US2174960A - Self-priming pump - Google Patents

Description

Oct. 3, 1 939. R, G, BARZEN 2,174,960

SELF-PRIMING PUMP A TTORNE Y.

Oct. 3, 1939. R. G. BARzl-:N

SELF-PRIMING PUMP Filed Dec. l5, 1936 4 Sheets-Sheet 2 1N V EN TOR.' Richard G BG/"z er),

A TTORNEY.

CCL 3. 1939. R. G. BARzEN SELF-PRIMING PUMP Filed Dec. l5, 193

4 Shee ts-Sheet 3 INVENTOR: Richard @.Bar'zen,

ATTORNEY.

4Oct-3, 1939. R. G. BARZEN SELF-PRIMING PUMP Filed Deo. l5, 1936 4 Sheets-Sheet 4 INVENToR.- EIC/)ard Bar'zen,

A TTORNE Y.

Patented Oct. 3, 1939 UNITED STATES 4PATENT oFFlcE ZCIaims.

means adapted to permit varying degrees of recirculation or bypassing of liquid from the discharge side of the pump back to the intake side thereof, in response to varying degrees oi' vacuum produced in the suction line or intake side of the o pump. Incidental to such bypassing action, the

provision for the recirculation may be adapted to entirely shut oif all by-passing action as soon as the pump is fully primed.

It is further sought to provide.for producing an injector action in connection with the operation of the pumping means for the trapping of air and thereby promoting the vacuum producing action, which injector action may be produced by means forming a part of the bypass structure.

In carrying out the aforesaid object provision /is preferably made to render the bypass and injector action entirely automatic for either restricting the by-passing or recirculating ow or entirely stopping said flow, as required by the needs of the pumpingoperatiom-la typical provision being that of an automatic element forming a part of the bypass structure and fulfilling the part of a bypass control as well as an injector element for effecting the ,injector function for inducing a secondary flow of either gas or liquid in conjunction 4witlr the bypass recirculation. Such automatic bypass structure may be adapted .to regulate but not entirely cut off the recirculation, whereby the pump, after priming, may produce a supplemental iiow or discharge action (due to the injector efl'ect) which will be somewhat in excess of that through the impeller chamber of the pump.

It is further sought to provide an improved construction of this character which may readily be adapted for and applied to use in connection with pumps of common commercial form.

Various other features of improvement also form a part of the object of the present invention as will appear in the following specification, and with these several objects in view the invention will now be described by reference to the accompanying drawings, illustrating suitable methods of accomplishing those objects, after which` such features and combinations as are deemed to be novel and patentable will be particularly set (ci. s- 113) pump construction provided with a self-priming structure embodying the present invention;

Figure 1a is a sectional view, representing a section taken on the line Ia-Ia of Figure 1;

Figures 2 and 3 are sectional elevations illus- 5 trating modified forms of construction;

Figure 4 -is an elevation, partly in section, illustrating an adaptation of the improved self-priming structure to pumps of ordinary commercial form; lo Figure 5 is a sectional elevation illustrating another modified form of construction;

Figure 5a is a sectional view, representing a section taken on the line 5a5a of Figure 5;

Figures 6, '7 and 8 are sectional elevations illus- 15 trating still other modied types of construction embodying the present invention; and

Figure 6a is a detail view representing a section taken on the line Gaf- 6a of Figure 6.

Referring now to the drawings in detail, and more particularly to Figure 1, this illustrates the y improved construction as comprising a pump casing I0 constructed to provide an outer chamber I2 and also ran interior volute shell or housing I4 forming an impeller chamber I5 having a discharge outlet I8 in position for directing the water as discharged by the action of the impeller member I8 toward the main pump outlet 20. 'I'hegimpeller member I8 is of conventional form having the vanes or blades 22 and carried by the end of a shaft adapted to be driven in any suitable manner, as by means of the drive pulley 25. 'I'his shaft is illustrated as journaled in a bearing 26 on a bracket 21 and also in a bearing 28 forming a part of a face plate 30 attached by screws 3l to the casing III and closing the outside of the impeller chamber Il.

