US3831855A

US3831855A - Variable flow, pressure venturi nozzle

Info

Publication number: US3831855A
Application number: US00368353A
Authority: US
Inventors: Z Mocarski
Original assignee: SRC LAB
Current assignee: SRC LAB; SRC LABOR INC US
Priority date: 1973-06-08
Filing date: 1973-06-08
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27

Abstract

A venturi type nozzle that uses pressurized fluid to induce flow of the secondary fluid with the size of the secondary fluid intake being varied in accordance with the difference of pressure existing at the nozzle exhaust and at the secondary fluid intake.

Description

United States Patent [111 3,831,855 Mocarski Aug. 27, 1974 [54] VARIABLE FLOW, PRESSURE VENTURI 1,377,479 5/1921 Hansen 239/416 NOZZLE 1,592,865 7/1926 Mox1ey 239/416 1.591033 8/1926 Gibbons 239/416 Inventor: Zenon Mocarskl, Easton, Conn- 1,748,004 2/1930 Urquhart 239/416 x [73] Assignee: S.R.C. Laboratories, lnc., Fairfield,

Conn. Primary Examiner-M. Henson Wood, Jr. Assistant ExaminerMichae1 Y. Mar [22] Ffled' June 1973 Attorney, Agent, or Firm--Emest M. Junkins [21] Appl. No.: 368,353

- [57] ABSTRACT [52] US. Cl. 239/416, 239/570 [51] Int. Cl B05b 7/00 A venturi ype z e that uses pressurized fluid to in- [58] Field of S ar h 239/416, 413, 4164, 417 duce flow of the secondary fluid with the size of the 239/569, 570, 423, 416,5 secondary fluid intake being varied in accordance with the difference of pressure existing at the nozzle ex- [56] I Refer Cit d haust and at the secondary fluid intake.

' UNITED STATES PATENTS 9 Claims 3 Drawing Figures 1,098,429 6/1914 Coleman 239/416 P R E 5 SU RI Z E D FLU! D (.0 N TAIN E. R

Mkinuw PUMP VARIABLE FLOW, PRESSURE VENTURI NOZZLE The nozzle of the present invention employs the venturi effect of a jet of pressurized fluid causing a reduced pressure to exist about its periphery. Normally the jet is contained within a passageway and may be annular or cylindrical in form with an intake communicating with the passageway adjacent the jets periphery. The reduced pressure periphery of the jet induces the flow of secondary fluid through the intake into the passageway where it is exhausted along with the pressurized fluid.

The ratio of the amount of secondary fluid induced to flow as compared to the amount of pressurized fluid generally determines the efficiency of the nozzle. Normally, the nozzle is adjusted or constructed to be most efficient at only one operation condition and deviations therefrom reduces the efficiency. Moreover, under some situations where the conditions exceed the designed condition some of the pressurized fluid may undesirably flow reversely through the intake.

It is accordingly an object of the present invention to provide a venturi type nozzle which is quite efficient over a wide range of operating conditions.

Another object of the present invention is to provide a venturi type nozzle which minimizes, if not substantially eliminates, any possible flow of pressurized fluid reversely through the intake.

A further object of the present invention is to achieve the above objects with a venturi type nozzle that is extremely simple in construction, quite inexpensive to manufacture and is durable and reliable in use.

In carrying out the present invention, the venturi type nozzle includes an inlet that is connected to a source of pressurized fluid and an exhaust with a passageway interconnecting the intake and exhaust. The inlet is designed to make the pressurized fluid form a jet in the passageway and an intake is formed to communicate with the periphery of the jet in the passageway. The invention further provides an adjustable means for controlling the size of the intake through which the secon dary fluid is induced to flow, and includes a movable member which is relatively movable with respect to other portions of the nozzle defining the intake. Thus by controlling the relative position of the movable member, the size of the intake may accordingly be selected.

To enable the nozzle of the present invention to inherently adjust itself to provide the size of the intake that is most efficient for the conditions under which the nozzle is operating, the movable member is made to have its relative position determined essentially by the difference in pressure that exists at the nozzle exhaust and at the intake. Thus, for a low difference in pressure, the movable member would be spaced such as to provide a relatively large intake area while for a large difference in pressure, the movable member only provides a small area intake. In such a manner, the movable member thus tends to assume a position which regulates the size of the intake so as to cause the nozzle to operate efficiently at the instantaneous condition.

In some instances where the exhaust pressure would be so high as compared to the intake pressure, as to tend to cause reverse flow through the intake, the movable member may completely block the intake so that only the pressurized fluid is exhausted through the nozzle.

Other features and advantages will hereinafter appear.

In the drawings:

FIG. l is a diagrammatic section of a nozzle made according to the present invention with the movable member being positioned for a condition where a low difference of pressure exists at the exhaust and the intake.

FIG. 2 is a view similar to FIG. 1 showing the position of the movable member for a higher difference of pressure existing at the exhaust and at the intake.

