US2059288A

US2059288A - Self-priming impeller pump

Info

Publication number: US2059288A
Application number: US25394A
Authority: US
Inventors: Albert C Stratton
Original assignee: ALFRED S MARLOW
Current assignee: ALFRED S MARLOW
Priority date: 1935-06-07
Filing date: 1935-06-07
Publication date: 1936-11-03
Anticipated expiration: 1953-11-03

Description

NOV. .3, `1936. I A; C. STRATTON 2,059,288

SELF PRIMING IMPELLER PUMP Filed June '7, 1955 3 Sheets-Sheet l A. C.A STRATTON Nov. 3, 1936. 2,059,288

` SELF PRIMING IMPELLER PUMP Filed June 7, 1935 3 Sheets-Sheet 2 wwwwww@ SELF PRIMING IMPELLER P UMP Filed June 7; 1931 s Sheets-sheet s by #y Patented Nov. 3, 1936 UNITED STATES ,PATENT OFFICE aosazss SELF-Paname mesura rom Albert c. Stratton. Ridgewood, N. J., assigner to Allred S. Marlow, Ridgewood, N. J.

`Application June 7, 1935, Serial-No. 25.394

18 Claims.

gas or mixtures of liquid and gas in different proportions or in varying proportions. l It is a further object to provide a priming arrangement for a centrifugal pump which is capable of maintaining the prime continuous under greatly and rapidly varying load conditions.

It is a further object of the invention to p ro- 4 vide a pumping system such as just characterized which isv capable of continuously maintaining a high vacuum even when the proportions of liquid and gas taken in .vary suddenly and over the full range, as from all liquid to all gas and vice versa.

priming arrangement the functioning of which is substantially independent of any head pressure on the discharge side of the pump. 1

It is'a still further object of the invention to provide a pumping system of this type which will be simple, as by having few moving parts; will be rugged, as by having no delicate valve parts; and will be certain in operation, as vby offering little or no chance for clogging by debris or ne particles.

It is well known that the centrifugal pump has found many different uses, and that a certain type has come to be known as a contractors outfit. In this last capacity it is subject to greatly varying operating conditions, such as different suction lifts and different discharge heads, as well as different load conditions; thus, when operating on excavation jobs the pump may be taking water in'to its full capacity or the water 40 supply may vsudenly fall and then the pump may be required to automatically remove small quantities of water, asthey collect in the intake sump; leaky suction lines are also frequently met with, which supply the outt with a mixturel of air and water, usually detrimental to the continued operation of a. centrifugal-pump.

Various schemes have been provided in which a reserve supply ofwater is arranged to renew the pnime of a centrifugal pump when it has been broken by a sudden failure of the'main water supply to keep the suction line lled. These arrangements have operated during reprlming in a manner closely resembling a reciprocating pump in that the pump will reprime and develop a vacuumforashorttimathmloseitsprimedue It is a further .object to provide an automatic to entrance of air and then again reprime, re-

peating this until water fills the pump.

It is evident that such action often makes the pump too slow in handling a sudden rush of water. It is furthermore obvious that a. leaking '5 suction line would seriously and continuously reduce the capacity of a pump operating in this f manner. f

Whereas the invention may be applied with advantage to centrifugal pumping outfits of the 10 type just referred to, it finds its most advantageous application in pumping systems in which the prime is continuously Amaintained against wide variations in the load condition, that is systems which on account of. the steadily maintained 15 prime continuously develop a high vacuum in the suction system, so that the pump at any time will be .capable of handling such load as maybe presented to it.

As will be apparent from the disclosure in my 20 application for Letters Patent, Serial No. 538,129. filed May 18, 1931 relating to improvements in Self-priming impeller pumps, an essential feature of apr-ime-maintaining centrifugal pumping system resides in the control of the flow of priming 25 liquid to the pump in response to the rate of main flow in the suction connection, or in other words in response to the amount of'air contained by the main ow, since only thereby it is possible to supply priming fluid tothe pump in anticipation 30 of. a break in the prime andthus prevent the. break from occurring. Other essential features are provisions for thorough mixing of the priming water withthe air in the suction line and for this mixing to take place close in front 'of the pumpl or eveninside the suction opening, so that no large bodies of air will have timev to form and break the seal.

