US3457893A - Interruptible-jet control means for producing short blasts of high pressure fluid - Google Patents

Description

y 29, 1969 J. P. LAVALIER 3,457,893

INTERRUPTIBLE-JET CONTROL MEANS FOR PRODUCING SHORT BLASTS OF HIGH PRESSURE FLUID Filed Dec. 29. 1966 INVENTOR JAMES P LAVAL/Ef? United States Patent 3,457,893 INTERRUPTlBLE-JET CONTROL MEANS FOR PRO- DUCING SHORT BLASTS OF HIGH PRESSURE FLUID James P. Lavalier, Mahtomedi, Minn., assignor to Hart- Carter Company, Chicago, Ill, a corporation of Delaware Filed Dec. 29, 1966, Ser. No. 605,730

- Int. Cl. Gk 9/00 US. Cl. 116137 9 Claims ABSTRACT OF THE DISCLOSURE An apparatus for intermittently releasing a short duration blast of high pressure fluid, wherein a bleed actuated diaphragm type main valve controlling a high pressure line is operated to release the blast of fluid by interruption of a fluid jet which normally acts against the diaphragm of a pilot valve to hold closed the outlet of a bleed line from the high pressure side of the main valve diaphragm, the duration of the high pressure fluid blast being determined by and commensurate with the time period that the fluid jet is interrupted to cause the pilot valve to open the bleed line.

Related application The subject of this application is disclosed in the copending application of Knowlton-J. Caplan, Ser. No. 572,295, filed Aug. 15, 1966, for Method of Filtering a Gaseous Medium and Means Therefor, said copending application being owned by the assignee of the present invention.

Background of the invention This invention pertains to that field of art which concerns the intermittent production ofvery short duration blasts or jets of high pressure fluid, the blasts being discharged, at predetermined intervals and each blast having a duration of a fraction of a second.

Prior means for this purpose involve the use of mechanically actuated pilot valves for operating a main valve controlling a high pressure line, as by means of cams or stops, or the use of complicated diaphragm and spring arrangements whereby a main valve is momentarily opened. at predetermined intervals determined by the rate of fluid flow through a restricted passage. In all such prior apparatus or devices the duration of the high pressure discharge was difficult to regulate and in most instances could not be reduced to the desired amount for a shockr type eflect. Also the prior devices often developed considerable and costly maintenance problems.

By 'the present invention the apparatus required is greatly simplified, moving parts are minimized, and positive and accurate control of high pressure blasts of substantially any desired duration is readily obtained.

A particularl use for the present invention resides in the controlling of a high pressure, high volume, pneumatic system by means of a relatively low pressure, lowconsumption, interruptible air jet for the creation of a single sonic velocity shock wave in each of successive hollow gaseous medium filter cells as an aid to the conventional flushing or back-washing operation.

Summary of the invention The inventive concept involved in this invention is to cause extremely rapid operation of a bleed controlled diaphragm valve for releasing periodic explosiv burst-s of a high pressure fluid by means of a pilot valve, in the bleed line, actuated by an interruptible jet of a relatively low pressure fluid. This is accomplished by means of a 3,457,893 Patented July 29, 1969 ice pilot valve of the diaphragm typ which normally holds closed the bleed line from the high pressure valve when the pilot diaphragm is pressured by a jet of the low pressure fluid. Interruption of the jet, as by the passage of a solid element across the jet stream, releases the holding pressure on the pilot valve diaphragm and, for the duration of the jet interruption, opens the bleed line to cause automatic opening of the main valve to pass high pressure fluid for the same time period.

The main object of the invention is to cause opening of the main valve, for very short periods and at regular intervals, to release successive explosive bursts of high pressure fluid which burst-s are of a constant fraction-of-asecond duration. According to the invention the periodicity and the duration of the bursts of high pressure fluid from the main valve are controlled by means of a continuous series of spaced, narrow interrupters traversing the controlling jet stream at a predetermined rate, the speed of relative movement between the interrupters and the controlling jet stream and the width of the interrupters impacted by the jet stream determining the duration of the respective bursts of high pressure fluid.

Description of the drawings A preferred embodiment of this invention is illustrated in the accompanying drawings in which:

FIG. 1 is a diagrammatic sectional View, showing the nature and operational relationship of the principal components comprising the improved control means, the valves being in the closed position resulting from action of the control jet on the pilot valve.

FIG. 2 is a similar view but showing the elements in the state resulting from an interruption of the control jet; and

FIG. 3 is a partly sectioned elevational view, showing the pilot valve and the interruptible jet elements as applied to the rotating member of a continuous gaseous medium filter of the kind wherein a shock wave is generated in each of successive hollow filter elements by the timed release of an explosive burst of high pressure gas thereinto.

