US1682336A - Robert hentschel - Google Patents

Description

Aug. 28, 1928. 1,682,336

R. HENTscHEI.

SUCTION DEVICE FOR MULTISTAGE GENTRIFUGAL PUMPS Filed. March 18, 1926 Patented Aug. 2s, 192s.

IRQBEBT HENTSCHEL, OF BREMEN, GERMNY.

i PATENT oFFicE.

SVUCTIQN DEVCE FOR MULTISTAGE CENTRIFUGAL-PUMPS.

Application led MarchrlS, 1926, Serial No- 95,591, and in Germany April 11, 1925;V

This invention relates to a suction device for multi-stage centrifugal pumps by means of a hydraulically operated jet air pump, and it has, in comparison withthe commonly known suction devices of'this type for its object a simplification of construction and operation and saving of power by utilizing Afor the production of the pressure in the water for working of the jet air pump the muliti-stage centrifugal pump to be evacuate z 1 An embodiment of the invention is illustrated, by way of example', in the accompanying drawing in which:

Fig. 1 's a vertical longitudinalsection through a two-stage :form of construction.

Fig. 2 is a cross section on line 2 2 of Fig. 1.

Fig. the lower half of the centrifugal pump with another valve arrangement between the two pumpstages.

Fig. 4; is a cross section corresponding with that of Fig. 2 showing a modification of the jet pump.

Fig. 5 shows, on larger scale, a longitudinal section through the upper half of the centrifugal pump shownin Fig. 1 comprising an arrangement for the return of leak 'water into the water circulation of the jet air pump and Fig. 6 shows in section a constructional detail of the jet air pump.

The rst stage with the impeller a is separated from the second stage with an impeller b' by a spring-controlled ring valve c so that for the second impeller b a comparatively large inlet space or flow channel,`

e. g. the annular space d, extending between the two stages is created. The jet air pump e communicates by pipe f with the pressure space g of the second stage, by pipe 7e,- with the suction space i oithe first stage and by pipe lo with the annular space Z.'

For operating the-jet air pumpe the inlet space Z oi the .second stage is almost completely filled with water, and after the shutting oii' device or the regulating slide valve m has been closed the shaft n of the entriiugal pump carrying the two impelle s a, b is revolved. A continuous flow of water through the jet nozzle o of thek air pump e is thus produced the air being sucked o from the suction space e' of the irststage through the pipe L. The sucked oi air iiowsl with the working water .in circulation into 3 is a longitudinal section' through the outer annular space p of the impeller b Where it is separated at the highest point of the water level and escapes into the atmosphere through the floating valve g and port 'l'. The circulating ywater flows through the upper slot s of the inner annular space Z in the intermediate casing back into the s'econd impeller. The annular space d and the annular space p may form one single space.

If, afterthe suction, the impeller Va begins to deliver, the water pressure produced at this occasion opens the ring-valve 0 and closes the floating valve g. By the opening- ,of lthe regulating Valve m the centrifugal pump begins now to deliver and the air Vpump e may-be shut off by the closing of the ]et 'waterand air-pipe so that from this moment it does not consume any energy.

The shutting oi' of the jet air pump may beei'ected, as-indicated in Fig. 5, by means of cocks t, u inthe pipes f and k. In the form of construction shown in Fig. 6 the shutting off is simplified by the arrangement that the jet waterand air-pipes f, l1. may be simultaneously shut olil ple way cock w.

-For the rmg valve 'o one or several other by a common multi- V shutting od devices may be substituted, for

instance after the manner of the' check flap w of Fig. 3.

Under general conditions the use of a mixing nozzle, such as y, Fig. 2'of suitable. di

mensions and having a single tapered portion directly connecting with the jet pump e will be found suliicient for securing an aspi-rating action of required suction force t0' eect a vacuumizing of the suction stage and the filling of the same with water from the source of supply in a rapid manner and within a reasonable period of time. ln some instances, however, the operation might be unduly prolonged because 1 ofi4 unfavorable head conditions and the presence in the supply line of a large amount of air or gas tending to unseat the valve c and to reduce the suction force of the jet air pump. For

thepurpose of meeting such conditions I,

provide a compound type of mixing nozzle, such as shown in Fig. 4, in which a tapered nozzle portion y of greaterlen'gth than the tapered portion y otFig. 2 is employed together with a second tapered portion or nozzlez. l The mixed air and water flowing successively through these'nozzles causes an increased velocity flow of the water, with an increase of'suction 1n the pump e, and a Tbetween said compression of the air flowing with the water into the space Z, whereby an increase of pressure in the space d is created, prosuction space or into the first impeller, the

leal; water can be returned into the circulating-water circulation. cording to Fig. 5, in such a manner that the leali-unter -tlowing oli' bushing is collected in an annular space 2 and sucked oil' again through the channel 3 by the jetA airpump.

