GB2158334A - An agricultural slurry distributor - Google Patents

Abstract

An agricultural Slurry Distributor comprises a pressure vessel (12) having an inlet duct (36) and an outlet duct (21) closable by a gate valve (22). A reversible compressor (15) serves to evacuate or pressurise the interior of the vessel (12) so that, when evacuated, fluids are drawn in through the inlet duct (36) the end of which carries a unidirectional valve (38) allowing fluids to be drawn into the vessel (12) but preventing escape of the fluids through the duct (36). Upon subsequent pressurisation of the vessel (12) by the compressor (15) the valve (38) is held firmly shut in a fluid tight manner whilst, opening of the gate valve (22) allows the fluid within the vessel (12) to be distributed through the outlet duct (21). <IMAGE>

Description

SPECIFICATION An agricultrual slurry distruibutor The present invention relates to agricultural slurry distributors, and particularly to slurry distributors of the type comprising a fluid tight pressurisable container carried on a trailer to be drawn behind a tractor vehicle.

Such slurry distributors are known.

Known slurry distributors generally com- prise an elongate cylindrical container mounted with its axis horizontal on a trailer frame which also carries a pump/compressor which is connectable to the vessel and adapted to be driven by the power take-off shaft of an agricultural tractor. At its rear end the vessel has a hinged closure door on which is mounted an inlet/ outlet duct incorporating a gate valve and a slurry distribution nozzle which is releaseably mounted on the duct.

The door can be opened to allow access to the pressure vessel for cleaning purposes, but normally in use remains closed and sealed in a fluid pressure-tight manner. The gate valve closes the inlet/outlet duct between the nozzle and the pressure vessel, and is usually provided with a linkage allowing it to be opened from the tractor cab. At its distribution end the nozzle is provided with a narrow outlet and a distributor plate is positioned just downstream of the outlet to act as an impact plate against which the ejected slurry is impinged in order to cause it to spread outwardly in a fine spray.When it is desired to load the vessel the nozzle is removed or hinged away from the inlet/outlet duct by releasing suitable sealing clamps, and a flexible dip tube the other end of which'is immersed in the slurry to be drawn into the tank is connected to the inlet/outlet duct using the same clamps. The pump is then operated to evacuate the vessel and when a suitable state of vacuum has been gener ated within the interior the gate valve is opened to allow slurry to be drawn into the vessel to a required level. The gate valve is then closed, the vacuum pump turned off and the dip tube is released by undoing the clamps holding it to the inlet/outlet duct. The distribution nozzle is then refitted to the outlet of the duct by positioning the clamps to hold it in place and the equipment is then towed from the slurry reservoir to the field where slurry distribution is to take place.

The spreading of slurry onto fields is often best done during the winter and spring periods when the weather conditions are appropriate, but because of the possibility of rain and bad weather making it unsuitable for heavy equipment to be taken onto the fields there are often only short periods of time during the winter and/or spring when the slurry spreading operation can take place and for this reason it is essential that it should be done as quickly as possible in order to take advantage of the "window" in the weather. However, as will be appreciated from the above description of the known slurry dispensing equipment, considerable time is wasted in removing the distribution nozzle to fit the dip tube and then, when the vessel is full, in removing the dip tube and refitting the distribution nozzle.Furthermore, this involves the tractor driver in leaving his seat, and walking round to the rear of the equipment through conditions where the slurry may have become spilt thereby acquiring a coating of slurry on his boots which is then transferred to the interior of the tractor, necessitating further cleaning operations after work has been finished. In fact, it has been established that the operations necessary in adapting the known equipment from its dispensing mode of operation to its intake mode of operation can occupy at least as much time if not more than the amount of time spent spreading the slurry on the fields.

Moreover, the clamps which fit the distribution nozzle and/or the dip tube to the inlet/outlet duct are difficult to man-handle, and they themselves become soiled with slurry during operation making the whole task unpleasant and dirty.

