EA038211B1 - Centrifugal pump - Google Patents

Abstract

A centrifugal pump contains a shaft-mounted impeller 6 in a housing 2, an inlet chamber 11 and a discharge chamber 10 of the pumped medium, as well as a jet ejector device with an inlet channel 12 for supplying the pumped medium from the inlet chamber 11 to the impeller 6, and with an inlet operating nozzle 13 installed in alignment with the above inlet channel 12 and connected to the discharge chamber 10 with its own inlet, as well as a valve made with a seat 24 and a spring-mounted and membrane 21 fixed shut-off control element 22 for regulating the flow of the pumped medium injected through the nozzle 13 of the ejector device. The impeller 6 contains two disks between which blades of a special form are fixed: they are curved in the direction opposite to the direction of the impeller 6 rotation. The inlet chamber 11 is equipped with an inlet fitting 17, the discharge chamber 10 is connected to an outlet fitting 18. In the housing 2, a bypass channel 14 is made hydraulically parallel to the nozzle 13 of the ejector device. The ejector device is equipped with a tube 3 placed in the discharge chamber 10 inside which the inlet channel 12 is arranged connected to the inlet fitting 17. The valve is arranged in a flow-type cavity 16 made in the housing 2 to control the shut-off control element 22 with the possibility of opening and closing the bypass channel 14. The flow-type cavity 16 is formed on one side by the membrane 21 and connected to the discharge chamber 10 with flow-type through holes 15 made in the housing 2, and to the inlet nozzle 13 of the ejector device - with flow-type through holes 25. The valve seat 24 is made on the edge of the bypass channel 14 facing the cavity 16 with the possibility of interaction with the shut-off control element 22 when the latter moves together with the membrane 21. As a result, the pump sizes and weight are reduced due to the optimal scale integration of the valve and the nozzle, while the head changes insignificantly, as the slope of the pump head-capacity curve in the most used operating range of flow values is significantly reduced.

Description

The invention relates to the field of mechanical engineering, in particular to vane pumps for supplying water for domestic or industrial purposes.

Known centrifugal pumps with a jet ejector device that enables the pump to start and self-priming during operation.

In particular, centrifugal pumps with jet ejector devices SU 108211, SU 234868, SU 1021819, US 2484105, US 2524770, EP 0401670, EP 0361329 are known.

Each known centrifugal pump has a fixed flow-pressure characteristic, which is the main indicator when choosing a pump for a water supply system. However, even the most optimal pump selection does not exclude pressure drops with varying flow rates due to the inverse relationship of these parameters in a centrifugal pump. In practice, this is reflected in deviations from the comfortable pressure value when opening or closing additional water draw-off points (sink taps, shower taps, etc.) and leads to the need for manual adjustment of the comfort mode.

The closest analogue to the claimed device is a centrifugal pump containing a vane impeller mounted on a shaft in a housing, suction and discharge chambers of the pumped medium, as well as a jet ejector device with a suction channel for supplying the pumped medium from the suction chamber to the impeller, and with an inlet impeller a nozzle installed coaxially to the specified suction channel and connected by its inlet with the pressure chamber, as well as a valve made with a seat and with a spring-loaded shut-off and control element fixed to the membrane to regulate the flow of the pumped medium through the nozzle of the ejector device (SU 108211, prototype).

The disadvantages of the closest analogue are large dimensions and weight, as well as a significant dependence of the pressure developed by the pump on the flow rate of the pumped medium, which changes the mode of fluid consumption when changing the analysis by consumers and thereby worsens the conditions for water supply to consumers.

The technical problem of the present invention is to create a compact centrifugal pump capable of maintaining a stable compressed range of a pressure value in a comfortable range at a flow rate varying in a certain and typical for a particular water supply system, as well as expanding the arsenal of centrifugal pumps

The technical result, allowing to solve the specified problem, is to reduce the slope of the flow-pressure characteristics of the pump in a wide range of flow rates, to reduce the size and weight of the pump due to optimal integration in one device.

In the drawing, FIG. 1 shows a cross-section of the JUMBO COMFORT centrifugal pump, FIG. 2 is a left side view of FIG. 1, FIG. 3 is a cross-section of a centrifugal pump in axonometric projection, FIG. 4 - flow-pressure characteristics of two standard sizes of the inventive pump, FIG. 5 is a left side view of a built-in ejector; FIG. 6 is a cross-section of a built-in ejector, FIG. 7- axonometric projection of the built-in ejector.

The centrifugal pump contains a vane impeller 6 mounted on a shaft in a housing 2, a suction chamber 11 and a pumped medium pumping chamber 10, as well as a jet ejector device with a pump suction channel 12 for supplying the pumped medium from the suction chamber 11 to the impeller 6, and with an inlet a working nozzle 13, installed coaxially to the specified suction channel 12 and connected by its inlet with the pressure chamber 10, as well as a valve made with a seat 24 and a spring-loaded shut-off and control element 22 fixed to the membrane 21 to regulate the flow of the pumped medium through the nozzle 13 of the ejector device ...

