JPH0381597A - Self-suction tank - Google Patents

Abstract

PURPOSE:To efficiently discharge the air from the inside of a tank and improve pumping efficiency by opening a suction port along the inner wall surface of the tank in the upper part thereof, and making the end of a connection pipe to the suction side of a pump open at the central lower end of the eddy current of a pumped-up swirling water flow. CONSTITUTION:A suction port 2d is made open along the inner wall surface of a self-suction tank 1 in the upper part hereof, and the swirl flow of pumped-up water is caused in the tank 1, thereby generating an eddy current 3. A connection pipe 4 leading to the suction side of a pump has an open end 4d at the lower end of the center of the aforesaid eddy current. The self-suction tank 1 quickly discharges the internal air thereof to the pump and can generate high negative pressure in the pump. According to the aforesaid construction, pumping efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a self-priming tank that is used in conjunction with, for example, a centrifugal pump instead of pumping water with a self-priming pump.

[Conventional technology 1 Self-priming pumps do not require priming and are particularly preferred for operation when drawing up water from pits, etc. where the water level is low, but they are relatively expensive compared to general centrifugal centrifugal pumps. In addition, after the pump is started, complete pumping does not begin while air and water are being separated, and it takes a long time to start pumping water.

Therefore, a self-priming tank has been developed that is connected to the suction port of a normal centrifugal pump and uses the negative pressure inside the tank to pump up water at the same time as the pump starts.3 In other words, the water sealed in the tank is sucked up by the pump. This creates a negative pressure within the tank, and this negative pressure is used to continuously pump water.

5 and 6 show conventional examples of such a tank, in which a connecting pipe 12 is connected to the pump suction pipe 4 to the tank body 11, and a water suction pipe 1 is connected to the pumped water suction pipe.
It consists of a simple configuration that includes 3. In order to ensure the water level in the tank, the water suction pipe 13 is elbow-shaped in FIG. 5 and the opening is located above the tank, and in FIG. 6 the water suction pipe 13 is installed at the upper part of the tank.

In such a structure, water is sealed in the tank, and by starting the pump, the water in the tank is sucked up, and by creating negative pressure, it can be pumped from the ground, for example, from inside the pit through the water pipe and suction pipe. This method performs continuous pumping.

[Problems to be Solved by the Invention] One of the problems with such a self-priming tank is maintaining the water level of the sealed water inside the tank when the pump is stopped. If the water level is low, the negative pressure generated in the tank will be weak when the pump is restarted, and the pumping force will be weak. However, in conventional self-priming tanks, the air becomes fine bubbles in the sealed water inside the tank and floats in a diffused state, and is not easily sucked into the pump side, so the air is discharged slowly and the water level recovers extremely slowly. .

When restarting the pump as a means of restoring the water level, there is a method of replenishing water into the tank by backflowing water from the pump's discharge pipe (jjjl) through a connecting pipe, but the make-up water is However, it was difficult to maintain the water level of the sealed water in the tank at the desired level.Therefore, when starting and stopping are repeated in a short period of time, the sealed water in the tank must be gradually reduced. However, in the end, it became impossible to pump water, and automatic continuous operation was not possible.

Therefore, the purpose of this invention is to create a structure that efficiently discharges the air inside the tank, to continuously increase the desired negative pressure in the tank, to increase pumping efficiency, and to improve pumping efficiency from the time the pump stops to the time it restarts. The purpose of the present invention is to provide a self-priming tank that is capable of restoring the desired water level of sealed water in the tank to the full level in a short period of time, is capable of pumping water immediately upon restart, and is suitable for continuous automatic operation.

[Means for Solving the Problems] In order to achieve the above object, as a result of intensive research, the present invention generates a swirling flow of pumped water in a tank, collects air at the center of the swirl of this swirling flow, and forcibly By drawing air into the pump, the air discharge function is enhanced, creating a strong negative pressure inside the tank, and the water level can be restored in a short period of time.

That is, the self-priming tank according to the present invention has a structure in which water is pumped by negative pressure within the tank by being connected to the pump suction side, and the suction port is opened along the inner wall surface at the upper part of the tank, so that the pumped water that has been drawn up is A swirling flow is generated in the tank, and a connecting pipe connected to the pump suction side is opened at the lower end of the swirl center of this swirling flow.

The diameter, opening area, etc. of the connecting pipe connected to the pump suction side are selected to be such that the ratio of water to air is optimal in relation to the flow rate and flow rate passing through this pipe. If the flow rate is too high, only air will be sucked in, not only will the desired function not be achieved, but the pump will also cause cavitation. The opening is preferably cut diagonally at the end of the tube so that suction can be made as smoothly and effectively as possible.

