Cottonseed Oil Production Process
Cleaning: Getting rid of organic impurity (stems and leaves, hull, rope, etc.), inorganic impurity (dust, silt, pebbles and metals), oiliness impurity(grain of insects, grain of faultiness, heterogeneity seeds, etc.). In this section we use Magnetic Separator, Vibrating Sieve, de-stoner, decorticator (Cotton seeds used hammering decorticator). Through cleaning the impurity, you can reduce the lost of oil & improve the oil yield and the environment of production plant. The material has been produced after pretreatment contains the impurities ≤ 0.1%.
Cracking: Adopting the toothed cracking roller to make the cotton seeds kernel into a right uniform pcs which can keep a moderate block size for squeezing out the oil.
Flaking: To make cracked Cotton seeds kernel pcs into uniform smaller flakes with thickness ≤ 0.5mm, less powder, non-oil spilled, pinching softly by hand and the ratio of smaller powder than 1mm sieve mesh is ≤ 10% – -15%.
Cooking: The process is to add the steam into the crushed/flaked seeds pcs, then to dry the seeds for getting rid off more water content. In this process, changing the protein of seeds with the water and temperature to make the oil moleculeo loose for pressing easily to get crude oil also get the better cake and oil. We adopt vertical stack cooker with five layers to cook flakes. Loading full in the 1-2 layers, played the purpose of steaming flakes, and then the temperature reached 95 – 100 degrees, In 3-5 layers should loaded to shallow, controlled about 40% which could get rid of water from flakes. The pressure of jacket steam is ≤ 0.6MPa. The temperature and water rate of flakes after cooking is:
Water Content: 12–14 %; Temperature: 95–100 degrees; Requiring Time: 60mins.
Expelling: Matching the modern style oil expelling press machines to get more oil, or you can use solvent after pre-pressing by oil expellers to get more oil. Solvent extraction is the commonly used commercial technique to recover oil from oilseeds.
Refining: In the crude oil contains residue and solid powder, so we have to remove them before packing or refining. The residue & solid powder is separated through automatic oil-dreg separator. After separating, we can get two products, one is crude oil with impurity of 1% which will be refined or filtered further by Filtered Press; the other is residue with oil which is conveyed back into Screw Press to repress to get rest oil.