The volute shellor housing I4 is formed with a central neck portion 33 providing a central 'ber I5. In alinement with this intake passage is a similar neck or tubular portion 35 which may be formed as a part of the outer wall of the casing I0, opposite the lower portion of the intake passage 36 provided by the casting or housing'31 attached by screws 38 to the outer face of the casing I0 with a plate 39 forming a partition between said passage 36 and the chamber I 2 and having an opening 38' leading into said neck 35. A suitable check valve 42 hinged to a plate M is secured in place at the entrance to said intake passage 36, for the purpose of maintaining a suiilcient supply of water for use in the next priming operation.

Attached to the neck portion 33, and retained thereon by a suitable clamping band 41, is a tubular section 48 of appropriate flexible and contractible resilient material, such as a hose section of rubber composition, and of such extent as` to project around the mouth of the neck portion 35, and also of somewhat greater diameter than said neck portion '35, so that the flexible element 48 in its normal uncontracted state, as represented by the full lines in Figure 1, will leave an annular space 50 around the neck 35 to permit bypassing of water through said space to the impeller chamber.

An inspection and cleanout opening 5I adapted to be covered by suitable cover plate 52, is provided in the outer face ofthe casing I0, below the intake housing -31. A drain opening 53 is also provided at the bottom of the chamber I2, as shown.

In the priming operation of the pump, it will be understood that the chamber I2 is initially partly full (preferably to a level sufcient to fill the impeller chamber), and the rotation of the impeller produces a circulation of this water in a direction indicated by the arrow in Figure 1a, or in the direction of the main discharge outlet 2U. The pumping of this priming supply of course kdraws air in through the intake passage 36, which is trapped and escapes through the discharge outlet 20. The.normal condition of the flexible element 48 leaves the passage 5D open for bypassing of water to' the impeller, for

recirculation to support the priming action. As

this amount of recirculated water which reaches the impeller through saidA bypass space is less than the pumps capacity, the actual priming action will take place in a more or less intermittent or pulsating manner, d ue to the impeller becoming intermittently air-bound, or until sufcient water reaches the impeller chamber through said passage 5I) to continue the priming action.

Besides the bypassing function mentioned it is evident that the nature of the structure is also such as to produce an injector effect, the iiow through either the tube 35 or the space 50 inducing a now throughthe adjacent space or passage; and thus tending to continue such now (of gas or liquid as the case may be) so long as the impeller is in operation.

'Ihe priming action would thus appear to be of a pulsating nature as produced by a succession of slugs of the liquid which trap the air between the slugs and carry it on through the impeller until the alr is nally released and allowed to escape by way of the aforesaid discharge outlet 20. So long as the proper degree of vacuum or suction is not reached in the intake 36, to support the normal pumping operation (as represented by the pump's capacity), the flexible element 48 will not be sufficiently contracted to close the bypass passage 50, thus permitting enough water to recirculate to the pump for priming purposes. The greater the degree of vacuum or suction which is produced however, the greater will be the degree of contracting action imparted to said flexible element for drawing the same into the position approaching that represented by the dotted lines for closing said passage 50, thereby restricting the bypass flow and finally shutting oli` all recirculation after the pump is fully primed, when no recirculation will take place, and the pump will operate at full pumping capacity. From the beginning of the priming action, however, and through the intermediate stages up to the point when the' pump i s fully primed, the element 48 undergoes continuous change in form, due to its constant and automatic respense to the state of vacuum being produced by the combined action of the impeller and injector effect resulting from air being sucked in from the intake through the passage 50. In this manner the element 48 continuouslyand automatically regulates the size of said passage in accordance with the needs of the priming operation.

In Figure 2 is illustrated a modification of the construction in which a different type of injector and bypass arrangement is used for carrying out the priming operation. In this form of the device the impeller chamber I5 communicates with the intake passage 36 by way of a passage 34' provided by a continuous neck 33', connecting the impeller housing with the outer wall of the casing I0, and the chamber I2 is closed, as at I2', against communication with the passage 36 except by way of said passage 34'.

For effecting the injector action as well as the recirculating function, a port 6I) is provided in the bottom of the neck 33', extending preferably at a slight angle, pointing in the direction of the impeller chamber. Fitted in this port is a short tube 62, projecting downwardly and in turn fitted with a short flexible element 64 of the same character, as regards composition and contractile properties, as the aforesaid element 48.

