I heard a friend say that their solvent consumption often hovered around 3 kg/ton. I wonder, before rapeseed for pre-press leaching solvent consumption is only in 1.4 kg / ton or so, now changed to soybean expansion leaching, how the solvent consumption not only does not fall but also rose twice it? After understanding, it is not their level of operation has any big problem, but most of their processing is the kind of soybean raw materials of questionable quality, the soybean raw material procurement cost is low, but it is a serious impact on the solvent unit consumption indicators.

The use of different leaching solvents its solvent loss is not the same. Industrial pure solvent than multi-component solvent loss is small, the more solvent components solvent loss is higher. This is because the high boiling point solvent in the mixture of oil evaporation, vapor extraction and wet meal desolvation is more difficult, resulting in increased solvent residue in the leaching oil and finished meal, and low boiling point solvent is more difficult to recover from the free gas, resulting in the amount of solvents with the exhaust air to the atmosphere increased.

In addition to unavoidable solvent loss, due to poor equipment manufacturing, operation and maintenance of improper reasons caused by the solvent run-off is the main cause of high solvent loss in the leaching plant. This part of the solvent loss in the production process can be controlled, so it is called avoidable solvent loss.

Solvent leakage can be roughly divided into two situations, one is solvent leakage through the sealing is not tight. Leakage of liquid solvents in the leaching plant is actually very small, because the sealing performance of container shells, pipelines, flange valves, instruments and sight glasses, etc. have been carefully inspected and can be easily found and solved. However, in the rotating shaft of the equipment, mixing shaft and pump rotating shaft, etc., due to the packing seal is not good, or after a long period of operation after the sealing effect is weakened, there will be solvent gas leakage to the outside, and sometimes even cause considerable solvent loss. Secondly, due to improper operation, due to failure to stop for maintenance, unclogging the pipeline and other circumstances caused by the solvent leakage. Leach storage box if the material is not enough storage, or sealing winch fails to play the role of material sealing and so on there will be more solvent leakage. If the leaching system can not maintain negative pressure, will also cause solvent vapor leakage to the outside. The amount of solvent loss due to failure to stop and repair is not easy to estimate, but if frequent stop and repair, this part of the loss in the solvent loss accounted for a high proportion.