AU2007100039B4 - Improved slurry valve - cylindrical open oriface slurry valve - Google Patents

Description

Australia Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT OPEN CYLINDER ORIFACE SLURRY VALVE THE FOLLOWING STATEMENT IS A FULL DESCRIPTION OF THIS INVENTION INCLUDING THE BEST METHOD OF PERFORMING IT KNOWN TO ME Improved Slurry Valve Cylindrical Open Oriface Slurry Valve The invention relates to improvements in the handling of high pulp density slurries or liquids containing a fine particle size and /or high relative density that require either even or varied distribution ratios for downstream process balance via a cylindrical open oriface slurry valve that is actuated on the centre line of the process flow and has variable flow control The invention is not limited to the processing of slurries but is open.

The invention has a number of defining features and is best described as a "Cylindrical Open Oriface Slurry Valve".

Though originally designed as a combination use valve that combines the attributes of single purpose valves currently available, the valve can also be used in a wide variety of different applications and multiple configurations and locations when processing difficult materials as mentioned above.

An example of this could be a symmetrical or radial slurry feed distributor which has multiple said valves set up symmetrically and /or radially.

The valve will overcome problems best described in the aforementioned and following statements.

The high wear areas of the valve are on the inside and outside of the cylindrical valve and no high wear components are within the main process flow. Because of the geometry of the valve flow control cylinder, the life of the replaceable valve cylinder can be substantially extended by the ability to vary the oriface shape, size and location within the oriface side of the valve cylinder. The replaceable cylinder can also be inverted in certain applications to further extend the life of the component.

Current methods of product distribution and balance in mineral and coal processing plants particularly via gravity include distribution boxes with adjustable weirs and dart valves conventional pressure slurry valves to achieve flow control and/or knife gate isolation valves to shut off flow combined with associated breather piping downstream to prevent syphoning.

The invention innovation patent is sought to allow design and manufacturing development to progress with industry suppliers to address a consistent problem that is encountered in but not limited to the mining and mineral processing industry in the handling of slurries.

The cylindrical open oriface slurry valve in accordance with this invention comprises a cylindrical outer high wear resistant surface which comes into contact during operation with the inflow slurry. The inside of the oriface valve has a high wear resistant surface. A seal or combination of seals provide isolation between the operating/flow control side of the valve and the shut off/isolation side of the valve A self lubricating high wear material is located above and below the mentioned seal or seals to allow movement of the valve.

These bearings are held in place by, the upper and lower bearings being protected by a built up and profiled area of high wear material or suitable high wear deflector cone just upstream of the bearing in the outflow position. A fixed or removable actuator attachment bracket section (preferably removable) to allow the valve to be turned around to extend life is attached directly opposite the outlet to allow attachment of actuating device. While a rotary actuator is desirable the method of actuation is open. The shape, size and location of the feed oriface on the inlet side of the valve is open. The shape of the valve casing is open to suit any particular process or processed slurry.

When arranged in a symmetrical and/or planetary manner,the valves provide for even distribution of difficult substances or slurries (particularly but not limited to gravity fed valve situations).

Many mineral processing plants (including but not limited to coal and gold) that have process streams containing high pulp density flowable substances experience problems with the even or variable distribution of slurries or substances that fall into the above or similar categories and is best suited to, but not confined to the distribution of gravity fed slurries that for process design reasons are flowing in pipes or vessels at or near their minimum allowable operating fall angles due to the abrasive or other specific characteristic nature of the substance being handled.

In many processing plants this problem is particularly evident in the product stream after most separation dewatering or deliquifying processes have been completed just prior to final dewatering or deliquifying of the product's fine particle sizes.

Uneven distribution or inflexible ability to vary process conditions "on the run": compromises plant product quality or output can cause partial "silting or sanding" up of distribution points or similar process stream interface connection points can cause plant or process stream stoppages to make adjustments can cause inconsistent product moistures or grades and hence inefficiencies of downstream processes and equipment may require the further addition of water or other liquid after the product has already been partially dewatered or de-liquified to allow the plant to continue at reduced output causes downstream equipment or process inefficiencies may cause increased power usage and maintenance of downstream equipment "favoured" by the uneven distribution results in increased water usage in certain processes can increase product effluent in large tonnage high throughput plants can cause recirculation of product (when distribution box overflows) back into an earlier stage of the process for reprocessing.

