GB2458570A

GB2458570A - Slurry distribution apparatus having a stone trap

Info

Publication number: GB2458570A
Application number: GB0905036A
Authority: GB
Inventors: Samuel Herbert Hughes
Original assignee: REDROCK ENGINEERING Ltd
Current assignee: REDROCK ENGINEERING Ltd
Priority date: 2008-03-27
Filing date: 2009-03-25
Publication date: 2009-09-30
Anticipated expiration: 2029-03-25
Also published as: IE20090226A1; GB0905036D0; GB2458570B; GB0805501D0

Abstract

A slurry distribution apparatus comprises a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets 12 arranged in one end 6 of the housing each connectable to a delivery pipe 14, cutting means rotatably mounted within the housing, the cutting means having a plurality of cutting blades 24 in sliding contact with the end wall 6 of the housing arranged to traverse the plurality of outlets 12 to comminute solid material within the housing, and drive means for rotating the cutting means, wherein a side chamber 42 is defined in a side wall region 2 of the housing, communicating with the interior of the housing to define a stone trap, the side chamber 42 further communicating with an access means 50 to permit removal of stones trapped therein. Also disclosed is apparatus for manuring land comprising a wheeled chassis, slurry tank and delivery means as described above. Also disclosed are slurry distribution apparatuses having cutting means comprising a plurality of radial arms or where the cutting blades are mounted on a central bushing permitting rotation and vertical movement of the blades, there being biasing means which may be a spring for biasing the blades towards the outlets.

Description

Slurry Distribution Apparatus This invention relates to slurry distribution apparatus and to an apparatus for manuring land incorporating such a slurry distribution apparatus.

It is desirable to apply slurry to soil to improve the nitrogen content of the soil.

Traditionally, slurry is spread on the land from pressurised slurry tankers towed by a tractor across the land and having a rear spray outlet from which the slurry is passed onto a splash plate whereby the slurry is crudely sprayed onto the land. This process can result in up to 80% of the available nitrogen being lost to the atmosphere in the form of ammonia.

Furthermore, increasing environmental concerns regarding the noxious effects of spraying slurry over the land and the problems of run off into waterways and of foliage soiling have led to a preference for delivery of slurry directly onto or into the soil via a plurality of trailing shoe slurry outlets, a band spreader or injection devices suspended from a boom and connected to a slurry tanker via individual delivery pipes.

Any system that involves pumping slurry through relatively small-bore delivery pipes will be prone to blockage as the slurry contains a high proportion of solid material. Therefore with band spreading, trailing-shoe and injection equipment it is necessary to remove or reduce the size of any solids from the slurry that might cause blockage. This can be achieved by mechanical separation of slurry through a slurry separator or by chopping with a macerator. However, such solutions lead to maintenance problems, particularly where the slurry contains stones or other hard objects that may jam or damage a macerator.

Typically slurry is passed from a tanker, which is usually pressurised by means of a pump to urge the slurry out of the tanker, into a distributor from where the slurry is passed under pressure into a plurality of delivery pipes leading to individual outlets. Typically the distributor comprises a sealed housing having an inlet aperture communicating with the tanker and a plurality of outlet apertures communicating with respective delivery pipes. The housing typically includes a macerator comprising a rotatable cutting element having cutting blades provided mounted thereon arranged to mix and maccrate solid materials contained in the slurry to reduce the risk of blockage of the relatively small diameter delivery pipes.

Stones contained in the slurry can become trapped between the cutting blades and the outlet apertures or regions of the housing, leading to jamming of the cutting blades and possible damage to the cutting surfaces thereof.

According to a first aspect of the present invention there is provided a sluriy distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets to comminute solid material within the housing, and drive means for rotating said cutting means, wherein a side chamber is defined in a side wall region of the housing, communicating with the interior of the housing to define a stone trap, said side chamber further communicating with an access means to permit removal of stones trapped therein.

Preferably a tubular pipe or sock extends from a lower region of said side chamber, said pipe or sock having an open end, a closure means being provided for closing said open end, said closure means being removable or openable to permit removal of material, including any stones, from said side chamber. Said closure means may comprise a clamp arranged to close a flexible lower region of said pipe or sock.

