JPH0751954B2 - Sewage transfer pump unit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pump unit (pump equipment) for transferring sewage, and particularly to a submersible pump having a pump suction nozzle having the same particle size as the particle size that can pass through the pump. Relates to a sewage transfer pump unit installed in a water tank.

[Conventional technology]

Conventionally, in a wastewater transfer pump unit as described above, as shown in FIG. 3, the suction nozzle 1 having the same inner diameter d as the particle size that can pass through the pump is extended downward to increase the outer diameter of the tip portion. , A bell mouth 1a having a small inflow loss, and the bell mouth 1a is a floor surface 2a of a water receiving tank (hereinafter referred to as a tank) 2.
The amount of residual water in the tank when the pump is stopped is reduced by bringing the space between the floor 2a and the floor surface 2a closer to the same dimension d as the inner diameter d.

However, the method (means) described above has a drawback that the amount of residual water in the tank also increases when the surface area of the residual water in the tank 2 is large.

In order to improve the above-mentioned drawback, as shown in FIG. 4, a recess 3 is provided on the floor surface of the tank 2, and the suction bell mouth 1a is inserted into the recess 3, whereby the pump residual water amount is reduced. Methods (means) to reduce the number are also used.

[Problems to be Solved by the Invention]

As shown in FIG. 4 above, in the case where the suction bell mouth 1a is inserted into the recess 3 provided on the floor surface of the tank 2, the outer periphery of the inlet flange 1b of the suction bell mouth 1a and the recess 3
The size of the gap between the inner diameter of the pump and the inner diameter is d so that foreign matter larger than the particle diameter d that can pass through the pump does not flow into the bell mouth 1a.
It accumulates on the entrance rim 1b of the bell mouth that is inserted into the inside of the bell mouth, and other foreign matter also clogs with it, so it is necessary to clean the inside of the tank in a relatively short time. There was a problem.

INDUSTRIAL APPLICABILITY The present invention solves the above-mentioned problems of the prior art, and even if a foreign substance having a particle size larger than the particle size that can pass through the pump is introduced, the pump can be operated for as long as possible without cleaning the inside of the tank. The purpose of this is to reduce the amount of residual water in the tank when the pump is stopped.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is a sewage transfer pump unit in which a submersible pump having a pump suction nozzle having the same inner diameter as the particle size that can be passed through the pump is installed in a tank. A cylindrical hollow having a uniform inner diameter up to the pump main body connection portion was formed, and a cylindrical recess having a gap approximately the same as the particle size that can pass through the pump was provided in the outer peripheral portion of the suction nozzle on the floor surface of the water receiving tank. It is characterized by that.

The second aspect of the present invention is such that the suction nozzle has a cylindrical recess having an approximately same gap as the passable particle diameter in the pump at the outer peripheral portion, and is directly at least at the same depth as the passable particle diameter in the pump. It is characterized by inserting a tubular pump suction nozzle.

[Work]

Since the present invention is configured as described above, when the pump is in operation, the sewage that has flowed into the tank is discharged to the outside (outside the tank) via the discharge pipe (16 in FIG. 2), and eventually the inside of the tank is discharged. The residual water is only the dirty water remaining in the depression, but in the process, it is formed by the outer peripheral part of the pump suction nozzle and the inner edge upper edge of the depression, and the suction nozzle inner diameter, that is, the particle size that can be passed through the pump is almost the same. Foreign matter with a large particle size, which is blocked by the gap of the same size and remains in the tank, is swept away by the dirty water entering the tank from the inflow pipe with almost no residual water in the tank, and is sucked in by the pump. It moves to a position away from the nozzle. When the water level in the tank rises to the specified water level again, the pump starts draining again, but every time the pump is stopped, foreign matter with a large particle size is caused to flow away from the pump suction nozzle by the inflowing wastewater. Therefore, unlike the conventional case (Fig. 4), foreign matter is not accumulated on the collar portion of the suction bell mouth to block the inlet portion of the suction nozzle, and a large amount of foreign matter having a large particle diameter is accumulated in the tank. The cleaning interval for foreign objects can be extended to the extent that the pump can be operated for a long time.