The impeller 6 consists of two discs, between which are fixed blades (not shown) of a special shape: they are bent in the direction opposite to the direction of rotation of the wheel 6. The suction chamber 11 is equipped with an inlet 17, the discharge chamber 10 is connected to the outlet 18.

In the housing 2, hydraulically parallel to the nozzle 13 of the ejector device, a bypass channel 14 is made. The ejector device is equipped with a placed injection chamber 10 with a tube 3, inside of which a suction channel 12 is made connected to the inlet fitting 17. The valve (i.e. its shut-off element 22) is located in additionally made in the body 2 of the flow cavity 16 for controlling the shut-off and regulating body 22 with the possibility of opening and closing the bypass channel 14.

The flow control cavity 16 is formed on one side of the said membrane 21 and is connected by several flow through holes 15 made in the housing 2 to the injection chamber 10 and several flow through holes 25 to the inlet nozzle 13 of the ejector device. The valve seat 24 is made on the edge of the bypass channel 14 facing the control cavity 16 with the possibility of interacting with the shut-off and control element 22 when the latter moves together with the membrane 21.

The tube 3 of the ejector device from the side of the nozzle 13 is made with a groove 26 connected with its bypass channel 14, in which the nozzle 14 is located, and the suction channel 12 is made in the form of a conical diffuser.

The shut-off and regulating body 22 of the valve is made of brass, spring-loaded by a cylindrical compression spring 23 installed in the removable cover 20 of the body and supported through a washer (not indicated) on the membrane 21.

The shut-off and regulating body 22 is equipped with a brass rod (not indicated) made integral with it, installed in a guide 27, made integral with a removable cover 20 fixed with screws 19.

The shut-off and regulating body 22 of the valve is made with a spherical working surface for interaction with the seat 24.

The valve seat 24 is tapered. The seat 24 is made of brass and is cast as an insert when casting the body 2.

The bypass channel 14 is made up of two bushings (not indicated), one of which is made integral (in one monolithic part 28) with the nozzle 13, and the other is coaxial with the opening of the body 2 with the valve seat 24.

The impeller 6 is equipped with a guide vane 4, enclosed in a housing 2 by a base 5, which separates the hydraulic part of the pump from the electric motor.

The ejector device on the side opposite to the nozzle 13 is made with a collar 29 for mounting the guide vane 4 on it.

The entire hydraulic part is plastic, made of polypropylene, which is a thermoplastic polymer of propylene (propene). Polypropylene is obtained by polymerizing propylene in the presence of metal complex catalysts.

The tube 3 and the part of the ejector device 28 are connected by ultrasonic welding, for which, along the perimeter of the joint with the tube 3, the part 28 has along its edge a protrusion (see Fig. 6) of an annular shape (not indicated), which is fused in an annular groove (not indicated) of the part (tubes) 3 when exposed to high-frequency ultrasonic vibrations on specialized equipment. This, in particular, ensures the compactness of the device as a whole and its minimum weight, in comparison with products for the same purpose.

The centrifugal pump is equipped with an automatic control unit 7 connected to the pressure chamber 10, which is connected to the pump casing 2 by means of a connecting nipple 9 and is fixed with a union nut 8, while the angle of the outlet nipple 18 relative to the pump axis (and the inlet nipple 17) can be arbitrary, which gives additional convenience during installation. The connecting piece 9 is in communication with the high pressure cavity 10 of the pump.

The centrifugal pump has an electric motor 1, mounted coaxially with a vane impeller 6.

The centrifugal pump works as follows.

Before starting the suction and discharge chambers, the housings are completely filled with water.

When the electric motor 1 is turned on, the pressure and movement of the liquid arise as a result of the action of the centrifugal force created by the rotation of the impeller 6.

Passing into the channel 12 through a nozzle 13 with a decreasing diameter, the flow of the liquid medium acquires a noticeable acceleration, which contributes to the formation of a low pressure region in the channel 12 at the suction of the pump.

Due to the appearance in the jet flowing from the nozzle 13, the vacuum effect into the channel 12 is directly sucked in the liquid medium in the chamber 11.

In the process of rotation of the impeller 6 blades in the casing 2 filled with water, the centrifugal force generated by them pushes the liquid from the center to the periphery, where an increased pressure arises, displacing water through the pressure chamber 10 into the outlet pressure connection 18.

In the central zone of the impeller 6, the pressure decreases, and water rushes there through the inlet nozzle 17, chamber 11 and channel 12 from a source - a reservoir, a well, a well, etc. As a result, the liquid is supplied continuously.

