JPH09228980A - Precedence standby type pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly switch an operation mode of gas/water operation, pumping operation, etc., in a precedence standby type pump. SOLUTION: In a casing of an impeller 3 in a vertical shaft precedence standby type pump, a through hole is provided in a lower side wall of the impeller 3, a base end of a reverse U-shaped suction pipe 5 with the other end opened to the atmosphere is connected to this through hole, also a breather valve 6 is provided in a top part of this suction pipe 5, a bypass pipe 5c connecting right/left leg pipes 5a, 5b of the suction pipe 5 is provided in a lower position of this breather valve 6, an electrically operated valve 7 is provided in this bypass pipe 5c, this electrically operated valve 7 is connected to a water level gage 8 provided in the lowest water level or less of the pump. When a water level of a water tank leads to in the vicinity of the lowest water level, in addition to suction air of the breather valve 6, air is sucked from the electrically operated valve 7, a pumping amount of the pump is squeezed, an operating condition can be smoothly switched to an operating mode of gas/ water operation, hold operation, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an operation device of a preceding standby type pump installed so as to cope with sudden water discharge and the like.

[0002]

2. Description of the Related Art Various types of pumps of the standby type of this type are installed in drainage areas. Actual fair 6-2375
7, JP-A-63-134897 are examples. In these devices, a through hole is provided in the side wall of the casing that forms the suction part of the impeller, and an intake pipe is connected to this through hole to allow the impeller to inhale when the water level in the pit drops. It is spinning idle.

[0003]

That is, when the water level in the pit is lowered, the vibration noise of the impeller due to the eddy current and the water-water mixture generated in the pit is prevented. In this case, It is difficult to set the water level to be inhaled. In particular, when the water suddenly flows out due to a flood or the like, the water level in the pit fluctuates significantly, and the pump itself must be changed to drainage operation, steam operation, idle operation,
Its operation control is difficult.

[0004]

The present invention utilizes the water level in the pit and the pressure difference in the impeller chamber to adjust the amount of intake air flowing through the intake pipe so that the impeller chamber is inhaled, and a sudden pressure is applied. The operation mode is smoothly switched according to the fluctuation, and the fluctuation of the vibration and the load on the driving machine is alleviated. That is,
The gist of the present invention is that a through hole is provided in the casing side wall below the impeller of a vertical shaft pump, one end of which is connected to the through hole, and the other end of the intake port is located above the impeller. A reverse U-shaped intake pipe that opens to the inside is provided, and a breather valve that opens and closes in response to the pressure inside the casing below the impeller is provided at the neck portion of the reverse U-shaped intake pipe. Is provided with a bypass intake passage connecting a pair of leg pipes of the intake pipe, an electric valve is provided in the bypass intake passage, and the electric valve is opened / closed below the minimum water level of the vertical mixed flow pump. It is a thing.

The amount of air sucked by the intake pipe varies depending on the size of the pump to be installed and the size of the water tank, but a breather valve and a valve such as a butterfly valve that can regulate the flow rate are installed on the rear side of the suction of the electric valve. By doing so, an appropriate intake passage is formed according to the sizes of the water tank and the pump.

Further, the water level gauge for operating the motor-operated valve is preferably installed between the lowest water level of the pump and the hold operation water level. However, the water level gauge is installed above the lowest water level so that the water level is the lowest. The intake from the breather valve may be assisted before reaching the water level.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is configured as described above, and when the amount of water in the water tank is extremely small and the water level is low, the chamber below the impeller communicates with the outside air. . At this time, the breather valve is closed and the motor-operated valve is also closed. When the pump is started in this state, air is sucked in from the lower surface of the bell mouth, the pump is not pumped, and the engine is idle.

Next, when water flows into the water tank in this state and the water level gradually rises, the impeller sucks the water in the water tank, and between the pressure inside the casing below the impeller and the atmospheric pressure. A pressure difference occurs and the outside air is sucked from the breather valve, and the idle operation is changed to the air-water mixing operation.

On the other hand, the above-mentioned rise of the water level is detected by the water level gauge connected to the motor-operated valve, the signal causes the motor-operated valve to open, and the outside air also flows to the bypass intake passage. Therefore,
The casing below the impeller is filled with air, and a so-called hold operation state in which pumping is held above the impeller without absorbing water is achieved. However, as the water level in the water tank still rises, the breather valve closes and the pumping operation becomes normal.

The water gauge for operating the motor-operated valve is installed between the lowest water level of the installed pump and the opening of the water suction pipe to the outside air. It is determined by the size of the tank and the capacity of the water tank. In addition, the breather valve and the manual on-off valve provided on the suction rear side of the motor-operated valve are for adjusting the flow rate of the air in the intake pipe, and are set in advance according to the size of the installed pump and the capacity of the water tank. is there.