FIG. 3 is a view of a further embodiment of a nozzle shown in a proposed fluid system.

Referring to the drawing, the nozzle of the present invention is generally indicated by the reference numeral l and includes a body 11 formed of rigid material to have the diammetric cross-sectional shape shown. A nut 12 is threaded into one end of the body and includes a bore 13 which through another hollow connector 14 provides communication to a hose or tube 15. The tube 15 is preferably connected to a source of fluid under pressure such that the pressurized fluid is caused to pass through the connector 14, bore 13 and be ejected from the end 16 of the bore as a cylindrical jet.

The other end of the body 11 has a stepped cavity formed by side walls 17 and 18 with a ledge 19 interconnecting the two surfaces. An annular movable member 20 is positioned within the stepped cavity and includes an outer surface 21 which essentially mates with a surface 18 and an outwardly extending flange 22. A spring 23 is positioned between the ledge 19 and the flange 22 and is tensioned to urge the movable member 20 leftwardly outwardly of the stepped cavity. However, a cap 24 engages the other side of the flange 22 to retain the movable member in the cavity. In order to assure sealing engagement between the two

surfaces

18 and 21, preferably an O-ring 24a is contained within a groove formed in the movable member.

Intermediate its two ends, the body 11 is formed with a cylindrical chamber 25 that is connected by way of a tube 26 to a source of secondary fluid which is desired to be moved by the nozzle 10.

In the operation of the nozzle, pressurized fluid is caused to flow through the tube 15 and out the end 16 to form within a passageway 27 defined by the interior surface of the movable member 20, a jet of pressurized fluid which moves through the passageway 27 to be exhausted at the exhaust end 28. As is well known in the art, an area of reduced pressure is formed about the periphery of the jet and this will induce flow of secondary fluid through the tube 26, the chamber 25 and between somewhat similarly curved

annular surfaces

29 and 30 formed on the nut 12 and the movable member 20 respectively. These elements constitute the intake to the nozzle.

The spring 23 urges the movable member 20 leftwardly while the pressure at the exhaust 28 acting on the movable members surface 31 tends to exert a force to move the member 20 rightwardly while the pressure on the movable members surface 30 tends to exert a force to move the member leftwardly. So long as the pressure at the exhaust exerts a force that is less than the pressure exerted by the sum of the forces caused by the spring 23 and pressure on the surface 30, the movable member will maintain its position as shown in FIG. 1. This position of the movable member provides the largest area between

surfaces

29 and 30 through which the induced secondary fluid may flow and thus the largest size of the intake.

When the pressure of the exhaust 28 exerts a force greater than the forces produced by the sum of the pressure on the surface 30 and the spring 23, the movable member 20 will move rightwardly until these forces are balanced. In doing so, the surface 30 approaches the surface 29 to reduce the area through which the induced secondary fluid may flow. Thus the difference in pressure at the exhaust and at the intake serves to set the position of the movable element 20 with the latter providing an increased area of intake for a low difference and a small intake area for a large difference.

By properly dimensioning the position of the nut 12 and the value of the spring 23 together with the areas of the

surfaces

31 and 30 on which the pressures act, the parts may be dimensioned to enable the nozzle to operate over a wide range of pressure conditions. It will be understood that the nut 12, by being threadingly connected to the body 11, may be easily initially adjusted to set the low pressure difference size of the intake. Also, the tension of the spring 23 may be altered by changing springs to also enable the nozzle to be adjusted for selected conditions.

One instance of where a wide range of pressure conditions may occur is shown in FIG. 3 in which there is a fluid source 32 and it is desired to pump the fluid therein into a closed pressured fluid container 33. The nozzle 10, of the present invention, may be employed together with a fluid pump 34 with the pump 34 provid ing the pressurized fluid to the inlet of the nozzle while the tube 26 constituting the intake of the secondary fluid is also connected to the fluid source 32. As surning that the container 33 and the fluid source 32 are essentially at the same pressures, the movable member initially provides a large area intake for the induced fluid such that the pressurized fluid will thus induce a substantial flow of induced fluid.

As the pressure in the container 33 increased, the difference in pressure at the exhaust, which is that in the container 33, and the intake will increase and the movable element 20 will move rightwardly to decrease the intake area for secondary fluid which enables the nozzle to operate substantially efficiently even with the higher exhaust pressure. As the pressure in the container 33 continues to increase by the pumping of more fluid therein, the difference in pressure will effect a sealing engagement between the surfaces 29 and and completely shut off the intake. Thus the pump 34 can now increase the pressure in the container 33 beyond that which it normally could have if the intake were not blocked as pressurized fluid is prevented from flowing back to the fluid source through the intake. Preferably to assure, an effective seal, an O-ring 35 may be provided on the surface 30.