The automatic control unit 7 is an independent device and, when working with the proposed pump, serves to connect the pump to the power supply when parsing water and disconnecting it in the absence of parsing, does not allow the pump to be turned on in the absence of water. Stop of the pump is determined by a decrease in the consumed flow to a minimum value with a delay of 7-15 s.

Subsequent starts of the pump are made by block 7 when the starting pressure is reached, after opening the valve.

The inventive automatic pump under the name JUMBO COMFORT with a built-in control valve allows maintaining the pressure value in a comfortable range at a flow rate varying in a certain and typical for a particular water supply system.

Regulation of the pressure (maintaining the optimal flow-pressure characteristics) of the pump in the comfortable range allows stabilizing the mode of consumption of the fluid when changing the analysis by consumers, i.e. avoid pressure surges when opening and closing several taps at the same time. As shown in FIG. 4, head of two standard sizes 60/35 comfort and 70/50

- 2 038211 the comfort of the proposed JUMBO COMFORT pump varies in the operating range of flow rates up to l / min within no more than 10 m, in contrast to the usual pump versions 60/35 and 70/50.

This is achieved due to the functioning of the valve built into the cavity 16, which regulates the ratio of the flow values in the bypass channel 14 and the nozzle 13, acting as follows. The pressure developed by the pump in the chamber 10 is monitored by the membrane 21, since the cavity 16 on one side of the membrane 21 is connected by windows 15 in the housing 2 with the injection chamber 10 - high pressure. On the other hand, the force of the spring 23 acts on the membrane 21. The stem of the shut-off-regulating element 22 is rigidly attached to the membrane 23, which, under the influence of the spring 23 on the one hand and the force acting on the membrane 21 of the pressure in the cavity 16, on the other hand, changes the flow area between the spherical surface of the locking and regulating element 22 and the conical surface of the seat 24 (the valve is opened or closed). When the valve seat 24 is opened, a larger volume of water is directed from the high-pressure chamber 10 through the holes (windows) 25 into the bypass channel 14 and then through the channel 12 of the ejector tube 3 back to the inlet of the impeller 6; camera 10.

As a result, a reduction in the dimensions and weight of the pump is ensured due to the optimal integration of the valve and nozzle, while the change in pressure is insignificant, since the steepness of the flow-pressure characteristic of the pump is significantly reduced in the most used operating range of flow rates.

Claims (10)

CLAIM 1. A centrifugal pump containing a vane impeller mounted on a shaft in a housing, suction and discharge chambers of the pumped medium, as well as a jet ejector device with a suction channel for supplying the pumped medium from the suction chamber to the impeller and with an inlet working nozzle installed coaxially to the specified channel suction and connected with its inlet to the discharge chamber, as well as a valve made with a seat and with a spring-loaded shut-off and control element fixed to the membrane to regulate the flow of the pumped medium through the nozzle of the ejector device, characterized in that a bypass channel is made in the body parallel to the nozzle of the ejector device , the ejector device is equipped with a placed pressure chamber with a tube, inside of which a suction channel is made, and the valve is placed in a shut-off-regulating body additionally made in the body of the control flow cavity with the possibility of full or partial opening and closing of the acceleration channel, while the control flow cavity is formed on one side of the said membrane and is connected by the flow through holes made in the housing with the pressure chamber and with the inlet nozzle of the ejector device, and the valve seat is made on the edge of the bypass channel facing the control cavity with the possibility of interacting with the shut-off -regulatory body when moving the latter together with the membrane. 2. The centrifugal pump according to claim 1, characterized in that the tube of the ejector device on the nozzle side is made with a groove connected to its bypass channel, in which the nozzle is located, and the suction channel is made in the form of a diffuser. 3. The centrifugal pump according to claim 1, characterized in that the shut-off and control valve body is spring-loaded by a cylindrical spring installed in a removable housing cover. 4. The centrifugal pump according to claim 3, characterized in that the shut-off and regulating body is equipped with a rod installed in a guide made in one piece with a removable cover 5. The centrifugal pump according to claim 1, characterized in that the shut-off and control valve body is made with a spherical working surface, and the valve seat is made conical. 6. The centrifugal pump according to claim 1, characterized in that the bypass channel is made up of two bushings, one of which is made integral with the nozzle in a single piece connected to the tube of the ejector device by ultrasonic welding. 7. The centrifugal pump according to claim 1, characterized in that the bypass channel is made up of two bushings, one of which is made integral with the nozzle, and the other is removable, integral with the valve seat. 8. A centrifugal pump according to claim 1, characterized in that the impeller is equipped with a guide vanes. 9. A centrifugal pump according to claim 1, characterized in that the ejector device on the side opposite to the nozzle is made with a collar for mounting a guide vane thereon. 10. The centrifugal pump according to claim 1, characterized in that it is equipped with an automatic control unit connected to the pressure chamber and an electric motor mounted coaxially with the impeller impeller.