The present invention seeks to provide agricultural slurry distribution apparatus in which a substantial amount of time can be saved by making the loading of the pressure vessel effectively automatic and by avoiding the necessity for removing the distribution nozzle to fit a trailing tube immersed in the slurry. The present invention also seeks to make the slurry distribution operation much easier to perform by arranging the equipment in such a way that it can be all operated entirely from the tractor cab without it being necess ary for the tractor driver to leave his seat to effect adjustments to the apparatus. This means that a larger number of loads of siurry can be spread onto fields in a given amount of time so that a shorter period of suitable weather conditions can be exploited in order to complete the operation.

According to one aspect of the present invention, therefore, agricultural slurry distribution apparatus comprises a pressure tight pressurisable vessel carried on a trailer which also carries vessel pressurisation and/or evacuation means in the form of a reversible compressor/pump adapted to be driven from the PTO shaft of an agricultural tractor, in which there are provided means by which the apparatus can be controlled from the tractor vehicle to draw in siurry from a reservoir thereof by dipping an inlet dip tube to the vessel into the slurry reservoir, and to dispense slurry under pressure through an outlet distribution nozzle thereof without at any stage in the process requiring the operator to leave the driving seat of the tractor.

In this way the slurry distribution operation can be performed extremely quickly with a considerable s aving in time and therefore a greater effectiveness in the use of both equipment and labour.

According to another aspect, the present invention provides an agricultural slurry distributor of the type comprising a sealable vessel having means fdr evacuating and/or pressurising the interior thereof for drawing slurry in and subsequently expeiling it through a delivery outlet, in which there is provided an inlet duct having a valve for allowing slurry to be drawn into the vessel when a controllable valve on the distribution nozzle is closed, and which is closable to prevent the escape of.

slurry from the vessel when the level of scurry in the vessel reaches a certain value and/or when the vessel is pressurised, whereby to allow controlled dispensing of the slurry through the distributor nozzle.

The inlet valve may be a controllable valve operated by a mechanical or hydraulic linkage to the tractor cab, or may be an automatically operating uni-directional valve allowing the fluid to flow only in the inward direction through the inlet duct.

The inlet duct is preferably formed in a wall of the vessel as a separate duct from the said delivery outlet although, as will be described below, alternative arrangements employing a combined inlet and outlet duct may be provided within the principles of the present invention.

In a preferred embodiment of the invention the delivery outlet has an associated duct leading to a distribution noule through which slurry is distributed from the vessel when the latter is pressurised.

In the preferred embodiment of the invention, as in the prior art, the vessel is preferably in the form of a generally cylindrical container having an openable vessel closure door at one end thereof and means for holding the door closed and sealed in a fluid tight manner at the end of the cylindrical container; in accordance with the principles of the present invention, moreover, the said delivery outlet and the said inlet duct are preferably both mounted on the said end closure door.

This allows access readily to both sides of the inlet and/or outlet ducts for maintenance and supervision purposes.

The said vessel may be mounted on a trailer, as in the prior art, to be drawn by a tractor vehicle, and in this case the s aid delivery outlet preferably has a controllable valve therein, there being provided remote control actuator means by which the operator may open or close this valve from a position on the tractor vehicle, there further being provided remote control means by which the said means for evacuating and/or pressurising the vessel, mounted on the trailer, may be controlled remotely from the tractor vehicle to drive a motor thereof in forward or reverse direction.

The inlet duct preferably has an associated flexible dip tube projecting as an extension thereof, the said flexible dip tube being sufficiently long to enter a slurry reservoir or other slurry container from the vessel. Such a flexible dip tube may trail on the ground or be only sufficiently long to reach close to the ground, but projects sufficiently far from the trailer for it to be possible to immerse the inlet end of the dip tube extension into the slurry in a reservoir by reversing the dispenser apparatus to a suitable position. If the flexible dip tube trails on the ground, this may not be an inconvenience since it can easily be provided with a consumable end piece which is readily replaced when worn.Aternatively, a sling or other support arrangement may be provided to enable the inlet end of the flexible extension to be raised from the ground when it is not being used to draw in slurry.

