and liquid level management must be carefully considered. Also, as shown by the arrow in Figure 2,
The liquid will be directed toward the center of the suction port 6 and will be sucked in, but the flow of the liquid toward the suction port 6 through both ends of the strut (A) 10 will become partially turbulent, resulting in a vortex (A). 9 occurs irregularly. To explain this with reference to Figure '#J1, since a vortex (A) 9 is generated at the suction port 6, as the liquid level decreases, there are more opportunities for air to be sucked in from the suction port 6, and as a result, This overlaps with the swirling phenomenon that naturally occurs at the suction port 6 described above, leading to a decrease in pump performance. The pump performance curve is shown in FIG. 3, so this will be used for explanation.

Originally, the performance curve for A would drop to the performance curve for mouth due to air intake. On the other hand, the piping loss curve of a pump is determined by the piping method and does not change unless the piping is changed, so the discharge amount that can be obtained will decrease from A to A, and the specified performance will not be achieved. In addition to problems such as insufficient discharge volume and insufficient pumping head, liquid level management,
It has the disadvantage of lowering the liquid level, such as the need to prepare a sufficient pre-layer of cypress wood, depth, etc., and install equipment.

An object of the present invention is to reduce the generation of irregular side vortices that occur at the suction port of a pump, and to increase the tolerance limit for a drop in the liquid level.

The advantage of the present invention is that a suction port wall is provided in which the pillar supporting the pump casing has a triangular shape with the apex on the suction port side in order to eliminate the generation of suction vortices.

One embodiment of the present invention will be described using four types of total sugars, with reference to FIG. 5, but parts of the structure that are the same as those of the prior art will be omitted.

The suction port 6 of the casing 3 is provided with an annular suction port 1111 whose highest height is the lower limit point P of the liquid level, and the structure is similar to the conventional technology in terms of operation and structure. do not have. In this structure, if the liquid level exceeds the lower limit point P and falls to the liquid level P' due to a decrease in liquid, the suction port 6 will not reach the liquid and the liquid will not be pumped even if the runner 4 continues to rotate. It is easily discovered that the fluid cannot be refilled and the fluid must be replenished.

According to the present invention, operation in an unstable state due to a decrease or shortage of liquid can be easily detected as a phenomenon in which liquid cannot be pumped, and liquid volume can be easily and reliably managed in practice. The effect is very large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a typical partial structure of the prior art, FIG. 2 is a diagram of a liquid suction state seen from cross section AA in FIG. 1, and FIG. 3 is a diagram of a pump performance curve. FIG. 4 is a cross-sectional view of a typical partial structure in the present invention, and FIG. 5 is a shape diagram of the suction portion as seen from cross section BB in FIG. 4. 1... Electric motor, 2... Shaft, 3... Casing, 4
...Runner, 5...Cover, 6...Suction port, 7
...Discharge flow path, 8...Discharge port, 10... Support column (A
), 4jl... wing, 11... suction port wall. $10

Claims (1)

[Claims] 1. Transfer of liquid by immersing only the pump section in the liquid. This is an immersion weir electric pump that performs circulation and has a surrounding wall around the suction port of the casing.