JPH0788825B2 - Electric pump with jet pump - Google Patents

Description

The present invention relates to an electric pump with a jet pump suitable as an automatic water supply device.

[Conventional technology]

A conventional electric pump with a jet pump
As described in Japanese Patent No. 164108, a jet pump is configured to be attachable to and detachable from a pump casing, and further, a booster of the jet pump is arranged so as to be orthogonal to the axis of the pump impeller, thereby achieving miniaturization. Are known.

[Problems to be solved by the invention]

In such an electric pump with a jet pump, there is a phenomenon that when the speed of water passing through the venturi of the jet part becomes high, pressure drop occurs and cavitation occurs. To solve this problem, the venturi is bypassed. It is necessary to provide a bypass valve and open the bypass valve when cavitation occurs.

However, the above-mentioned conventional technique has a problem in that no consideration is given to the specific arrangement and configuration of the bypass valve.

[Means for solving problems]

A feature of the present invention is that the jet pump (4) is replaced by the pump (2).
And a suction passage (60) which is configured to be detachable from the casing (16) and which is connected to the suction port (20) by aligning the jet pump (4) with the axis of the impeller (12) of the pump (2). ,
The pressure line (58) connected to the pressure port (24) and the pressure line (5)
8) and the suction passage (60) are connected to each other, the water from the pressure passage (58) is made into a jet, the water is sucked from the communication passage (64), and the sucked water flows out in a direction orthogonal to the suction passage (60). Provided on the opposite side of the synthetic resin booster (52) from the suction port (20) of the suction passage (60), the suction passage (60) and the communication passage (in the range not interfering with the water flowing out from the booster (52) ( It is composed of a valve element that communicates both passages in response to the pressure difference on the 64) side.

[Action]

The jet pump receives the pressurized water from the pressure port, sucks the water from the communication passage by the booster, and discharges the water so as to be orthogonal to the suction passage.

Then, when the pressure difference between the suction passage of the jet pump and the communication passage becomes equal to or greater than a predetermined value, the valve element opens and the water from the communication passage is bypassed and supplied to the suction passage.

According to this configuration, the bypass valve acts at a position where it does not interfere with the flow of water of the jet pump while achieving downsizing, so that the correct operation of the bypass valve is guaranteed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

As is clear from FIG. 1, the electric pump with a jet pump has an electric centrifugal pump 2, a jet pump 4, and an automatic operation control device 6 as main functional parts.

A centrifugal impeller 12 is attached to the tip of a rotary shaft 10 of an electric motor 8 that drives the pump 2. Further, the casing 16 and the bracket 18 form a pump chamber 14 for housing the impeller 12, and the pump chamber 14 has a suction port for pumping water.
20, a pressure increasing passage 22 for efficiently converting the velocity head of the discharge water from the impeller 12 into a pressure head, and a pressure port 24 for supplying a part of the pressure increasing water to the jet pump 4 on the downstream side of the pressure increasing passage 22. A discharge port 26 for discharging the remaining pumped water and a water conduit 28 leading to the automatic operation control device 6 are provided. Either the discharge port 26 or the water conduit 28 may be combined. Further, the jet pump 4 is attached across the suction port 20 and the pressure port 24.

Further, the automatic operation control device 6 includes a pressure accumulator 30, an electric circuit switching device 32 of the electric motor, and a flow rate control device 34. In this example, the pressure accumulator 30 is a gas pressure pre-filling type pressure tank, and the inside of the pressure vessel 36 is divided into two parts by a thin film pressure receiver 38 such as a rubber bag, and the air supply plug 40 on one chamber side is connected. An air-sealing chamber 42 for compressing and enclosing a gas is provided, and a water guiding chamber 44 for introducing a part of pumped water is provided on the other chamber side.

As the opening / closing device 32, a pressure-responsive type such as a pressure switch for sensing the internal pressure to control the pump operation, or a flow-sensitive type such as a flow rate switch for sensing the running water amount to control the pump operation is used. . In this embodiment, a pressure switch will be described as an example.

The flow rate control device 34, for example, between the pressure accumulator 30 and the pump chamber 14, when the pumped water flows into the pressure accumulator 30, to narrow the flow path to suppress the inflow speed, from the accumulator 30 to the pump chamber. In the case of outflow to 14, the resistance valve 46 is provided so that the flow path is widened to reduce the resistance, so that the flow amount of water to the pressure accumulator is appropriately adjusted and the frequency of operation of the switchgear 32 is prevented from increasing. It is a thing. Further, a water supply plug (not shown) communicated with a water supply pipe is attached to the downstream side of the discharge port 26.