In the priming action of this type of the device, the flexible element remains normally uncontracted, thereby adapting the port 60 to participate in an injector effect under the innuence of the intake flow at 34', and also permitting a recirculation of the priming liquid through the port for maintaining the priming effectin a manner similar to that explained in my Patent No. 2,041,586, dated May 19, 1936. 'I'his recirculating flow continues, entering the lower end or mouth of the element 64 and passing upwardly through the tube 62 and port 60 and thence into `the impeller chamber, the extent of such flow varying automatically in accordance with the degree of vacuum being produced in the intake 36, which of course imparts a varying degree of contracting action to the element 64 for either increasing or restricting the ow through the port 60.

After a suicient degree of vacuum or suction is developed in the intake passage 34' for supporting the normal pumping operation, the suctional action which is imparted to the flexible element 64 results in contracting the latter, as represented by dotted lines, thereby closing the passage therethrough and consequently shutting off recirculation through the port 60. The contracting and expanding action of the element 64 thus constitutes an entirely automatic response to the suction for restricting the recirculation in accordance with the needs of the priming action.

In Figure 3 a modified form is illustrated which is similar to that shown in Figure 1, but employs a different arrangement of the bypass structure. In this form, a priming port 61 is provided in the side wall of the impeller chamber I4, and into this port is tted a short tube 68 carrying a ilexible tubing element I0 of the same character as the aforesaid flexible element 64. In addition, a port Il is provided in the Wall I2' separating the chamber I2 from the intake passage 36, and this port is fitted with a piece of tubing I2 of smaller diameter than either of the elements 68 and 10 and in position to project centrally through the contractile portion of the element 10 and into the mouth of the-tube 68, as illustrated. Thus a bypass space 14 is provided, surrounding said tubing 12 and between ifa/nd the tube 68 and the contractile portion of the flexible element 10.

The priming action of this form of the device takes place on the same principle as that of Figure 1. So long as the priming operation of the impeller continues, insufficient suction is developed to close the contractile end of the flexible element 10, and hence water may recirculate by entering the mouth of said element 10 and flowing through the ,space 14 into the impeller chamber. Besides this bypass function. it is also evident that the structure will produce an injector effect, the flow through either the tube 12 or the passage 14 inducing a corresponding 110W through the other, and tending to continue such ow (of gas or liquid as the case may be) so long as the impeller is in operation,-the liquid recirculating through the passage 14 of course trapping any gas that is sucked from the intake 36 through the tube 12. Obviously the size of the space or passage 14 will vary automatically in accordance with the degree of vacuum being produced in the intake 36 and tending to contract the flexible element 10, thereby either increasing or restricting the ilow through the passage 14 and thus constituting a completely automatic response to the suction for regulating the recirculation through said passage in accordance with the needs of the priming action. When a sufficient degree of vacuum or suction is attained in the intake passage 36 for maintaining a normal pumping operation, the suctional action is transmitted to the contractile portion of the tubing element 10 with suflicient for'ce to close the recirculating space 14, as represented by the dotted lines and thus cut oil' all recirculation through the port 61 and permit the pump to operate at full capacity.

In Figure 4 is illustrated a form of construction enabling y.the principle of the priming structure shownin Figure 1 to be utilized in connection with common types of commercial pumps in which the priming feature, as shown in said Figure 1, could not be directly incorporated in the main pump casing. For such common types of pump construction, I provide a set of connections between the intake 18 of the pump 80 and its intake conduit 8|, said connections comprising a fitting 82 for attachment to said intake 18 and also a fitting 83 for attachment to the conduit 8|, which fittings are provided with internal neck portions 84 and 85, respectively, in alinement as shown, while the tting 83 further comprises a casing 86 of suitable diameter for forming an annular chamber 81 around the neck portions 84 and 85. To the intake portion 84 is secured av flexible tubing element 88 (of the same contractile type as the aforesaid element 48) and of larger di meter than the neck portion 85 to provide a pass space 90 between the chamber 81 and the flow space 9| between the neck portions 84 and 85, as shown. To complete the circuit for the priming liquid, a pipe 92 is provided for connecting a chamber 93. mounted in connection with the discharge outlet 94 'of the pump, with the casing 86 and in communication with the space 81. Preferably a filtering and straining device 95 is included in the pipe connection between said chamber 93 and the casing 86.

Obviously, the arrangement and construction just described operates in the same fashion as that illustrated in Figure 1, the only difference being that the recirculation of the priming liquid takes place by Way of the chamber 93 and its connections to the space 81, instead of directly from the pump chamber |2 to the space 50 as in the first form of construction; but this modified form demonstrates the facility' with which the same principle of operation may be applied to pumps already in general commercial use.