Further, in the cylindrical recess provided on the floor surface of the water tank, at least at the same depth as the suction nozzle inner diameter equal to the suction nozzle inner diameter capable of passing through the pump, by inserting the straight tubular pump suction nozzle, Combined with the narrow gap between the outer periphery of the suction nozzle and the inner diameter of the recess, the suction of air due to the generation of vortices at the inlet of the pump suction nozzle is eliminated, and the pump can be operated to a very low water level. Become.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention,
In the figure, the same reference numerals as those shown in FIG. 4 indicate the same or similar parts.

In the figure, the pump suction nozzle 11 is formed in a straight tube shape having an inner diameter d that is the same as the particle diameter that allows passage in the pump, from the tip portion 11b to the pump body connecting portion (11c in FIG. 2),
An outer peripheral portion of the suction nozzle 11 and an inner diameter portion of a recess 13 on the floor surface of the water receiving tank 2 into which the suction nozzle 11 is inserted are formed in a gap d that is substantially the same as the particle diameter that allows passage in the pump.

Further, the length (depth) of the suction nozzle 11 inserted into the recess 13 is also the same as the particle size that can be passed through the pump, that is, the suction nozzle inner diameter d, or at least smaller than the inner diameter d. There is.

Since it is configured as described above, when the pump is operating, the tank 2
The sewage that has flowed in is discharged to the outside through the discharge pipe (16 in FIG. 2), and the only residual water in the tank is the sewage remaining in the depression 13, but in the process, the suction nozzle 11 Perimeter and dent
Suction nozzle inner diameter d formed by the inner diameter upper edge of 13
It is left in the tank blocked by the gap of about the same size as
Foreign matter with a size larger than the dimension d is washed away by the dirty water entering the tank from the inflow pipe (5 in FIG. 2) with almost no residual water in the tank, and is separated from the pump suction nozzle 11. Will move to the wrong position. Then, when the water level in the tank rises again to the specified water level, the pump starts draining again, but every time the pump is stopped, foreign matter with a large particle size is separated from the pump suction nozzle 11 by the inflowing wastewater. As it is washed away, unlike the conventional example (Fig. 4), foreign matter having a large particle size does not accumulate on the collar portion 1b of the suction bell mouth 1a to block the inlet portion of the suction nozzle. It is possible to extend the cleaning interval for foreign substances until the water is accumulated in the tank, and the pump can be operated for that long.

Further, the straight tubular suction nozzle 11 is inserted into the cylindrical recess 13 on the floor of the tank at a depth at least as large as the particle size d that can pass through the pump (that is, a depth equal to or larger than the dimension d). As a result, the gap between the outer peripheral portion of the suction nozzle 11 and the inner diameter portion of the recess 13 is narrow as described above, and the suction of air due to the generation of vortices at the inlet portion of the suction nozzle is eliminated, which is extremely small. The pump can be operated to a low water level.

Since the suction nozzle 11 is formed in a straight tube shape as described above, the inflow loss is slightly larger than that of the conventional bell mouth, and the pump discharge amount is reduced by that much, but the difference is slight, and as described above, It is more effective to drive to low water level.

FIG. 2 is an overall sectional view showing an embodiment of a wastewater transfer pump unit (equipment) using the present invention, in which the same reference numerals as those shown in FIG. 1 denote the same parts. I shall.

In the figure, a submersible pump 10 driven by an electric motor
A straight tubular suction nozzle 11 is attached to the suction port, and the suction nozzle 11 is inserted into a recess 13 formed in the floor surface of the tank body 2. On the other hand, the discharge port of the pump is detachably attached to a discharge base 15 which is installed at the bottom of the tank body 2 and has a guide pipe 14 vertically upward.
15 is guided to the outside of the tank main body 2 via a discharge pipe 16, and a check valve 17 and a ball valve 18 are attached midway.

Therefore, when a cloth-like foreign object is blocked at the inlet of the pump suction nozzle 11 or the submersible pump 10 needs to be inspected and maintained, the submersible pump 16 can be easily left as it is.
Only you can pull up. In the figure, 4 is a manhole cover and 5 is an inflow pipe.