The said delivery outlet may be provided with an outlet duct leading to a distribution nozzle and incorporating a closable flow control valve, in which the inlet duct is formed as a branch duct of the outlet duct between the flow control valve and the delivery outlet, and the inlet flow control valve is positioned in the said branch ducts to allow fluid flow into the said delivery duct from the branch duct.

In such an arrangement the vessel has only a single opening leading to an inlet/outlet duct which then branches to an inlet duct leading downwardly to a dip tube and a distribution duct leading to the outlet noule.

A suitable uni-directional valve in the inlet duct may be provided to prevent reverse flow of fluid when the vessel is pressurised and in its slurry distribution mode, or alternatively, a closable flow control valve may be provided which has to be operated by the operator prior to pressurising the vessel and opening the gate valve controlling distribution. A suitable hydraulic or mechanical interlock may be provided to ensure that the pressurisation of the vessel and opening of the distribution gate valve cannot take place until the inlet duct flow control valve has been closed in order to prevent slurry from being passed out through this inlet duct and thereby not being distributed in the required fine spray achieved in the usual manner by impinging the outlet jet from the nozzle onto a suitably inclined impingement plate.

Wherever it is positioned the uni-directional inlet valve may conveniently be formed as a hinged flap valve closing the inner end of the inlet duct and opened by a pressure differential across the inlet. In the preferred embodiment the said flap valve is pivotally mounted in such a way that in its opening movement the flap cannot extend beyond a position in which the general plane of the flap is horizontal such that it is urged towards the closure position by the contents of the vessel once they have reached a certain threshold level therein. In a branching duct arrangement such as that outlined above, of course, the flap valve may be closed in the horizontal plane and allowed to rise above this since the slurry within the combined inlet/outlet portion of the duct will always be above the flap valve and therefore able to close it.One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view from above and behind of a slurry distribution app ar atus formed in accordance with the principles of the present invention; Figure 2 is a perspective view from the other side of the vessel illustrated in Figure 1, showing a closure door in its open position; and Figure 3 is a cross sectional view taken on the line Ill-Ill of Figure 1 and showing the position of the uni-directional valve when open.

Referring first to Figure 1, the agricultural slurry dispensing apparatus illustrated therein comprises a pressurisable vessel 1 2 of generally cylindrical form mounted with its axis horizontal on a trailer frame 1 3 carried on wheels 14 in a known way. Also mounted on the frame 1 3 is a pressurising/evacuating compressor/ pump 1 5 connected to be driven from a drive shaft 1 6 having an adaptor 1 7 for connection to the PTO shaft of a tractor which can be connected to the trailer frame 1 3 to draw the apparatus and drive the motor of the pump/compressor 1 5.

The cylindrical vessel 1 2 has an end closure door 18 hinged at 1 9 and having a lock 20 on the diametricaily opposite side. In a lower central position on the door 1 8 is a delivery duct 21 having a gate valve 22 operated by a linkage generally indicated 23 to close and open the valve 22 as required. The linkage 23 comprises a rod 24 connected to the valve gate and leading to a bell crank 25 pivotally mounted at 26 to the vessel 1 2. A rod 27 links the bell crank 25 with a cranked lever 28 pivotally mounted on a mounting 29 and having an operating handle 30 which can be reached from the tractor cab to open or close the gate valve 22 as required.

The outlet duct 21 has a distribution nozzle 31 connected thereto by releasable clamps 32. The nozzle 31 is conically tapered to a narrow outlet orifice 33 and a distribution plate 34 is held at an angle to the jet issuing from the orifice 33 by a bracket arm 35 attached to the body of the nozzle 31.

Adjacent the duct 21 is an inlet duct 36 which, as can be seen in Figures 2 and 3, has a inward end 37 projecting into the vessel 1 2 and the inner end of which carries a unidirectional valve 38 comprising a plate 39 having an annular shoulder 40 receiving an annular sealing ring 41. The plate 39 carries two ribs 42, 43 having projecting arms 44, 45 pivotally mounted to a bracket 46 carried by the projecting end 37 of the inlet duct 36.

