Variable Nozzle

Abstract

A nozzle system is provided having a nozzle with variable and controllable orifice.

Description

This invention relates to fluid pressure devices and more particularly to systems including nozzles.

Nozzles with variable orifices have been known in the past. Typically, such nozzles have been used in situations where a fluid stream carries non-fluid (i.e., solid) material through a restricted zone. The variable nozzle reduces or eliminates the tendency of the restricted zone to become plugged or obstructed by an accumulation of the non-fluid material. The nozzle may also to a certain extent control the pressure within the system. In the past such variable nozzles commonly have been a frusto-conical tube constructed of resilient material such as rubber or flexible material such as converging spring metal blades. The natural resistance of the material to stretch or flex has been the sole means for maintaining and controlling the restriction of the orifice. Such construction has certain inherent disadvantages foremost of which is the general lack of control. The particular material used in such construction possesses certain defined resistance to stretch or flex and the resistance cannot be varied as desired. The rubber resilient materials may be used only under very limited temperature conditions. The flexible spring metal blades do not provide a continuous surface around the orifice. Moreover, the resilient or flexible material tends to become fatigued over a period of time and thus gradually loses its effectiveness.

The present invention provides a variable nozzle system that overcomes such disadvantages. The present invention provides a system including a variable nozzle and a control that permits opening of the variable nozzle when the pressure exceeds a desired value. In one embodiment of the present invention the control may be adjusted to permit opening of the nozzle at any of various pressures.

In the drawings:

FIG. I shows an embodiment of the present nozzle system;

FIG. II shows a cross-sectional view of the nozzle portion of the present system in one position of operation;

FIG. III shows an end view of the nozzle portion of FIG. II;

FIG. IV shows a cross-sectional view of the nozzle portion of the present system in another position of operation;

FIG. V shows an end view of the nozzle portion in the operation position of FIG. IV;

FIG. VI shows an exploded view of the nozzle portion of FIG. II;

FIG. VII shows a cross-sectional view taken along the line VII--VII of FIG. VI; and

FIG. VIII shows a control panel of FIG. I.

The nozzle assembly 10 of the present invention, one embodiment of which is shown in FIG. I, may include a fluid carrying feed line 11, a nozzle 12 and a control system 13.

The feed line 11 may carry any of various types of fluid streams issuing from any of various types of apparatus. The line 11 feeding nozzle 12, for example, may be the gun barrel of the puffing apparatus shown in U.S. Pat. No. 3,231,387, the disclosure of which is incorporated herein by reference. Alternatively, the line 11 may be the processing tube of the apparatus disclosed in commonly assigned patent applications Ser. No. 58,318 and Ser. No. 58,317, which disclosure is incorporated herein by reference. The line 11 may be carrying any pressurized flowable stream such as a gaseous stream, a gaseous stream carrying solid or liquid particles, a liquid stream, a liquid stream carrying solid particles, or a stream of flowable solid particles.

The nozzle 12 of FIGS. I-VII has a rear portion 16 and a forward portion 17. The rear portion 16 (FIG. I) includes a pipe or tube 18 that may be of the same internal diameter as line 11. The pipe 18 may be mounted on line 11 such as by coupling 19. The pipe 18 (FIG. II) has an enlarged threaded portion 21 at the forward end. The threaded portion 21 may be provided by sliding a short threaded piece of a larger pipe over pipe 18 and welding the portion 21 in place. A recess 22 is machined in the enlarged threaded portion 21. The pipe 18 (FIG. I) has a bracket 23 mounted thereon. The bracket 23 may be a U-shaped member prepared by bending a metal strap. The bracket 23 may be secured to pipe 18 by welding. The bracket 23 has a pair of upwardly extending legs 24 each having a pin receiving opening therein.

The forward portion 17 of nozzle 12 (FIG. II) includes a frusto-conical tube 27, a plurality of blade-like fingers 28, a first housing member 29, a second housing member 30, and a retaining cap 31. The frusto-conical tube 27 has a flexible or expandable sleeve 34 that may be fabricated from stainless steel sheet material. The frusto-conical tube 27 further involves a shoulder 35 which may be a ring that is welded to sleeve 34. The shoulder 35 has an external diameter small enough for snug insertion into recess 22 of pipe 18.

The blade-like fingers 28 over-lay the sleeve 34 of tube 27 and are held in place by first housing member 29. Each finger 28 is a thin, elongated bar having a forwardly and radially inwardly sloping surface 37 approaching the forward end thereof. Each finger 28 also has a radially outwardly extending flange 38 at the rear end thereof.

The first housing member 29 is cylindrically shaped and has a shoulder portion 39 with a plurality of slots 40 therein. Each slot is for reception of the flange 38 of one of the fingers 28. The slots 40 retain the fingers in place and prevent either circumferential or forward displacement of the fingers. The housing member 29 further includes a radially inwardly extending wall 41 at the forward end with a plurality of slots 42 defined therein. The slots 42 receive the fingers 28 and help maintain the fingers 28 in proper alignment with tube 27. The cap 31 slides over housing member 29 and is threadedly engaged with the enlarged portion 21 of pipe 18. The shoulder 39 of housing member 29 and the shoulder 35 of tube 27 are securely held between the cap 31 and the pipe 18.

The second housing member 30 is cylindrically shaped and snugly slides over the first housing member 27. The housing member 30 has a shoulder 47 at the rear end thereof and a radially inwardly extending wall 48 at the forward end thereof.