The side chamber provides a space into which large stones, and other solid particles that cannot be suitably reduced in size by the cutting means, may pass to avoid jamming or damage of the cutting means by such solid particles. This stone trap is readily accessible during routine maintenance of the apparatus and enables stones and other solid particles to be removed from the distribution apparatus without requiring substantial disassembly of the apparatus. The position of the side chamber on the side wall of the housing enables stones to be carried out into the side chamber under the centrifugal forces resulting of the rotation of the cutting means Preferably side wall regions of the side chamber extend substantially tangentially to the adjacent side wall of the housing.

in a preferred embodiment, the housing is arranged in a substantially horizontal or slightly inclined plane such that the end walls of the housing define upper and lower walls of the housing. Preferably said inlet is centrally positioned in the housing, preferably in the upper wall of the housing. Preferably said outlets are provided in the lower wall of the housing.

The drive means may comprise a reversible hydraulic motor. The hydraulic motor may be controlled to rotate the cutting means in a reverse direction should the motor stall due to excessive resistance to movement of the cutting means, for example due to a blockage between the cutting blades and the outlets.

The cutting means may be journalled for rotation about a rotational axis coaxial with the central axis of said housing. Preferably said drive means is mounted on a bottom wall of said housing.

In one embodiment, the cutting means comprises a plurality of radially extending arms extending from a central rotational axis, each arm having a cutting blade mounted on a distal end thereof. A substantially circular plate may be mounted to the lower faces of the arms coaxially with said central rotational axis to prevent solid material from becoming jammed between the arms and the bottom wall of the housing.

Each cutting blade may comprise a disc having a peripheral cutting edge, said cutting edge lying in a plane parallel to the bottom wall of the housing. Preferably each cutting blade is mounted to be freely rotatable about a central axis of the cutting disc during operation of the cutting means to ensure even wear of the cutting edge thereof.

In one embodiment, each cutting blade is mounted on a central bushing permitting vertical movement of the cutting blade with respect to its mounting, biasing means, preferably in the form of a compression spring, being provided for biasing the cutting blade towards the outlet openings to bias each blade against the lower wall of the housing. The provision of such biasing means ensures good contact between the cutting blades and the lower wall of the housing while permitting deflection of the blades should they encounter obstructions to prevent damage of the cutting edge of the blade.

According to a second aspect of the present invention there is provided a slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein the cutting means comprises a plurality of radially extending arms, each arm having a cutting blade mounted on a distal end thereof.

By mounting each cutting blade at the end of separate radially extending arms, the arms act as sweeping and mixing members as they move through the slurry within the housing, providing an even distribution of slurry to the outlet apertures and providing mixing of the slurry. Advantageously the sweeping action of the radial arms, rotating during operation, encourages stones or the debris into the stone trap housing due to the centrifugal effect created.

According to a further aspect of the present invention there is provided a slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein each cutting blade is mounted on a central bushing permitting rotation and vertical movement of the cutting blade with respect to its mounting, biasing means, preferably in the form of a compression spring, being provided for biasing the cutting blade towards the outlet openings to bias each blade against the lower wall of the housing.

According to a further aspect of the present iiivention there is provided an apparatus for manuring land comprising a wheeled chassis having a tank mounted thereof for containing slurry, slurry delivery means mounted on the chassis, said slurry delivery means comprising a plurality of slurry delivery outlets for delivering the slurry directly onto or into the soil, and a slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connected said tank, a plurality of outlets arranged in one end of the housing each connected to a delivery pipe communicating with a respective slurry delivery outlet, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein a side chamber is defined in a side wall region of the housing, communicating with the interior of the housing to define a stone trap, said side chamber further communicating with an access means to permit removal of stones trapped therein. Preferably the apparatus includes means for pressurising the tank.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: -Figure 1 is a perspective view of a slurry distribution apparatus according to an embodiment of the present invention; Figure 2 is a perspective view of the apparatus of Fig. 1 with the upper wall of the housing removed for clarity; Figure 3 is a detailed side view of one of the macerator arms of the apparatus of Fig. I; Figure 4 is an exploded perspective view of a modification of the apparatus of Fig. I; Figure 5 is a detailed view of the macerator of the modified apparatus of Figure 4; and Figure 6 is a plan view of the modified apparatus of Figure 4.

