JPH11132181A - Backflow prevention device and submersible pump unit equipped with this device - Google Patents

Abstract

(57) [Summary] [Problem] To easily attach an air release valve and reliably perform air release. SOLUTION: An inflow pipe portion 32 is integrally provided with a valve casing 22 of a check valve 21 so as to communicate with an inflow port 23. An air discharge hole 33 is opened in the inflow pipe portion 32. A discharge pipe 34 is connected to the air discharge hole 33. An air vent valve 35 is provided at the downstream end of the discharge pipe 34. Of the air and the liquid material W that have flowed into the discharge pipe 34, the air is discharged from the air vent valve 35, but the liquid material W is not discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention device and a submersible pump unit provided with the device, and more particularly, to a check valve provided with a measure for bleeding air when transporting a liquid material.

[0002]

2. Description of the Related Art Conventionally, when transporting various liquids such as clean water, sewage or polluted water, for example, Japanese Patent Application Laid-Open No. 7-286
A submersible pump as disclosed in Japanese Patent Application Publication No. 595 is submerged in a liquid material, and the submerged pump is activated to pump the liquid material to a discharge pipe and to pump it. In this submersible pump, if air is present in the pump chamber, the liquid cannot be pumped to the discharge port at an appropriate pressure.Therefore, an air vent valve is incorporated in the pump casing to discharge air from the pump chamber to the outside. I have to. In general, a check valve as disclosed in Japanese Utility Model Publication No. 2545929 is provided downstream of the discharge pipe so as to prevent the pumped liquid from flowing back.

By the way, even if the air is discharged from the pump chamber of the submersible pump as described above, the air in the pump chamber cannot always be completely discharged from the air release valve, and a part thereof is discharged. May enter tube. Then, when this air accumulates in the discharge pipe portion between the discharge port of the submersible pump and the inflow port of the check valve, the air in the discharge pipe is compressed by the pressure when the liquid is pumped by the submersible pump. Since the fluid is compressed at the inflow port, an appropriate pressure does not act on the valve body of the check valve, and the valve body may not be operated. In this case, the liquid material cannot be pumped.

Therefore, generally, an air vent valve is provided in the middle of the discharge pipe, and the air accumulated in the discharge pipe is discharged to the outside from the air vent valve.

[0005]

However, when an air vent valve is provided in the middle of the discharge pipe, an air discharge hole is opened in the discharge pipe, and one end of the discharge pipe is connected to the air discharge hole by welding or the like. Since the air vent valve is attached to the other end of the discharge pipe, installation work such as drilling and welding is required, which complicates piping work and is uneconomical.

Further, since the interposed portion of the air vent valve is located in the middle of the discharge pipe, it is possible that air may flow downstream from the interposed portion, which may hinder the operation of the valve element of the check valve. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object of the present invention is to easily attach an air release valve and to reliably release air.

[0008]

In order to achieve the above object, the present invention is characterized in that an air vent valve can be attached to a check valve.

More specifically, the present invention includes a check valve having a valve body housed in a valve casing having an inlet and an outlet, and the valve body of the check valve is supplied from the inlet through the inlet. Opening the above-mentioned inlet to allow the liquid to flow from the inlet to the outlet, while not operating when the pressure of the liquid is not working, closing the inlet The following solutions are provided for a backflow prevention device configured to prevent the liquid material from flowing back out of the inlet and a submersible pump unit equipped with the device.

That is, the invention according to claims 1 to 7 is
The first aspect of the present invention relates to a backflow prevention device, wherein the invention described in claim 1 is based on the premise as described above, and an inflow pipe portion is integrally protruded from a valve casing of a check valve so as to communicate with the inflow port. I do. Further, an air discharge hole is provided in the inflow pipe portion.

According to a second aspect of the present invention, in the backflow prevention device of the first aspect, a discharge pipe is connected to the air discharge hole.

[0012] With the above arrangement, in the first and second aspects of the present invention, the air discharge hole is formed in the inflow pipe portion integrally protruding from the valve casing of the check valve. By simply connecting the discharge pipe to the existing air discharge hole by welding or screwing, the work of attaching the discharge pipe is easily performed, and the processing for the discharge pipe is not required, so that the piping work is simplified and economical. Further, since the air vent hole is located very close to the inlet of the valve casing, air is reliably discharged from the discharge pipe without being accumulated during this time, and there is no hindrance to the operation of the valve body of the check valve.

