Spray Dryers for Food & Dairy Powders - GEA Niro - #19

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page 15 Preheating Prior to atomization, the product is preconcentrated and possibly preheated. The feed must remain liquid and the viscosity kept sufficiently low to allow for proper atomization. However, a higher concentration of dry matter in the feed to the dryer results in reduced energy consumption of the overall process and the powder achieves a higher density. Atomization GEA Niro spray dryers are equipped with a rotary atomizer or high-pressure nozzles. For maximum operational flexibility some dryers can be designed for nozzle as well as rotary atomization. This allows the plant operator to choose the best atomization system for specific products. GEA Niro air dispersers are designed to fit GEA Niro atomizers and to ensure maximum contact between particles and drying air whilst preventing wet particles reaching the chamber wall. The Chamber The spray drying chamber is sized for the required capacity, and the design is chosen to match the type of atomization used and the product to be dried. Some chambers are equipped with static, integrated fluid beds for better energy utilisation and gentler product treatment at lower temperatures. Product Separation The drying chambers have a conical base where the first separation of powder and drying air takes place. The remaining dust from the drying air is removed in a cyclone and/or bag filter. Conventional spray dryers work with cyclones, which are still in use for some applications. However, most modern spray dryers are equipped with a bag filter, which can be cleaned in place – the SANICIP™. From this bag filter, the powder fraction can be recycled to the process, giving insignificant powder loss. Fines The powder fraction from the SANICIP™ bag filter or the cyclone is recycled to the process, where it can be used for agglomeration. If agglomeration is not required, the fines can be conveyed to the VIBRO-FLUIDIZER™ Conical part of spray drying chamber with the integrated fluid bed in a CDI Dryer MSD™ Dryer with removable insulating panels Conical part of CDP Dryer with powder outlet duct from the integrated fluid bed Powder layer on the belt of the FILTERMAT™ Spray Dryer