GB2270827A - Slurry spreader. - Google Patents

Abstract

An effluent applicator particularly adapted for towing behind an agricultural vehicle, for example a tractor, comprises a spray bar (10) which has nozzles (6) mounted in apertures in the spray bar (10). The spray bar is connected to an effluent reservoir via a hose. The nozzles are configured such that effluent is ejected from the spray bar (10) at a low trajectory relative to the ground to minimise the effect of wind drift. When not in use the hose can be wound onto a hose reel (2). A pressure control system can also be provided to control pressure in the hose particularly when the effluent is fed back to the reservoir during overpressure. <IMAGE>

Description

APPARATUS FOR APPLYING EFFLUENT TO LAND This invention relates to apparatus for applying effluent to land and more particularly to such apparatus which is adapted to be towed behind a vehicle such as an agricultural tractor.

Industrial effluent applicator machines are known which apply large quantities of effluent or sludges to land, for example 250,000 gallons a day, however such applicator machines are very expensive to run and require the use of large bore high tensile hoses to supply the effluent to the machine. Accordingly such machines do not lend themselves easily to agricultural use.

Conventional agricultural effluent applicator machines are usually in the form of self-propelled irrigators which are driven by winches operated by the flow of and pressure of the effluent flowing through the machine.

Accordingly it will be appreciated that the forward speed of these types of machine is restricted to the velocity of flow of effluent ejected from the machine during application. A further problem with these latter type of machines is that if the MAFF guidelines are to be adhered to, (5mm precipitation), only low flow rates can be achieved.

Accordingly it is an object of the present invention to provide apparatus for applying effluent to land which overcomes or at least minimises the abovementioned problems associated with known arrangements. It is also an object of the invention to provide an applicator in which the effect of wind drift and consequent odour problems can be minimised or eliminated.

According to a first aspect of the present invention therefore there is provided apparatus for applying effluent to land comprising an applicator means and an effluent transport means linking said applicator means and an effluent reservoir, said applicator comprising one or more nozzles which act to efficiently direct said effluent over said land uniformly in such a manner that wind drift is substantially eliminated.

With this arrangement it is possible to provide apparatus which allows effluent to be spread over land in a cost effective and efficient manner.

Said applicator means may comprise an elongate hollow spreader bar having multiple apertures in the wall thereof into which a nozzle may be connected.

Preferably said effluent transport means comprises a flexible semi-rigid hose.

Preferably said nozzles comprise a member having an internal bore therethrough, an outer surface of the nozzle adjacent an outlet of said bore having a generally helical channel therein.

Preferably said apparatus is adapted to be towed behind an agricultural vehicle for example a tractor and, when used in this manner, means may be provided on said apparatus to store said effluent transport means when not in use.

In accordance with a second aspect of the present invention there is provided apparatus for applying effluent to land comprising applicator means and an effluent transport means linking said applicator and an effluent storage means, said effluent transport means comprising a flexible hose, said applicator further including a storage reel onto which said transport means can be wound when not in use.

Preferably said storage reel is removable from said apparatus and said storage reel may be accordingly connected to said apparatus by way of a quick-release connection.

A further problem with known apparatus for applying effluent to land which utilises an applicator means linked to an effluent reservoir by way of a flexible hose, is that in order for application to be efficient, a working pressure must be present in the hose at all times during application. However, when the flow of effluent from the reservoir is stopped at the applicator, a pressure build up in the hose causes the pressure there to rise above the working pressure and if this pressure is not alleviated then damage to the apparatus may arise.

It is a still further object of the present invention to provide a method whereby excess pressure in the effluent transport means can be alleviated.

According to a third aspect of the present invention therefore there is provided a method of controlling pressure within a effluent transport means of apparatus for applying effluent to land, said method comprising sensing the pressure in the effluent transport means and, if said pressure is substantially greater than a predetermined value, causing opening of a return valve means thereby allowing the effluent to be directed to effluent reservoir means thereby relieving excess pressure in said transport means and providing a nonreturn valve in said transport means which is operable to maintain pressure in said transport means at said predetermined value when said return valve means is open.

With this arrangement it is possible to provide an efficient method of relieving excess pressure in the effluent transport means, whilst maintaining a predetermined pressure therein in a simple and convenient manner.

According to a fourth aspect of the present invention therefore there is provided a pressure control system for apparatus for applying effluent to land, said system comprising a pressure sensing means operable to sense the pressure of effluent in a effluent transport means, a return -valve means operable to open upon detection of a pressure value substantially greater than a predetermined value, thereby allowing said effluent to return to a effluent reservoir means and a non-return valve means adapted to maintain pressure in said transport means at said predetermined value when said return valve means is open.

The invention will now be described further by way of example only and with reference to the acompanying drawings of which: Fig. 1 is a side view showing the reeler and the applicator; Fig. 2 is a front view taken from the direction of arrow A in Fig. 1; Fig. 3 is a schematic representation of the valve system; and Fig. 4 is a flow chart showing the operating sequence.