According to a third aspect of the present invention, in the first aspect of the present invention, the valve element of the check valve is a ball-type valve element.

According to the third aspect of the present invention, the configuration of the valve body of the check valve is embodied.

According to a fourth aspect of the present invention, in the first aspect, an air vent valve in which a valve body is accommodated in a valve casing having an inflow port and an outflow port is connected to an air discharge hole. The valve body of the air vent valve is not actuated by the pressure of the air flowing from the inlet, and the outlet is opened to allow the air to flow from the inlet to the outlet. The liquid material is operated by the pressure of the liquid material flowing in from above, and the outlet is closed to prevent the liquid material from flowing out of the outlet.

According to a fifth aspect of the present invention, in the second aspect, an air vent valve in which a valve body is accommodated in a valve casing having an inflow port and an outflow port is connected to a discharge pipe. The valve body of the air vent valve is not actuated by the pressure of the air flowing from the inlet, and the outlet is opened to allow the air to flow from the inlet to the outlet. The liquid material is operated by the pressure of the liquid material flowing in from above, and the outlet is closed to prevent the liquid material from flowing out of the outlet.

With the above arrangement, in the inventions according to the fourth and fifth aspects, even if air flows into the air vent valve via the inflow port (in the fifth aspect, from the discharge pipe through the inflow port), the valve body operates. However, the inflowing air is discharged through the outflow port, but when the liquid material flows into the air vent valve through the inflow port, the valve body operates to close the outflow port, and the inflowing liquid material flows out of the air release valve. Do not go.

The invention described in claim 6 is the invention according to claim 4 or 5
In the invention described in (1), the valve body of the air release valve is a ball-shaped valve body.

According to the above configuration, according to the sixth aspect of the invention, an embodiment of the valve body of the air vent valve is embodied.

The invention according to claim 7 is the invention according to claim 4 or 5.
In the invention described in (1), the valve body of the air vent valve is a bellows type valve body.

According to the above configuration, another aspect of the valve body of the air vent valve is embodied in the invention described in claim 7.

The invention according to claim 8 relates to the latter submersible pump unit, which is disposed in a liquid material,
A submersible pump for pressure-feeding the liquid substance sucked from the suction port to the discharge port, and a discharge pipe connected to the discharge port of the submersible pump and discharging the liquid substance pumped through the discharge port by the submersible pump, A backflow prevention device according to any one of claims 1 to 7 is provided downstream of the discharge pipe.

With the above arrangement, according to the invention described in claim 7, the liquid material is pumped up and discharged under pressure by the start of the submersible pump, and is discharged through the check valve. The liquid material passing through the check valve is prevented from flowing backward by the function of the check valve, and does not return to the upstream side of the discharge pipe. Further, when air flows into and accumulates in the discharge pipe, the accumulated air is reliably discharged to the outside from the air vent valve, and the liquid material does not leave the air vent valve.
And it is as described in the invention of claims 4 and 5.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a submersible pump unit A according to one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a submersible pump, which is provided with a pump casing 2.
And the pump chamber 4 are vertically partitioned by a lower bearing member 5. A rotating shaft 6 extending in the vertical direction is rotatably supported at the center of the motor chamber 3 by the lower bearing member 5 and an upper bearing member (not shown). The rotating shaft 6 is a motor 9 including a rotor 7 and a stator 8. The rotation of the shaft around the axis is started by the activation of the. The lower end of the rotating shaft 6 faces the pump chamber 4, and an impeller 10 is attached to the lower end, and the impeller 10 is rotated by the activation of the motor 9. A suction port 11 is provided at the center of the lower surface of the pump casing 2 so as to communicate with the pump chamber 4, and a discharge port 12 is provided at an upper side of the suction port 11. A discharge pipe 13 extending in the direction is connected.

The discharge pipe 13 comprises an upstream discharge pipe 14 and a downstream discharge pipe 15. A backflow prevention device B is interposed between the upstream discharge pipe 14 and the downstream discharge pipe 15, and The upper end flange 16 of the side discharge pipe 14 and the lower end flange 17 of the backflow prevention device B, and the lower end flange 18 of the downstream discharge tube 15 and the upper end flange 19 of the backflow prevention device B are fastened with bolts 20, respectively. Thus, the backflow prevention device B is disposed downstream of the discharge pipe 13 to integrally connect the three members.

