US3586023A

US3586023A - Fluidic throttle

Info

Publication number: US3586023A
Authority: US
Inventors: Theodore J Fussell
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1969-03-13
Filing date: 1969-03-13
Publication date: 1971-06-22
Anticipated expiration: 1988-06-22

Abstract

The invention involves a structure of the general type commonly found in fluid amplifiers. The ability to change the direction of flow of a fluid stream is employed to cause the fluid to undergo a change from flow through a primary discharge leg at essentially full line pressure to a flow through the same leg at a very substantially reduced pressure. The pressure drop can be used, by way of example, as a means of activating or deactivating a valve as well as a means of attenuating water hammer, a means for conserving fluid in a continuous flow system by decreasing flow rate in accordance with the needs of the system and as an amplifier by converting a weak signal at the control port into a signal of greater magnitude at the discharge port.

Description

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[72] inventor Theodore J. Fussell 3,425,433 2/1969 Moore 137/81.5 Bound Brook, NJ. 3,470,894 10/1969 Rimmer 137/81.5 [21] App]. No. 807,634 3,483,883 12/1969 Hartmann 137/81.5 [22] Filed Mar. 13,1969 3,192,938 7/1965 Bauer 137/81.5 [45] Patented June 22, 1971 mary Examiner-Samuel Scott Asslgnee it s: gg Attorneys-Sheldon H. Parker, Tennes 1. Erstad and Robert o. Crooks [54} FLUI-D 1C THROTTLE-2 ABSTRACT: The invention involves a structure of the general 9 Claims, 8 Drawing Figs.

type commonly found in fluid amplifiers. The ability to change U.S. the direction of flow ofa stream is employed to cause the to undergo a change from flow through a primary [50] Fleld 0 Search 1 discharge leg at essentially line pressure to a flow through the same leg at a very substantially reduced pressure. The [56] References (med pressure drop can be used, by way of example, as a means of UNITED STATES PATENTS, activating or deactivating a valve as well as a means of at- 2,247,301 6/1941 Lesser 137/8l.5 UX tenuating water hammer, a means for conserving fluid in a 3,181,546 5/1965 Boothe l37/81.5 continuous flow system by decreasing flow rate in accordance 3,193,197 7/1965 Bauer 137/81.5 X with the needs of the system and as an amplifier by converting 3,204,652 9/1965 Bauer 137/81.5 a weak signal at the control port into a signal of greater mag- 3,397,713 8/1968 Warren 137/81.5 nitude at the discharge port. a

3 /22 j) x 13 2/1 x M r- 16 2 3 2 2 1O 12 J PATENTEUJUHZZIQTI 3586023 SHEET 1 OF 3 FIG! FIG. 3

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INVENTOR. Theodore J. Fussell FLUIDIC THROTTLE BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to a fluid control mechanism and more particularly to a fluidic switching mechanism which can automatically produce a substantial pressure drop or decrease of flow rate of a fluid.

2. Descriptionof the Prior Art It is known that a stream of fluid which issues into a chamber can be caused to deflect and adhere to either of two opposite walls in the chamber in response to the opening or closing of a control port located in one of the walls adjacent the inlet to the chamber.

By virtue of the fact that the fluid adheres to either of two opposite walls, the fluid can be caused to selectively issue from any one of two or more outlet legs from the chamber.

SUMMARY It has now been found that by contouring onewall of the switching chamber and providing one outlet leg, the phenomena of deflecting the fluid issuing from a nozzle, into the switching chamber, can be used to control or restrict the flow of fluid through the outlet leg.

In accordance with the present invention, a fluidic control is provided a fluid inlet, a control inlet, a fluid outlet leg and a flow reversal region. The flow reversal region has an outer wall, a portion of which is curved so as to cause fluid directed toward the flow reversal region to flow backwards toward the fluid inlet.

The objects, features and advantages of the present invention will become apparent with the reading of the specification, particularly when taken in conjunction with the drawings wherein:

FIG. 1 is a schematic representation of an amplifier in accordance with the present invention;

FIG. 2 is a schematic representation of the amplifier of FIG. 1, at a different stage of operation;

FIG. 3 is a schematic representation of an amplifier which is not in accordance with the present invention;

FIG. 4 is a-schematic representation of a refill mechanism employing an amplifier of the type illustrated in FIG. 1;

FIG. 5 is a schematic representation of another modification of a fluidic control in accordance with the instant invention; and

FIGS. 6, 7 and 8 are schematic representations of the structure of FIG. 5, at different stages of operation.

Broadly, the invention employs a structure of the type normally found in the field of fluid amplification, that is, the controlling of a large amount of fluid with a relatively small amount of control fluid. Basically, fluid amplification involves the switching or changing direction of a high energy fluid power stream by means of a low energy fluid control system.

The instant invention employs the principle of changing the direction of a high energy fluid as a means of lowering the energy level of the fluid. As shown in FIG. 1, a fluid stream 10 passes through a nozzle 12, into a switching chamber 14.