The above-mentioned objects and features are. attained in accordance with the invention by passing the main suction flow to the pump through a movable chamber, the position' of which will change inv accordance with the ratio of air to water in the flow passing through the chamber at 45 any moment. The changing position of the chamber is utilized to operate the shutter or valve which controls the flow of priming water into the pump.

By such an arrangement a large force is made 50 available for. quick and certain operation of the priming valve.

The reactive force on the chamber. may be obtained ln different ways. Thus in accordance with one specific-embodiment of-the'inventlon 65 a the chamber may be placed within the priming tank to be submerged in the priming water, in which case the buoyancy of the tank will increase and decrease with the rate of air fiow taken in by the pump. In accordance with another embodiment of the invention the chamber is mounted in bearings and has an unsymmetrical overhang which is forced downward by the weight of the main water flow at any instant and is counterbalanced by a weight or a spring; when certain limiting conditions arise, the chamber is caused to take different positions as the ratio of air to water in the flow through the chamber changes.

It is evident that whether the control chamber is submerged in the reserve water tank or is mounted outside the tank 'and counterweighted its operation will not be affected by any head pressure on the discharge side of the pump.

The operation of the priming valve by the moving chamber may be accomplished in different ways. This and other features of the invention will be apparent from the following detailed description of different embodiments of the invention.

It should be understood that these embodiments illustrate specific ways in which the invention may be carried out and are merely typical examples. The invention is adaptable for various modifications as will be apparent to those skilled in the art. Thus it is possible to place the movable chamber in the discharge connection to be moved by the discharge flow from the pump to control the priming valve on the suction side of the pump in accordance with the amount of air contained in the discharge flow.

The invention will now be described more in detail as applied to different characteristic embodiments shown in the accompanying drawings,

in which:

Fig. 1 shows a pumping outfit equipped with a submerged tank for control of the reserve water valve.

' Fig. 2 is a view of the reserve water valve in Fig. 1, showing the valve in open position.

Fig. 3 is a fractional view of an outitvsimilar to that shown in Fig. 1 with an alternative arrangement for control of the reserve water valve by the submerged tank.

Figs. 4 and 5 show a pumping o utt in which the pump is submerged in the reserve water tank, and shows a submerged control tank and valve of a simplified design.

Fig. 6 is a fractional view of the outt in Fig. 4, showing the valve in open position.

Figs. '7v and 8 show a pumping outt in which the reserve water valve is controlled by a counter-weighted hinged portion of the intake pipe.

Figs. 9 to 12 show different positions of the valve in Fig. 7 and the operating mechanism therefor. v c

Fig. 13 shows an alternate arrangement for counter-balancing the hinged portion of the lntake pipe in Fig. 7.

Figs. 14 and 15 arrangement for a water the stationary and the take pipe in Fig. 7.

Referring now more particularly to Figs. 1 and 2, the centrifugal pump I0 may be of any conventional `or special design; it may be driven s ough its shaft I I by means of a motor-or other source ofl power. The pump has an intake'or suction opening I2 and an output or discharge opening I3.

A reserve water tank 20, preferably of sumclent are detail views, showing an capacity to supply the pump for its initial primthe bottom one opening ZI connected directly to the discharge opening I3 of the pump, and another opening 22 connected by a passage 23 to the suction opening I2. The passage 23 may be of piping, as shown in the drawings or may be a casting integral with or connected to the volute of the pump I0. The tank further has an opening 24 at the top for discharge of water either simply by overflow or through any convenient discharge system 40, and an opening 25 for intake of water' through a suction line 4I from a main supply.

