Filtration is designed to remove from oil the residue, which means contaminants from oil pressing.
Filtration is supplied as a system (homogenization tank – automatic / manual / filter – safety filter) along with the conveyors, pumps, electrical wiring and regulation. Filtration is carried out cold at a temperature of 40-50°C.
The technology works continuously and may be fully automated.
Oil is driven to the filter by the pump from the homogenisation tank. The filter can be operated manually or automatically.
Manual filters /filter presses/ are used for small operations, up to approximately 1000 kg seeds/hour, that is about 400 kg oil/hour.
Start-up, filter filling, and filtration itself is overseen by the operators. When the filter becomes clogged, the operators must empty the filter, have it dried and cleaned of filter cake.
This type of filter can be extruded and dried by air only because the polypropylene construction of the filtration slabs and sheets does not tolerate the temperature of the saturated steam.
Automatic filters /AMA filters/ are used for higher performance. Plate, pressure, sedimentation filter is characterized by the fact that the actual filtration is carried out on the layer of suspended solids – the so-called filter cake. To improve the properties of the filter, we can use a filtering substance which means it is not desirable to remove the entire residue before filtration (for example by sedimentation).
The filter works in fully automatic mode. It can be extruded and dried by air and steam, because stainless steel sieves are used for filtering.
Steam is used to mitigate the losses in the filter cake and where there is a risk the filter cake is flammable.
Description of filtration:
The homogenisation tank comes before filtration, acting as intermediate storage of pressed oil. Mixing prevents sedimentation of the residue and ensures the balanced delivery of oil with the residue into the automatic/manual/ filter. A filtering substance can be added to the homogenisation tank to improve and accelerate filterability. Heating keeps oil at the filtration temperature.
Automatic /and manual/ filter works in cycles:
A bag filter is in the pipe behind the automatic filter, which is designed to capture any small debris from the main filter and when the main filter is damaged.
During the regeneration cycle the filtration cake drops from the automatic filter into the hopper under the filter. The filtration cake can be added to oilcakes or returned to the presses.