GB2181214A - Fluid operated valve - Google Patents

Abstract

A fluid operated valve 1 includes a housing 2 with an inlet 10 and an outlet 12 interconnected by a flexible tube 14 encased within a rigid pipe 8 of the housing. Two diametrically opposed ports 18 are provided in the pipe 8 and in use upon application of fluid pressure the flexible tube 14 is constricted thereby controlling flow therethrough. <IMAGE>

Description

SPECIFICATION Fluid operated valve This invention relates to a fluid operated valve.

In particular, the present invention concerns such a valve having a through passage of variable dimensions so that in use the flowtherethrough can be quantitatively controlled. The valve may have application to fluid materials generally, for example those in liquid form, or slurries, or discrete materials in particulate, granular or pulverous form.

It is known to convey discrete materials using pneumatics and increasinglyfeeders in for example combustion systems are of the type in which the particulate solid fuel, e.g. coal, is transported from a blowtankto the point of use, i.e. the combustion chamber. One ofthe more difficult aspects of pneumatic conveyance is the measure and manner of controlling the delivery of the fuel . This can be achieved in a limited manner by regulating the air flows to thetankand to the conveying pipe: by varying the ratio between the two airflows,theturndown can be varied accordingly. However, the max imum turndown achievable is ofthe order of5: 1.

This gives a fine tuning, but in practice the approximate product flow rate is obtained by the installation of an orifice plate attheexit portofthe blowtank.

An object of the present invention is to provide an improved fluid operated valve capabale ofyielding a greaterturndown range than that obtainable from conventional systems.

According to the invention a fluid operated valve includes a housing provided with an inlet and an outlet inter connected byaflexibletubular member, and at least one port in the housing communicating with the cavity defined between the member and the interiorwall ofthehousing,wherebyin usetheapplication of fluid pressure in the cavity controls flow through the valve. Conveniently, the valve is pneumatically operable. The housing may comprise a flanged inlet and a flanged outlet, the flanges being connected bya length of rigid pipe,theflexible tubular member extending within the pipe and inter connecting the inletand outlet in theflanges.

Theflexibletubularmember is secured to the housing in any suitable manner.

The at least one port is formed in the pipe atan appropriate location intermediate the flanges. Preferablytwo ports are provided, oppositely disposed in relation to one another such that is use application of fluid pressureto both ports causes a constriction in the flexible member to control flowtherethrough.

Byway of example only, one form offluid operated valve according to the invention is described below with reference to the accompanying diagrammatic drawing which is a cross-section through the valve.

Referring to the drawing, a fluid operated valve 1 includes a housing 2 formed of an inletflange 4, an outlet flange 6 and a rigid pipe 8 inter connecting the two flanges. An inlet 10 in the flange 4 is connected to an outlet 12 intheflange 6 byaflexibletube 14 secured at each end to the respective flange. An annular cavity 16 is defined in the pipe 8 between its innerwall and the outer surface ofthetube 14 and two diametrically opposed ports 18 are provided in the pipe 8 about halfway down.

In use, the fluid operated valve 1 is secured through the agency offlange 4to the discharge outlet of a blow tank (not shown) having a valved inlet and a pressurised air/gas inlet, the outlet flange 6 being connected to a conveying pipe (notshown).

The blow tank, in the form of a pressurised vessel, is changed with particulate material, for example coal, through its valved inlet. When delivery is required the tank is pressurised with air to force a quantity of the material into the conveying pipe. The flow quantity passing from the tankinto the pipe is controlled by the valve 1 ofthe present invention. Pressurised air is applied to the ports 18 and in so doing causes a constriction in the flexible tube 14thereby determin- ing the flow rate therethrough. By varying the pressure so applied, the degree to which thetube 14 is constricted can be varied.In this way a simple and yet effective means are provided for controlling the discharge flow rate from a pressurised transport system, there being no moving parts and no requirementfor complex variations in airflow rates such as are characteristic of earlier systems.

1. Afluid operated valve including a housing provided with an inlet and an outlet inter connected by a flexible tubular member, and at least one port in the housing communicating with the cavity defined between the member and the interiorwall ofthe housing, whereby in use the application of fluid pressure in the cavity controls flow th rough the valve.

2. Avalveaccordingtoclaim 1 inwhichthevalve comprises a flanged inlet and a flanged outlet, the flanges being connected by a length of rigid pipe,the flexible member extending within the pipe and interconnecting the inlet and the outlet in the flanges.

3. Avalve according to claim 2 in which the at least one port is formed in the pipe.

4. Avalve according to claim 3 in which two ports are provided and oppositely disposed in relation to one another such that in use application offluid pressure to both ports causes a constriction in the flexible memberto control flow thereth rough.