The preferred embodiment As shown in FIGS. 1 and 2, my improvedsystem for creating short duration for explosiveblasts'of high pressure fluid comprises a mainvcontrol valve 10 connected to-a high pressure compressed air line 12 leading from a surge tank 14 having communication with a suitable source of supply, not shown. The outlet 16 of the main valve 10 leads directly to a shock wave generator 18 which has a blast discharge orifice 20 in its side wall.

The main valve 10 shown is of the diaphragmtype wherein the diaphragm 22 serves to open and close the outlet 16 as well as the inlet 17 of the valve in response to pressure changes in the chamber 24 on the highpressure side of the diaphragm. As shown, the valve chamber 24 communicates directly with the compressed .air. line 12 by way of a by-pass passage 26 and opens into a bleed line 28 which terminates outwardly in a pilot valve 30.

It will be understood that the main control valve 10 may be of any suitable pilot operated kind capable of rapid release and stopping of a high pressure gas.,flow. One valve suitable. for this purpose is the ASCO- No. 83533 pilot operated valve madeby the Automatic Switch Company. v

The pilot valve 30, as shown, comprises a hollow body housing a diaphragm32 which divides the body into separate sections 34 and 36. The section 34 is the receiver for the control jet and opens from a relativelynarrow receiver passage 38 into which the control jet is normally directed, as will be described hereinafter. The body section 36 is the bleed chamber into which the bleed line 28 terminates through a nozzle 40 disposed in axial alignment with a plunger-valve member 42 mounted centrally on the diaphragm 32 and normally in axial abutment with the nozzle 40 to close the same. As shown, the plungervalve member is supported for axial sliding movement by an internal brace means 44 disposed in the bleed chamber behind the diaphragm 32. Also, the bleed chamber is open to atmosphere through body openings 46.

The control jet is delivered into the receiver passage 38 by means of an axially aligned nozzle 48 mounted in a suitable air pressure suply means 50, the nozzle 48 being spaced from the inlet end of the receiver passage 38 to permit passage therebetween of an interrupter element 52.

It will now be seen that as long as the air flow across the ambient gap 54 (the space between the nozzle 48 and the receiver passage 38) is undisturbed the jet stream 56 from the nozzle 48 transmits a velocity pressure to the low pressure side of the diaphragm 32. Since this pressure is acting over a large area, the plunger 42 of relatively much smaller area is forced against the bleed outlet seat 40. As a result the bleed line 28 is closed even though the static pressure therein is substantially the same as the line pressure of the conduit 12. The high pressure in the main valve pressure chamber 24, supplied by the by-pass 26, thus holds the main valve control diaphragm 22 in closed position against the valve outlet 16 leading to the shock wave generator 18, and against the inlet 17, as shown in FIG. 1.

When an interference element or interrupter 52 intercepts or passes through the jet stream 56 in the ambient gap 54, as shown in FIG. 2, the normal pressure transmitted into the receiver 34 is blocked, momentarily relieving the holding force on the low pressure side of the diaphragm 32, and permitting the plunger 42 to be unseated by the pressure in the bleed line 28 leading from the main control valve pressure chamber 24. This allows the pressure in the chamber 24 to be relieved to atmosphere through the openings 46 of the pilot valve 30, and the diaphragm 22 is suddenly fiexed (for a fraction of a second) to open communication between the ports 16 and 17 and allow the sudden passage of high pressure air from the line 12, under the impetus of the large volume of the surge tank 14, into the line 18. This sudden and explosive momentary discharge of high pressure gas through the orifice 20 creates a single pressure wave which travels at, or close to, sonic speed away from the orifice 20 in the axial direction thereof. When the interrupter 52 is removed these operations are reversed and the jet force 56 seats the plunger 42 on the bleed outlet 40, causing the high pressure from the line 12, through the by-pass 26, to reseat the diaphragm 22 and cut off the pressure flow from the valve through the outlet 16, the parts returning to the condition of FIG. 1.

This operation of the control system is extremely rapid and the opening and closing movement of the diaphragm 22 occurs between the entry of the interrupter 52 into the jet stream 56 and the exit of the interrupter therefrom. Thus the duration of high pressure gas flow from the valve 10 into the conduit 18 is determined by the size of the interrupter element and its speed of movement across the jet stream.

In the preferred embodiment of this control system as a shock wave generator the nozzle 48 is 0.030 inch in diameter; the gas pressure at the jet nozzle 48 is about 10 to p.s.i.g.; the ambient gap 54 is 0.375 inch; and the receiver 38 has an inside diameter of about 0.100 inch. The interrupter 52 is a rod or peg having a diameter of 0.0315 inch, and the interrupter crosses the jet stream 56 at a speed of substantially 28% inches per minute. With this relationship of the components of the control means and speed of relative movement of the jet stream interrupter, the on time of the high pressure blast discharge of the main control valve is 0.150 second.

