JPH0450475Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention connects a pump with a semi-open impeller directly to a submersible motor via a shaft sealing device such as a mechanical seal, and a strainer is installed below the pump. The installed vertical shaft type submersible pump is suitable for use as a construction drainage pump, especially as it has a structure that prevents sand lock and air lock.

[Conventional technology]

In the submersible pump as described above, as shown in FIG. 5, a pump casing 3 is directly connected to a submersible motor 1 via a mechanical seal 2, and a strainer 4 is attached below the pump casing 3. Inside the pump casing 3, a semi-open impeller 5 is attached to the lower end of the pump shaft 6, and a suction cover 7 is attached to the pump casing 3 while maintaining a gap with the lower surface of each blade of the impeller 5. It is attached to the bottom surface of the strainer 4, that is, the top surface of the strainer 4.

During operation, when the submersible pump is immersed in water and the impeller 5 is rotated, water (liquid) is sucked through the numerous holes 4a drilled in the outer cylindrical surface of the cylindrical strainer 4, and the impeller 5 rotates. The pressure of the water is increased and the water is pumped outside from the discharge port 9.

[Problem that the invention attempts to solve]

In the conventional submersible pump described above, when used in a place with a lot of sand, etc., the area around the strainer 4 becomes buried with sand, making drainage impossible (called a sand lock). The stirring blades were attached in the shape of a skewer to float the sand around the strainer 4 in the water to prevent the sand from accumulating, but this structure had the problem of high cost.

In addition, since this type of pump uses a semi-open impeller 5, a suction cover 7 is required to properly adjust the gap between the impeller 5 and the suction cover. installed in
When water enters around the pump after piping is installed with a check valve, as shown in Figure 4,
Since there is no air escape inside the pump, air remains in the area of the air layer A, resulting in a condition where the pump cannot drain water even if the pump is operated (called an aerosk). In order to release the above airlock, the tip of the vane retaining nut 8 is extended to the water surface through the air layer (air area) as shown in the figure, and when the pump is operated, the vane retaining nut 8 prevents water. A method of forcibly pushing the blade into the casing has been adopted, but this structure has the problem that the blade retaining nut 8 becomes long, resulting in high cost.

The technical object of the present invention is to provide a submersible pump of this type that has a simple structure and can prevent air locks and prevent sand locks at construction sites with a lot of sand.

[Means for solving problems]

In order to solve the problems and technical problems of the prior art described above, the present invention uses a vortex type pump as the pump that is directly connected to the submersible motor via a shaft sealing device, and the pump is located above the strainer installed below the pump. The pump casing is characterized in that a plurality of vertical holes are provided on the outer peripheral plane of the pump casing to form an auxiliary strainer.

The above-mentioned vortex type pump has the rear shroud of the semi-open impeller set back within the pump casing, and the distance between the front side of the impeller and the side surface of the casing (or the bottom surface in the case of a vertical shaft) is widened.
During pump operation, the rotation of the impeller causes the liquid mainly in front of the impeller to rotate together with the impeller, thereby creating a turbulent vortex within the casing. In other words, it is a pump designed to transfer the liquid passing through the pump casing without coming into direct contact with the impeller as much as possible.

[Effect]

Since the present invention is constructed as described above, during pump operation, the transferred liquid flows through the entire casing and flows out to the discharge port due to the turbulent vortices within the casing formed by the rotation of the vortex impeller. I'll go. During this time, there is less flow between the blades of the impeller, and therefore the wear in the vortex pump is less on the impeller and more on the inside of the casing.

On the other hand, the strainer installed below the pump casing prevents sand from being sucked in from the construction site, but depending on the location or the quality of the sand,
The strainer will be completely buried in the sand.
However, even in such a case, water can be sucked in and discharged through an auxiliary strainer that is opened in the outer circumference of the pump casing above the strainer. Also, the auxiliary strainer is in the vertical direction (vertical direction).
Since the strainer has a large number of holes penetrating through it, sand can fall from the top, so it is less likely that the strainer will become clogged and obstruct the inflow of water.

In addition, after installing the submersible pump in a pit and installing a check valve on the discharge side and piping, if water flows into the pit, there is no place for the air in the pump casing to escape. The inside of the casing becomes an air pocket, but since the air below the casing escapes to the outside through the auxiliary strainer, water infiltrates up to the pump suction port. For this reason,
Even if the length of the wing retaining nut for preventing aerodynamics is minimized, aerodynamics will not occur.

〔Example〕

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

FIG. 1 is a side sectional view of a vertical shaft type submersible pump showing an embodiment of the present invention, and in the figure, the same reference numerals as those shown in FIG. 5 indicate the same or similar parts.

In the figure, an intermediate casing 11 is attached to the frame of an underwater motor 1 via a mechanical seal 2.
A pump casing 13 (see FIG. 3) with an open upper surface is arranged on the lower surface of the intermediate casing 11, and the pump casing 13 is attached to the frame of the submersible motor 1 by bolts 14. installed on.

