Dewaxing of waxes is the separation process at low temperature, as the temperature decreases, the polarity of the ester bond in enhanced oil wax molecules at less than 30 ¡æ (about 0 ¡æ) i.e. formation of crystallized, forming more stable colloidal system. In this low for some time after the wax crystals agglomerate to form larger solid grains to increase the proportion to form a suspension. Finally, wax separation.
Typical dewaxing process: the oil is slowly cooled to 5-10 ¡æ, holding at least 6h wax crystals. After crystallization stable, then the oil temperature rise is usually around 15 ¡æ, in order to reduce the viscosity for easy filtering.
During operation dewaxing process:
The accurate measurement of waxy, fat oils and cold solvent (ethane 18-20 ¡æ) in proportion (40% oil: 60% solvent) into the mixer. Then, with a pump continuously into the mold in series. Accordance with the conditions set by it slow cooling and crystallization (including raising the grain about 8-10h).
The mold can be divided according to the set time period only 2-5 series. Each comes with stirring (10-13r / min) and is equipped with a special rotating blade mezzanine and slow heat exchange (coolant) to prevent the precipitation of crystals deposited on the cooler wall. After crystallization the suspension, with compressed air directly to a continuous vacuum filter for separation. When the degree of vacuum filtration control in133.2kPa (400mmHg), speed 15r / min, sprayed on the diatomaceous earth precoat drum filter aid if necessary.