GB2300246A - A float valve for a slurry tank - Google Patents

Abstract

A float (7) operated valve for controlling the flow of slurry/dirty water or other liquid comprises a duct or housing defining a flow port and a planar or substantially planar valve seat (2). A valve closure member (3) presenting a flat or substantially flat closure surface is mounted for movement towards and away from the valve seat between a closed position in which the port is closed by the flat surface and an open position. The valve closure member is mounted such that when the flat closure surface is moved towards or away from the valve seat it travels along a path which is not at right angles nor parallel to the plane in which the valve seat lies. The closure member (3) is provided with a cutting edge. A guide member (4) and an extension (6') ensure that closure member (3) is maintained oriented parallel with the plane in which the valve seat lies.

Description

A FLOAT VALVE The present invention relates to a float valve and particularly although not exclusively to a valve suitable for use in the control of the flow of slurry/dirty water from a slurry store into a reception pit.

It has recently become common practice to store agricultural slurry/dirty water in an above-ground storage tank and to have a reception pit adjacent thereto so that the contents of the pit may be pumped into the tank or the pit may be filled from the tank via an outlet pipe. A valve is provided in the outlet pipe to control the flow of slurry/dirty water from the tank. If the valve malfunctions e.g. by becoming blocked, or if the operator fails to close the valve off if the pipe becomes blocked, there is a danger the slurry will overflow from the pit and cause serious damage.

It is an object of the present invention to provide a float valve particularly suitable for controlling the flow of agricultural slurry/dirty water.

According to the present invention there is provided a float valve for controlling the flow of slurry/dirty water or other liquid comprises a duct or housing defining a flow port and a planar or substantially planar valve seat, a valve closure member presenting a flat or substantially flat closure surface and mounted by mounting means for movement towards and away from the valve seat respectively between a closed position in which the port is closed by the flat surface moving onto the port and into contact with the seat and an open position in which the port is open, and float means for moving the valve closure member between the open and closed positions; wherein the valve closure member is mounted such that when the flat closure surface is moved towards or away from the valve seat it travels along a path which is not at right angles nor parallel to the plane in which the valve seat lies.

Preferably the mounting means for the valve closure member is such that during displacement the flat closure surface remains parallel to the plane in which the valve seat lies.

Also the mounting means preferably includes the closure member being pivotally mounted on the end of a float support arm or an extension thereof, and at least one further pivotally mounted arm or linkage for maintaining the closure surface displaceable in a plane parallel to the plane of the valve seat.

Preferably if the valve closure member is a flat plate pivotally connected to two extension arms of the lever arm of the float means. Also the flat plate preferably has a plate-like extension at the upper end extending away therefrom and over the flow port.

Preferably a casing extends forwardly from the housing to enclose at least the upper and side regions and the lever arm of the float means and any extension thereof and other mounting means are mounted on said casing.

Preferably the mounting means is a parallelogram mounting means.

Also preferably the valve closure member travels along an arcuate or inclined path inclined at less than 900 to the central axis of the outlet and valve seat such than the spacing of the valve closure member forwardly of the seat increases or decreases.

Preferably when the valve closure member is seated on the valve seat in the closed position of the valve, the mounting means for the closure member is such that preserve of liquid on the surface of the closure member still exerts an opening moment on the moving means to facilitate opening of the valve.

Preferably the closure members has a cutting edge.

Also according to the present invention a float valve for controlling the flow of slurry/dirty water comprises a duct or housing defining a flow port and a valve seat, a valve closure member in the form of a flat plate with a cutting edge, mounted for movement down towards and up away from the valve seat respectively between a closed position in which the port is closed by the flat surface moving onto the port and into contact with the seat and an open position in which the port is open, and float means for moving the valve closure member between the open and closed positions. Preferably the valve is lockable preferably by the provision of lock means engageable with an extension for the valve closure member.

The valve closure member is preferably a flat plate and preferably of resilient material such as steel and the surface of the plate and of the seat will be complementary to each other to provide good sealing.

