Centrifugal spray dryerDrying materials must be effectively separated and recovered from the waste gas entrained in the drying chamber to ensure the recovery rate of drying products and prevent fine powder from escaping into the atmosphere to cause environmental pollution. Dry or wet recovery equipment can be used. The material recovered by dry process can be delivered to the next processing or packing workshop. The material recovered by wet process can be sent to the pretreatment part of the feed cycle or used as a waste treatment. Dry process recovery equipment (such as cyclone separator, bag filter or electrostatic precipitator, etc.) for the first stage of separation and recovery. Generally, the quality of the product will not be affected, but through the cyclone separator, those brittle materials will be broken and reduced particle size. If there is still a small amount of fine powder in the exhaust gas leaving the first stage separation equipment, and the exhaust gas must be discharged into the atmosphere after dust removal, the wet dust removal equipment (such as wet scrubber, Wet Cyclone separator, washing fan, etc.) will be used as the second stage separation and recovery. In general, the liquid from the scrubber is too low concentration, concentration and drying is not economical, therefore, can only be sent to the wastewater treatment.

Cyclone separator is widely used because of its low cost and simple maintenance. Generally speaking, the separation efficiency of cyclone separators is high enough for most spray drying products, and can not be used in second stage collection equipment. However, it should be noted that no matter how efficient the cyclone is, the efficiency of the cyclone separator can not be reached even under the best operating conditions.100%. If complete separation is required, other separation devices, such as bag filters, should be selected, with efficiency substantially achieved.100%It is possible, but the advantage of using such a device to vent dust-free waste gas into the atmosphere will be smoothed by difficulties in its maintenance and cleaning. It is very difficult to repair the bags if the bags are not installed correctly. It is a difficult and time-consuming task to check the integrity of cloth bags in a dusty environment and to break them out of work, and it can cause long-term shutdown (from a clean point of view, bag filters are still used to recover dust).