When the above-mentioned water level further rises and normal pumping operation is performed, the breather valve is closed by submerging the tip of the intake pipe, and the motor-operated valve has the water level exceeding the intake port of the intake pipe. By the way, it will be closed by the signal of the water level gauge.

As is apparent from the above description, the motorized valve is
Within the operating range of the breather valve, that is, when the water level is between the lowest water level of the impeller and the hold water level of the impeller, the intake amount of the breather valve is assisted to perform the air-water operation, hold operation, pumping operation, and pump operation mode. Can be smoothly transferred. Hereinafter, the present invention will be specifically described with reference to the drawings.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a vertical shaft pump 2 installed in a water tank 1. In the drawing, reference numeral 3 is an impeller, 4 is a bell mouth provided under a casing of the impeller 3, and 5 Is an intake pipe whose base is connected to a through hole in the side wall of the bell mouth.

The intake pipe 5 is formed in an inverted U-shape by rising along the pump 2 and bending its tip downward.
Its tip is open to the atmosphere. The intake pipe 5 is provided with a breather valve 6 which opens and closes in accordance with a pressure fluctuation in the bell mouth 4 and a bypass pipe 5c which connects the left and right leg pipes 5a and 5b of the intake pipe 5 to the neck portion thereof. The bypass pipe 5c is provided with an electric valve 7 that opens and closes according to the water level in the water tank 1.

The motor-operated valve 7 has a water level H2 at which the impeller 3 starts intake from near the hold water level H1 of the pump 2.
Is connected to the water level gauge 8 provided between the water levels, and is openly connected between the water levels and is closed so as to be closed except between the water levels.

Manual open / close valves 9 are provided on the intake rear side of the breather valve 6 and the motor-operated valve 7, respectively. The on-off valve 9 is provided for adjusting the breather valve line of the intake pipe 5 and the motor-operated valve circuit, respectively, and the opening degrees thereof are based on the capacity of the water tank 1, the size of the pump 2, and the like. Is set in advance.

Next, the operation of the device according to the present invention will be described. 2 to 4 schematically show a state in which the pump according to the present invention is waiting in advance for pumping up the discharged water. In the state of FIG. 2, the water level h1 in the water tank 1 is It is much lower than the lowest water level (LWL) at which water absorption starts, and even if the impeller 3 is driven, pumping is not performed in the air operation, and it is in a state of waiting for the water level in the water tank 1 to rise due to water discharge.
In this state, the engine is idling even if it is started.

The water level h in the aquarium 1 after entering the water from the state shown in FIG.
When 1 rises as shown in FIG. 3, water is absorbed from the lower surface opening of the bell mouth 4 and pumping starts. However, when the water level in the water tank 1 is equal to or lower than the minimum water level (LWL), the intake pipe 5 is used for intake of air-water mixture operation. This state is shown in FIG.

When the water level in the water tank 1 further rises and exceeds the minimum water absorption level (LWL), the bell mouth is filled with suction water from its lower surface, and normal drainage operation is performed. At this time, the other end of the intake pipe 5 is closed by the aquarium water, and the motor-operated valve 7 is also closed in conjunction with the water level gauge due to the rise of the water level. This state is shown in FIG.

That is, the preceding standby operation is to start the drainage pump from the idle operation in advance and perform the drainage operation when it is predicted that a sudden increase in water will flow into the water tank 1 as in the case of a flood. This is to prepare for the submersion of the pump operating room, etc. due to a sudden flood.

The preceding is a description of the preparatory standby operation in preparation for a sudden water outflow. The abrupt water outflow as described above occurs due to a change in the weather, etc., and usually increases and decreases. The device according to the invention is capable of performing suitable drainage work in response to an increase / decrease in water output. This will be described with reference to FIGS.

FIG. 5 shows a state of normal operation in which the water level in the water tank has returned to the normal water absorption level h3 as described above. From this state, when the amount of inflow into the water tank 1 decreases and falls below the minimum water level (LWL), the breather valve 6 opens, and the outside air is sucked into the bell mouth to perform a pumping operation in which air and water are mixed. This is shown in FIG.

When the water level in the water tank 1 further drops, the water level is detected by the water level gauge 8 and the electric valve 7 opens, and flows into the bell mouth together with the air from the breather valve 6 and the impeller 3 moves. The air reservoir A is generated below and the pumping is stopped. This is shown in FIG. That is, the operation is continued with the pumped water being held in the impeller chamber and the pumping pipe.

This hold operation state is continued unless the water level rises due to the stop of water discharge or the like, but if a long time elapses, water will fall from the obstacle between the impeller 3 and the casing, and there is a risk of water increase. Impeller 3 when it is predicted that there is no
Is to stop.

