1 Hydration degumming:

usually adopts high-temperature hydration process, the oil temperature is 70 ~ 80 , and water is 315 times of phosphatide content in the oil, water temperature is 80 or so, finish within 20 minute once. After the glue obvious precipitation static sedimentation 3 h ~ 4 h, then separate oil foot.

2 Alkali refining acid,

alkaline amount shall be calculated according to MAO oleic acid value .Lye concentration should be depending on MAO oleic acid value, when the acid value is less than 3, lye concentration is 7% ~ 7%;When the acid value is 3 ~ 5, lye concentration is 8% ~ 8%;When the acid value of 5 ~ 10, lye concentration is 10% ~ 10%;When acid value is more than 10, lye concentration of 12% ~ 14%, and total alkali should be finished within 10 minute one plus. Alkali refining oil when initial temperature of 30 and 40 , the final temperature of 60 ~ 65 . When soap-grain obviously after precipitation static sedimentation 6 ~ 8 h, then separate soap stock.

3 Washing drying:

washing when adjust the oil temperature to 85 , join and oil washing with warm water, according to the situation of washing 1 ~ 3 times, each time for oil water quantity of 10% ~ 15%, after adding the water let stand for 1 h or so, letting off waste water. After washing the oil contains about 0.15%

4 Decolorization:

Usually use activated clay as decoloring agent. Above the drying process can be done in the decolorizing pot, put water pump or inhaled decoloring pan, keep the pot is below 8 kPa of absolute pressure will start dewatering oil heated to above 80 , until the pot fog dissipates (water content in oil of < 0.11%), said to fulfill the requirements of dehydration. Decoloring oil temperature rise to about 90 , while adding activated clay for heavy oil for the amount of (3% ~ 5%) mixed with oil, decolorization for 20 m to 30 min in time. After the decoloring oil cooling to below 70 , broken vacuum, will pump out filtration separation of clay. If wash oil before entering the decoloring pot into the filter, using the last shipment of decoloring oil filter residue after clay on decoloring, again into the decoloring pan decolorization effect is better.

5 Deodorization:

the decoloring oil suction deodorization pot and keep the pot under the absolute pressure of 113 kPa, deodorization temperature 170 ~ 180 , deodorization time 3 h ~ 8 h. After deodorization, oil cooling to pump out filter under 70 , is the refined oil products. Deodorization direct steam superheat treatment should be performed, in order to prevent the water into the pot. ■