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 getting 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 failure occurs
- 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.
- [Spraying mode]
- Because unprocessed liquids are sprayed into high temperature rapid hot airflow through a venturi tube, it dries the liquids instantly and good quality products can be produced without any influence by heat degeneration.
- [Drying chamber]
- Due to flash drying, wet powders hardly reach the surface of walls; therefore, adherence within the drying chamber is little which allows reducing a diameter of the drying chamber smaller. In addition, burnt powders getting mixed in as adherence does not occur, prolonged operation is possible without installing a hammering device.
- [Two-phase drying system]
- In our two-phase drying system, the temperature of draft air in the drying chamber is kept as low as possible and residual moisture is removed by re-dryer, therefore, it is possible to obtain high thermal efficiency and fine-tuning of residual moisture is also available. Cooling of the product is also possible.
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. No explosion can occur because an inert gas and nitrogen are circulated.
- [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, vitamin, amino acid, blood, plasma, herbal medicines
- [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
- [Others]
- Agricultural chemicals, detergents, dyes, and latex