The ribs 42, 43 have projections 42a, 43a which extend beyond the arms 44, 45-jn such a way that they contact the inner face of the door 1 8 when the plate 39 is approximately horizontal to prevent this from rising above the horizontal plane.

The inlet duct 36 has a flexible extension 47 releaseably connected to the end thereof by a coupling 48 illustrated as a screw coupling, but which can be any convenient type.

The end of the flexible extension 47, which is not shown, may be provided with a consumable end piece so that the flexible end may merely trail on the ground, or (again not shown) there may be provided a sling for supporting the end of the inlet extension 47 when it is not required to immerse this in the slurry. A linkage similar to that operating the gate valve 22 may be provided for raising and lowering such a sling.

In use of the app aratus described above the slurry distributor is reversed to a position where the flexible extension 47 can have its free end immersed in the slurry in a reservoir, and the motor 1 5 is driven to evacuate the interior of the vessel 1 2 whilst the gate valve 22 is closed. The uni-directional valve 38 is opened as the slurry is drawn into the vessel 1 2 through the inlet tube 36 and when the slurry reaches a certain level, detected by sensors, (not shown), the motor 1 5 is switched off and the valve 38 automatically closes under the weight of the slurry in the container such that the sealing ring 41 engages the rim of the proj ecting end 37 of the inlet tube 36 and completely closes this against the escape of slurry.The free end of the flexible extension 47 is then raised, if this is provided with such a mechanism, or if not the apparatus is simply towed to the distribution point where the motor 1 5 is driven to introduce compressed air into the interior of the vessel 1 2 and the gate valve 22 is opened to allow slurry to escape through the nozzle 31 and be sprayed after impingement on the plate 34.

After the tank 1 2 has been emptied to a sufficiently low level to no longer escape through the tube 21 the gate valve 22 is closed and the tanker transported back to the slurry reservoir where it is reversed to immerse the free end of the extension 47 into the slurry and the process repeated. At no stage is the tractor driver required to leave the driving seat and the time taken for slurry to be drawn into the vessel 1 2 is merely that required for the pump 1 5 to evacuate the vessel 1 2 sufficiently for the slurry to be drawn into it.

In an alternative embodiment not shown the uni-directional valve 38 is replaced by a controllable valve in the duct 36, and this allows the filling operation to be conducted even more quickly since the vacuum pump 1 5 can be operated to evacuate the vessel 1 2 during the time that the apparatus is being returned from the field to the slurry reservoir so that immediately upon arrival the vessel 12 has a substantial vacuum therein and upon opening the valve (once the dip tube 47 is immersed in the slurry) the slurry can immediately enter at high speed into the vessel 12.

The apparatus of the invention has the advantage of being economical, robust and very reliable. Further, the saving in time when filling the tanker from the slurry lagoon or other reservoir is very considerable and the arrangement makes this job far more pleasant because it is no longer necessary for the operator to remove the nozzle 31 by means of the clips 32 in order to attach a separate hose immersed in the slurry. Indeed, the only requirement for the retaining clamps 32 is for access for cleaning purposes, and a simpler and more economical construction may be provided thereby enabling a part of the cost of the additional valve arrangement to be offset by savings in structure made redundant thereby.

The inlet tube 36 may be provided with a closure plate which may be fitted to the end of the tube 36 after removal of the coupling 48 to enable the slurry tanker to be used as an existing conventional slurry tanker by drawing in and ejecting slurry through the tube 21. It is also possible for the alignment of the flexible tube 47 to be such that the free end is in line with the wheel 14 so that it follows any ruts made by the wheel the likelihood of fouling is diminished.

Claims (14)

1. An agricultural slurry distributor of the type comprising a sealable vessel having means for evacuating and/or pressurising the interior thereof for drawing slurry in and subsequently expelling it through a delivery outlet in which there is provided an inlet duct having a valve for allowing slurry to be drawn in to the vessel when a controllable valve on the distribution nozzle is closed, and which is closable to prevent the escape of slurry from the vessel when the level of slurry in the vessel reaches a certain value and/or when the vessel is pressurised whereby to allow controlled dispensing of the slurry through the distribution nozzle.