A tubular section 50 is placed within the tank 20 to lead the water from the pump to the discharge di). The tube 50 has numerous perforations for admitting discharge water to the tank without passing debris of appreciable dimensions, which otherwise would interfere with the automatic prime-maintaining operations. The tube 5I) is preferably placed at a small angle from the vertical in a manner to impart a circulatory movement to the water within the tank; by this means air which may have entered the tank with the discharge water will segregate in the center of the tank, rise and escape through the uppermost perforations and the opening 24 and will thus be prevented from reentering the pump and reduce the certainty of the priming action.

A submerged tank 60 is placed within the tank 20 and forms part of the intake circuit.

The tank 60 has an opening at the top, the rim 6I of which is guided for vertical movement by the tube 62 which connects the interior of the tank 60 with the suction line 4I and which is fitted watertight in the opening 25 of tank 20. An airtight exible seal is formed about the sliding junction 6 I, 62 `by means of a short section of flexible corrugated rubber tube 63, or the like, which is clamped by means of

rings

64 and 65 to the rim 6I and guide 62 respectively; the tube 63 is prevented from collapsing under the discharge pressure by means of metal rings 66 placed inside the tube. or any other convenient reinforcement.

The tank 60 also has an opening at the bottom which leads into a spout or nozzle 1I fastened in a tube 12 which in turn leads through the opening 22 of the main tank and is fastened to the ,bottom of -the main tank in any convenient manner; thus as shown in the'drawings a flange 13 may serve to hold both the tube 12 and the pipe connection 23 and to fasten them watertight to the bottom of the main tank 20. has one 'or more ports 14 for from the reserve tank 20 to the pipe connection 23 and to the pump; and the tank 60 has fastened to its bottom a collar 15 which cooperates with the outer surface of tube 12 to guide the vertical movement of the tank 60, and which also serves as a shutter for the ports 14 as the tank 60 moves up and down. Before the outfit isl first started the

tanks

20 and 60 will usually both be filled, and upon starting the tank 60 will immediately be emptied by the pump, whereas the tank 20 always will remain filled. With the reserve tank 20 filled with water and with the submerged tank 60 empty, the latter will obviously move to its uppermost position, thereby opening the ports 14, as shown in Fig. 2 and admitting reserve water to the pump for priming.

With the pump running there will be a circulation of reserve water between the reserve tank 20 and the Dump, which however, will be limited by admitting water The tube 12' maintain the priming seal about the impeller blades in the pump. Under these conditions a vacuum will be set ,up in the suction line and the pump will take in air from the line 4| together. with water from the reserve tank 20. By the arrangement of the ports 14 about the'nozzle 1| the air and water will be thoroughly mixed when the ow enters the pump and there will be little danger of the prime breaking due to the continued intake of air. The pump thus will develop a continuous suction which is not appreciably impaired by the limited intake of reserve water.

I When, upon continued operation, water enters the submerged tank 60 from the suction line 4|, this tank will lose its buoyancy to a degree which depends on the amount of air taken in together with the main water flow. The tank 60 consequently will sink to more or less close the ports 14 and shut ofi the reserve water. The adjustment should preferably be such that, when enough water is being taken in from the suction line to safely maintain the priming seal about the propeller blades in the pump, the reserve water from tank 20 would be completely shut off.

This construction is simple andl rugged and affords little chance forclogging by such litter and particles as are usually met with on contractors jobs.

The outfit shown in Fig. l may be modified as shown in Fig. 3. In this embodiment the submerged tank 60 has a tubular guide portion 16 at its bottom which ilts into the tube i2. The ports 16 communicate with the reserve water tank 20 through a passage 90 which has a mouth 9| opening directly into the tank 26. A pivoted shutter 92 is connected, as by a link 93, to the tank 60 to open and close the mouth 9| as the tank 60 is moved up and down, respectively, by the presence of varying amounts of water in its interior.' thus controlling the flow of reserve water through the ports to the pump. A watertight seal 60, similar to the seal 63 at the top of tank 66, may be placed about the sliding junction l, 1t. On advantage of this embodiment is that grit is almost entirely prevented from entering the sliding junctions both at top and bottom of tank 6@ and thus from interfering with the free movement of tank 6d.