In Figures 5 and 5a the construction illustrated comprises a pump casing |0a with its intake portion 96 and internal impeller housing |4a, the discharge conduit |6a from which is fitted with a tubular element 98. of an expansible resilient character and projecting into the lower neck portion |00 of a discharge chamber |0|. The impeller housing is also provided with an intake conduit |02 of elbow form extending to the bottom portion of the pump chamber |2a, and this conduit is also fitted with a tube |04 connecting the chamber |2a with the opening |05 into said impeller housing and in central axial alinement therewith, for facilitating the passage of air thereto after the water level has dropped below the axis of the impeller. A plug |06 is provided for access tothe tube |04 for cleaning purposes. Similar plugs |06 are provided for draining the pump chambers.

The flexible tube element 98 is of smaller diameter than the neck portion |00 leading into the chamber |0|, so that normally, while said element 98 is contracted, a bypass or return flow space |01 for the priming liquid is left between sliod element and the mouth of said neck portio In this construction, the operation of the initial 'priming action of course establishes an initial partial vacuum lin the intake, due to the pumping full lines, the liquid discharged by the operation of the impeller may recirculate by a back flow into the pump chamber |2a byway of the passage |01. During this operation, the form of the impeller intake |02 enables the pump to utilize` the priming liquid to substantially the full capacity of the chamber |2a, while the provision of the tube |04 facilitates the ow of gasto the impeller for developing the proper degree of suction in the intake passage. In this connection it will also be seen that the arrangement of said tube |04 opposite the passage |05 makes for an injector effect, the flow through either said tube or said passage |05 inducing a ow through the other and tending to continue such induced flow (of gas or liquid as the case may be) so long as'the impeller is in operation; and also that any liquid flowing through the space |05 will of course trap any gas sucked through the tube |04 and carry such gas on through to the discharge chamber. When the pump becomes fully primed, the surge of the full discharge flow from the pump through the outlet |6a tends to expand the flexible element 98 to the position indicated by the dotted sis and discharge openings |08 and respectively, and its chamber |2b is divided by a combination partition and impeller intake structure i!)v providing an impeller intake tube |02a similar to that of Figure 5, and also fitted with a similar air feed tube |04a. The bottom portion of the partition structure |00 is formed with a port |0 fitted with a flexible nozzle element ||2 projecting to that side of the partition on which the impeller housing Mb is located and adapted to collapse under a given rise in pressure' on that side of the partition due to the operation of the impeller.

'I'he action in priming is, in principle, similar to that characterizing the operation of thei'orm of the device illustrated in Figure 5, in that the flexible nozzle element H2 will permit a bypassing of the priming liquid from one side of the partition structure |09 to the other, for recirculation to the intake |02a and back to the impeller chamber,air being meanwhile drawn through |0la by the same injector effect as that already described. However, as a degree of vacuum or suction is attained for the normal pumping action of the impeller, the surge of pressure in that side of the pump chamber which includes the impeller combined with the suction in the intake chamber will react upon the flexible nozzle element |2 and tend to collapse the' same, thereby restricting the iiow bypassing through the port ||0 and gradually stopping the recirculating movement of the liquid, so that the pump may finally operate at full capacity.

In this form of construction also no check valve is required at the main intake opening |08.

In Figure 7, the modification illustrated is in the main similar to that shown in Figure 5, the principal difference being that the bypass or recirculating feature provides for both a contracting and an expanding function of the exible element forming a part of the structure which is provided for regulating or controlling the by-pass of liquid at the discharge outlet from the pump chamber.

Accordingly, as shown, the impeller housing is provided with an elbow-shaped intake |02b and also a discharge conduit portion |6b which is formed at its upper or discharge end with a nozzle tip I4. This nozzle tip element is positioned opposite the mouth of a Venturi-type tube ||5 which is supported by an annular structure formed with a plurality of orifices ||6 within the neck portion |00 of the discharge chamber |0|.

Just below the nozzle tip element ||4, the discharge conduit |617 is provided with an enlarged portion formed with a plurality of ports or orifices H8 and carrying a flexible tube element |20 of suitably resilient composition, such as rubber, adapted for both contracting and expanding action for bypass control or'regulating purposes.