The jet pump 4, as shown in FIG.
On the side opposite to the casing 16 of the
54 and a holder 56 are attached. In this body 50, a pressure path 58 communicating with the pressure port 24 of the pump chamber 14 is provided.
And a suction passage 60 communicating with the suction port 20 is provided.
Further, the booster 52 has a rectangular parallelepiped shape made of synthetic resin, and has a pressure water jet passage 52A and a pumped water inflow passage 52B.
The mixing path 52C for mixing the pressure water and the pumped water, and the discharge port 5
2D and 2D are integrally formed. This booster 52
By mounting the opening surface 52F side of the above to the mounting surface 50F provided on the body 50, these flow paths are formed respectively, so there is no restriction due to the material of the casing 16, corrosion resistance, or surface finishing accuracy. The mixing passage 52C is provided with a gradually expanding passage 52E whose flow passage area gradually increases toward the discharge port 52D. In this gradually expanding passage 52E, the energy of the mixed water of the pressure water and the pumping water from the pump chamber 14 gradually slows down, and the energy conversion action of converting the velocity head into the pressure head to perform a pressure increasing action is performed. Is. These jet channels 52A and inflow channels 5
Since 2B and the mixing passage 52C are provided so as to open on the same side of the booster 52, in the case of the synthetic resin molding of the booster 52, the mold can be demolded in one direction, so the moldability is good. is there. In addition, compared with a conventional jet pump in which the jet passage and the mixing passage are configured as separate parts, the jet passage
The coaxiality between 52A and the mixing path 52C can be formed with high precision, and the performance of the jet pump 4 can be kept high.

Further, if the booster 52 is detachably attached to the body 50, even if foreign matter is stuck inside the body 50 or the booster 52, it can be easily removed and cleaned, and the maintainability is good. Also, by combining with boosters of different dimensions,
Different pump characteristics can be obtained only by changing the booster 52,
The field of application as a device will also be wide-ranging.

Further, if the booster 52 is configured to be sandwiched between the body 50 and the casing 16, the booster 52 generated at the time of synthetic resin molding
That and the deformation can be corrected, and the performance of the jet pump 4 can be further improved. Further, the external force applied to the booster 52 is only a small compressive force due to the pinching, and even if the pump chamber 14 becomes hot due to abnormal operation or the like, the deformation of the booster 52 is suppressed, so a special high-strength material is used for the booster 52. There is no need to use it.

Also, booster 52 and casing 16 or mounting surface 50A
If an elastic sealing material such as flat packing is interposed between
Even if the casing 16 and the body 50 are made of metal, it is possible to suppress the effects of corrosion and finish accuracy.

Further, the disc-shaped valve body 54 is formed of an elastic body such as synthetic resin or rubber. Further, the holding body 56 has a tubular guide portion 56A that loosely holds the valve body 54, a disc-shaped locking portion 56B, and a holding portion 56C attached to the body 50, which are integrally formed of synthetic resin. There is.

As shown in the front cross section of the jet pump 4 in FIG. 3, a partial opening 62 is provided in the middle of the suction passage 60.
The valve body 54 is attached to the suction port 20 side by a holding body 56 so as to be movable in the axial direction.

The valve body 54 opens and closes the opening 62 in response to the pressure difference between the upper passage 60A and the lower passage 60B of the suction passage 60. Here, in the opening 62, the respective axes are vertically shifted so that the lower channel 60B is higher than the upper channel 60A. This is because the air in the pipes stays in the upper flow passage 60A during self-priming operation to cause an air lock, or the pump performance is not adversely affected by the air flow from the upper flow passage 60A to the lower flow passage 60B. It is designed to be able to move quickly.

As described above, the booster 52 is detachably attached to the body 50 so as to extend between the pressure passage 58 and the suction passage 60.

The ejection passage 52A of the booster 52 communicates with the pump chamber 14 through the pressure passage 58. Further, the outlet 52D of the mixing passage 52C is provided with a suction passage 60 which leads from the valve body 54 to the impeller 12.
The lower channel 60B is opened at a right angle from below. This outlet 52D
Is opened by shifting the dimension of the suction passage 60 by the dimension L so that the valve element 54 is not located on the extension line of the mixing passage 52C, and prevents the outflow water from adversely affecting the opening / closing operation of the valve element 54. To be done.

