The process of bleaching vegetable oil, the method of bleaching oil a lot, the most widely used in industrial production is the method of adsorption bleaching. In addition to bleaching by heating, oxidative bleaching, chemical bleaching method, etc. In fact, in the process of refining vegetable oil, the removal of oil from the pigment is not completely dependent on the bleaching section, alkaline cleaning, such as acid cleaning, hydrogenation, deodorization, has an auxiliary effect discoloration.
Adsorption discoloration, oil adsorption discoloration, the use of certain pigments with strong selective adsorption material (such as bleaching earth, active white earth, activated carbon, etc.), Under certain conditions, adsorption oil pigments and other impurities to achieve the goal of decolorization. Through the adsorbent oil treatment, not only to improve the color of the oil, the purpose of removing pectin, but also can effectively remove traces of metal ions, and some can cause poisoning of some hydrogenation catalysts of the substance, thus, for further purification of oils and fats (hydrogenated, deodorization) provide good condition.
The adsorption discoloration process of frying oil, the adsorption discoloration is intermittent and continuous. Periodic discoloration of the oil, batch and adsorbent, continuously completed adsorption equilibrium class and separation process; Adsorbent continuously completes the adsorption equilibrium of a kind of process, now the points mentioned below
1. The remaining type of discoloration
Intermittent discoloration of the oil and adsorbent in an intermittent state through adsorption equilibrium and the process of complete discoloration of vegetable oil.
The usual bleaching process, a tank in oil in a decolorizing decolorizing tank, heating the drying under vacuum, and the adsorbent can inhale the adsorbent while stirring until complete contact, complete the adsorption equilibrium, then cool with a pump, pump out the pressure, filter the filter, separate the adsorbent. After filtering the discoloration of the oil in formation, intake or injection of oil by a pump into the deodorization process, a vacuum filter press with suction in an adsorbent filter cake in a tank for processing residual oil.
2. The continuous process of discoloration of vegetable oil
The process of bleaching oil for continuous cooking in the pipeline: this process is designed to maintain stable conditions, to ensure stable product quality in the modern process of bleaching. Using this process, the inlet of the acid oil pump, after the flow meter, to adapt to the process flow into the harmonic tank, under the influence of the circulation flow completely mixed with the adsorbent of the quantitative dosimeter, and then using the pump through the heater, previously heated to a certain temperature, drying in deoxidation dehumidifier, again with a heater to heat the pump to a temperature of decolorization in the reactor after completion In adsorption equilibrium, then in the cooler to filter the temperature, the pump separates the adsorbent separation filter.