Centrifugal Hot Gas Spray Dryer

Product description

Spray drying is a method of producing dry powder from liquid or paste-like materials by rapidly drying hot gas. This is the preferred method for drying many heat-sensitive materials such as food and medicine.

The liquid material is pumped into the top-mounted rotating disc atomizer through a single pump, and atomized into fine droplets in the drying chamber. The heated clean hot air is blown into the air distributor at the same time. The uniform and swirling hot air is in complete contact with the droplets for heat transfer. The droplets are dried into powder in a few seconds, and then sucked into the cyclone separator to be discharged through the exhaust fan.

LPG series spray dryers have been widely used in the pharmaceutical, chemical and food industries to dry liquid materials into fine powders.

main features

1) Particle size control: The dry particle size can be easily controlled through the atomization of the liquid feed and the design of the hot gas inlet. The spray dryer usually produces a bell-shaped distribution with an average particle size between 30 and 500 microns.

2) Evaporative cooling of the product: The heat and mass transfer during drying occurs in the air and vapor film around the droplets. This protective layer of vapor keeps the particles at the saturation temperature. As long as the particles do not become "dry bones", evaporation will still occur, and the solid temperature will not approach the dryer outlet temperature.

3) Short residence time: The surface area generated by the atomization of the liquid feed can make the gas residence time short, depending on the application, in the range of 3-10 seconds, which allows spray drying without thermal degradation.

4) Flow characteristics of dried products: Most spray-dried particles are spherical in shape, which can provide fluid-like flow characteristics. This makes many downstream operations (such as packaging, pressing, filtering and processing) easier and cheaper.

5) Design of the size of the drying chamber: The size of the drying chamber is specially designed to prevent the droplets from sticking to the inner wall, so that the dry powder accumulates on the conical part, and ensure sufficient residence time.

main parameter