GB1585519A

GB1585519A - Fluidic flow control devices

Info

Publication number: GB1585519A
Application number: GB2752076A
Authority: GB
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1977-09-30
Filing date: 1977-09-30
Publication date: 1981-03-04

Description

(54) IMPROVEMENTS IN OR RELATING TO FLUIDIC FLOW CONTROL DEVICES (71) We, UNITED KINGDOM ATOMIC ENERGY AUTHORITY, London, a British Authority, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to fluidic control devices in particular to vortex amplifiers, that is to say devices in which a supply fluid flow is controlled by forming in the fluid a vortex which operates to control the supply fluid flow, the vortex being formed by the injection of a control fluid flow into the supply flow.Such a device requires a chamber in which the vortex can be formed, a supply fluid inlet and outlet to and from the chamber and at least one further inlet to the chamber arranged to direct a control fluid flow to interact with and throttle the supply fluid flow.

The throttling effect of the control flow is determined by the form of the inlet or inlets into the chamber for the control fluid flow and the invention seeks to provide a fluidic control device whose performance characteristics can be varied to meet operational requirements by changing the form of the inlet or inlets for the control fluid supply without changing or altering the remaining component parts of the device.

According to the present invention a fluidic control device, in particular a vortex amplifier, comprises a casing formed from two abutting releasable parts, a supply fluid inlet communicating with the interior of the casing through a central opening in one end wall of the casing, a fluid outlet shaped as a diffuser communicating with the interior of the casing through a central opening in the opposite end wall of the casing, a member within the casing cooperating with the opposite end wall to define a vortex chamber, at least one further inlet for a control fluid in a wall of the casing, at least one removable further member within the casing defining at least a portion of the periphery of the vortex chamber and disposed between the or each further inlet and the vortex chamber, the or each further member having one or more openings therein for directing the control fluid into the vortex chamber, and the removability enabling selection according to the required performance.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: - Figure 1 is an axial section of a first embodiment of a vortex amplifier according to the invention, the section being on the line I-I in Figure 2, Figure 2 is a view of the amplifier along the line II-II in Figure 1, and Figure 3 is an axial section of a second embodiment of a vortex amplifier according to the invention.

Figures 1 and 2 illustrate a vortex amplifier having a casing 10 formed in two abutting parts which can be releasably secured together, for example, by nut and bolt assemblies engaging peripheral flanges on the casing parts. It will be realised that other means can be employed for releasably securing the casing parts together. The interior of the casing communicates by way of a central opening in one end wall of the casing with an inlet 11 which conveniently can be butt-welded to the casing.

In a similar manner an outlet 12, conveniently shaped in the form of a diffuser, communicates with the interior of the casing through a central opening in the opposite end wall of the casing. The outlet 12 can also be butt-welded to the casing.

A rectangular partition 16 is positioned within the casing at a fixed, predetermined distance from the above mentioned opposite end wall of the casing by means of four spacer plates 14 arranged one at each corner of the partition 16. Each spacer plate 14 is formed with a channel or slot which terminates in a nozzle 15, as seen in Figure 2. In addition, each spacer plate 14 is provided with an externally threaded hollow stub which communicates with the channel or slot and projects through a preformed opening in the opposite end wall of the casing to engage a corresponding in ternally threaded end of a port 13. The partition is secured and mounted on the spacer plates 14 by means of bolts passing through countersunk holes 19 in the partition and engaging in tapped holes in the spacer plates.

A substantially conical member 17 having a smooth convex surface is mounted centrally on the partition 16 and on the axis of the outlet 12. The member 17 is mounted on the side of the partition which faces the outlet 12.

Preferably the free edges of the partition between the spacer plates are chamfered.

The chamfers are provided on the side of the edges directed towards the outlet 12 and are indicated by reference numeral 20 in Figure 2. Alternatively, or in addition, portions of the partition 16 can be removed or cut-out from the regions between the spacer plates. Such cut-out portions are indicated by the reference number 21 in Figure 2.

The volume between the partition 16 and the previously mentioned opposite end wall of the casing defines a vortex chamber 18.

In operation, a fluid supply enters the casing 10 through the inlet 11 and passes over the free edges of the partition 16 to enter the vortex chamber 18. From the vortex chamber, the fluid enters the outlet 12 and the latter is shaped as a diffuser whereby to regain pressure loss in the fluid.

