Slurry tanker
A liquid manure spreader is an agricultural device for spreading liquid manure or liquid manure on fields or grassland . Liquid manure tanks often have their own trailer chassis , but there are also devices for mounting on a carrier vehicle. If the slurry tanker is designed as a trailer, it is pulled by a tractor ; the pumping device of the barrel is driven by the PTO shaft of the towing or carrier vehicle. In the case of the slurry tanks built as trailers, it is sometimes possible to drive the trailer axle via the tractor's PTO shaft (so-called drive axle).
Vacuum tank truck
In the case of vacuum tankers, a vacuum pump , usually a rotary vane pump , puts the tank of the liquid manure tank under vacuum during the filling process, thereby sucking the liquid manure into the container. The compressor is switched over for emptying, so that an overpressure is generated in the container and the liquid manure is thus forced out of the container under pressure. With regard to pressure or negative pressure, there are increased requirements for the construction of the container. In order to improve the filling of the vacuum truck - especially with viscous manure - hydraulically driven filling accelerators are often used. On the one hand, the filling process can be accelerated and, on the other hand, a higher degree of filling can be achieved beyond the pure vacuum effect. In contrast to rotary lobe pumps or eccentric screw pumps, the vacuum pump does not come into contact with the liquid manure. The vacuum pump can therefore be regarded as more favorable in terms of wear. Since there are limits to the vacuum and pressure inside the tank of a slurry tanker (EU Pressure Equipment Directive), there are limits to the performance at large suction depths or spreading widths.
Positive displacement tank trucks
In the case of displacement pump tank trucks, also called pump tank trucks, the liquid manure is sucked out of the liquid manure pit with a rotary piston or eccentric screw pump and pumped into the tank truck. For spreading, the manure is then fed from the tank via the pump to the distributor using three-way taps or slides. The direction of rotation of the pump is not changed and the suction or pressure side of the pump remains the same. In the case of pump tankers, composite materials such as GRP ( glass fiber reinforced plastic ) are often used instead of steel . These materials bring a great weight advantage, so that a higher payload of the drum is possible. In contrast to vacuum slurry tankers, the pump comes into contact with the medium to be pumped, i.e. the slurry, so that, as a rule, greater wear and tear occurs. Stone traps or cutting units are often used to protect the pump from foreign bodies.
Centrifugal pump tankers
In the case of centrifugal pump tank trucks, also known as centrifugal tank trucks, independent suction from the manure pit is not possible, as no negative pressure can be generated. The tanker is filled with an external slurry pump or a pumping station, which remains stationary at the slurry pit. For spreading, the liquid manure is accelerated by a centrifugal pump at the end of the tank truck and pushed into a channel in such a way that the liquid manure is passed on with overpressure against an impact head or another distributor. The centrifugal tank truck also does not need a pressure or vacuum-tight tank, so that a higher payload is possible with these compared to the vacuum tank truck.
Distribution technology
Broad distributor
Wide spreaders distribute the liquid manure flat over a certain width. They are usually the better choice for grassland. The working width reaches up to approx. 18 m.
- With baffle plates , the liquid manure is directed onto a round baffle plate, which directs the jet upwards and distributes it. Impact plates have not been permitted in Germany since the beginning of 2016 due to poor distribution accuracy and increased emissions.
- The pendulum or swivel distributor distributes the liquid manure by pendulum movement. It remains coarse droplets, is therefore low in nitrogen loss, and has good distribution accuracy.
- Impact head distributors deflect the slurry jet downwards and to the side. The liquid manure hits a smooth or bent sheet metal vertically. They are also known as "gooseneck distributors"
Precision distributor
Precision distributors use a forced feed to distribute the same amount of liquid manure to each area of the surface. They are significantly more expensive than the wide distributors. When applying on uncultivated farmland simultaneous incorporation can be by means of gravitational grubber or discs egge effected. The working width decreases here due to the pulling force requirement of otherwise max. 24 m to usually about 5 m; With the appropriate motorization, cultivator injectors with a working width of over 10 m are also possible.
- With the drag hose , the liquid manure is fed into hoses that drag across the ground behind the device and is thus directed directly to the ground. This method has the particular advantage of reduced odor nuisance and lower nitrogen losses, etc. This technology also offers advantages when the seeds have already emerged, as the green parts of the plants come into less contact with the manure and are therefore less corrosive. The drag hose is less suitable for grassland , as the hoses can damage the grass and the manure is applied directly to the grass, as the vegetation is too dense for the manure to get directly onto the ground. In addition, the spreading in strips is uneven and not all areas receive the same amount of slurry.
- With the drag shoe spreader (also: slotted shoe spreader ), the slurry from the hoses is scratched directly into the sward with additional metal runners. The main focus here is on grassland.
- When Güllegrubber found at the end of the tanker tines with arranged behind these tubes, through which the slurry flows into the current drawn by the Grubberschar earth trench. The falling back, loosened soil immediately covers the liquid manure.
Disk injector
Trailing shoe distributor
Slurry cultivator
Multiple nozzle manifold
This system is a cross between the two distribution methods above. Here the liquid manure is routed to two or more small wide spreaders via hoses. This unites the advantages of the precise distribution of the precision distributors and the wide spreading of the wide distributors.
See also
- List of agricultural implements and machines
- Liquid manure hoses as an alternative application method
literature
- Agricultural. Volume 3 - Agricultural engineering and construction . BLV Verlagsgesellschaft, Munich, ISBN 3-405-14349-7 .
- Horst Eichhorn (editor): Landtechnik . 7th edition, Ulmer, Stuttgart 1952/1999, ISBN 3-8001-1086-5 , p. 549 ff.
Web links
Individual evidence
- ↑ Liquid manure spreading: Old baffles banned from 2016 Chamber of Agriculture Lower Saxony. Retrieved November 30, 2018.
- ↑ Samson Tridem barrel with 10.25 m cultivator