As long as fluid can be freely drawn into the control chamber 14, through the vent conduit 18, the fluid stream will be deflected toward the wall 16 which is opposite the wall 20 which contains the venting inlet 18.

The fluid thus, during this portion of the cycle, travels relatively unrestricted through the fluid control 22.

If, for any reason, the vent conduit 18 is closed, the fluid 10, will be diverted from wall 16, to the opposite wall 20.

However, because of the curvature of the wall 20, the fluid is caused to turn and flow in the reverse direction. A high back pressure results and the fluid attempts to find a path of least resistance and attempts to flow directly towards the outlet leg 24 of the fluidic control. The fluid flow redirected by the curvature of wall 20 and the fluid flow seeking a path of least resistance, in effect, interfere with each other thus causing a substantial pressure drop between the nozzle 12 and the outlet leg 24.

By way of contrast, FIG. 3 shows that the mere use in a fluidic control of a primary outlet leg 26 and a restricted outlet leg 28 produces a totally different type of result from that obtained with the structures of FIGS. 1 and 2.

The structure of FIG. 3 would produce an instantaneous interruption in the flow through outlet leg 26, at the moment the flow was diverted from the leg 26 to the leg 28. However, the flow would seek the path of least resistance and after the momentary interruption, resume flowing through the outlet leg 26, even though the vent conduit 18 was closed.

As shown in FIG. 4, the pressure reducing system can be employed to actuate a valve.

Fluid flow through the fluidic control 30, is started by initially moving the actuating rod 32 in the direction indicated by the arrow 34. This causes the the valve 36 to move away from the valve seat 38 thus permitting fluid in the inlet leg 40 to flow to the intermediary leg 42 and into the switching chamber 44.

A portion of the fluid flowing through the outlet leg 46 will flow through the diaphragm conduit 48 into the diaphragm chamber 50. The fluid acts against one side 54, of the diaphragm 52, applying a fluid pressure in the direction of arrow 34, thus automatically holding the valve 36, in the open position.

As previously noted, as soon as the vent conduit 18 is closed the switching action starts and the fluid pressure in the outlet leg 46 drops appreciably.

The system can be designed such that the full line'pressure acting on the valve 36 is great enough to move the valve 36, in the direction indicated by the arrow 56. This force must be sufficient to overcome the reduced fluid pressure in the diaphragm chamber 50. A spring 58 can be employed for the purpose of having an additional force exerted in the direction indicated by the arrow 56. The spring is held under compression when the valve 36 is in the open position and thus acts as a constant closing force.

FIG. 5 shows a flow mechanism which employs the pressure reducing feature as a means of reducing or eliminating the water hammer effect which can result when a valve is suddenly closed.

Conduit 60 is at all times in communication with the refill liquid. In the case of a-water closet refill system, water typically at a pressure in the range from 20 to 120 pounds per square inch would be supplied to conduit 60. The fluid pressure acts on ball 62, keeping the ball firmly seated on valve seat 64, thus sealing the vent opening 66. Similarly, the ball 68 is firmly seated against the valve seat 70, sealing the passage to refill conduit 72. I

As shown in fig. 6, the plunger 74 is depressed against the force of spring 76, causing the ball 68 to move away from the valve seat 76. The movement of the ball opens the passage to the refill conduit 72 thus permitting fluid to flow through the refill conduit 72 and into the receptacle being filled. Simultaneously, the pressure holding ball 62 in its seat is relieved and air is drawn through the vent or control port 66 as a result of the low pressure created by fluid entrainment in the jet issuing from the inlet nozzle 80. The jet remains attached to the upper wall 82 of the control chamber 84 due to the low pressure created by fluid entrainment in the jet near the upper wall and the nearambient pressure in the lower part of the control chamber provided by the inflow of air through the control port 66. The jet will thus continue to flow into leg 88 and thence discharge through port 90 until the liquid level of the reservoir being filled reaches the mouth of the control port duct 66 and blocks the flow of air to the control chamber 84. With the cessation of air flow into the control chamber as shown in FIG. 7, the jet will attach to the lower wall 86 of the control chamber 84 and discharge through leg 94 moving ball 68 toward its seat 70.

As shown in FIG. 7, a portion of the fluid flow continues through the leg 94, while the major portion of the flow goes through a flow direction reversal and interferes with the flow, that is, blocks itself, to a sufficient extent to bring about a substantial pressure drop.

As shown in FIG. 8, the ball 68 becomes firmly seated on the valve seat 70 thus completely stopping the flow through the outlet leg 72.

Water hammer is attenuated because the fluid flow, rather than stopping while the fluid is at full line pressure, stops after a substantial pressure drop has been encountered, thus resulting in a relatively gradual, or gentle, shutting-off action.

Although the invention has been described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms has been made only by way of example, and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

What I claim is:

l. A fluidic control having:

a. a fluid inlet;

b. a first fluid outlet leg;

c. a control inlet, said control inlet causing fluid to flow toward said first fluid outlet leg or a flow reversal region;

d. a flow reversal region, said flow reversal region having an outer wall, a portion of which has a curvature such that fluid directed toward said region flows backwards toward said fluid inlet in the region of contact between the fluid from the fluid inlet and the backflow throttles the fluid flowing from said fluid inlet.

