Cleaning methods of spray dryer

The principle of spray dryer is to spray the material into droplets and disperse them in hot air by spray method The material is contacted with the hot air in the way of parallel flow, countercurrent or mixed flow, so that the moisture evaporates quickly and achieves the purpose of drying By adopting the spray drying equipment drying method, the unit operation such as concentration, filtration and crushing can be omitted, and granular products of 30~500 M can be obtained And the drying time is short, generally 5-30s The spray dryer is suitable for drying the materials which are easily dispersed in the concentration process of high heat sensitive materials and liquid, and the fluidity and instant solubility of the products are good In order to ensure the cleaning of the drying tower and its pipes and all the parts contacted with the finished products, it is necessary to have regular cleaning equipment When the product variety is changed, or the spray dryer equipment has been discontinued for more than 24h and not cleaned, a thorough and thorough cleaning should be made Cleaning method, according to the actual choice of dry cleaning, wet cleaning or chemical cleaning Dry cleaning: clean with brush and vacuum cleaner (suitable for small dryer) Wet cleaning: use 60 ~ 80 ℃ hot water for cleaning Chemical washing: wash with alkali, acid and various detergents Among them, pickling: prepare HNO3 into a solution with a concentration of 1-2%, wash it at a heating temperature of no more than 65 ℃, and then wash it with water; alkali washing: prepare NaOH into a solution with a concentration of 0.5-1%, wash it at a heating temperature of no more than 65 ℃, and then wash it with water After wet washing and chemical washing, the equipment and components shall be installed and sterilized at high temperature for 15-30min When cleaning the spray dryer, attention should not be given to washing with chlorine and its compounds The air filter shall be cleaned according to the ambient conditions, i.e the air dust content Generally, it shall be cleaned once every 3-6 weeks with high content and once every 6-8 weeks with low dust content The stainless steel filaments shall be evenly laid into the frame of the air filter after being washed by alkali washing method and sprayed with light spindle oil or vacuum pump oil.