Decolorrization Tank

The decolorization tank adsorbs pigments or other impurities in the liquid material through activated carbon or other activated clay, so as to achieve the purposes of decolorizing, deodorizing, removing fishy smell, degreasing, removing impurities, purifying, refining, and perfecting refined sugar, monosodium glutamate, glucose, starch sugar, chemical auxiliaries, dye intermediates, pharmaceutical intermediates, food (additives), beverages, liquid medicine preparations, biochemical products, oils and fats, etc.

To achieve the best effect of the decolorization tank, the decolorization tank is generally a stirring reaction kettle with stirring. Heating medium is introduced into the jacket to heat the materials in the tank. Powdered activated carbon or clay, with the operation of the stirrer in the tank, fully mixes, stirs, and contacts with the materials at a suitable temperature condition to achieve adsorption and decolorization. Therefore, the main factors affecting the decolorization effect of the decolorization tank include the following aspects:

1. The structure of the stirrer of the decolorization tank. Different stirring structures affect the mixing effect and the heat transfer during the heating process. The design of the stirrer should ensure the simultaneous axial and radial circulation of the liquid surface, with up – and – down  flipping, and uniform mixing and stirring.
2. The type of activated carbon or clay. Activated carbon includes sugar – using activated carbon, pharmaceutical – using activated carbon, and needle – type activated carbon. Selection should be made according to the characteristics of the materials. Different substances have different adsorption capacities by activated carbon. The specific surface area and pore size of activated carbon should be fully considered. Generally, the smaller the average pore size, the greater the dispersion force and the stronger the adsorption capacity. However, it is not that the smaller the particles, the better. If the pore size is too small, the molecules of colored substances cannot enter the pores of activated carbon, and the adsorption effect will decrease. The adsorption effect of powdered and flaky activated carbon is significantly better than that of granular and amorphous activated carbon. Generally, powdered activated carbon is mostly used.
3. Heating temperature. Since there are other substances to be retained or removed besides activated carbon, while ensuring the activity of other materials in the tank, try to achieve the best adsorption effect. The specific adsorption temperature needs to be judged according to the nature of the mixture. Generally, the effect of heating is better than that of not heating, and the general heating temperature is between 70 – 80°C.
4. Adsorption time. It is not that the longer the adsorption time, the better. To achieve the best decolorization effect, the characteristics of the materials should be recognized, the components to be removed should be identified, and the time should be optimized while ensuring the effect of the materials.
5. The decolorization effect is related to the adsorbent, as well as to auxiliaries, such as water or organic solvents, and also to the pH value of the solution. Specifically, it is necessary to design a control experiment according to the characteristics of the materials to explore the best decolorization temperature, pH, etc.

A relatively common material for decolorization tanks is stainless steel, that is, stainless steel decolorization tanks are quite common. The heating method can be selected as electric heating or steam heating. Since activated carbon is a relatively common decolorizing agent, most decolorization tanks are generally activated carbon decolorization tanks. A decolorization tank is a stirring – type reaction kettle, and usually, paddle – type stirring is commonly used. The specific stirring speed can be selected according to the materials. A decolorization tank is usually vertical and of a fully – enclosed structure, with a manhole to facilitate the addition of activated carbon. Common volumes: 50L, 100L, 200L, 300L, 500L, 600L, 1000L – 5000L, etc. Other specifications can be customized! Stirring is carried out at the top center, and the output shaft of the reducer and the stirring paddle shaft are connected by a loose sleeve, which is convenient for disassembly, assembly, and cleaning. The process parameters to be provided for the selection of an activated carbon decolorization tank include: material properties, working pressure, working temperature, operating conditions, etc.