The embodiment shown in Figs. 4, 5 and 6 is arranged with the pump ||0 submerged in the reserve water within the reserve tank |26, the discharge opening H3 of the pump opening directly into the reserve tank at a point immediately below the discharge 'connection |40, and the volute being fastened to the side of the reserve tank by means of the bearing structure llt for the pump shaft l I and screws lib.

The lower end |10 of the elbow |60 is in juxtaposition to the suction opening H2 of the pump and is adapted to seat against the rim of the suction opening for shutting oif reserve water from the pump, when the elbow is lled with water during the operation of the pump. When the elbow carries little or no water its buoyancy will act to swing it about the pivot |61 and away from the rim oi the pump to admit reserve water through the annular opening thus formed, as shown in Fig. 6.

For the purpose of facilitating the operation of the elbow tube |60 a diaphragm |82 of flexible material, such as rubber reenforced with thread or fabric, is clamped across an opening |64 in the back of the elbow substantially opposite the suction opening ||2. The diaphragm and its clamping are substantially airtight. A double shouldered pin |8| is clamped airtight to the center of the diaphragm, and a stationary bracket |83, mounted on the pump housing or in any other vconvenient manner, has its slotted end extending Y up between. the shoulders of the pin |B| to practically prevent the pin from moving in a lengthwise direction, yet permitting a slight transverse movement of the pin when the tank |66 swings -about the pivoting point |61 as shown in Fig. 6.

'Ihe object of the arrangement just described is to substantially neutralize the forces acting on the elbow |60 which are due to the suction within the elbow, so that the movements of the elbow will be due solely to the gravitational and buoyancy forces arising 4from the presence and absence, respectively, of water within the elbow.

The consequences are that the angular move-- ments of the elbow will bear a definite relation tothe rate of water flow in the suction connection and that reserve water will be admitted in desired proportions to the air flow in the suction connection.

The explanation of this equalizing effect or the diaphragm may be found in the tact that the two lower openings |16 and |66 in the elbow are of the same size and face in opposite directions. Thus the suction forces acting on these two areas will always be equal and opposed. It is evident 'that the tendency of the suction forces is to reduce the volume of the elbow interior, for which reason the force acting at the suction opening will tend to swing the elbow toward the stationary pump, whereas the force acting at the diaphragm will tend to swing the elbow toward the stationary pin; these tendencies being practically equal in degree and opposed in direction, they will substantially neutralize each other.

An additional advantage oi the present arrangement lies in the fact thatA when the elbow tube is contacting with the edge about the suction opening M2 and the main flow is decreasing any tendency of the elbow to stick to the edge on account of the high vacuum, will be counteracted bythe tension in the diaphragm itt which under this condition will be stretched as shown in Fig. 4:. It is furthermore evident that by changing the size of the clamping rings for the diaphragm, or by choosing diaphragms of diiferent rigidity it is possible to readily establish Various operating properties of the outt as desired.

In the twoembodiments described above Ain connection with Figs. 1 and i the movable tank or chamber which controls the reserve now is operated in one direction by the weight of the suction ilow through the chamber and in the i f between the suction line 2M and the pump. The

rim 26H at the intake opening of the chamber is l formed to t on the rim of the stationary intake or vane 292 to shut or open for the annulus 225 formed in the standard 262i; the rim of the output opening 27|@ oi' the chamber forms a similar annular` iit onto the suction opening attachment 2712 on the suction opening of the pump. The two circular rims are aligned with each other and thus form bearings about which the tank 26|! can swing.

