GB2079898A - Fluid flow control valve - Google Patents

Abstract

A length of conduit (1) has mounted therein, by means of spiders (2 and 3), an inflatable sealing element (7) which in the deflated condition allows flow through the conduit but which may be inflated, as indicated at 7a, to block flow through the conduit (1). The element (7) may be inflated by means of compressed air admitted through a line (4) and may be deflated by exhausting to a line (5). Valves of this nature may be combined to form changeover valves and in view of their expansibility may also provide a pumping operation. <IMAGE>

Description

SPECIFICATION Fluid flow control valve This invention relates to fluid flow control valves.

Fluid flow control valves normally includes some sort of valve member cooperating with a valve seat, at least one of which cooperating parts is flexible. Means have to be provided to actuate the parts to bring them into and out of cooperating relationship and, particularly in the food industry, great care has to be taken in designing the parts to avoid crevices, which could act as centres of infection, and to provide ready cleanability.

According to the present invention, there is provided a flow control valve installed or adapted to be installed in a fluid flow passage, the said valve comprising an inflatable element which in the uninflated condition allows fluid flow but which in the inflated condition blocks fluid flow by expanding against the boundary of the flow passage.

The inflatable element is preferably mounted in length conduit with which it cooperates to close or open a flow passage through the conduit.

The inflatable element may be mounted between two spider mountings, at least one of which carries inflation supply and/or discharge means.

Each inflatable element thus acts as a single flow shut off valve and the elements may for instance be mounted in pairs with appropriate connections to provide changeover valve. Further, the valves may be duplicated to provide an arrangement analogous to a double-seat valve with a vented space between the two valves.

Other arrangements of the valves are also possible. For instance, since the inflatable element itself is a greater volume when inflated than when not, it may also be arranged to provide some pumping action by locating it in a volume having a closable inlet and a non-return valve at the outlet.

The inlet itself may be closed by a further inflatable element. In order to provide a mixing and pumping arrangement, there may be two such closable inlets for first and second fluids to be mixed.

The invention will be further described with reference to the accompanying drawings, which show various embodiments of the invention, and in which:~ Figure 1 is a sectional view of a single inflatable element in a length of conduit; Figure 2 is a partial end elevation of the arrangement of Figure 1; Figure 3 is a diagrammatic illustration of a changeover valve incorporating two inflatable elements; Figure 4 is an end elevation showing an alternative arrangement; Figure 5 is a perspective view of an element of the arrangement of Figure 4; Figure 6 is a diagrammatic illustration of a further arrangement of element; Figure 7 is a diagram showing an arrangement of three inflatable elements to form a flow diverter; Figures 8a to 8d are diagrammatic illustrations of a pair of inflatable elements arranged to provide a pumping operation, in various operational stages;; Figure 9 is a diagrammatic arrangement of three inflatable elements to form a mixing pump: and Figure 10 is a diagrammatic arrangement illustrating inflation and deflation arrangements for a flow diverter of the type shown in Figure 7.

Turning first to Figure 1, the valve illustrated there is mounted in a length 1 of conduit by means of spiders 2 and 3, of which a spinder 2 is partially illustrated in Figure 2. A spider 3 carries an inlet type 4 to carry pressure air, and a discharge or vacuum pipe 5. A central support element 6 is mounted between the spiders 2 and 3 and carries an inflatable sealing member 7 of plastics material or rubber which is shown in full lines in its deflated state and in dash lines as indicated at 7a in its inflated or sealing state.

Inflating air is supplied via the line 4 and an internal conduit 8 in the support member 6 to the interior of the sealing element 7, and a similar arrangement (not shown) is provided to connect the interior of the sealing element 7 to the discharge or vacuum line 5.

Figure 3 shows two inflatable elements 7 arranged in a key element 11 so as to provide a changeover valve by selectively inflating one element and deflating the other to connect an inlet 12 with an outlet 13 or an outlet 14.

Figure 4 shows an alternative arrangement in which an inflatable element 7 is attached to a sliding shaft 8 which passes through a gland 9. In the uninflated state of Figures 4 and 5 the inflatable element is diametral of the conduit 1 so as not to provide any substantial barrier to flow.

When air is admitted via a conduit in the shaft 8, the element expands and the shaft 8 moves radially until such time as the element 7 engages the conduit all the way round so as to block flow.

Figure 6 shows an alternative arrangement in which the inflatable element 7 is attached to two fixed pipes 1 5, one of which may provide inflation and the other deflation.

Turning now to Figure 7, there is shown a Y-form of flow diverter with an inflatable element 7 in each limb. The limb 11 is assumed to be an inlet and the outlets are through the limbs 12 and 13, and it will be seen that if the element 7 in the limb 11 is inflated, there is no flow but if it is deflated then the direction of flow is selected by whichever of the limbs 12 and 13 has a deflated sealing element 7.

Turning now to Figures 8a and 8b, a pair of sealing elements 21 and 22 are shown in conjunction with a non-return valve 23. In the position of Figure 8a, the elements 21 and 22 are both deflated and in this condition fluid flows into the arrangement. The sealing element 21 is then inflated to arrive at the Figure 8b position so that fluid is trapped in a chamber formed between the sealing element 21 and the non-return valve 23.

Inflation of the sealing element 22 then raises the pressure in this chamber so that some of the fluid is forced out through the non-return valve 23 as indicated by the arrow 24. The sealing element 22 is then deflated preferably by the application of vacuum to provide positive deflation so that subatmospheric pressure then prevails in the chamber, and by deflation of the valve 21, further fluid is induced into the chamber and the cycle recommences.

Figure 9 shows a further refinement of this arrangement in which there are provided two inlets 25 and 26 each with a sealing member 27 and 28 respectively. Different fluids may be induced passed the sealing members 27 and 28 as these are deflated. Accordingly, selection of the material to be introduced may be made and mixing achieved. For instance, the sealing member 27 may first be deflated to allow one liquid to enter, and then re-inflated to trap it.

Sealing member 22 is then inflated to force some fluid out through the non-return valve 23.

Deflation of the sealing member 22 creates suction conditions and by opening of the sealing member 28, a volume of the other inlet fluid is induced to mix with the fluid already in the chamber. This alternation may continue as often as is required, and the one-to-one sequence may of course by replaced by any other mixing ratio desired.

If necessary, a micro-processor may be used to control the operation.

Figure 10 shows a diversion arrangement of Figure 7 in conjunction with an air pressure line 31 and the vacuum line 32 which acts as mains and are connected by appropriate control valves 33 to the respective sealing elements 7 to provide inflation and positive deflation as required.

Various modifications may be made within the scope of the invention.

Claims (5)

1. A flow control valve installed or adapted to be installed in a fluid flow passage, the said valve comprising an inflatable element which in the uninflated condition allows fluid flow but which in the inflated condition blocks the fluid flow by expanding against the boundary of the flow passage.

2. A flow control valve as claimed in claim 1, in which the inflatable element is mounted in a length of conduit with which it cooperates to close or open a flow passage through the conduit.

3. A flow control valve as claimed in claim 2, in which the inflatable element is mounted between two spider mountings at least one of which carries inflation supply and/or discharge means.

4. A flow control valve as claimed in any of the preceding claims, in which inflation is by compressed air and deflation by application of suction.

5. A flow control valve substantially as hereinbefore described with reference to the accompanying drawings.