Suitable varieties:
Corn oil, rapeseed oil, sunflower seed oil, soybean oil, etc.
Main specifications:
Daily capacity: 3 tons, 5 tons, 10 tons, 30 tons, 50 tons
Universal dewaxing method only depends on freezing crystallization, and then uses mechanical method to separate oil and wax without any auxiliary agent and auxiliary way. Pressure filtration, vacuum filtration and centrifugal separation are used in separation. The simplest method of this method is primary crystallization and filtration. For example, the deodorized rice bran oil (at a temperature above 50℃) is transferred to a tank with a cooling device, stirred slowly, and cooled down to 25℃ under normal pressure. The whole cooling crystallization time is 48hr, and then the oil and wax are filtered and separated. The filtration pressure should be maintained at 0.3–0.35Mpa, and the oil-fat contained in the wax should be timely blown out by the compressed air after filtration.
Due to the low dewaxing temperature, high viscosity and difficult separation, the rice bran oil of more wax content is usually filtered by twice crystallization. That is, the deodorized oil is fully cooled down to 30℃ in the cooling tank, the cooling crystallization time is 24hr. The first filtration is carried out to remove most of the wax by the oil filter. The pressure of the filter should be below 0.35Mpa. The filtered oil is put into the second cooling tank, and then low temperature cold water is continuously injected to make the oil temperature below 25℃. The second filtration is carried out after 24 hours, and the filtered oil is called dewaxing oil. After twice filtration, the wax content in the oil (expressed as acetone insoluble) is below 0.03%.
Technology Process:
Deacidification rice bran oil → Cooling crystallization → Fabric bag filtration → Dewaxing oil
↓
Wax paste → Melting → Pressing → Crude wax
↓
Palmitin
The cooling crystallization is carried out in the cooling room, the indoor temperature is 0-4℃.
When the oil temperature is about 70℃, it’s coated with insulation warm layer, sent into the cooling tank. The cooling time is 72hr, and the final oil temperature of the cooling tank is 6-10℃. The average cooling rate was 2℃ / h in the first 24 hr, 0.5℃/h in the next 24 hr, finally fell into 1-2℃ in the last 24hr.
The fabric bag filtration is carried out in the filtration room, the indoor temperature is kept among 15-18℃ and the filtration time is 10-12hr. The fabric bag can be made of dacron khaki,
vinylon cotton or cotton fabric. The sequence of filtration is dacron khaki > vinylon cotton > cotton fabric. The dewaxing effect is quite good. When the filter oil is freezing tested at 0℃, it is transparent and clear for more than 2hr, and the wax content in dewaxing oil is less than tens of mg / kg. The sequence of strength of filter media subjected to freezing test is cotton fabric > vinylon cotton > dacron khaki.
The wax paste (15%-17% of the total oil) is poured into the melting pot, heated to 35-40℃ and packed into the press. The press adopts 90 type hydraulic press, the plane pressure of the press plate is 2.5-5mpa, and the pressing time is 12 hr. Tender press and frequently press, no loss of the wax paste when operation. About 61% of the palmitin and 39% of the crude wax were separated by pressing. Crude wax contains 40%-45% of the oil.