The tank is shaped to be unsymmetrical with respect to its bearings, but forms a'smooth, continuous path for the flow from the suction line into the pump; it has, however, preferably a bale plate or obstruct-ion 2li extending transversely of the straight path of the'suction iow, between the openings within the bearings, thereby forcing the flow outward from said straight path. The overhan'ging portion of the tank 269 extends in a horizontal or nearly horizontal direction from its bearings, so that the weight of the liquid ilowing in the suction line will tend to swing the overhanging portion downward. An adjustable counter-weight 300 is attached to the chamber 260 for swinging it in the upward direction when little or no water ilows in the suction line and the chamber.

It should, of course, be understood that this arrangement may be modified by providing a. straight path for the greater part of the main suction flow between the openings 26| and 210 and for the chamber 260 to form a smaller by path for a proportion of the main flow.

This automatic action of the main suction flow through chamber 260 is utilized to control the reserve water flow through the passage 280, by causing it to control the position of the shutter passage 29|).A The vane 292 is operated by a rod 293 which is/ turned by a pinion 294 meshing with a toothed sector 295 fastened to or integral with the elbow chamber 260. The small angular movement of the chamber 260, shown in Figures 9 and 11, which is due to the absence or presence f water in the chamber, respectively, thus suillces to turn the shutter 292 from the open to the closed positions shown in Figs. 10 and 12, respectively, thereby admitting reserve water to the pump or shutting it ofi therefrom.

The check valve 225 serves to prevent loss of reserye Water, especially when the pump is not operating.

It is of course possible to use a large spring instead of the counter-weight for swinging the chamber 260 upward as shown in Fig. 13 by attaching one end of the spring 30| to the chamber and the other to a. stationary part of the outfit.

In Figs. 14 and 15 is shown a suitable arrangement whereby the junction between the swinging tank 260 and the stationary parts may be made water-tight and air-tight. For this purpose an annular collar or ring 3|0, of waterproof, flexible material, such as rubber, is tightly clamped along one edge to the movable member, such as the rim 26| of the elbow 260, and along its other edge aosaase to a flange 3i i integral with the stationary member, such as the bearing standard 268 or fastened thereto in a manner to preclude passing of air between these parts. The clamp on ange il i is preferably corrugated to flute the flexible ring rdill and thus give it a freedom of movement in its own plane which a flat ring would not possess.

What is claimed is:

l. i centrifugal pump for pumping liquids, a priming ilow system, valving means for controlling the flow of priming liquid from said system to said pump, a main ow system connected to said pump, and a movable chamber inserted in said main flow system and connected to open said valving means as the rate of the main iiow through said chamber decreases and to close said valving means as said rate of flow increases.

2. A pumping system for pumping gas and liquid comprising a centrifugal pump, a source of' priming liquid, a passage for the flow from said source into said pump, and a main ow connection for said pump having a portion thereof movable in accordance with the rate of the main liquid ow to control the ilow in said passage.

3. A pumping system for pumping gas and liquid comprising a centrifugal pump, a priming ow connection to said pump, valving means for control of the ilow through said priming ow connection into said pump, and a main flow connection for said pump having a short section thereof movable by the flow therethrough to operate said valving means in accordance with the rate of liquid flow through said section.

4. A pumping system in accordance with claim 3 in which said section is movable in a. direction parallel with the direction of the ow therethrough.

5. A pumping system in accordance with claim 3 in which said section is movable in a direction at right angles to the direction of the ow therethrough.

6. A pumping system for pumping gas and liquid comprising a, centrifugal pump, a priming flow connection to the suction side of said pump,

.valving means for control of the ilow through said connection, a mainv iowA connection to the suction side of said pump and a movable chamber connected to said main flow connection to carry at least a portion of the ow in said main flow connection and to be moved in accordance with the rate of liquid flow in said chamber to operate said valving means. accordingly.

7. A centrifugal pump, a priming tank above said pump, valve means for control of reserve iow from said tank into said pump, a suction connection from said pump to a main flow supply, a movable chamber serially connected into said suction connection and counterbalanced to operate said valve means in accordance with the weight oi' the flow at any moment passing through said chamber.

