Experimental Study On Egg White Powder And Milk Powder By Pulse Combustion Spray Drying

Pulse combustion spray drying technique uses high temperature and high velocity pulsating jets produced by the technology of combustion-driven oscillations directly to atomize and rapidly dry the liquid. Compared with the traditional pressure nozzle spray drying, pulse combustion spray drying has merits including the intensive heat and mass transfer, efficiency, energy saving, low environmental emission, simple structure, low operation cost,and high material suitability.Pulse combustion spray drying technique has been used in the field of industrial products,such as nanosized ceramic materials,Zirconia mud,silicon-based non-oxide ceramic and etc,and sludge drying process.Whether it can be used for the heat-sensitive food materials needs a comprehensive investigation.The egg white and milk which has wide industrial applications were selected as the as the experimental materials. The pilot-scale pulse spray dryer in the PCS company was used to prepare PC dired egg white powder and milk powder and their drying energy consumption and product quality were compared with the commercial ones produced by the traditional spray drying,aiming to evaluate the application potential of the pulse combustion spray drying in food industry.The main work and finding of this thesis includes:(1) Using the pilot-scale pulse spray dryer to prepare egg white powderand then compared egg white powders by pulse combustion spray drying and traditioanl spray drying respectively in energy consumption,chemical composition,particle size distribution,structure characteristics,foaming ability and stability,gelling and protein denaturation.The experimental results show that pulse combustion spray drying has lower energy consumption;almost same chemical composition;smaller mean particle size and more tight size distribution,a hollow particle structure and less particle agglomeration;better foaming stability and low protein denaturation,foaming and gelling ability can be improved by further processing.Thus,it can be preliminarily ascertained that pulse combustion spray drying may be used to produce egg white powders.(2) Using the pilot-scale pulse spray dryer to prepare milk powder and then compared milk powdesr by pulse combustion and traditional spray drying in energy consumption, chemical composition,particle size distribution, tructure characteristics.The experimental results show that pulse combustion spray drying has lower energy consumption;almost same chemical composition,smaller mean particle size.However,the particle agglomeration was found in the PC-dired milk powder and this was caused by the wall deposit in the spray drying chamber walls.A possible solution to address this problem was proposed in the work.