In addition, the IV-IV cross section of FIG. 3 is shown in the right half of FIG. 4, and as shown in FIG. 5 showing the VV cross section of FIG.
A communication passage 64 is provided in the body 50 so as to connect the inflow passage 52B of the booster 52 and the upper flow passage 60A. Booster 52
By attaching the to the body 50, the communication passage 64 and the lower flow passage 60
B and the pressure path 58 are separated from each other. The body 50 is detachably and watertightly attached to the casing 16 by a plurality of bolts 68 via an annular sealing body 68 mounted in the storage groove 66. Further, a check valve 70 is provided in the upper flow path 60A portion upstream of the communication passage 64, and the check valve 70 is provided.
In the present invention, is composed of an elastic umbrella-shaped valve 72 and a valve seat 74 having a plurality of openings. The upstream passage 60A is connected to the water source via the check valve 70. Therefore,
The water source and the booster 52 of the jet pump 4 are connected by a communication passage 64 and an upstream passage 60A which is a part of the communication passage 64.

Since the pressure passage 58, the suction passage 60, the opening 62, the communication passage 64, and the storage groove 66 of the body 50 are formed so as to open in the axial direction of the suction passage 60, respectively, even in the case of using synthetic resin, Die cutting can be done in one direction, making it easy to mold the body 50 and reducing the number of parts. Further, the booster 52 is held between the body 50 and the casing 16 so that the suction passage 60 is
The axial length of the body can be significantly shortened compared to the conventional jet pump, the pump as a whole can be downsized, and the bending moment applied to the body 50 due to the weight of the suction pipe can be reduced. The reliability of the pump can be improved by maintaining the hermeticity between 16 and maintaining the strength.
Further, since the mixing path 52C is formed by combining the booster 52 made of synthetic resin and the body 50, it is possible to prevent performance deterioration due to the generation of rust.

Next, the pumping action will be described. Prior to the operation of the pump, the pump chamber 14 and the jet pump 4 are filled with priming water. At this time, the pressure port 24 is opened in the lower portion of the pump chamber 14, and the upper flow passage 60A and the booster 52 communicate with each other through the communication passage 64, and the lower flow passage 60B is higher than the upper flow passage 60A. , The priming water poured into the pump chamber 14 is a pressure port
The air flows into the jet pump 4 from 24, and the internal air is pushed upward toward the upper flow path 60A, so that the air is discharged and the water and the air are quickly filled.

Next, when the electric motor 8 is energized, the centrifugal pump 2 starts the self-priming action prior to the pumping operation. The air in the suction pipe sucked into the impeller 12 together with the priming water is separated into water and water on the discharge side of the pressurizing passage 22, the water is supplied to the jet pump 4 through the pressure port 24 at the lower part of the pump chamber 14, and the air is discharged. It is discharged from the outlet 26. The water supplied to the jet pump 4 is ejected from the ejection passage 52A of the booster 52 to generate a low pressure in the surroundings, and when it flows into the upper passage 60A of the suction passage 60, the air in the suction pipe passes through the communication passage 64 from the inflow passage 52B. Inhale. The air is mixed with water in the mixing passage 52C, and is sucked into the impeller 12 again through the lower passage 60B of the suction passage 50. In addition, during this self-priming operation, the impeller 12
Due to its own suction force, when the upper flow passage 60A of the suction passage 60 flows in, a part of the air in the suction pipe passes through the lower flow passage 60B via the opening 62 and the valve body 54 and is sucked into the impeller 12 as it is. .

At this time, the opening 62 is provided close to the upper end of the upper flow path 60A, and the lower flow path 60B is positioned above the upper flow path 60A so that the ceiling wall of the lower flow path 60B is located above the ceiling wall of the upper flow path 60A. It is eccentric upwards. Therefore, the air in the suction pipe floating on the ceiling wall of the upper flow passage 60A can be promptly introduced into the lower flow passage 60B through the opening 62 and sucked into the impeller 12, so that the self-priming performance is improved. In addition, by opening the mixing passage 52C of the booster 52 so as to intersect with the lower flow passage 60B, the air staying in the ceiling portion of the lower flow passage 60B is atomized by the jet water from the booster 52 and is actively used as priming water. Air-mixing in the lower channel 60B can be prevented by mixing air and water. In this way, the priming water circulates between the pump chamber 14 and the jet pump 4 through the pressure port 24. Further, since the pressure port 24 is provided in the pump chamber 14 at a position lower than the suction port of the impeller 12, only the water separated in the pump chamber 14 is supplied to the booster 52, and the air is jet pumped. Since it is suppressed from being caught in 4, the self-priming performance is improved, and the pumping operation is not adversely affected. In this way, air suction, air-water mixing, air-water separation, air discharge, and priming water circulation are continuously performed, whereby air is gradually discharged to a low pressure in the suction pipe, and finally water is pumped from the water source. It