The wall of the plate forms the closure means.

The valve closure member is preferably parallelogram mounted on support means which are preferably in the form of three or four spaced apart arms or a bifurcated arm carrying an axle or other pivot mounting means for the closure member and said support means is preferably pivotally mounted on said housing or on one or more extension or spacing members mounted thereon. The support means is preferably rigidly connected to one or more float support arms so as to be displaceable therewith to open and close the valve. The float means or member may be of any suitable shape such as cylindrical, spherical or any other suitable shape and is preferably hollow. The float member is such as to float on the surface of the slurry/dirty water and to move up and down with that surface - thereby pivoting the valve closure member between open and closed positions.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a part schematic perspective view of an embodiment of a float valve according to the invention; Fig. 2 is a side elevational view of the valve of Fig. 1 in the fully open position; Fig. 3 is a side elevational view of the valve of Fig. 1 in the fully closed position; Fig. 4 is a schematic elevational cross section of member 5 being a lockable lever, the valve of Figs. 1 to 3 in a typical installation; Figs. 5 and 6 and Figs. 7 and 8 are elevations and details of a modified float valve in open and closed positions; and Fig. 9 is a perspective view of the mounting side of a valve closure member ser se showing the three pivot mountings.

A lockable float valve is illustrated comprising a cylindrical tubular housing 1 extending from a rectangular backing plate 1' and defining a valve port through which slurry/dirty water is to pass. The housing 1 is formed with a cylindrical end 2 lying in a plane which is normally vertical in use and which effectively forms the valve seat of the valve adjacent to the port valve. A box-like casing 1A (shown in broken line) extends from the backing plate 1' and has outwardly diverging laterally and top side walls with end mounting parts 1B, 1C and cross members 1D, 1E together forming support means. A valve closure member 3 is pivotally connected (via small lugs) to the ends of lever support arms 6 of a cylindrical float 7 with said arms 6 in turn being pivotally mounted at the bottom of parts 1B, lC, of the parts indicated casing 1A connected to the housing 1.

Closure member 3 is a flat plate defining the planar closure face and has a flat plate-like extension 3' as a baffle and surface for receiving a control member. The flat plate is mounted on a parallelogram lever arrangement and is complementary to the surface of the cylindrical valve seat 2.

The cylindrical float 7 is rotatably mounted on the ends of lever/support arm 6 which are pivotally mounted at the lower end of support members 4 and has extensions 6' pivotally connected to closure member 3. A linkage or guide member 4 is pivotally mounted on cross member 1D and is pivotally connected to closure member 3 and such that with extensions 6' ensures the float plate 3 forming the closure member is displaceable whilst remaining parallel to the plane in which the valve seat lies as it moves on its curved path towards and away from the valve float.The linkage mounting of closure member 3 is such that in the closed position (Fig. 3), the links/arms or the pivot points are not in a horizontal plane i.e. there always remains a turning moment in the closed position exerted by the pressure of liquid on face 3 so as to facilitate opening of the valve and prevent jamming with closed position.

A control rod 5' extends from top plate 3' of the closure member 3 and is pivotally connected to a manually adjustable lever 5 which is pivotally mounted on cross part 1E of the casing 1A and enables manual displacement of the closure member 3, if required.

Suitable locking means (not shown) such as a padlock may connect through an aperture (not shown) in lever 5 and through an aperture lug (not shown) on casing 1A.

The float 7 is disposed to float on the surface of the slurry/dirty water in a slurry pit 10 as shown in Fig. 4. The pit 10 is disposed adjacent a slurry storage tank 11. A pipe 12 leads from the pit 10 to the top of the tank and a motor driven pump 13 is provided for pumping slurry/dirty water from the pit through the pipe 12 into the tank 11. A further pipe 14 is provided leading to the pump 13 to enable slurry/dirty water to be pumped into a tanker or irrigation system 10'. Tankers would normally be drawn up to the pit 10 by means of a tractor. The pit 10 is filled from tank 11 via an outlet pipe 15 and the valve described with referenced to Fig. 1 is disposed on the outlet end of pipe 15.