As shown in FIGS. 2 and 3, the backflow prevention device B includes a check valve 21 serving as a main body thereof.
The check valve 21 has a valve casing 22.
An inlet 23 communicating with the upstream discharge pipe 14 is provided at the lower end of the valve casing 22.
A conical valve seat 24 is mounted around the periphery. An outlet 25 communicating with the downstream discharge pipe 15 is provided at an upper end of the valve casing 22.

A valve chamber 26 is formed in the valve casing 22. The valve chamber 26 accommodates a ball-shaped valve body 27 in which the surface of a steel ball 27a is covered with an elastic material 27b having excellent corrosion resistance. When no pressure is applied, the valve body 27 does not operate and sits on the valve seat 24, closes the inflow port 23 and shuts off the discharge pipe 13.

The side wall of the valve chamber 26 is constituted by a lid 28,
The lid 28 is provided between the O-ring 2 and the valve casing 22.
The cover 28 is fastened to the valve casing 22 by bolts 30 with the cover 9 interposed. The cover 28 is opened when the valve body 27 is accommodated in the valve chamber 26 or maintenance is performed.

A pair of guides 31 are formed on the inner wall of the valve chamber 26 from the side wall facing the lid 28 to the upper wall in a curved manner. When the pressure of the liquid material W is acting on the valve body 27, the valve is closed. The liquid material W in which the body 27 flows from the inflow port 23
That is, the valve body 27 is pushed up from the valve seat 24, retreats along the guide 31 as shown by the imaginary line in FIG. 1, and opens the inflow port 23. In this open state of the inflow port 23, the liquid material W flows from the upstream discharge pipe 14 via the inflow port 23 to the valve chamber 26 of the check valve 21.
, And is further discharged from the downstream discharge pipe 15 through the outlet 25. On the other hand, when the pressure of the liquid material W is not acting on the valve body 27, the valve body 27 does not operate and sits on the valve seat 24 as shown by the solid line in FIG.
To prevent the liquid material W from flowing back to the outside of the inlet 23, that is, to the upstream discharge pipe 14.

At the lower end of the valve casing 22 of the check valve 21, an inflow pipe portion 32 is integrally formed so as to communicate with the inflow port 23, and the inflow pipe portion 32 has an air discharge hole 3.
The air discharge hole 33 is connected to one end of an L-shaped discharge pipe 34.

At the other end (downstream end) of the discharge pipe 34, an air vent valve 35 is attached. This air vent valve 35
Is provided with a cylindrical valve casing 36, an inflow port 37 communicating with the discharge pipe 34 is opened at the lower end of the valve casing 36, and an upper wall member 38 is fitted at the upper end. At the center of the upper wall member 38, an outlet 39 that is open to the atmosphere is opened.

The inlet 37 in the valve casing 36
As shown in FIG. 4, a pair of plates 40 are arranged at intervals on the side, and the inner wall surface of the upper wall member 38 is formed in a tapered surface 38a.
The space between the upper wall member 38 and the upper wall member 38 forms a valve chamber 41. The valve chamber 41 also accommodates a ball-shaped valve body 42 in which the surface of a steel ball 42a is covered with an elastic material 42b having excellent corrosion resistance, similarly to the valve body 27 of the check valve 21. Normally, air is discharged from the inflow port 37 to the outflow port 39 through a gap between the plates 40 supported by the pair of plates 40 and not supporting the valve body 42.

The valve element 42 is connected to the inflow port 37.
Does not operate depending on the pressure of the air flowing in from the inlet port, the outlet port 39 is opened to allow the air to flow from the inlet port 37 to the outlet port 39, while the pressure of the liquid material W flowing from the inlet port 37 increases. The liquid material W is actuated and guided by the tapered surface 38a of the upper wall member 38 to close the inflow port 37 as shown by the imaginary line in FIG. 1 so as to prevent the liquid material W from flowing out of the outflow port 39.

As described above, the check valve 21 and the air release valve 3
5 is connected by a discharge pipe 34, and the backflow prevention apparatus B comprises an upstream discharge pipe 14 and a downstream discharge pipe 15;
Submersible pump unit A including a discharge pipe 13 interposed between the submersible pump 1 and the submersible pump 1 to which the discharge pipe 13 is connected.
As shown in FIG. 1, is used, for example, when a liquid material W such as sewage is pumped up at a sewage treatment plant or the like. The processing tank 4 is provided on the bottom surface of the pump casing 2 of the submersible pump 1.
A ground leg 44 is provided on the bottom surface 43a of the base 3 and a power cable 45 for supplying power to the motor 9 is provided at the upper end.