The chamfered free edges 20 of the partition reduce the formation of eddies and swirls in the fluid entering the vortex chamber and the cut-out portions 21 serve to reduce the resistance of the flow path. Control fluid is injected into the vortex chamber through the ports 13 and the nozzles 15 to throttle the supply flow by interaction therewith.

Preferably, and as shown in Figure 2, each nozzle 15 is arranged such that control fluid flow issuing therefrom will strike the facing surface of the next spacer plate at a position behind the nozzle in that plate. This enables the flow issuing from each nozzle to clear and disperse any deadspots and eddies which can occur at the surface of the next spacer plate and to the rear of the nozzle in that plate.

It is possible to predict the performance characteristics of a vortex amplifier before assembly and the construction of the embodiment of Figures 1 and 2 is such that it can readily be assembled and dismantled.

As a result, the casing 10 and the partition 16 can be offered as standard parts for use with a variety of different forms of spacer plates. Thus, sets of spacer plates having different thicknesses and/or orifices which differ in site and/or direction can be used to vary the throttling effect and hence the performance of the amplifier. The construction is such that the removal and replacement of the spacer plates can be accomplished without difficulty.

Figure 3 shows an alternative embodiment of the invention.

In Figure 3, a casing 30 is again formed in two portions 31 and 32 which can be releasably connected together in any desired manner. The casing portions can be formed with abutting flanges secured by nut and bolt assemblies as in the case of the embodiment of Figures 1 and 2 or a threaded coupling ring can be employed to achieve a releasable connection. Other examples of releasable connections will be apparent and do not require elaboration.

An inlet 33 is connected to the casing part 31 and an outlet 34, in the form of a diffuser, is connected to the part 32. A central opening in the part 31 defines a chamber 35 in communication at one with the inlet 33 and containing a cylindrical body 36 supported therein by a spider 37.

The end of the body 36 remote from tbe inlet is provided with a central protruberance 38 which is arranged to lie substantially on the axis of the outlet.

A ring 39 having a plurality of apertures 40 extending through the wall thereof between the outer and inner peripheries is located between the casing parts 31 and 32 and held in position by means of bolts 41.

When assembled the sides of the ring abut against and sealingly engage the corresponding faces of the casing parts. The apertures are arranged to direct a control fluid into vortex chamber of the amplifier. A supply of control fluid is connected to a port 42.

In use, a fluid entering the amplifier at the inlet flows around the body 36 and into vortex chamber 43. The inner peripheral surface of the ring is curved to provide a smooth flow surface for the fluid.

Throttling is achieved in the vortex chamber by injecting the control fluid through the apertures 40 and into the vortex chamber. The number, size and angular orientation of the apertures will be chosen to meet the operational requirements of tbe amplifier. The ring can be removed and replaced by an alternative ring in order to change the characteristics of the amplifier. Thus a ring can be selected to meet the required performance characteristics of the amplifier.