2. An agricultural slurry distributor as claimed in Claim 1, in which the inlet duct is formed in a wall of the vessel as a separate duct from the said delivery outlet.

3. An agricultural slurry distributor as claimed in Claim 1 or Claim 2, in which the delivery outlet has an associated duct leading to a distribution nozzle through which slurry is distributed from the vessel when the latter is pressurised.

4. An agricultural slurry distributor as claimed in any preceding Claims, in which the vessel is in the form of a generally cylindrical container having an openable vessel closure door at one end thereof and means for holding the door closed and sealed in a fluid-tight manner to the end of the cylindrical container, and the said delivery outlet and the said inlet duct are both mounted on the said end closure door.

5. An agricultural slurry distributor as claimed in any preceding Claims, in which the said vessel is mounted on a trailer to be drawn by a tractor vehicle and the said delivery outlet has a controllable valve therein, there being provided remote control actuator means by which the operator may open or close this valve from a position on the tractor vehicle, there further being provided remote control means by which the said means for evacuating and/or pressurising the vessel mounted on the trailer may be controlled remotely from the tractor vehicle to drive a motor thereof, in forward or reverse direction.

6. An agricultural slurry distributor as claimed in any preceding Claim, in which the inlet duct has an associated flexible dip tube proj ecting as an extension thereof, the said flexible dip tube being sufficiently long to enter a slurry reservoir or other slurry container from the vessel.

7. An agricultural slurry distributor as claimed in any of Claims 1 or 3 to 6, in which the said delivery outlet is provided with an outlet duct leading to a distribution nozzle and incorporating a closable flow control valve, in which the inlet duct is formed as a branch duct of the outlet duct between the flow control valve and the delivery outlet, and the inlet flow control valve is positioned in the said branch duct to allow fluid flow into the said delivery duct from the branch duct.

8. An agricultural slurry distributor as claimed in any preceding Claim, in which the inlet flow control valve is a unidirectional valve.

9. An agricultural slurry distributor as claimed in Claim 8, in which the unidirectional valve is a hinged flap valve closing the inner end of the inlet duct and opened by a pressure differential across the inlet.

10. An agricultural slurry distributor as claimed in Claim 9, in which the said flap valve is pivotally mounted in such a way that in its opening movement the flap cannot extend beyond a position in which the general plane of the flap is horizontal such that it is urged towards a closure position by the contents of the vessel once they have reached a certain threshold level therein.

11. An agricultural slurry distributor as claimed in Claim 10, in which the flap valve pivot is provided with shoulders engageable against co-operating abutment means to deter mine the fully open position of the valve.

1 2. An agricultural slurry distributor as claimed in any of Claims 9 or 11, in which the flap valve is provided with a sealing ring engageable over the projecting end of a tubular member inside the vessel constituting an inner projection of the inlet duct.

1 3. Agricultural slurry distribution apparatus comprising a pressure tight pressurisable vessel carried on a trailer which also carries vessel pressurisation and/or evacuation means in the form of a reversible compressor/pump adapted to be driven from the power take off shaft of an agricultural tractor, in which there are provided means by which the apparatus can be controlled from the tractor vehicle to draw in slurry from a reservoir thereof by dipping an inlet dip tube to the vessel into the slurry reservoir, and to dispense slurry under pressure through an outlet distribution nozzle thereof without at any stage of the process requiring the operator to leave the driving seat of the tractor.

14. An agricultural slurry distributor as claimed in Claim 12, in which all the controls for driving and/or reversing the vacuum/pressurisation pump for the vessel and for controlling the valves at the inlet and outlet of the vessel are taken to the tractor cab or within reach of the driver therefrom.

1 5. An agricultural slurry distributor as hereinbefore described with reference to the accompanying drawings.