A grid 16 closes off the top of the pit. The float valve operates automatically to maintain the level of slurry/dirty water in the pit at a predetermined level. When the valve is open (as shown in Fig. 2), slurry/dirty water flows out through pipe 15. As the level of slurry/dirty water in the pit rises, so also does the float 7, which is floating on the surface. This in turn rotates valve closure member to progressively close the flow valve - via valve closure member is provide the flat plate 3 which is displaced along a arcuate path whilst being maintained in a vertical or substantially vertical plane.

The valve may be made of metal or synthetic plastic materials. To resist any tendency of the slurry/dirty water to stick to the plate and thereby impair its function, the plate may be coated with a nonstick material such as polytetrafluoroethylene.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the scope of the invention.

Claims (16)

1. A float valve for controlling the flow of slurry/dirty water or other liquid comprises a duct or housing defining a flow port and a planar or substantially planar valve seat, a valve closure member presenting a flat or substantially flat closure surface and mounted by mounting means for movement towards and away from the valve seat respectively between a closed position in which the port is closed by the flat surface moving onto the port and into contact with the seat and an open position in which the port is open, and float means for moving the valve closure member between the open and closed positions; wherein the valve closure member is mounted such that when the flat closure surface is moved towards or away from the valve seat it travels along a path which is not at right angles nor parallel to the plane in which the valve seat lies.

2. A valve as claimed in claim 1, in which the mounting means for the valve closure member is such that during displacement the flat closure surface remains parallel to the plane in which the valve seat lies.

3. A valve as claim in claims 1 or 2, in which the mounting means includes the closure member being pivotally mounted on the end of a float support arm or an extension thereof, and at least one further pivotally mounted arm or linkage for maintaining the closure surface displaceable in a plane parallel to the plane of the valve seat.

4. A valve as claimed in claim 3, in which the valve closure member is a flat plate pivotally connected to two extension arms of the lever arm of the float means.

5. A valve as claimed in claim 4 in which the flat plate has a plate-like extension at its upper end extending away therefrom and over the flow part.

6. A valve as claim in claim 1, in which a manually operable control member extends from the valve closure member to permit manual displacement thereof.

7. A valve as claim in claim 6, in which the manual control member is pivotally connected to a manually operable displacement lever arm.

8. A valve as claim in claims 6 or 7, in which lock means are provided engageable with said control member or lever arm to enable the valve to be securely locked to prevent unauthorised opening or closing.

9. A valve as claim in any of claims 1 to 8, in which a casing extends forwardly from the housing to enclose at least the upper and side regions, and in which the lever arm of the float means and any extension thereof and other mounting means are mounted on said casing.

10. A valve as claimed in claim 7, in which the control member extends through an aperture in said casing.

11. A valve as claimed in any of claims 1 to 10, in which the mounting means is a parallelogram mounting means.

12. A valve as claimed in any of claims 1 to 11, in which the valve closure member travels along an arcuate or inclined path inclined at less than 900 to the central axis of the outlet and valve seat such than the spacing of the valve closure member forwardly of the seat increases or decreases.

13. A valve as claimed in any of claims 1 to 12, in which when the valve closure member is seated on the valve seat in the closed position of the valve, the mounting means for the closure member is such that pressure of liquid on the surface of the closure member still exerts an opening moment on the moving means to facilitate opening of the valve.

14. A float valve for controlling the flow of slurry/dirty water comprises a duct or housing defining a flow port and a valve seat, a valve closure member in the form of a flat plate with a cutting edge, mounted for movement down towards and up away from the valve seat respectively between a closed position in which the port is closed by the flat surface moving onto the port and into contact with the seat and an open position in which the port is open, and float means for moving the valve closure member between the open and closed positions.

15. A float valve as claimed in claim 14, in which the valve is lockable.

16. A float valve substantially as herein described with reference to the accompanying drawings.