Referring to Figs. 1 and 2, there is shown apparatus for applying effluent to land, which is adapted to be mounted or towed behind an agricultural machine, for example a tractor. The apparatus includes a hose reel 2 on which a flexible hose may be wound. An idler or guide roller 4 is used to guide the hose onto the hose reel 2.

The reel housing and associated support members 22 are supported by four telescopically retractable support legs 12. The support members 22 have an engagement means 8 mounted thereon to engage with corresponding means on the applicator. This lock mechanism 8 allows quick release of the hose reel 2 from the apparatus as shown in dotted outline in Fig. 1.

The applicator comprises a spray bar 10 which is formed by three rectangular cross-section sections being telescopically engaged and supported by hinges 14.

Nozzles 6 are detachably mounted on the spray bar 10.

The spray bar 10 is supported by support members 24 which provide engagement means of the lock mechanism 8 for maintaining the hose reel 2 on the apparatus.

The effluent is fed from the reservoir (not shown) through the hydraulically operated gate valve 20 into the spray bar 10 and through the nozzles 6. The nozzles 6 are configured such that the effluent is ejected from the spray bar at a low trajectory relative to the ground surface, (typically 150mm from the ground) in order that the effects of wind drift and consequent odour problems can be eliminated or at least minimised.

The reel 2 mounted on the apparatus in the manner described above is driven by an hydraulic drive unit 16 with a spool valve 18. By driving the reel in one of two opposite directions it is possible either to wind the hose onto the reel or to unwind the hose from the reel respectively.

Referring to Fig. 3, there is shown a pressure control system for controlling the pressure in the hose.

The system includes a pressure transmitter D which detects the pressure in the main pipeline from the positive displacement pump which will typically have a pumping rate of 25 m3/ha. An increase in pressure in the pipeline will cause transmitter D to send a signal to an actuator control circuit F, which in turn causes valve B to open so that the effluent is fed back to the reservoir R. At the same time, back pressure in the hose beyond the valve B causes non-return valve C to close, thereby maintaining pressure in the hbse. If desired, a mechanical over-pressure relief valve can also be fitted to relieve excess pressure in the hose in the event of electrical failure. A control panel can conveniently be used to mount control switches to control operation of the system as is shown in Fig. 3. These controls can be, for example, stop/start, open/close valve, output/input and automatic/manual mode. The panel also incorporates a pressure gauge H.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Claims (13)

1. Apparatus for applying effluent to land comprising an applicator means and an effluent transport means linking said applicator means and an effluent reservoir, said applicator comprising one or more nozzles which act to efficiently direct said effluent over said land uniformly in such a manner that wind drift is substantially eliminated.

2. Apparatus according to claim 1 wherein said applicator means comprises an elongate hollow spreader bar having multiple apertures in a wall thereof into which a nozzle may be connected.

3. Apparatus according to claiml or claim 2 wherein said effluent transport means comprises a flexible semirigid hose.

4. Apparatus according to any one of claims 1 to 3 wherein said nozzles comprise a member having an internal bore therethrough, an outer surface of the nozzle adjacent an outlet of said bore having a generally helical channel therein.

5. Apparatus according to any one of claims 1 to 4 adapted to be towed behind an agricultural vehicle, for example a tractor.

6. Apparatus according to claim 5 wherein means is provided on said apparatus to store said effluent transport means when not in use.

7. Apparatus for applying effluent to land comprising applicator means and an effluent storage means, said effluent transport means comprising a flexible hose, said apparatus further including a storage reel onto which said effluent transport means can be wound when not in use.

8. Apparatus according to claim 7 whrein said storage reel is removable from said apparatus by way of a quick release connector.

9. A method of controlling pressure with an effluent transport means of apparatus for applying effluent to land, said method comprising sensing the pressure in the effluent transport means and, if said pressure is substantially greater than a predetermined value, causing opening of a return valve means thereby allowing the effluent to be directed to effluent reservoir means thereby relieving excess pressure in said transport means and providing a non-return valve in said transport means which is operable to maintain pressure in said transport means at said predetermined value when said return valve means is open.

10. A pressure control system for apparatus for applying effluent to land, said system comprising a pressure sensing means operable to sense the pressure of effluent in an effluent transport means, a return valve means operable to open upon detection of a pressure value substantially greater than a predetermined value, thereby allowing said effluent to return to an effluent reservoir means and a non-return valve means adapted to maintain pressure in said transport means at said predetermined value when said return valve means is open.

11. Apparatus according to claim 1 or claim 7 substantially as hereinbefore described with reference to the accompanying drawings.

12. A method according to claim 9 substantially as hereinbefore described with reference to the accompanying drawings.

13. A pressure control system according to claim 10 substantially as hereinbefore described with reference to the accompanying drawings.