US 3892361 A
A nozzle that uses pressurized fluid to induce flow of secondary fluid by having two stages with the first stage using pressurized fluid to induce secondary fluid flow and with the discharge from the first stage being the pressurized fluid for the second stage that induces further secondary fluid flow to thus increase the efficiency of the nozzle especially for low differential pressure operating conditions.
Description (OCR text may contain errors)
United States Patent [191 Mocarski 5] July 1,1975
[ TWO STAGE NOZZLE  Inventor:
 Assignee: S.R.C. Laboratories, Inc., Fairfield,
 Filed: Apr. 18, 1974 [2H Appl. N0.: 461,843
Zenon R. Mocarski, Easton, Conn.
52 us. CI. 239/432 5: Int. Cl B05b 7/06 58 Field of Search 239/4l7, 432, 417.3, 434.5, 239/DIG. 7
 References Cited UNITED STATES PATENTS l,908,l35 5/1933 Forster 239/432 2,600940 6/1952 Widmayer 239/417 SECGUDARY FLU ID 2,630,l83 3/l953 Foutz .i 239/432 X 2,826 454 3/l958 Coanda 239/432 3.l57,36l ll/l964 Heard .4 239/432 Primary Examiner-Lloyd L. King Attorney, Agent, or FirmErnest M. .lunkins 5 7 1 ABSTRACT A nozzle that uses pressurized fluid to induce flow of secondary fluid by having two stages with the first stage using pressurized fluid to induce secondary fluid flow and with the discharge from the first stage being the pressurized fluid for the second stage that induces further secondary fluid flow to thus increase the efficiency of the nozzle especially for low differential pressure operating conditions,
2 Claims, 2 Drawing Figures PRESSURIZED FLUID PRESSURIZED FLUID SECONDQRY FLU 0 D TWO STAGE NOZZLE in my copending U.S. application Ser. No. 422.880. filed Decv 7. l973 and, now U.S. Pat. No. 3.845.904, issued Nov. 5, I974 assigned to the assignee of the present invention. there is disclosed a two stage nozzle in which pressurized fluid is used to induce flow of secondary fluid. The nozzle is constructed to be variable so as to adapt itself automatically to different operating conditions to thus widen the efficient operating range of the nozzle.
While such a nozzle has been found completely satisfactory, it has been found that in some instances it is desirable to set the nozzle solely for use at one condition. The setting may be by a fixed construction or by a construction that enables the selection of one of a plurality of settings. each for use with a different operating condition. Such a nozzle is especially applicable to conditions which involve a relatively small difference in pressure between that of the secondary fluid and that where the nozzle discharges. Thus though the nozzles efficiency in inducing secondary fluid flow may vary somewhat as the operating condition deviates from the setting for a selected condition. it normally remains greater than that obtained by just a single stage nozzle.
It is accordingly an object of the present invention to provide a two stage nozzle that is fixed for operation at only one operating condition.
Another object of the present invention is to provide a two stage nozzle that is quite efficient in operation for variations in condition about its selected setting.
Another object of the present invention is to provide a two stage nozzle which has a plurality of different settable positions and in which any one of the positions may be selected.
A further object of the present invention is to achieve the above objects with a two stage nozzle that is extremely simple in construction, economical to fabricate and reliable and durable in user In carrying out the present invention of the two stage nozzle, both the first and the second stage are each formed to have a through passageway having an entrance and an exit. Both entrances are in communication with a secondary fluid whose flow is desired to be induced and the exit of the first stage passageway is adjacent the entrance of the second stage passageway. Pressurized fluid is directed into the entrance of the first stage passageway to induce flow of secondary fluid therethrough and the discharge therefrom is directed into the entrance of the second stage passageway. The first stage discharge of combined pressurized fluid and secondary fluid thus becomes the powering or in effect, pressurized fluid. for the second stage which in turn induces more secondary fluid to flow through the nozzle to be discharged from the exit of the second stage pas sageway. The nozzle thus requires only the use of pressurized fluid in its first stage even though it induces secondary fluid flow in two stages.
Other features and advantages will hereinafter appear.
Referring to the drawing:
FIG. 1 is a diametric cross section ofa two stage nozzle made in accordance with the present invention.
FIG. 2 is a fragmentary view showing a further embodiment of a two stage nozzle.
Referring to the drawing. the nozzle of the present invention is generally indicated by the reference numeral l0 and includes a housing 11 that is formed with an opening 12 for communication with a source of sec ondary fluid so that the latter is thus within the housing.
A source of pressurized fluid is connected to a pipe 13 to flow through a port 14 formed between a conical valve stem 15 and an apertured tube 16. Port 14 is located adjacent an entrance 17a of a passageway 17 formed in an annular member 18 secured as by a screw 18a to the housing. The passageway 17 is shaped so that the flow of pressurized fluid from the port 14 and through the passageway induces flow of secondary fluid into the entrance 17a as shown by the arrows 19 to have the combined fluids be discharged from an exit 17!) of the passageway.