However, when the inflow of water to the water tank 1 fluctuates due to heavy rain or flooding and the increase in water is predicted, the hold operation state is left as it is and the water level in the water tank 1 rises again as shown in FIG. As shown in FIG. 9, air can be taken in through the intake pipe 5 and a normal drainage operation can be performed through a steam-water mixing operation. That is, the pump according to the present invention prepares for water discharge by starting the pump before water discharge when a flood or the like is predicted, and after that, drainage work can be performed without stopping the pump in response to increase and decrease of inflow water into the water tank. It is possible.

The operating state of the pump when the water level in the water tank is lowered from the hold operation state is as described above, and thus the apparatus according to the present invention is arranged so that the apparatus waits in advance depending on whether the water level in the water tank rises or falls due to a flood or the like. The operation can be automatically switched from the operation to the steam-water mixing operation, the hold operation, and the normal operation. Particularly, when the operation is switched from the steam-water mixing operation to the hold operation, in addition to the breather valve 6, the motorized valve 7
Since it is provided, a predetermined amount of air can be fed into the bell mouth at an appropriate time by assisting the intake from the breather valve 6, and the operation mode can be switched appropriately. In the preceding standby type pump, it is possible to prevent the vibration generated at the time of switching the operating state between the steam operation and the hold operation and the adverse effect on the driving machine based on the upper and lower sides of the water level in the water tank.

The breather valve 6 and the motor operated valve 7
The on-off valve 9 attached to each is capable of adjusting the amount of air flowing through the intake pipe 5, and sets the optimum amount of suction air according to the size of the pump, the capacity of the water tank 1, and the like. Is useful for.

Further, according to the present invention, when a plurality of pumps are installed in one water tank as shown in FIG. 10, different water levels are used to operate the motor-operated valves provided in the intake pipes of the respective pumps. That is, each pump can be controlled individually, that is, the steam-water operation and the hold operation can be controlled separately, and only the pumps that are suitable for the amount of water input can be operated without operating all the pumps in response to fluctuations in the amount of water input to the water tank. This allows economical drainage operation.

As described above, the apparatus according to the present invention smoothly switches the operation modes of the pump in the preceding standby type pump in response to the rapid and frequent fluctuations in the amount of water flowing into the water tank. It is possible to prevent harmful effects such as vibrations that occur during the conversion of.

[Brief description of drawings]

FIG. 1 is a schematic side view of a state where a preceding standby pump according to the present invention is installed.

FIG. 2 is likewise a schematic side view of the in-air operating state.

FIG. 3 is likewise a schematic side view of the steam-water mixing operation state.

FIG. 4 is a schematic side view of the same normal operating condition.

FIG. 5 is a schematic side view of a normal operation state, showing a state where the water level in the water tank is decreasing.

FIG. 6 is a schematic side view of a steam-water mixing operation state, showing a state in which the amount of drainage is decreasing.

FIG. 7 is likewise a schematic side view of a hold operation state.

FIG. 8 is a schematic side view of a steam-water mixing operation state, showing a state in which the water level in the water tank is rising.

FIG. 9 is a schematic side view of a normal operation state, showing a state where the water level in the water tank is high.

FIG. 10 is a schematic side view showing a state in which a plurality of pumps according to the present invention are installed in a water tank.

[Explanation of symbols]

 1 water tank 2 vertical pump 3 impeller 4 bellmouth 5 intake pipe 5a leg pipe 5b leg pipe 5c bypass pipe 6 breather valve 7 electric valve 8 water level meter 9 open / close valve

Claims (4)

[Claims] 1. A through hole is provided in a casing side wall below an impeller 3 of a vertical mixed flow pump 2, a base end is connected to the through hole, and the other end is located above the impeller 3 in the atmosphere. A reverse U-shaped intake pipe 5 opening to the
A breather valve 6 that opens and closes in response to a pressure change in the casing below the impeller 3 is provided at the top of the character-shaped intake pipe 5, and the intake pipe 5 further includes a pair of leg pipes 5a of the intake pipe 5. And a bypass intake passage 5c for connecting 5b,
A motor-operated valve 7 is provided in the bypass intake passage 5c, and the motor-operated valve 7 is used as a water level gauge 8 in a water tank 1 in which the vertical shaft mixed flow pump 2 is installed.
A preceding standby type pump which is connected to and opens and closes when the water level is below the minimum water absorption level of the vertical mixed flow pump 2. 2. A preceding standby type in which the motor-operated valve 7 according to claim 1 is connected to a water level gauge 8 provided in the water tank 1 between the minimum water level and the hold level of the vertical mixed flow pump 2. pump. 3. A preparatory standby type pump, wherein a manual opening / closing control valve 9 is provided on the rear side of the breather valve 6 and the motor-operated valve 7 according to claim 1, respectively. 4. A preceding standby pump in which the other end of the inverted U-shaped intake pipe 5 according to claim 1 is opened near the lowest water level of the water tank 1.