The nozzle assembly 10 further includes a control linkage 51 (FIG. I) for controlling the movement of the second housing member 30 with respect to the fingers 28. The control linkage 51 has a yoke 52 with a pair of upper ends 53 that are attached to legs 24 of bracket 23 by a pivot pin 54. The yoke 52 is attached at the lower end 56 to actuating apparatus 57 which may be a two-way piston system. The actuating apparatus 57 alternatively may be any other type of apparatus that is capable of moving the lower end of yoke 52 in a forward and rearward motion. The control linkage 51 further includes a push-pull rod 58. The rod 58 is attached at one end to yoke 52 and at the other end to housing member 30. The rod 58 transmits the movement from the yoke 52 to the housing member 30.

The actuating apparatus 57 may be coupled to a control panel 59 which is capable of recognizing pressure changes in the line 11. The control panel 59 then causes the actuating apparatus 57 to either open or close the nozzle as hereinafter described. The control panel 59 shown in FIG. I is connected to the line 11 by sensing line 62, which may be a small diameter pipe. The control panel 59 is shown in detail in FIG. VIII and includes a low pressure switch 63 and a high pressure switch 64 that control a solenoid switch 65. The solenoid switch 65 controls the flow of air from the air supply 67 to the two-way piston 57 and either sends the air pressure through line 68 to one side of piston 57 or through line 69 to the other side of the piston 57, thus driving the piston in one direction or the other. A master switch 71 may be provided for turning the control panel on and off.

It is believed that operation of the present invention is apparent from the preceeding description; however, the operation will be set forth in even further detail hereinafter.

The present nozzle assembly 10 is first assembled by holding the housing member 29 in a vertical position and inserting the fingers 28 one by one into housing member 29 with flange 38 lying in slot 40. The frusto-conical tube 27 is then inserted into housing member 29 and holds fingers 28 in place as retaining cap 31 is guided over member 29 and secured to threaded portion 21 of pipe 18. The second housing member 30 is guided over first housing member 29 and the control linkage 51 is attached to member 30. The nozzle system 10 is placed in operating condition by turning on the master switch 71. The low pressure switch senses the low pressure in line 11 and actuates the solenoid switch 65 which in turn directs the air supply through line 69 to the two-way piston system 57. The two-way piston system 57 pulls the yoke 56 and thus housing member 30 rearwardly. The wall 48 of housing member 30 produces a caming action on surface 37 of fingers 28 as the housing member 30 moves rearward thereby forcing the fingers 28 radially inwardly. The fingers 28 in turn force the flexible sleeve 34 into the fluted position of FIG. V thereby reducing the cross sectional area of the orifice or opening in the tube 27. If pressure builds up in line 11 above the predetermined value, such as when plugging of the nozzle occurs, the high pressure switch is activated thereby reversing the position of solenoid switch 65 sending the air supply through line 68 which shifts the position of the piston system 57 forward thus moving housing member 30 forward. The wall 48 of housing member 30 no longer holds the fingers 28 in the innermost position and the internal pressure in tube 27 forces the tube to expand to the position of FIG. III thus opening the orifice. Once the nozzle opens the pressure drops in line 11 and the low pressure switch is operated thereby closing the nozzle to the position of FIG. IV.

Claims

I claim:

1. a nozzle comprising an elongated flexible metal tube including an outlet end, means for attaching said tube to a fluid feeding line, and means for releasibly moving circumferentially spaced portions of said tube radially inwardly, said moving means comprising a plurality of fingers lying longitudinally along said tube and extending substantially the length of said tube, said fingers being pivotable toward and away from the center axis of said tube, and reciprocable sliding means for pivoting said fingers, whereby said fingers act on circumferentially spaced points around said tube thereby flexing the tube to restrict and open the passageway through said tube and whereby said fingers act longitudinally along said tube to strengthen said tube.

2. The nozzle of claim 1 wherein said tube is a flexible tube and wherein the moving means include a plurality of elongated blade-like pivotable fingers overlaying said tube, said fingers laying substantially in the direction of fluid flow through said tube and means for pivoting the end of said fingers adjacent said outlet end toward the center axis of said tube thereby moving said spaced portions inwardly toward said axis, and means for releasing said pivoted fingers whereby fluid pressure within said tube moves said inwardly moved portions outwardly to open the passageway through said tube.

3. The nozzle of claim 2 wherein said finger pivoting means comprise caming means.

4. The nozzle of claim 3 wherein said caming means comprise radially inwardly sloping surfaces on said fingers and ring-shaped means for movement along said surfaces to move said fingers radially inwardly.

5. The nozzle of claim 4 wherein said tube is a frusto-conically shaped metal tube.

6. A nozzle assembly comprising:

a flexible elongated frusto-conical tube having an inlet at one end and an outlet at the opposite end, said tube being comprised of flexible sheet metal;

a plurality of elongated fingers lying along the outer surface of said tube, said fingers being spaced around the circumference of said tube, said fingers each including a pivot means at the end toward said tube inlet and a cam surface adjacent the end toward said tube outlet, said fingers each acting in a plane that extends along the axis of said tube;

first cylinder means overlying said fingers, said first cylinder means holding said fingers in said acting plane;

second cylinder means overlying said first cylinder means, said second cylinder means being mounted for reciprocably sliding along said first cylinder means, said second cylinder means including wall means, said wall means engaging said cam surface of each finger;

whereby said second cylinder means may be moved in a first direction to pivot the cam end of said fingers radially inwardly and moved in the opposite direction to permit said fingers to move radially outwardly and whereby said fingers move circumferentially spaced portions of said tube radially inwardly to reduce the cross-sectional area of said tube and permit said spaced portions to move radially outwardly to increase the cross-sectional area of said tube.

7. The nozzle of claim 6 wherein said fingers extend substantially along the entire length of said tube and act as strengthening ribs.

8. The nozzle assembly of claim 6 wherein said first cylinder means includes a radially inwardly extending wall means, said wall means including guideways for maintaining said fingers in alignment.

9. The nozzle assembly of claim 8 wherein said guideways comprise slots defined in said first cylinder wall means.