To explain an example of use of the submersible pump unit A, first, the submersible pump unit A is submerged in the processing tank 43, and the legs 44 of the submersible pump 1 are connected to the bottom surface 43 of the processing tank 43.
a, the submersible pump 1 is stabilized. On this occasion,
The air release valve 35 is made to protrude upward from the water surface.

Next, the submersible pump 1 (motor 9) is started. As a result, the impeller 10 rotates, and the liquid material W is sucked into the pump chamber 4 from the suction port 11, and
Through the discharge pipe 13. The liquid matter W sent to the discharge pipe 13 is pushed up in the discharge pipe 13 and is checked by the check valve 21.
Is reached, the valve body 27 is pushed up by the pressure of the liquid material W, separates from the valve seat 24, is guided by the guide 31 and retreats to the side inside the pump casing 2 as shown by the phantom line in FIG. To release. The opening 23 opens the inflow port 23 and the outflow port 25, and the liquid W is discharged from the inflow port 23 through the outflow port 25 to the outside of the processing tank 43 through the downstream discharge pipe 15.

At this time, when air is fed into the discharge pipe 13 together with the liquid material W, the air flows into the discharge pipe 34 from the inflow pipe 32 of the check valve 21 and reaches the air release valve 35. The valve element 42 of the air vent valve 35 does not operate even if air flows in, and the inflow air flows out of the gap between the plates 40 supporting the valve element 42 through the outlet 39 to the outside. If the liquid material W flows into the air bleeding valve 35 from the discharge pipe 34 via the outlet 39, the valve body 42 is actuated by the pressure of the liquid material W and closes the outlet 39. It does not leave the valve 35.

Further, since the air vent valve 35 is connected to the inlet 23 of the valve casing 22 in the immediate vicinity by the discharge pipe 34, air can be reliably discharged from the discharge pipe 34 without collecting air during this time. A situation in which the valve body 27 of the check valve 21 does not operate due to the presence of air can be avoided.

Further, since an air discharge hole 33 for guiding the air in the discharge pipe 13 to the air release valve 35 is formed in the inflow pipe part 32 which is integrally formed with the valve casing 22,
The air release valve 35 can be installed in the discharge pipe 34 by a simple mounting operation of simply connecting the discharge pipe 34 to the established air discharge hole 33 by welding or screwing, and the like.
Piping work can be simplified and made economical.

Thereafter, when the pumping operation of the liquid material W is completed, the submersible pump 1 (motor 9) is stopped, and the pressure feeding of the liquid material W to the discharge pipe 13 is completed. As a result, the pressure of the liquid material W is released, and the valve chamber 26
The valve body 27 retracted to the side is moved to the valve seat 2 as shown by the solid line in FIG.
4, the inlet 23 is closed by the valve body 27. Due to the blockage of the inlet 23, the inlet 23 and the outlet 2
5 is blocked, the backflow of the liquid material W pushed up to the downstream discharge pipe 15 side is prevented, and the liquid material W on the downstream discharge pipe 15 side can be prevented from returning to the processing tank 43.

The air vent valve 35 is not limited to the above-described one, and for example, an air vent valve 35 shown as a first modified example in FIGS. 5A and 5B may be employed. The air release valve 35 of the first modification is the plate 4 in the above-described embodiment.
A mesh-like material 46 having air permeability is adopted in place of 0,
The mesh 46 is arranged so as to partition the inside of the valve casing 36 up and down, and the air flowing in from the inlet 37 is discharged to the outside from the outlet 39 through the mesh of the mesh 46. It has become.

FIG. 6 shows a second modification of the air vent valve 35, in which the plate 40 in the above-described embodiment and the mesher 46 in the first modification are eliminated. 38.

FIG. 7 shows a third modified example of the air vent valve. Unlike the above three examples, a bellows type valve element is adopted as the valve element. That is, the plate-shaped valve element 49 is pivotally attached to the upper wall plate member 48 having the outlet 39 so as to be rotatable in the vertical direction by the hinge 50, and the plate-shaped valve element 4 is received by the receiving member 51 provided therebelow.
9 is held at a predetermined inclination angle.