8. An impeller pump, a priming tank above said pump, a passage for a reserve ow from said tank into said pump, a suction connection -from said pump to a main ow supply, said connection having a U-shaped movable section and said section being hinged and counterbalanced and connected to vary said passage in accordance with above said pump, valving means for control of reserve water flow from said tank into said pump, a vsuction connection from said pump tov a main water supply, an overhanging U-shaped portion of said suction connection, bearings for both ends of said portion, means for counterbalancing said overhanging portion and mechanical means for control of said valving means by the movements of said U-shaped Aportion in accordance with the weight of water present at any momentin said portion.

10. In combination an impeller pump for air and water, a main circuit for said pump, a tank containing reserve water for said pump, a movable chamber submerged in said tank and `connected in said main circuit for varying its position in accordance with the ratio oi air to water passing through said main circuit, and valving means connected to said chamber for control of the flow of reserve water from said tank for priming of said pump in accordance with the varying positions of said chamber.

11. In combination, a centrifugal pump for gas and liquid,'a tank for reserve liquid, a main circuit including said pump, a movable chamber forming a part of said circuit, a passage fromV said tank to saidv main circuit, valving means connected to said chamber and included inv said ypassage for the control of reserve water flow to said pump, said chamber being subject to internal pressure resulting from the proportion of gas to water within said chamber for movement in one direction and to an external pressure from vthe liquid in said tank for movement in the opposite direction for the operation of said valving means.

12. In a self-priming pumping outfit for pumping of air and water, an impeller pump having a main circuit including intake and discharge openings and connections therefor, a tank for storage of reserve water-having connecting passages to said openings, a movable chamber within said tank connected into said intake connection andv adapted to be moved in one direction by the water in said chamber and to be moved in the opposite direction by the water in said tank when said chamber contains air and valve means mechanically connected to said chamber for control of the flow of reserve water from said tank through s'aid pump in accordance with the positions of said chamber.-

13. An impeller pump for air land water, an intake circuit and a discharge circuit for said pump, a tank containing reservewater for said pump, a' passage between said tank and said intake circuit, a floating container connected into said intake circuit and placed within said tank to be subject to opposing pressures by the water in said tank and the intake water within said container in accordance with the proportion of air in the intake water, movable connections bemovements of said container under saidopposing pressures to admitreserve water to said inta'ke circuit in accordance with the proportion of air in the intake water.

14. An impeller pump for air l, and water, an

V intake circuit and a discharge circuit for said pump, a tank containing. reserve water for said pump, a passage between said tank and said intake circuit, arfloating container connected into said intake circuit, and placed within said tank to be subject to opposing pressures by the water in said tank and the `intake water'within said container in accordance with the proportion of air in the intake Water, a flexible connection from the intake side of said container and a sliding connection from the output side of said container to said intake circuit, said sliding connection comprising a stationary element forming part of said intake circuit and a moving element forming part of said container, aport for passage of reserve water in one of said elements to be 4opened and closed by the relative movements of in the reserve Water in said tank, said container being mounted for movement relative to said tank and connected to open and close said passage in accordance with the ratio of air to water in the flow from said intake circuit.

16. An impeller pump for air and water, an intake circuit for said pump, a container for reserve water for said pump, apassage between said container and said intake circuit, said intake circuit passing through said container and having a movable portion submerged in said container and subject to a buoyant force from air passing through said section to open said passage for admitting reserve water to said pump.

17. An impeller pump for air and water hav- 'from said container to said pump through said intake opening.

18. A pumping system in accordance with claim being hinged at one end 17 in which said submerged section has an airtight piston-like insert in one wall and-mounting means are provided for holding said insert substantially stationary relative to the movelments of said section Ato compensate for the suction effect at the seated end of said section.

ALBERT C. STRA'ITON.