[Operation] A swirling flow of the pumped water as described above is generated in the tank, and the pump suction 1 is located at the lower end of the center of the swirl of this swirling flow. When the connecting pipe is opened, the air inside the tank is drawn into the center of the vortex and smoothly discharged to the pump, creating a strong negative pressure. In addition, because the air is discharged quickly, the water level is quickly restored and achieved in an extremely short time, and even if the tank is repeatedly stopped and started, the water in the tank remains sealed and automatic continuous operation is possible. becomes.

[Example] The embodiments shown in the accompanying drawings will be described below.

FIG. 1 is a schematic diagram (not showing an embodiment) of a self-priming tank according to the present invention, in which 1 is a tank main body, 2 is a water suction pipe connected to a pumped water suction pipe, and the suction port 2a is located at the upper part of the tank and the inner periphery. The opening is opened along the wall surface, thereby causing a swirling flow of pumped water within the tank, thereby creating a vortex 3. 4 is a connecting pipe connected to the pump suction side, and is housed with an opening 4a located at the lower end of the center of the thin case.

211] (a) to (d) explain the relationship between the pump drive and the water level in the tank. Figure (a) shows the state before the pump starts, and the sealed water in the tank is full as shown. Leave it as the state. If you start the pump in this state, as shown in figure (b), the sealed water in the tank will be sucked out and the water level will start to fall.The negative pressure generated in the tank will cause pumping to start from day 2a. start. (c)
The figure shows the state during operation, and the water level is rapidly rising due to the inflow of pumped water. As shown in Figures (b) and (c), the pumped water that flows in almost simultaneously with the start of the pump flows along the inner circumferential wall of the tank, so a swirling flow is generated in the tank, and a connecting pipe is formed in the center of the tank. A vortex 3 is formed whose bottom reaches the opening 4a of the tank 4, and the air in the tank is caught in the center of this vortex and is smoothly pumped (regularly discharged) from the opening 4a through the connecting pipe 4 without being diffused. I wanted to do it, (C
) As shown in the figure, the water level in the tank quickly recovers while the pump is in operation, and when the pump is stopped, as shown in figure (d), the water level returns to the same level as before the pump was started, waiting for the next start. Therefore, water can be pumped immediately when the pump is restarted.

FIG. 3 is a schematic diagram of general tank equipment using a self-priming tank and a centrifugal pump according to the above embodiment, and shows the suction water head H
s=3m is shown as an example. In the drawing, 5 is a suction pipe connected to the water suction pipe 2 of the tank, 6 is a centrifugal pump, 7 is a motor,
8 is a pump discharge pipe, 9 is an initial water injection pipe, and 10 is an initial exhaust pipe.

Next, in such tank equipment, FIG. 4 shows the results of performing a performance test on the self-priming tank according to the above embodiment and the conventional self-priming tank. In FIG. 4, UL is the water level when the tank is full, LL is the lowest water level immediately after the pump is started, ML is a diagram showing the falling state of the water level immediately after the pump is started, and A is the tank according to the embodiment of the present invention. A diagram showing the relationship between pumping time and water level rise, and a similar relationship diagram for a conventional tank. As is clear from this figure, in the conventional tank, the water level rises slowly and cannot return to the full state, whereas when using the Byakugan tank according to the embodiment of the present invention, the water inside the tank after starting the pump is The water leakage rapidly recovered, and the water level returned to full and stable continuous pumping was achieved.

[Effects of the Invention] As described above, the self-priming tank according to the present invention can rapidly discharge the air inside the tank to the pump side to generate strong negative pressure, and the water level can be quickly and completely recovered, resulting in stable We were able to provide a self-priming tank capable of continuous automatic operation.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a self-priming tank according to the present invention, in which (A) is a front view, (B) is a sectional view taken along line AA, and FIGS. 2 (a) to (d) are FIG. 3 is a front view showing the relationship between the water level in the self-priming tank and the pump driving state, in which (a) shows before starting, (b) immediately after starting, (c) shows during operation, and (d) shows when stopped. Figure 3 is a schematic diagram of general tank equipment using the same self-priming tank, Figure 4 is a comparison diagram showing the results of a performance test between the same self-priming tank and a conventional self-priming tank, and Figure 5 Figures and Figure 6 are
FIG. 2 is a schematic front view of a conventional example. 2... Water suction pipe 3... Whirlpool 4a... Opening 6... Pump

Claims (1)

[Claims] (1) In a self-priming tank that is connected to the pump suction side and pumps water using negative pressure inside the tank, the suction port is opened along the inner circumferential wall surface at the top of the tank, and the vortex center of the swirling flow of pumped water that is generated by this A self-priming tank characterized in that a connecting pipe located at the lower end and connected to the pump suction side is opened.