An exemplary arrangement of the pilot valve and interruptible jet means is shown in FIG. 3 wherein the control means is mounted on the rotatable hollow trunk 60 of a gaseous medium filter such as that described in the before-mentioned'copending application of Knowlton J. Caplan, Ser. No. 572,295.

As shown in FIG. 3, the jet air supply means 50 connects with a compressed air supply line 62 through a passage 64 in the trunk body. This air is discharged as a jet from the nozzle 48, across the ambient gap 54, into the receiver inlet 38 0f the pilot valve 30. With this arrangement the pilot valve and jet nozzle travel together, angularly, as the trunk 60 rotates and the pilot is intended to operates to cause a predetermined number of blasts of high pressure air during each complete revolution of the trunk 60. Thus there must be an interrupter for each high pressure blast to occur in one revolution of the trunk 60 and these interrupters must be stationary and angularly spaced in the path of the traveling jet-pilot elements to correspond with the angular location of each blast delivery.

As shown in FIG. 3, the ambient gap 54 opens downwardly to straddle the vertical rim of a cup-like member 66. The several interrupters 52, here small diameter rods, are mounted on the rim of the member 66, in appropriate angularly-spaced relation, and extend upwardly a distance sufficient to cross the-jet stream. Thus, as the trunk 60 rotates, the jet stream flow into the receiver 38 is intercepted momentarily as it passes each interrupter 52 and the pilot valve 30 is operated to perform its function of causing the release of a short duration blast of high pressure air.

Major advantages of my improved control system reside in the substantial elimination of moving parts, minimum maintenance requirements, and the fact that it is practically insensitive to environmental conditions.

Although but one specific embodiment of this invention have been hereinshown and described, it will be understood that details of the structures involved may be altered or omitted without departing from the spirit of the invention as defined by the following claims.

I claim:

1. Apparatus for producing short duration blasts of a high pressure fluid from the discharge outlet of a bleed controlled main valve connected with a high pressure supply line by means of a pilot valve for opening and closing a bleed passage leading from the high pressure side of said main valve and terminating in an outlet orifice. wherein the improvement comprises a pilot valve into which said bleed passage terminates and which has a diaphragm operable to open and close the said outlet orifice, means for directing pressure from a fluid-jet stream against the side of the pilot valve diaphragm opposite the side adjacent the said outlet orifice for closing the same, and means for interrupting said fluid-jet stream for predetermined short periods of time.

2. Apparatus according to claim 1 wherein the pilot valve comprises a receiver section and a bleed section separated and sealed from each other by the diaphragm, each of said sections having an opening to ambient atmosphere and the fluid-jet stream being directed into the opening of the receiver section from a nozzle spaced therefrom.

3. Apparatus according to claim 2 wherein the bleed line outlet comprises a nozzle from which the outlet orifice is directed toward said diaphragm.

4. Apparatus according to claim 2 wherein a valve member in said bleed section is axially aligned with the bleed line outlet orifice and is held seated against the orifice by the diaphragm when the diaphragm is acted upon by the pressure of said fluid-jet stream.

5. Apparatus according to claim 3 wherein a plungervalve member in said bleed section is axially aligned with the orifice of said bleed line nozzle and is held seated against said nozzle by said diaphragm to close said orifice when the receiver section is under the pressure of said fluid-jet stream.

6. An apparatus according to claim 1 wherein the means for interrupting the fluid-jet stream comprises a rod disposed normal to the said jet stream and laterally traversing the jet-stream at a predetermined speed.

7. An apparatus defined by claim 2 wherein the means for interrupting the fluid-jet stream comprises a rod disposed normal to the said jet stream and laterally traversing the jet-stream through the space between the jet nodzle and the opening of the receiver section at a predetermined speed.

8. A shock wave generating means comprising an apparatus according to claim 1 and wherein the burst f high pressure fiuid from the main valve is discharged into a hollow elongate body closed at one end and having its other end connected to the discharge outlet of the said main valve, the said elongate body having a shockwave producing blast-discharge orifice in its side wall.

9. A shock wave generating means comprising an apparatus according to claim 6 and wherein a hollow elongated cylindrical body closed at its distal end is connected to the discharge outlet of the main valve and is provided 'with an orifice in its side wall intermediate its ends for producing a single shock-wave by the issue of a blast of high pressure fluid therefrom.

References Cited UNITED STATES PATENTS 2,065,702 12/1936 Hubbard. 2,526,972 10/ 1950 Ray 25l45 XR 3,216,252 11/1965 Chapman et a1. 73-229 3,258,023 6/1966 Bowles 13781.5

FOREIGN PATENTS 1,021,560 3/1966 Great Britain.

LOUIS J. CAPOZI, Primary Examiner US. Cl. X.R.

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