The spray drying process is one of the most important procedures for the production of powders from liquids or liquid mixtures. The process is primarily used for the production of milk powder, coffee powder, cocoa powder, medication or instant powders. During the spray drying process, a nozzle sprays a pure liquid or liquid mixture, the so-called base product,  onto an atomizer disc at high speed. The base product is split into minuscule droplets entering a high temperature air stream. The high temperatures quickly dry the liquid droplets forming solid particles. The mixture of hot air and particles is then transferred to a cyclone precipitator via stainless steel piping. Inside the piping, an ionization electrode is installed. When the exhaust air flows through the spray drying system, the ionizer creates a strong electric field inside the piping. Due to the created charge difference, moste dried particles are driven to the piping’s inner walls, where they build-up and are ultimately removed. The exhaust air continues to flow through the system up to the cyclone precipitator. The cyclone precipitator then further extracts dried particles from the hot air stream. The solid particles sink to the bottom and can be further processed.

Afterwards the exhaust air is led into the electrostatic precipitator module. Here the last remaining solid particles are removed and the purified exhaust air is returned into the cycle. Especially in the pharmaceutical sector, product recovery represents an important economic factor that is included in the planning of production and exhaust air purification plants.

For this specific reason, KMA Umwelttechnik has developed its stainless steel hygiene filter KMA AAIRMAXX®. Thanks to its hygienic particle filtration, the KMA AAIRMAXX® ensures the reusability of the product recovered during the filtration process. Unlike conventional bag filters, , the innovative tube shape of the KMA Aairmaxx® prevents build-up and residues from clogging the precipitator module. This makes the KMA AAIRMAXX® an energy-efficient filtration system – without any pressure loss and a high energy efficiency. Combined with an automatic filter cleaning system (CIP), the exhaust air purification system maintains a constantly high separation efficiency and allows for fast product changes. Optionally, the KMA AAIRMAXX® filtration system can be combined with a heat recovery system to realize efficient energy recuperation.