Reference numeral 15 denotes a semi-open portex impeller, and the rear shroud 15a is moved back to approach the intermediate casing 11 as shown in the figure.
The vortex impeller 15 is attached to the pump shaft 6, and the distance between the front surface of the vortex impeller 15 and the bottom surface of the pump casing 13 is wide.

As described above, since the vortex impeller 15 is used, (a) a vortex chamber unlike a conventional spiral pump is not required on the outer periphery of the impeller 15, so that the pump casing can be designed to be small. Therefore, since the pump casing 13 can be designed smaller, a space (vacant space) for forming a vertical hole can be provided between the outer periphery of the casing 13 and the outer periphery of the strainer 4. () Furthermore, since it is not necessary to adjust the gap between the front surface of the vortex impeller 15 and the casing, the suction cover 7 (FIGS. 4 and 5) in the conventional type is not required. Therefore, a space can be provided between the outer periphery of the casing 13 and the outer periphery of the strainer 4 to form a vertical hole.

By adopting a vortex type pump as described above, a space is provided between the outer periphery of the casing and the outer periphery of the strainer, so the present invention utilizes this space to improve the outer circumferential plane of the pump casing 13 located above the strainer 4. An auxiliary strainer 16 opened in the vertical direction (vertical direction) is formed on the top. The auxiliary strainer 16, as shown in a plan view taken from the line in FIG. 1 in FIG. 2, is comprised of a number of vertical holes 16a bored at appropriate intervals in the circumferential direction.

In addition, in the figure, 17 is a handle, 18 is a cable, 19 is a hose joint, 21 is a wing retaining nut,
22 is a mounting bolt for the strainer 4.

According to this embodiment, when the submersible pump is used by being immersed in a pit, the transferred liquid is moved inside the casing 13 by the turbulent flow inside the casing 13 formed by the rotation of the vortex impeller 15. While flowing through the whole area, it flows into the discharge port as shown by the arrow C, and the strainer 4 prevents it from being sucked in at a normal construction site. However, in places with a lot of sand or depending on the quality of the sand, the strainer 4 may be completely buried in the sand. However, even in such a case, the auxiliary strainer 16, which is located above the strainer 4 and has holes in the outer circumference of the pump casing,
Since it has a large number of holes 16a penetrating in the vertical direction (vertical direction) (Fig. 2), the sand above the strainer 4 falls through these vertical holes 1 so that it falls from the top.
6a, it is unlikely that the auxiliary strainer 16 will become clogged and obstruct the inflow of water, and therefore it is possible to suck water through the auxiliary strainer 16 and discharge the sand, and in this way, the sand lock is Prevented.

Furthermore, after installing the submersible pump in a pit and installing a check valve on the discharge side and piping, if water flows into the pit, the air inside the pump casing will not be able to escape because there is no place for the air to escape. Although this becomes an air pocket, since the air below the casing escapes to the outside through the vertical hole 16a of the auxiliary strainer 16, water can enter up to the pump suction port. For this reason, the blade retaining nut 21 for preventing aerodynamics is
This prevents aerodynamics from occurring even if the length is minimized.

In the embodiment described above, the auxiliary strainer 16
Although the structure in which the vertical holes 16a constituting the vertical holes 16a are distributed in the circumferential direction as shown in FIG. 2 has been described,
It goes without saying that the size of these vertical holes 16a, their cross-sectional shape, and the number of installed vertical holes 16a can be changed in various ways depending on the condition of the installation location of the submersible pump.

[Effect of idea]

As explained above, according to the present invention, the pump that is directly connected to the submersible motor via the shaft sealing device is a vortex type pump, and the pump casing, which is located above the strainer and which has a space created by the use of the pump, is By forming the auxiliary strainer by providing multiple vertical holes on the outer peripheral plane, when the submersible pump is installed in a pit, the air below the pump casing is expelled to the outside through the vertical holes of the auxiliary strainer. When used at a construction site with a lot of sand, even if the strainer is buried in sand, the vertical hole of the auxiliary strainer on the outer circumferential plane of the pump casing located above the strainer will allow the sand to flow upward. Since water can be sucked in and discharged from the auxiliary strainer without falling through and clogging the vertical hole, sand lock can be prevented at low cost.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Fig. 2 is a plan view along the line shown in Fig. 1, Fig. 3 is a side sectional view of the pump casing, and Fig. 4 is a submersible pump showing a conventional example. FIG. 5 is a sectional view of the entire submersible pump. 1... Submersible motor, 2... Mechanical seal,
4... Strainer, 6... Pump shaft, 11... Intermediate casing, 13... Pump casing, 15
... Vortex impeller, 16 ... Auxiliary strainer, 16a ... Vertical hole.

Claims (1)

[Scope of utility model registration request] In a vertical shaft type submersible pump in which a pump having a semi-open impeller is directly connected to a submersible motor via a shaft sealing device and a strainer is attached below the pump, the pump is a vortex type pump and is located above the strainer. A vertical shaft type submersible pump characterized in that a plurality of vertical holes are provided on the outer peripheral plane of the pump casing to form an auxiliary strainer.