While the embodiment shown in FIG. 3 is illustrious of the nozzle exhausting into a container that has increasing pressure, it will be clear that it operates similarly when the fluid source 32 is a closed container and the nozzle 10 is exhausting the fluid therein with generally the exhaust being open to the atmosphere. In such an instance, the difference in pressure would still increase in view of the increasing vacuum in the contained fluid source until the maximum value of the vacuum is achieved. The seal 35 would thus prevent the pressurized fluid from flowing into the container thereafter to thereby maintain the maximum vacuum.

It has been found that when used to product a vacuum in a closed container, that the nozzle with the pressurized fluid at about psi, may at the beginning initially evacuate two volumes of induced secondary fluid for each volume of pressurized fluid while at about 25 inches of mercury vacuum, 20 volumes of pressurized fluid will produce perhaps one volume of induced fluid flow.

Thus the nozzle of the present invention more quickly fills or evacuates a closed container as opposed to a nozzle that must be adjusted to either a maximum exhaust pressure or intake pressure, and operated at such a condition until the container achieves such a pressure. Moreover, the quantity of pressurized fluid needed is substantially reduced as the nozzle tends to act efficiently throughout the changing difference in pressure conditions.

While the nozzle disclosed herein uses a cylindrical jet of pressurized fluid, it will be clear that, if desired, the present invention may be employed with a venturl type nozzle that has an annular jet.

It will accordingly be understood that there has been disclosed a venturi type nozzle which adapts itself to its instantaneous operating condition of the pressure at its exhaust and at its secondary fluid intake. This is achieved by the use of a movable member which responds to the difference of pressure therebetween to regulate the size of the intake. In so doing, the nozzle tends to act substantially efficiently over a wide range of pressure conditions.

If desired, a stop 36 may be used to limit rightward movement of the member 20 and by setting the position of the nut I2, the maximum difference pressure may thus be easily preset. Though alternatively, the stop may be made adjustable instead of adjusting the nut 12. In either event, this limits the minimum area of the intake.

As used herein, a venturi type nozzle completely contains the pressurized fluid until it issues as a jet, controlled as to direction and shape, rather than relying upon the pressurized fluid flowing along a surface and using the Coanda effect.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. A venturi type nozzle comprising an inlet, an exhaust, a passageway communicating with the exhaust, said inlet being formed to receive a flow of pressurized fluid and direct it into the passageway, an intake communicating with the passageway and the periphery of the flow and being connectible to a source of secondary fluid, said flow inducing the flow of secondary fluid through the intake into the inlet and through the passagway, and adjustable means for varying the size of the intake communicating with the passageway, said adjustable means including a movable portion responsive to the difference in pressure at the intake and the exhaust.

2. The invention as defined in claim I in which at least for values of differential pressure exceeding a selected value the adjusting means completely closes the intake.

3. The invention as defined in claim I in which the movable portion of the adjustable means reduces the size of the intake as the pressure difference increases.

4. The invention as defined in claim 3 in which the adjustable means includes means for urging the movable portion to increase the size of the intake against the action of the pressure difference tending to reduce the size.

5. The invention as defined in claim 1 in which the adjustable means includes a stationary portion and a movable portion with the latter being mounted for movement toward and away from the stationary portion and in which the intake is formed between adjacent surfaces of the movable and stationary member.

6. The invention as defined in claim 5 in which the movable portion includes a first surface exposed to the pressure at the exhaust and a second surface exposed to the pressure at the intake.

7. The invention as defined in claim 6 in which the adjustable means includes spring means tending to exert a force to move the portion in the direction that the intake pressure tends to move the portion.

8. The invention as defined in claim 1 in which there are means for initially setting the size of the intake.

9. A venture type nozzle comprising a body formed connector a passageway, a connector secured at one end of said passageway and having a bore connectible to a source of pressurized fluid, said bore having an end terminating in the passageway and out of which a jet of pressurized fluid issues, a movable annular member mounted in the other end of said passageway and having a first end surface exposed to the pressure at the other end and a second end surface, said jet passing through said movable member, an intake connectible to a source of secondary fluid formed between the second end surface of the movable member and an adjacent surface of the container and means for normally urging the movable member away from the adjacent surface.

Pdlwso UNETED STATES PATENT OFFKCE CERTIFICATE OF CORRECTIQN Patent No. 3, 3 55 Dated August 2?,197L

Inventor(s) Zenon R. Mocarski It is certified that error appears in the above-identifiedpotent and that said Letters Patent are hereby corrected as shown below:

Column 2, line f, "diagramma ould' be "increases" Column 3,"l1ne 41, "increased" sh claim 920E connector (first occurrence) Column 6, line 5,

a" substituted should be deleted and wi claim 9), "container" should be "connector" Column 6, line 16,

Signed and sealed this 24th day of December 1974.

(SEAL) Attest:

McCOY M. GIBSON JR]; c. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims

2. The invention as defined in claim 1 in which at least for values of differential pressure exceeding a selected value the adjusting means completely closes the intake.

3. The invention as defined in claim 1 in which the movable portion of the adjustable means reduces the size of the intake as the pressure difference increases.