Coulter spray dryer
The Coulter spray dryer was developed by Dr. Coulter at the University of Minnesota in the U.S., and includes many superior features. The system dries sprayed liquids (solid components) with hot air in a drying chamber. (Also effective as a granulation system.)
- Can be operated at high temperature due to flash drying.
- Low running costs.
- Burnt powders do not get mixed in as adherence does not occur, making prolonged operation possible.
- The necessary floor space is minimized because of the compact design.
- High thermal efficiency because of the two-phase drying method.
- Increased operating rate because no failures occur.
- High collection efficiency of the product because of blowdown.
- High-viscosity solutions can be dried due to a high-concentration spray mechanism being developed.
- Automatic control.
- Automatic cleaning also available (option).
After spray drying, a scrubber cools, cleans, and releases dry air into the atmosphere.
In addition to the open type, a closed type is available, which circulates dry air instead of releasing it into the atmosphere.
The closed type is used in the following cases
- Organic solvents are used as the raw solution.
- When raw solutions are dried, odorous gases are emitted.
- Dried raw solutions that are easily oxidized.
- Materials that may cause dust explosions, or ignitable materials.
A condenser liquefies an organic solvent in order to recover it. And no explosions can occur because an inert gas and nitrogen are circulated.
Examples of actual applications of the spray dryer for drying process
[Examples related to dairy products]
Whole milk, skim milk, whey, casein, cream, milk cocoa, and cheese whey
[Examples related to food]
Starch, onions, soybean protein, garlic, gluten, soybean milk, yeast, enzymes, instant coffee, tea, soy sauce, caramel, various seasonings, dextrin, powder candy, cyclodextrin, bean jam, food coloring, and gelatin
[Examples related to drugs]
Culture media, vitamins, amino acids, blood, blood plasma, and crude drugs.
[Examples related to inorganic materials]
Potter's clay, kaoline, alumina, titanium oxides, salt, niobium hydroxide sodium silicate, calcium phosphate, sodium sulfate, and calcium carbonate aluminum sulfate.
[Examples related to organic materials]
Stearic acid, chlorinated rubber, malic acid, acrylic acid, sodium formate, stearate, polyvinyl alcohol, and polyacrylic acid gel polymer flocculant.
Agricultural chemicals, detergents, dyes, and latex.