In the operation of this type of construction,

it ,will be apparent that with the exible tube indicated by dotted lines), thereby causing the bypass ilow to take place entirely outside the element |20. In the course of the priming action,

the inertia of the water in the tank |0| builds up some back pressure, sufilcient to overcome the injector action to a certain degree, under which pressure the element |20 may expand toward the neck |00 (as also indicated by dotted lines), allowing some water to recirculate back through the ports ||8. However, as the surge of the pump ow rises, to the point of overcoming said back pressure, the suctional conditions at the ports I 8 become restored so that when the priming operation is complete, additional water is pulled upward through the ports ||8 in the subsequent pumping operation, thus effecting an increase in the pumping capacity over that provided for bythe discharge conduit |6b. l

It is also apparent that this construction requires no. check valve in relation to the main intake opening 96 of the pump casing |0c.

In Figure 8 is illustrated a modication having a flexible bypass control arrangement similar to that shown in Figure 1, combined with the nozzle injector feature illustrated in Figure 7. In this modification, the pump casing |017 is formed `with an integral extension 3l for the main intake passage 36 for the pump and including an integral neck portion 35 corresponding to the neck 35 of Figure 1 and in the same relation,y to the flexible tubular element 48. In this case, moreover, the `impeller outlet terminates in a Inozzle tip ||4' positioned opposite the moutli'of a Venturi-type tube ||5' with an intervening space |25 provided by a casing |26 connecting said tip and the tube H5 and also provided with a tube |21 communicating with the intake passage 36'. As shown, this nozzle tip and tube I5' are alined with the discharge outlet 20' from the pump casing.

The operation of this type of the device in priming is the same as that characterizing the form shown in Figure 1, with the addition of the injector action characterizing the corresponding elements of the construction shown in Figure 7, in that the structure comprising the nozzle tip ||4 and the tube H5' promotes the same vacuum-producing action by the drawing of air from the intake passage 36 through the tube |21 and into the space |25 and discharging the same through the tube H5' into the discharge outlet 20', in substantially the same manner as already explained with reference` to Figure 7.

Obviously this modied form of the construction also requires no check valve structure to be provided in connection with the intake'passage 3 l. l

From the foregoing it will be apparent that a practical and eiicient arrangement and construction have been devised for carrying out the aforesaid objects of the invention. In each of \the .forms of construction illustrated, automatic means is provided for allowing the necessary bypassing of liquid for the degree of recirculation required for continuing the priming operation, and as the priming action is completed for establishing the full pumping operation, then such bypassing is automatically shut off, so that no loss of the pumpsb capacity issuffered by any continued recirculation. In those forms of the even added to common and well-known forms of pumps with very slight modication thereof,'as above explained.

While-I have illustrated and described what I have found to constitute satisfactory and efcient forms of construction which are suitable for the embodiment of the described features of my improvements, it is also obvious that various changes, modications or substitutions are quite possible with the spirit and scope of the actual invention; I therefore desire to be understood as reserving the right to make all such changes as may fairly fall within the scope of the appended claims.

What I claim, and desire to secure by Letters Patent, is:

1. A self-priming pump apparatus comprising, a pumping means provided with a discharge chamber, an intake connection to said pumping means, and an automatic by-pass structure in axial alinement with said pumping means and connected with the intake side thereof, said by pass structure comprising spaced coaxial members with a flexible tubular element secured to one of said members and surrounding the other member but spaced therefrom and thereby forming an annular passage therebetween for recirculation of liquid from the discharge chamber to the intake side of the pump, said flexible element being responsive to the suctional action of the pumping means for regulating the size of said passage and thereby controlling said liquid recirculation.

2. A self-priming centrifugal pump comprising a volute pump housing provided with a dis charge member, a rotary impeller member within said housing and the latter having an intake opening in alinement with the axis of the impeller, a pump intake connection having a pipe terminal portion in alinement with said intake opening and slightly spaced therefrom, and a exible tubular element having one end attached to the margin of the intake opening and its other end surrounding said pipe terminal portion in spaced relation thereto to provide an annular passage for recirculation of liquid from said discharge chamber to the intake side of the pump, said flexible element thereby forming the outer Wall of said passage to respond to the suctional action of the impeller member for effecting Aan adjustable closure function for regulating the size of the passage and thereby controlling said liquid recirculation, said discharge chamber being in communication with the free unattached end of said flexible element. l

RICHARD G. BARZEN.

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