In more than two-stage centrifugal pumps several stages may be used for sucking olf the air, and inversely.

I claim 1. A multistage centrifugal pump having ay suction stage, a compression stage provided with a valved outlet, a flow passage between said stages, a hydraulically operated jet air pump operative under water pressure produced in said pressure stage, conducting connections between said jet air pump and said suction and compression stages, means for opening or closing said connections for opening or closing communication between said jet air pump and said suction and pressure. stages, and a valve normally closing said flow passage and adapted to open under a predetermined pressure in the suction stage.

2. A multistage centrifugal pump having a suction stage, a compression stage provided with a valved outlet, a flow passage stages, a water and air chamber between the stages and in communication with the flow passage, said chamber having an air vent outlet, a valve governed by the water level in said chamber and controlling said vent outlet, a hydraulically operated jet air pump operative under water pressure produced in said pressure stage, connections between said jet air pump and said suction and compression stages, means for opening or closing communication between said jet'air pump and said suction and pressure stages, and a valve normally closing said flow passage and adapted to open under a predetermined pressure in the suction stage.

3. A multistage centrifugal pump having a suction stage and a pressure stage, a, hy-

draulically operated jet air pump operative under water pressure produced in said pressure stage, air and water flow channels between the jet air pump and the suction and pressure stages, a flow passage between the pressure stage and suction stage, an automatic valve controlling said passage, and means controlling said channels for open` This is etfected, ac-

through the shaftpressure stage,

ing and closing communication between the jet air pump and the suction and pressure stages. v

4. A multistage centrifugal pump having a suction stage and a pressure stage, a hydraulically operated jet air pump operative by water pressure produced in the pressure stage and including a mixing nozzle, a flow passage between the suction and pressure stages, a normally closed valve governing said passage and adapted to open under a predetermined pressure in the suction stage, valve cont-rolled conductors for connecting said jet air pump with the suctionand pressure stages, and a second mixing nozzle connected to said' mixing nozzle of said jet air pump for converting into pressure the flow energy of the water and air mixture so as to hold the valve governing the flow passage closed against pressure in the suction stage when the jet air pump is in action.

5. A multistage centrifugal pump having a suction stage, a pressure stage provided with a valve controlled outlet, a water and air chamber disposed between said stages, a liow passage between said stages and communicating at its highest level with said chamber, a normally closed valve controlling communication between the suction stage and said passage and adapted to open under a predetermined pressure in the suction stage, an automatic vent for the discharge of air from the Water and air chamber, a hydraulically operated jet air pump operative under water pressure produced in the pressure stage, air and water flow channels respectively connecting said jet air pump with the suction and pressure stages, valves for opening and closing said channels, and a mixing pipe connecting the water and air chamber with the jet air pump.

6. A multistage centrifugal pump having a suction stage, a pressure stage provided with a valve controlled outlet, an air and water chamber between said stages provided with an air vent outlet, a liow passage between saidstages Communicating at its highest level with the water and air chamber, a normally closed valve controlling communication between said passage and the suction stage and adapted to open under a predetermined pressure in the suction stage, a hydraulically tive under water pressure produced in the conductors connecting the jet air pump with the suction and pressure stage and theair and water chamber, respectively, valves for opening and closing the conducoperated jet air pump operators between the jet air pump and the sucz water chamber between said stages provided with an airy vent outlet, a flow passage between said stages communicating at lits highest level with the water and air chamber, a normally closed valve controlling communication between said passage and the suction stage and adapted to open under a predetermined pressure in the suction stage, a-hydraulically operated jet air pump o erative y 10 under water pressure produced in t e pressure stage, conductors connecting thel suction and pressure stages with said jet air pump, valves for opening and closing said conductors, and a conductor connecting the air and water chamber with vthe jet air pump', said conductor being provided .with a plurality of mixing nozzles.

In testimony whereor` I aflx my signature.

ROBERT HENTSCHEL.

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