It is most efficient to use gravity for transport of basic materials and products. For this reason it is advisable to install the whole plant in a building with several floors.
The main storage of the seed can be placed outside or inside the oil mill building. Conveying machinery transports the seed up to the buffer silo above the press. There the seed will be warmed up to room temperature before dropping into the press by garvity. The buffer silo should be the size of the daily processing capacity. A level sensor controls the filling.
It is important to clean the seed from stones, possible metal prices and plant parts. This provides a more constant oil quality and reduces the risk of damaging the press. The contamination should be under 2%. A sieve is used to remove stones and plant parts, and a magnetic separator removes possible meral parts. For cleaning rape seed, a sieve with a mesh size between 2.2 to 2.5mm is recommended. The seed is prewarmed to about 20℃ by a special unit or by a heat exchanger that makes use of the heat from the warm press cake. Pre-heating the seed to over 20 ℃ has no addition benefit.
For economic reasons, automatic operation of the oil mill is onlu recommended for capacities over 500kg/h for rape seed and over 700kg/h for sunflower seed. Hereby the filtering process should follow immediately the pressing (e.g. with a self-cleaning filter). A buffer storage tank directly after pressing with homogenisation unit is recommended if using a semiautomatic or automatic operating filter, in order to have the particles from the raw oil distributed. The size of the tank should be 1 to 2 times the daily capacities.
For automatic operation of the whole process it is necessary to control the following parameters: ►throughput-control on the press cake outlet ►temperature control for nozzle and press cake tank ►filling-level of clean oil tank and press cake tank
