In the equipment for filtering edible oil, there are media filtration and non-medium filtration. Media filtration is also oil filter cloth filtration. Often no salt water is added. Centrifugal oil filter is medium-free filtration and need to add salt water. Today, I will talk about centrifugal type. Why does the filter add salt water?
First of all, the squeezed crude oil belongs to the colloidal system, and the peptic impurities include phospholipids, proteins, mucilage and glycosyl diglycerides. The presence of peptizing impurities affects the stability of grease. For example, crude oil is prone to foaming, stasis, and smoke. Crude oil needs to remove peptic impurities.
Secondly, edible oil is often hydrated and degummed.
Hydration and degumming: Using the hydrophilicity of peptic impurities such as phospholipids, add a certain amount of hot water or salt and other electrolyte aqueous solutions to the hot oil under stirring. The particles increase, and then gather with each other and gradually separate out and suspend in the oil phase. With the increase of water absorption, the degree of swelling increases, and the small colloidal particles attract each other to condense into large micelles, which lays the foundation for centrifugal oil filter separation.
Centrifugal oil filter Through high-speed rotation, the oil and slag are separated.