Next, the pumping action and performance will be described with reference to FIG.
When the faucet on the discharge side is fully opened and the operating head is low (head Hb or less), the water supplied from the pump chamber 14 to the booster 52 through the pressure passage 58 is also at low pressure, and the booster 52 is mixed. Since the flow passage area of the passage 52C is small and the flow resistance is large, the lower flow passage 60B has a lower pressure than the upper flow passage 60A due to the suction force of the impeller 12, and the valve body 54 opens the opening 62 due to the pressure difference. Therefore, most of the pumped water is sucked into the impeller through the opening 62 from the upper channel 60A and directly from the lower channel 60B. Therefore, the amount of pumped water is significantly increased compared to the maximum amount of water (water amount Q) when all boosters 52 are pumped (Q to Q).
_max ). Further, since the booster 52 is not located in the suction passage 60, the flow passage area can be sufficiently secured, and therefore cavitation can be prevented.

Next, the faucet is squeezed and the water supply decreases (the pumping amount Q point),
When the pressure on the discharge side becomes high (lift head Hb point), the amount of water supplied from the pump chamber 14 to the booster 52 through the pressure passage 58 also becomes large due to the high pressure, and the boosting action of the booster 52 becomes stronger. . Therefore, the high pressure water from the booster 52 causes the lower flow path 60
The pressure of B becomes higher than that of the upper flow path 60A, and the valve body 54 closes the opening 62. Therefore, when the amount of pumped water is less than the point Q, all of the pumped water passes from the upper flow path 60A through the communication passage 64 and the booster 52.
From the inflow channel 52B to the mixing channel 52C, and the pressure is increased
It enters 60B and is sucked into the impeller 12. Therefore, the lift is H
With respect to the pumping characteristics when the pumping head is higher than b (the amount of pumping is a small amount of water below the Q point), the pressure gradient remarkably increases as compared with the case of a low pumping head (below Hb). Therefore, with this jet pump 4,
A remarkable pressure increasing effect is obtained as compared with the maximum head (Hp) in the case where the impeller 12 is operated alone. Thus, when the amount of water is small,
The high pressure required to operate an automatic operation control device such as a pressure switch is obtained.

〔The invention's effect〕

According to the present invention, since the bypass valve for preventing cavitation is operated at a position where it does not interfere with the jet flow of the jet pump while achieving downsizing of the electric pump with a jet pump, accurate operation of the bypass valve is achieved. Can be guaranteed.

[Brief description of drawings]

FIG. 1 is an electric pump with a jet pump showing an embodiment of the present invention, FIG. 2 is a development configuration diagram of the jet pump of FIG. 1, and FIG. 3 is a central sectional view of the jet pump of FIG. 4, the left half is a front view of the jet pump, the right half is the IV-IV sectional view of FIG. 3, and FIG. 5 is the VV line of FIG.
A sectional view and FIG. 6 are pumping characteristic diagrams of the electric pump with a jet pump according to the present invention. 2 ... Vortex pump, 4 ... Jet pump, 10 ... Rotating shaft, 12 ... Imperor, 14 ... Pump chamber, 20 ... Suction port, 50
…… Booster, 60 …… Suction path.

Claims (1)

[Claims] 1. A jet pump (4) having a suction port (20) connected to an impeller (12) of a pump (2) and a pressure chamber (24) for discharging a part of boosted water from the impeller (12). ), The jet pump and a communication passage (64) connected to a water source are connected to each other, and water from the pressure chamber (24) is caused to flow into the jet pump (4). In an electric pump with a jet pump that sucks water from a water source from the communication passageway (64) by a jet of water and supplies it to the suction port (20), the jet pump (4) is a casing of the pump (2) ( 16) A suction passage (60) that is configured to be detachable from the suction pump (4) and that connects the jet pump (4) to the suction port (20) in line with the axis of the impeller (12) of the pump (2). And a pressure path (58) connected to the pressure port (24)
And the pressure passage (58) and the suction passage (60) are connected to each other, the water from the pressure passage (58) is jetted to suck the water from the communication passage (64) and the sucked water is sucked into the suction passage. Booster (52) made of synthetic resin flowing out in the direction orthogonal to (60)
And the suction passageway (60) and the communication passageway (64) side provided on the opposite side of the suction passageway (60) from the suction opening (20) and within a range that does not interfere with the water flowing out from the booster (52). An electric pump with a jet pump, characterized in that it is configured with a valve body that communicates both passages in response to the pressure difference of the above.