WHAT WE CLAIM IS: - 1. A fluidic control device, in particular a vortex amplifier, comprising a casing formed from two abutting releasable parts, a supply fluid inlet conimunicating with the interior of the casing through a central opening in one end wall of the casing, a fluid outlet shaped as a diffuser communicating with the interior of the casing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ternally threaded end of a port 13. The partition is secured and mounted on the spacer plates 14 by means of bolts passing through countersunk holes 19 in the partition and engaging in tapped holes in the spacer plates. A substantially conical member 17 having a smooth convex surface is mounted centrally on the partition 16 and on the axis of the outlet 12. The member 17 is mounted on the side of the partition which faces the outlet 12. Preferably the free edges of the partition between the spacer plates are chamfered. The chamfers are provided on the side of the edges directed towards the outlet 12 and are indicated by reference numeral 20 in Figure 2. Alternatively, or in addition, portions of the partition 16 can be removed or cut-out from the regions between the spacer plates. Such cut-out portions are indicated by the reference number 21 in Figure 2. The volume between the partition 16 and the previously mentioned opposite end wall of the casing defines a vortex chamber 18. In operation, a fluid supply enters the casing 10 through the inlet 11 and passes over the free edges of the partition 16 to enter the vortex chamber 18. From the vortex chamber, the fluid enters the outlet 12 and the latter is shaped as a diffuser whereby to regain pressure loss in the fluid. The chamfered free edges 20 of the partition reduce the formation of eddies and swirls in the fluid entering the vortex chamber and the cut-out portions 21 serve to reduce the resistance of the flow path. Control fluid is injected into the vortex chamber through the ports 13 and the nozzles 15 to throttle the supply flow by interaction therewith. Preferably, and as shown in Figure 2, each nozzle 15 is arranged such that control fluid flow issuing therefrom will strike the facing surface of the next spacer plate at a position behind the nozzle in that plate. This enables the flow issuing from each nozzle to clear and disperse any deadspots and eddies which can occur at the surface of the next spacer plate and to the rear of the nozzle in that plate. It is possible to predict the performance characteristics of a vortex amplifier before assembly and the construction of the embodiment of Figures 1 and 2 is such that it can readily be assembled and dismantled. As a result, the casing 10 and the partition 16 can be offered as standard parts for use with a variety of different forms of spacer plates. Thus, sets of spacer plates having different thicknesses and/or orifices which differ in site and/or direction can be used to vary the throttling effect and hence the performance of the amplifier. The construction is such that the removal and replacement of the spacer plates can be accomplished without difficulty. Figure 3 shows an alternative embodiment of the invention. In Figure 3, a casing 30 is again formed in two portions 31 and 32 which can be releasably connected together in any desired manner. The casing portions can be formed with abutting flanges secured by nut and bolt assemblies as in the case of the embodiment of Figures 1 and 2 or a threaded coupling ring can be employed to achieve a releasable connection. Other examples of releasable connections will be apparent and do not require elaboration. An inlet 33 is connected to the casing part 31 and an outlet 34, in the form of a diffuser, is connected to the part 32. A central opening in the part 31 defines a chamber 35 in communication at one with the inlet 33 and containing a cylindrical body 36 supported therein by a spider 37. The end of the body 36 remote from tbe inlet is provided with a central protruberance 38 which is arranged to lie substantially on the axis of the outlet. A ring 39 having a plurality of apertures 40 extending through the wall thereof between the outer and inner peripheries is located between the casing parts 31 and 32 and held in position by means of bolts 41. When assembled the sides of the ring abut against and sealingly engage the corresponding faces of the casing parts. The apertures are arranged to direct a control fluid into vortex chamber of the amplifier. A supply of control fluid is connected to a port 42. In use, a fluid entering the amplifier at the inlet flows around the body 36 and into vortex chamber 43. The inner peripheral surface of the ring is curved to provide a smooth flow surface for the fluid. Throttling is achieved in the vortex chamber by injecting the control fluid through the apertures 40 and into the vortex chamber. The number, size and angular orientation of the apertures will be chosen to meet the operational requirements of tbe amplifier. The ring can be removed and replaced by an alternative ring in order to change the characteristics of the amplifier. Thus a ring can be selected to meet the required performance characteristics of the amplifier. WHAT WE CLAIM IS: -

1. A fluidic control device, in particular a vortex amplifier, comprising a casing formed from two abutting releasable parts, a supply fluid inlet conimunicating with the interior of the casing through a central opening in one end wall of the casing, a fluid outlet shaped as a diffuser communicating with the interior of the casing

through a central opening in the opposite end wall of the casing, a member within the casing cooperating with the opposite end wall to define a vortex chamber, at least one further inlet for a control fluid in a wall of the casing defining at least a portion of the periphery of the vortex chamber and disposed between the or each further inlet and the vortex chamber, the or each further member having one or more openings therein for directing the control fluid into the vortex chamber, and the removability enabling selection according to the required performance.

2. A fluidic control device as claimed in claim 1 in which the or each removable further member comprises a nozzle plate fitted over the or each further inlet.

3. A fluidic control device as claimed in claim 2 in which the nozzle plate further constitutes a support for a wall of the vortex chamber.

4. A fluidic control device as claimed in claim 1 having only one removable further member in the form of a ring having a plurality of apertures therein for the passage of control fluid supply, the ring forming a wall of the vortex chamber.

5. A fluidic control device substantially as herein described with reference to and as illustrated in Figures 1 and 2; or Figure 3 of the accompanying drawings.