A second annular member 20 is positioned within the housing and is also formed to have a passageway 21 having an entrance 21a and an exit 21b. The passageways 17 and 21 are in alignment with the entrance 210 being positioned adjacent the exit 17b so that a space or area is formed therebetween through which secondary fluid, as indicated by the arrows 22. may flow. The size of this area or distance between the entrance 21a and exit 171; may be set to one operating condition by movement of the annular member 20 within the housing and the securement thereto as by a set screw 23 so that the position thus becomes fixed though, of course. if desired a securement may be effected by other means, as for example. welding. construction of the parts. a tapped hole in member 20 for the screw 23, etc.
In the operation of the two stage nozzle of the present invention. a pressurized fluid flowing from the port 14 into the entrance 17a induces flow of secondary fluid as indicated by the arrows l9 and the combined fluids are discharged from the exit 17b. As the exit 17b and the entrance 210 are adjacent and in alignment. this discharge is thus directed into the passageway 21 and in doing so induces flow of secondary fluid as indicated by the arrows 22, into and through the passageway 21. Thus the pressurized fluid or powering means for operation of the second stage which induces more secondary fluid to flow. is thus solely the discharge from the first stage.
With this construction the pressurized fluid which flows through the port 14 is thus capable of causing secondary fluid flow in both stages as indicated by the arrows 19 and by the arrows 22. The discharge from the nozzle is from the exit 21b and is thus the combined pressurized fluid and secondary fluid.
During operation, a pressure will exist about the discharge 2lb (which is normally atmospheric pressure if the nozzle discharges into an open area and the fluids are air) and also the secondary fluid will have a pressure which is generally the same throughout the housing and so is present about the entrance 21a. For operating conditions where the difference between these two pressures is quite small, the member 20 may be spaced relatively far from the member 18 so as to provide a large area through which the secondary fluid. as indicated by the arrows 22. may flow. For an operating condition where the pressure difference is higher. on the order of perhaps 4 or 5 inches of mercury. the member 20 is positioned closer to the member 18 so as to reduce the area between the two members through which the secondary fluid may flow. Thus. depending upon the operating condition as set by the difference in pressure. the relative position of the members 20 and 18 may thus be selected and fixed in position.
Generally the operating condition is either known or desired. and the selected position is that which provides the most efficient operation of the nozzle at that condition. if the differential pressure increases above the selected condition. there is a tendency for the discharge from the first stage to increasingly flow reverscly to the direction of the arrows 22. which reduces the efficiency and may even prevent operation of the nozzle. For lesser differential pressures than the selected condition. less secondary fluid is induced to flow by the second stage than would he possible by a different setting. thus again tending to reduce the efficiency of the nozzle.
Referring to FIG. 2 there is shown a modification of the two stage nozzle in which the position of the member may be selected from one of a plurality of different settable positions. Thus a spring pressed plunger 24 is secured on the housing ll and the periphcry of the member 20 adjacent thereto is formed with a plurality ofindentations 25 such that rotational linear movement of the member 20 permits selection of the position of the member 20 for one of a plurality of different settings. It will be understood that once the spring pressed plunger 24 is positioned in an indentation 25 that the member 20 is thus in effect fixed in position.
lt will be noted that the diameter of passageway 21 is somewhat greater than the diameter of the passageway 17. In one embodiment of the invention which has been found satisfactory the diameter of the passageway 17 may be Va inch while that of the passageway 21 may be about is inch.
It will accordingly be appreciated that there has been disclosed a two stage nozzle in which both stages induce the flow of secondary fluid. The first stage uses pressurized fluid to induce the secondary fluid flow while the second stage employs the discharge of the first stage as its pressurized fluid for inducing further secondary fluid flow. The discharge of the nozzle consists of the pressurized fluid and the induced secondary fluid in both stages, The nozzle is designed to be set at a fixed position for one operating condition in which the condition is basically determined by the difference in pressure between the ambient pressure existing at the discharge of the nozzle and the pressure of the secondary fluid at the entrance to the second stage. For conditions of higher differential pressure the second stage is positioned closer to the discharge of the first stage. while for essentially no pressure difference. the second stage is positioned furthest from the discharge of the first stage. in another embodiment of the invention, the position of the second stage may be selected from one of a plurality of different positions to thereby enable mechanical alteration of the setting should it become necessary to adjust the nozzle for a different operating condition.
Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.
1. A two stage nozzle comprising a first stage means having a first passageway formed with an exit, means connectible to a source of pressurized fluid for directing a flow of pressurized fluid into the first passageway and means for communicating the first passageway with a source of secondary fluid whereby flow of pressurized fluid through the first passageway induces flow of secondary fluid therethrough to have both fluids be discharged from the exit; a second stage means having a second passageway formed with an exit. means for directing the flow from the first stage means into the second passageway and means for communicating the second passageway to a source of secondary fluid, said flow of fluid from the first passageway into the second passageway being the sole energizing force for inducing the flow of secondary fluid into and through the second passageway with the fluids being discharged from the second passageway exit. in which the sources of secondary fluid are the same. in which the two passageways are elongate and aligned and in which the second stage means passageway has an entrance positioned adjacent the exit of the first stage means passageway and in which the second stage means is capable of relative movement with respect to the first stage means and there are means for fixing the stage means in one relative position.
2. The invention as defined in claim I in which the means for fixing has means forming a plurality of different relative positions and in which the last named means enables one of said positions to be selected as the fixed position.