The model to define optimum volume for slurry tanker
Research Institute of Agriculture, 13 Teaduse St. EE75501 Saku, Estonia;
The capacity of a slurry tanker is affected by different variables. According to previous studies, the most significant influence is the tank volume. In the present version of the selection model of a tanker a pattern is composed to determine the optimum volume for a slurry tanker. The aim of the paper is to introduce the pattern and give an overview of the model. The optimality criterion is minimum slurry distribution cost. In the results the importance of optimum value for tank volume is discussed and the impact of a non-optimal solution is explained. The the impact of the parameters on distribution costs is also clarified. The calculations show that the bigger the annual amount, the longer the transportation distance is and the shorter the tolerated distribution period – then the bigger the optimum value is for the tank size if slurry is transported with the distributor itself. Only for short distances (<3 km) and big slurry amounts (>4,000 m3 ) is the transportation with the distributor itself a cost benefit. However, in most of the cases it is cheapest to use a separate tanker for slurry transportation, while the distance has no effect on the optimum size of a distributor tank. There, in most cases only one set of the application equipment is required to supply the farm with sufficient distribution capacity. If an annual amount is 4,000 m3 or less then a 5 m3 tank is sufficient to serve a farm with the required distribution capacity. If an annual amount is 8,000 m3 then a 10 m3 tank is optimal.