Optimising the application technique for silage additive ... · CV% Loss% 31 22 46 8 29 14 23 9 CV % Loss % 28 17 CV % Loss % 46 1 26 7 . The top flap was a bad place of application,
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Optimising the application technique for silage additive in harvesting machinery Agrifood Research Finland Matts Nysand
Loader wagon: traditional application only from above, over the pickup, with flat-fan nozzles. The aim was to see if this location is better than application before the pickup, since the layer of forage is thinned out a little on the pickup compared to the windrow, because the pickup tines rotate faster than the driving speed. However, this location did not give better results than application before the pickup.
New method developed at MTT: simultaneous application both from above (flat fan nozzles) and from below (solid jets from a perforated pipe), which improved the additive distribution compared to the traditional methods. The forage slides over the lower pipe. In this Krone wagon and in most loader wagons on the market there is a gap in the pickup at this location, which allows the pipe to be installed partly below the pickup surface, which eliminates the risk that forage gets entangled to the pipe. We have not tried the pipe in any wagon which lacks this gap in the pickup, then the pipe has to be installed on top of the pickup surface. We can not say whether there is a risk of forage getting entangled to the pipe in that case. The hole diameter in the lower pipe was 1.1 mm and the distance between the holes was 10 cm, but it would probably produce even better distribution if the distance is reduced, for instance to 5 cm or even smaller. However, it has to be assured that both pipes still produce proper jets with the bigger number of holes.
The application in the towed chopper was done with flat fan nozzles in the inlet channel between the pickup and the chopping mechanism. The plastic film (wind protection) seen in the picture on the inlet channel was not there in this part of the trial; the upper side of the inlet channel was open.
The top flap was a bad place of application, it caused uneven distribution. Application in the top flap gave small loss (1%), but the difference to the other losses in black numbers was not statistically significant. The results for the lower part of chute, solid jets in the inlet channel and the pickup can be considered to be equally good. The method which can be recommended in practice is the lower part of the chute, since the installation is technically easier than with the elements in the inlet channel. The pickup is not worth recommending since the losses can be expected to be higher in windier conditions.
The forage is thrown up in the chute, along the upper side of the chute (grass side). There is mostly air passing along the lower wall (air side). On the air side, the inlet pipes for additive were installed through the cleaning hatch and protruded about 4 cm into the airstream. On the grass side, the inlets were level with the inner wall of the chute.
The best application place was the inlet channel. With application in the chute, up to a third (22-36%) of the forage got less than 3 litres of additive per ton, which is clearly too little additive. With application in the inlet channel no forage got less than 3 l/t (meaning that all forage got over 3 l/t). Shall be seen in relation to the target dose 5 l/t. The realised dose (consumption from the additive vessel) was 4.4 – 5.8 l/t for the different methods.
Application of acidic additive in the open space at the front opening of the inlet channel caused unpleasant acid odour in the driver’s cabin. Therefore it is better to apply the additive further back in the inlet channel, where the space is closed so the acid vapour is not spread to the cabin. Good application locations are before the knife rotor or before the accelerator.