Other configurations of the first to third modifications are the same as those of the above-described embodiment, and therefore, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. The operation and effect are the same as those of the above embodiment.

In the first and second modified examples except the third modified example, the ball type valve element 42 is a solid ball type valve in which the surface of a steel ball 42a is covered with an elastic material 42b having excellent corrosion resistance. Although a body was adopted, a float type having a hollow inside may be used. Also in the present embodiment, the present invention is not limited to the ball-shaped valve body 27 as described above, but in essence, any valve having a function of preventing the backflow of the liquid material W may be used.

[0047]

As described above, according to the present invention, the inflow pipe portion is integrally formed on the valve casing of the check valve and the air discharge hole is opened in the inflow pipe portion. Piping work can be carried out with a simple installation work simply by connecting a discharge pipe to the hole, which is economical. In addition, an air vent hole is located very close to the inlet of the valve casing,
Air can be reliably discharged from the discharge pipe without collecting air, so that operation of the valve element of the check valve is not hindered.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a submersible pump unit including a backflow prevention device.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5A is a longitudinal sectional view showing a first modified example of the air vent valve, and FIG. 5B is a sectional view taken along line VV in FIG. 5A.

FIG. 6 is a longitudinal sectional view showing a second modified example of the air vent valve.

FIG. 7 is a longitudinal sectional view showing a third modified example of the air vent valve.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 submersible pump 11 suction port 12 discharge port 13 discharge pipe 21 check valve 22 valve casing 23 inflow port 25 outflow port 27 valve element 32 inflow pipe section 33 air discharge hole 34 discharge pipe 35 air release valve 36 valve casing 37 inflow 39 flow Outlet 42 Valve body A Submersible pump unit B Backflow prevention device W Liquid

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor ▲ Kuni ▼ Keishi Hara 1-1-1, Shinmeiwa-cho, Takarazuka-shi, Hyogo Shinmeiwa Industry Co., Ltd. Industrial Machinery Systems Division

Claims (8)

[Claims] A check valve having a valve body accommodated in a valve casing having an inflow port and an outflow port, wherein the valve element of the check valve is actuated by the pressure of a liquid material flowing from the inflow port. The liquid inlet is opened to allow the liquid material to flow from the inlet to the outlet, but does not operate when the pressure of the liquid material is not acting. A backflow prevention device configured to prevent backflow to the inflow pipe, wherein an inflow pipe portion is integrally provided with a valve casing of the check valve so as to communicate with the inflow port; A backflow prevention device characterized in that an air discharge hole is opened in the part. 2. The backflow prevention device according to claim 1, wherein a discharge pipe is connected to the air discharge hole. 3. The backflow prevention device according to claim 1, wherein the valve body of the check valve is a ball-shaped valve body. 4. The backflow prevention device according to claim 1, wherein an air vent valve in which a valve body is accommodated in a valve casing having an inlet and an outlet is connected to an air exhaust hole, and the valve body of the air vent valve is It does not operate due to the pressure of the air flowing in from the inflow port, but opens the outflow port to allow the air to flow from the inflow port to the outflow port, while operating by the pressure of the liquid material flowing in from the inflow port. And a backflow prevention device configured to close the outflow port to prevent the liquid material from flowing out of the outflow port. 5. The backflow prevention device according to claim 2, wherein an air vent valve in which a valve body is accommodated in a valve casing having an inlet and an outlet is connected to a discharge pipe. It does not operate by the pressure of the air flowing in from the inflow port, while opening the outflow port to allow the air to flow from the inflow port to the outflow port, and operates by the pressure of the liquid material flowing in from the inflow port. A backflow prevention device configured to close the outflow port to prevent the liquid material from flowing out of the outflow port. 6. The backflow prevention device according to claim 4, wherein the valve body of the air release valve is a ball type valve body. 7. The backflow prevention device according to claim 4, wherein the valve body of the air release valve is a bellows type valve body. 8. A submersible pump arranged in the liquid material and for pumping the liquid material sucked from the suction port to the discharge port, and connected to the discharge port of the submersible pump and pumped through the discharge port by the submersible pump. A discharge pipe for discharging a liquid material, wherein the backflow prevention apparatus according to any one of claims 1 to 7 is provided downstream of the discharge pipe. Submersible pump unit equipped with