2. The structure of claim 1, further including a second outlet, the cross-sectional area of said second outlet leg being substantially less than the cross-sectional area of said first outlet leg.

3. The structure of claim 1, wherein said control inlet is a vent inlet positioned at substantially a right angle with respect to said first fluid inlet and is in the outer wall of said flow reversal region.

4. The structure of claim 3, further including a second outlet leg having a first end opening in said flow reversal region, and a second end communicating with valve means.

5. The structure of claim 3, further including a second outlet leg having a first end opening in said first outlet leg and a second endopening in a chamber of a diaphragm valve, and wherein flow normally is from said fluid inlet to said first fluid outlet leg and closing said control inlet causes the inlet fluid to flow into the flow reversal region, resulting in a throttling of 6. The structure of claim 5, wherein said diaphragm valve controls the flow to said fluid inlet, and the normal fluid pressure in said second fluid outlet leg maintains said diaphragm valve in the open position and the throttled fluid pressure is inadequate to maintain said diaphragm valve in the open positron.

7. A flow rate control device, comprising:

A. a control chamber having:

a. a primary fluid inlet,

b. a control fluid port, 7

c. a primary fluid outlet leg,

d. a primary fluid flow path for downstream flow of fluid from said inlet to said outlet leg,

e. a flow reversal region, said region including a wall of said control chamber which has a downstream section which curves inwardly and in a generally upstream direction and thereby directs fluid in a generally upstream direction along said primary fluid flow path thereby throttling the fluid flowing from said primary fluid flow inlet.

8. The flow rate control device of claim 7, wherein said control chamber has a pair of substantially parallel walls and a pair of walls which diverge in the upstream direction, toward the flow reversal region, said wall of saidcontrol chamber being one of said diverging walls.

9. The method of regulating the rate of flow of fluid through aconduit, comprising:

a. passing a primary fluid through a nozzle into a control region, and along a primary fluid flow path to an outlet,

b. regulating the flow of control fluid between said control region and a source of said control fluid,

c. causing a portion of said primary fluid to divert, in response to the quantity of control fluid flowing between said control region and said source of control fluid, from said primary flow path through said control region to a flow reversal region,

d. in said flow reversal region reversing the direction of flow of said portion of said primary fluid and causing said portion of said primary fluid to flow along said primary flow path, in an upstream direction against the downstream primary fluid flow resulting in a controlled degree of pressure drop.

Claims

1. A fluidic control having: a. a fluid inlet; b. a first fluid outlet leg; c. a control inlet, said control inlet causing fluid to flow toward said first fluid outlet leg or a flow reversal region; d. a flow reversal region, said flow reversal region having an outer wall, a portion of which has a curvature such that fluid directed toward said region flows backwards toward said fluid inlet in the region of contact between the fluid from the fluid inlet and the backflow throttles the fluid flowing from said fluid inlet.

5. The structure of claim 3, further including a second outlet leg having a first end opening in said first outlet leg and a second end opening in a chamber of a diaphragm valve, and wherein flow normally is from said fluid inlet to said first fluid outlet leg and closing said control inlet causes the inlet fluid to flow into the flow reversal region, resulting in a throttling of the fluid.

6. The structure of claim 5, wherein said diaphragm valve controls the flow to said fluid inlet, and the normal fluid pressure in said second fluid outlet lEg maintains said diaphragm valve in the open position and the throttled fluid pressure is inadequate to maintain said diaphragm valve in the open position.

7. A flow rate control device, comprising: A. a control chamber having: a. a primary fluid inlet, b. a control fluid port, c. a primary fluid outlet leg, d. a primary fluid flow path for downstream flow of fluid from said inlet to said outlet leg, e. a flow reversal region, said region including a wall of said control chamber which has a downstream section which curves inwardly and in a generally upstream direction and thereby directs fluid in a generally upstream direction along said primary fluid flow path thereby throttling the fluid flowing from said primary fluid flow inlet.

8. The flow rate control device of claim 7, wherein said control chamber has a pair of substantially parallel walls and a pair of walls which diverge in the upstream direction, toward the flow reversal region, said wall of said control chamber being one of said diverging walls.

9. The method of regulating the rate of flow of fluid through a conduit, comprising: a. passing a primary fluid through a nozzle into a control region, and along a primary fluid flow path to an outlet, b. regulating the flow of control fluid between said control region and a source of said control fluid, c. causing a portion of said primary fluid to divert, in response to the quantity of control fluid flowing between said control region and said source of control fluid, from said primary flow path through said control region to a flow reversal region, d. in said flow reversal region reversing the direction of flow of said portion of said primary fluid and causing said portion of said primary fluid to flow along said primary flow path, in an upstream direction against the downstream primary fluid flow resulting in a controlled degree of pressure drop.