3 The cylindrical open oriface slurry valve is preferably made from high alumina or basalt cylinders either alone or attached to a steel or stainless steel casing, however other materials can be used. Depending on the characteristics of the materials handled fabrication from various grades of polymer based materials for the bearings and seals is probable, however other materials can be used In some applications the cylindrical open oriface slurry valve, casing, bearings and seals can all be manufactured from high wearing polymer based materials ceramics or materials of various grades and types.

The invention may be better understood with reference to the illustrations and embodiments of the invention which Figure A is an isolated elevation of the main valve components Figure B is an isolated section of the main valve components Item 1 The solid self lubricating bearing which may be cylindrically shaped, profiled and toleranced to suit the open orifaced slurry valve wearing material. Other optional shapes include a circular cross sectioned self lubricating solid bearing that is located in semicircular grooves in item 2 and the upper and lower valve body. This self lubricating high wear material is located above and below the mentioned seal or seals to allow movement of the valve.

Item 2 The cylindrical open oriface slurry valve cylindrical outer high wear resistant surface (in most applications) which comes into contact during operation with the inflow slurry. The inside of the oriface valve has a high wear resistant surface (in most applications). The upper and lower bearings being protected by a built up and profiled area of high wear material or alternatively a suitable high wear deflector cone just upstream of the bearing in the outflow position.

Item 3 A seal or combination of seals provide isolation between the operating/flow control side of the valve and the shut off/isolation side of the valve If a single solid seal is used it may be profiled to give 2 sealing points similar to provide a labyrinth seal Item 4 Removable flanges or other fixing method threaded and screwed) above and below the valve in the valve casing The shape of the casing is open to suit different installation requirements.

Item 5 Actuator attachment bracket section (preferably removable) to allow the valve to be removed or turned around to extend valve life is attached directly opposite the outlet to allow attachment of the actuating device.

Item 6 Rotary actuator is preferable, however the method of actuation is open.

Item 7 The shape size and location of the feed oriface on the inlet side of the valve is open.

Item 8 The valve casing inside is cylindrical (or conical) to match the valve.

Item 9 The valve casing preferably but not necessarily has a water or other suitable process fluid injection point or points to allow the valve to be cleaned while the valve is in operation.

Claims (4)

1. An open cylinder oriface slurry valve with an inlet and an outlet comprising a casing with a cylindrical or conical inner surface with an open or closed top, fed either by pressure or gravity with a revolving inner surface containing an oriface of any shape, size or number in it's wall within a zone bounded by a seal or number of seals that enable it to be partially rotated and act as a variable flow control valve and when fully rotated past the limit of the aforementioned zone seal or seals enters a second zone bounded by a seal or number of seals with no oriface in it's wall which enables the valve to act as an isolation or shut off valve with wear resistant product contact surfaces which prevent the valve from failing in highly aggressive conditions the revolving section of which rotates within solid self lubricating bearings above and below the valve held in place by flanges or other means above and below the bearings, which positively locate the bearings.

2. A slurry valve as claimed in claim 1 that is operated along it's cylindrical centre line and it's method of attachment to any device for mechanical movement is via a permanent or preferably removable actuator bracket described as Item 5 in the aforementioned text and shown on the attached drawing and enables the valve to be inverted in it's operating position to prolong the life of the valve.

3. A slurry valve claimed in claim 1 that, with an open top acts as a downstream breather as it is located after the inlet entry point to the valve and with a closed top and suitable seal or seals around the actuator shaft allows the valve to operate in a closed pressurised environment.

4. A slurry valve claimed in claim 1 that has a valve casing that may incorporate sprays, compressed air or any other cleaning method that enables same valve to be cleaned "on the run" while it is in operation. A slurry valve claimed in Claim 1 manufactured from any material or combination of materials which may include basalt, high alumina or any internal lining material except that the supporting shell is to be located on the inside of the valve so that the valve has a high wear resistant surface on the outside face of the valve (the inlet side) and a steel or less wear resistant supporting shell on the inside of the valve (the outlet side) that during it's operation, the shell wears away and is sacrificial in nature thus exposing the basalt or high wear resistant face thus extending the life of the valve.