Spray drying is the ideal way to dry large quantities of liquids quickly and efficiently, and this is a core goal that dryer manufacturers have been pursuing. In order to evaluate the performance of various types of dryers, we need to focus on their quality and economic performance. Spray dryers are classified according to two main criteria: the flow direction of the hot air and feed and the flow circuit of the system.
Depending on the flow of air and feed, spray dryers can be divided into three types designed to improve the thermal efficiency of the system. The choice of airflow direction depends on the characteristics of the material being treated.
First of all, in the parallel flow spray dryer, the feed spray and hot air flow in the same direction. This design performs best among all spray dryers. The advantage is that the wet droplets are quickly exposed to hot air, resulting in rapid initial drying and rapid cooling, reducing the risk of overheating. For heat-sensitive products, parallel flow systems are particularly suitable.
Secondly, in the counter-current spray dryer, the feed material is sprayed in the opposite direction with the hot air. This design allows the dry pellets to be in full contact with the hot air and is highly energy efficient. Common areas of application include the production of minerals, soaps, detergents, etc.
Finally, the mixed-flow spray dryer combines the characteristics of parallel flow and counter-flow. In this type, hot air is extracted from the top of the drying chamber while the feed spray is in the center. Mixed-flow systems are suitable for products that require longer residence times.
In order to determine the most suitable drying system for a particular material, experts recommend conducting field tests. With our expertise and experience, we can help you choose the right spray dryer to ensure you get the solution and performance you need.