During operation, sewage flows from the inflow pipe 5 and the water level in the tank 2 rises. For example, when the water level reaches a specified water level set near the inflow pipe 5, the submersible pump is operated by the action of a float switch (not shown) or the like. When 10 starts, the waste water in the tank is discharged from the discharge pipe 16. Then, when the water level in the tank reaches, for example, the lowest water level set near the pump body (casing), the timer is operated, and the operation of the submersible pump 10 is continued until the time set by the timer ends. The waste water in the tank is emptied by the recess 13
Only the remaining sewage remains inside, and the pump sucks in the air to finish draining the sewage.

On the other hand, the foreign matter having a large particle size, which is blocked by the outer peripheral portion of the pump suction nozzle 11 and the upper edge portion of the inner diameter of the depression 13 and remains in the groove 2,
As described above, almost no residual water in the tank is washed away by the dirty water flowing from the inflow pipe 5, and moves to a position away from the pump suction nozzle 11. In this way, every time the pump is stopped, foreign matter having a large particle size is swept away by the inflowing waste water, so that the cleaning interval of the foreign matter can be extended until a considerable amount of the foreign matter having a large particle size is accumulated in the tank.

〔The invention's effect〕

As described above, according to the present invention, the pump suction nozzle having the same inner diameter as the particle size that can be passed through the pump is formed into a straight tube having the same inner diameter from the tip portion to the pump body connecting portion,
The following effects can be obtained by providing a cylindrical recess on the outer peripheral portion of the suction nozzle with a gap substantially equal to the inner diameter of the suction nozzle on the floor surface of the tank.

(I) Foreign matter having a large particle size that cannot pass through the inside of the pump does not enter not only the pump suction nozzle but also the depression, and is flushed to a position away from the suction nozzle by the inflowing dirty water every time the pump is stopped. Can be extended,
The pump can be operated for as long as possible.

(Ii) By inserting the straight tubular pump suction nozzle into a cylindrical recess on the floor of the tank at a depth at least as large as the particle size that allows passage in the pump, the outer peripheral portion of the suction nozzle and the inner diameter of the recess. Combined with the narrow gap between the and, the intake of air due to the generation of vortices can be eliminated, so the pump can be operated to an extremely low water level, and the residual water content in the tank can be reduced.

(Iii) As described above, since the pump can be operated to a very low water level, the residual water in the tank when the pump is stopped is extremely small, and as a result, the oil and fat and organic matter floating on the water surface are also reduced. Since it is discharged, scum (oxidation and decay film of impurities floating on the surface of the liquid) is prevented from occurring, so the offensive odor of the scum also disappears, and periodic scum removal work becomes unnecessary. Become.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, and FIG. 2 is a sectional view of the whole sewage transfer pump unit using the present invention,
FIG. 3 and FIG. 4 are cross-sectional views of a main part showing a conventional example. 2 ... Water tank, 4 ... Manhole cover, 5 ... Inflow pipe, 10
…… Submersible pump, 11 …… Pump suction nozzle, 11b …… Suction nozzle tip, 11c …… Pump body connection, 13 ……
Cavity, 14 …… Guide pipe, 15 …… Discharge base, 16 …… Discharge pipe.

Claims (2)

[Claims] 1. In a sewage transfer pump unit in which a submersible pump having a pump suction nozzle having the same inner diameter as the particle size that can be passed through the pump is installed in a water receiving tank, the pump suction nozzle is the same from the tip to the pump body connection portion. A sewage characterized by being formed in a straight tube having an inner diameter, and having a cylindrical recess provided on the outer peripheral portion of the suction nozzle with a gap approximately the same as the particle size that allows passage in the pump, on the floor surface of the water receiving tank. Transfer pump unit. 2. A straight-tube pump suction nozzle is inserted into a cylindrical recess provided on the floor of the water tank at a depth at least equal to the particle size that allows passage in the pump. The sewage transfer pump unit according to Item 1.