As shown in the drawings, a slurry distribution apparatus according to an embodiment of the present invention comprises a housing I having a substantially cylindrical side wall 2 and bounded by upper and lower end walls 4,6 to define a closed chamber. A central inlet 8 on the upper wall 4 communicates with an inlet conduit receiving slurry from a tanker upon which the distribution apparatus is mounted. The slurry exits the chamber via a plurality of outlet apertures 12 formed around the periphery of the lower wall 6, each outlet aperture communicating with a delivery conduit 14 for supplying slurry to an exit, for example an opening in a trailing shoe for delivering the slurry directly onto the soil. The upper section of the housing I, including the upper wall 4, is pivotally attached to the remainder of the housing to permit removal thereof for cleaning and maintenance of the distribution apparatus.

A cutting device in the form of a macerator is rotatably mounted within the chamber of the housing for mixing and maccrating the slurry to avoid blockage of the delivery conduits.

The macerator comprises a plurality of radially extending arms 20 extending from a central axle 22 and each terminating in a cutting disc 24. The cutting discs 24 are arranged to slidingly engage the lower wall 6 of the housing to traverse over the outlet apertures 12 to Cut up any solid particles that may pass into the outlet apertures 12, such as particles or straw or grasses. The macerator may be rotatably driven by a hydraulic motor 26 arranged to rotate in a reverse direction should rotation of the macerator stall due excessive resistance caused by blockages in the chamber. The radial arms 20 act on the slurry to agitate and distribute the slurry out towards the outlet ports 14.

A circular disc 23 is mounted on the lower faces of the arms, arranged coaxially with the central axle 22, to prevent solid material from becoming jammed between the arms and the lower wall 6 of the housing. As shown in Figs. 4 to 6, in a modified design the disc 23 may extend to the ends of the arms, cutouts being formed in the peripheral edge of the disc around each cutting disc 24. Radially extending projections may be provided on the peripheral edge of the disc 23 for deflecting stones Out towards the stone trap, as described below.

As shown in Figs. 3 and 5, each cutting disc 24 is mounted at the end of a respective radial arm 20 upon a vertically arranged shaft 26 having a bushing 28 upon which the disc 24 is axially slidable to permit the disc 24 to move vertically with respect to the end of the respective arm 20, each disc 24 being biased downwardly by means of a compression spring arranged around the shaft 26 above the cutting disc 24 to maintain good contact between the lower wall 6 and the cutting discs 24 while permitting vertical displacement or deflection of the cutting discs 24 over obstructions to prevent damage of the cutting edges of the cutting discs 24. The mounting of the cutting discs 24 on said bushings 28 also allows free rotation of the cutting discs 24 to ensure even wear of the cutting surfaces thereof. A tapered screw 32 secures the disc 24 to the shaft 26. This arrangement also enables the cutting disc 24 to freely rotate about a central vertical axis thereof, thereby ensuring even wear of the cutting edge of the cutting disc 24.

A problem with prior art slurry distribution systems is that hard particles, such as stones, may pass into the macerator and cause damage or jamming of the cutting means and blockage of the delivery conduits. To avoid this problem, a stone trap 40 is provided on one side of the housing communicating with the chamber to allow stones to be removed from the chamber by the sweeping action of the radial arms 20.

The stone trap 40 comprises a side chamber 42 communicating with the main housing chamber and having side walls 44 extending substantially tangential to the side wall 2 of the housing 1. The position of the stone trap on the outer periphery of the chamber allows stones to be carried Out into the stone trap by means of the centrifugal forces created by the sweeping action of the radial arms 20. Tn the modified version of the apparatus shown in Figures 4 to 6, the radial projections on the plate 23 assist in deflecting stones towards the stone trap 40. A tubular pipe 46 extends downwardly from the stone trap for collecting stones and other particles trapped therein, a lower end of the pipe 46 terminating in a flexible sock 48. A clamp 50, which can be removed periodically to permit the stone trap 40 to be emptied, closes the open end of the flexible sock 48.

The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.

