Heat exchange and energy saving in the production of food grade calcium carbonate

As an important inorganic chemical product, food grade calcium carbonate is widely used in the fields of food and medicine. Its production is made of lime, calcined and then digested, carbonized, filtered and dried. The production process is long and energy consumption is large. Therefore, to improve the quality of the product in the process of production, to reduce the cost of energy consumption in the production process and enhance the competitiveness is the focus of the enterprise. The most mature food grade calcium carbonate carbonization process requirements carbide material before the temperature drops to about 300C, if the use of calcium hydroxide slurry cooler instead of the cooling coil is arranged in the purification of calcium hydroxide slurry storage tank, pass into the freezing water slurry cooling method, can greatly reduce the power consumption of cooling and cooling time. The principle is to use the high temperature calcium hydroxide slurry and the cold air countercurrent to directly contact the heat. The high heat generated by carbonization process of calcium hydroxide slurry will affect the quality of products. Therefore, it is necessary to put chilled water into the jacket of the carbonization kettle and use the lower deep well as the cooling water source. The end temperature of the food grade calcium carbonate slurry is not more than 350C, and the food grade calcium carbonate slurry has high temperature during filtration, which can easily affect the service life of the plate and frame filter press. Using plate heat exchanger to carry out heat exchange between slurry before and after package can reduce the temperature of the slurry after the package and heating the wrapped slurry, and it can save a lot of steam and energy consumption of nano CaCO 3 package.