5. A valve according to any one ofthe preceding claims which is pneumatically operable.

6. Afluid operated valve substantially as here it before described with reference to the accompanying drawing.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fluid operated valve This invention relates to a fluid operated valve. In particular, the present invention concerns such a valve having a through passage of variable dimensions so that in use the flowtherethrough can be quantitatively controlled. The valve may have application to fluid materials generally, for example those in liquid form, or slurries, or discrete materials in particulate, granular or pulverous form. It is known to convey discrete materials using pneumatics and increasinglyfeeders in for example combustion systems are of the type in which the particulate solid fuel, e.g. coal, is transported from a blowtankto the point of use, i.e. the combustion chamber. One ofthe more difficult aspects of pneumatic conveyance is the measure and manner of controlling the delivery of the fuel . This can be achieved in a limited manner by regulating the air flows to thetankand to the conveying pipe: by varying the ratio between the two airflows,theturndown can be varied accordingly. However, the max imum turndown achievable is ofthe order of5: 1. This gives a fine tuning, but in practice the approximate product flow rate is obtained by the installation of an orifice plate attheexit portofthe blowtank. An object of the present invention is to provide an improved fluid operated valve capabale ofyielding a greaterturndown range than that obtainable from conventional systems. According to the invention a fluid operated valve includes a housing provided with an inlet and an outlet inter connected byaflexibletubular member, and at least one port in the housing communicating with the cavity defined between the member and the interiorwall ofthehousing,wherebyin usetheapplication of fluid pressure in the cavity controls flow through the valve. Conveniently, the valve is pneumatically operable. The housing may comprise a flanged inlet and a flanged outlet, the flanges being connected bya length of rigid pipe,theflexible tubular member extending within the pipe and inter connecting the inletand outlet in theflanges. Theflexibletubularmember is secured to the housing in any suitable manner. The at least one port is formed in the pipe atan appropriate location intermediate the flanges. Preferablytwo ports are provided, oppositely disposed in relation to one another such that is use application of fluid pressureto both ports causes a constriction in the flexible member to control flowtherethrough. Byway of example only, one form offluid operated valve according to the invention is described below with reference to the accompanying diagrammatic drawing which is a cross-section through the valve. Referring to the drawing, a fluid operated valve 1 includes a housing 2 formed of an inletflange 4, an outlet flange 6 and a rigid pipe 8 inter connecting the two flanges. An inlet 10 in the flange 4 is connected to an outlet 12 intheflange 6 byaflexibletube 14 secured at each end to the respective flange. An annular cavity 16 is defined in the pipe 8 between its innerwall and the outer surface ofthetube 14 and two diametrically opposed ports 18 are provided in the pipe 8 about halfway down. In use, the fluid operated valve 1 is secured through the agency offlange 4to the discharge outlet of a blow tank (not shown) having a valved inlet and a pressurised air/gas inlet, the outlet flange 6 being connected to a conveying pipe (notshown). The blow tank, in the form of a pressurised vessel, is changed with particulate material, for example coal, through its valved inlet. When delivery is required the tank is pressurised with air to force a quantity of the material into the conveying pipe. The flow quantity passing from the tankinto the pipe is controlled by the valve 1 ofthe present invention. Pressurised air is applied to the ports 18 and in so doing causes a constriction in the flexible tube 14thereby determin- ing the flow rate therethrough. By varying the pressure so applied, the degree to which thetube 14 is constricted can be varied.In this way a simple and yet effective means are provided for controlling the discharge flow rate from a pressurised transport system, there being no moving parts and no requirementfor complex variations in airflow rates such as are characteristic of earlier systems. CLAIMS

1. Afluid operated valve including a housing provided with an inlet and an outlet inter connected by a flexible tubular member, and at least one port in the housing communicating with the cavity defined between the member and the interiorwall ofthe housing, whereby in use the application of fluid pressure in the cavity controls flow th rough the valve.

2. Avalveaccordingtoclaim 1 inwhichthevalve comprises a flanged inlet and a flanged outlet, the flanges being connected by a length of rigid pipe,the flexible member extending within the pipe and interconnecting the inlet and the outlet in the flanges.

3. Avalve according to claim 2 in which the at least one port is formed in the pipe.

4. Avalve according to claim 3 in which two ports are provided and oppositely disposed in relation to one another such that in use application offluid pressure to both ports causes a constriction in the flexible memberto control flow thereth rough.

5. A valve according to any one ofthe preceding claims which is pneumatically operable.

6. Afluid operated valve substantially as here it before described with reference to the accompanying drawing.