Claims

Claims 1. A slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets to comminute solid material within the housing, and drive means for rotating said cutting means, wherein a side chamber is defined in a side wall region of the housing, communicating with the interior of the housing to define a stone trap, said side chamber further communicating with an access means to permit removal of stones trapped therein.
2. A slurry distribution apparatus as claimed in claim I, wherein a tubular pipe or sock extends from a lower region of said side chamber, said pipe or sock having an open end, a closure means being provided for closing said open end, said closure means being removable or openable to permit removal of material, including any stones, from said side chamber.
3. A slurry distribution apparatus as claimed in claim 2, wherein said closure means comprises a clamp arranged to close a flexible lower region of said pipe or sock.
4. A slurry distribution apparatus as claimed in any preceding claim, wherein side wall regions of the side chamber extend substantially tangentially to the adjacent side wall of the housing.
5. A slurry distribution apparatus as claimed in any preceding claim, wherein the housing is arranged in a substantially horizontal or inclined plane such that the end walls of the housing define upper and lower walls of the housing.
6. A slurry distribution apparatus as claimed in claim 5, wherein said inlet is centrally positioned in the housing.
7. A slurry distribution apparatus as claimed in claim 6,whcrein said inlet is located in the upper wall of the housing.
8. A sluny distribution apparatus as claimed in any of claims 5 to 7, wherein said outlets are provided in the lower wall of the housing.
9. A slurry distribution apparatus as claimed in any of claims 5 to 8, wherein said drive means is mounted on a bottom wall of said housing.
10. A slurry distribution apparatus as claimed in any preceding claim, wherein the drive means comprises a reversible hydraulic motor.
11. A slurry distribution apparatus as claimed in claim 10, wherein the hydraulic motor is controlled to rotate the cutting means in a reverse direction should the motor stall due to excessive resistance to movement of the cutting means, for example due to a blockage between the cutting blades and the outlets.
12. A slurry distribution apparatus as claimed in any preceding claim, whereiii the cutting means are journalled for rotation about a rotational axis coaxial with the central axis of said housing.
13. A slurry distribution apparatus as claimed in any preceding claim, wherein the cutting means comprises a plurality of radially extending arms extending from a central rotational axis, each arm having a cutting blade mounted on a distal end thereof.
14. A slurry distribution apparatus as claimed in claim 13, wherein a substantially circular plate may be mounted to the lower faces of the arms coaxially with said central rotational axis to prevent solid material from becoming jammed between the arms and the bottom wall of the housing.
15. A slurry distribution apparatus as claimed in claim 1 3 or claim 14, wherein each cutting blade comprises a disc having a peripheral cutting edge, said cutting edge lying in a plane parallel to the bottom wall of the housing.
16. A slury distribution apparatus as claimed in claim 15, wherein each cutting blade is mounted to be freely rotatable about a central axis of the cutting disc during operation of the cutting means to ensure even wear of the cutting edge thereof.
17. A slurry distribution apparatus as claimed in claim 15 or claim 16, wherein each cutting blade is mounted on a central bushing permitting vertical movement of the cutting blade with respect to its mounting, biasing means, preferably in the form of a compression spring, being provided for biasing the cutting blade towards the outlet openings to bias each blade against the lower wall of the housing.
18. A slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein the cutting means comprises a plurality of radially extending arms, each arm having a cutting blade mounted on a distal end thereof
19. A slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connectable to a source of slurry, a plurality of outlets arranged in one end of the housing each connectable to a delivery pipe, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein each cutting blade is mounted on a central bushing permitting rotation and vertical movement of the cutting blade with respect to its mounting, biasing means, preferably in the form of a compression spring, being provided for biasing the cutting blade towards the outlet openings to bias each blade against the lower wall of the housing.
20. An apparatus for manuring land comprising a wheeled chassis having a tank mounted thereof for containing slurry, slurry delivery means mounted on the chassis, said slurry delivery means comprising a plurality of slurry delivery outlets for delivering the slurry directly onto or into the soil, and a slurry distribution apparatus comprising a substantially cylindrical housing having an inlet connected said tank, a plurality of outlets arranged in one end of the housing each connected to a delivery pipe communicating with a respective slurry delivery outlet, cutting means rotatably mounted within said housing, said cutting means having a plurality of cutting blades in sliding contact with said end wall of the housing arranged to traverse said plurality of outlets, and drive means for rotating said cutting means, wherein a side chamber is defined in a side wall region of the housing, communicating with the interior of the housing to define a stone trap, said side chamber further communicating with an access means to permit removal of stones trapped therein.
21. An apparatus as claimed in claim 20, further comprising means for pressurising the tank.
22. A sluny distribution apparatus substantially as described herein with reference to the accomanying drawings.
23. An apparatus for manuring land substantially as herein described with reference to the accompanying drawings.