SPRAY DRYING

Spray drying involves the atomization of a liquid feed into a spray of droplets and contacting the droplets with hot drying air in a process chamber.
The following evaporation of moisture from the droplets results in formation of dry particles into a powder.

FLUID BED PROCESSING

Fluid bed processing involves drying, agglomeration, granulation, and cooling of particulate materials.
In fluid bed drying heat is supplied by air/gas through the product layer thereby removing moisture contents in the powder material.
Alternatively heating panels or tubes immensed in the fluidized powder layer can act as additional drying source.

EXTRACTION

Niro supplies two extraction systems: Continuous and batchwise.
In true continuous extraction the solids is transported by helicoidal screws placed in a tilted trough with heating panels. Hot extraction liquid flows downwards through the solids thereby absorbing the product media.
The conventional continuous extractor uses a system of batch-operated percolator columns. The solids is fed into the vertical placed percolator tubes and hot extraction liquid flows downwards. The extraction takes place under pressure.

EVAPORATION

The thermal evaporation concept includes Falling-Film Evaporators and Rotary Thin-Film Concentrators for the concentration of liquid streams.
The processes are used to increase solids content or to reduce volume by removing water.
Evaporation features either thermal or mechanical recompression ensuring low temperature and short product residence time. The process runs under vacuum and controlled heat without degradation of sensitive products.

FREEZE DRYING

Freeze Drying is a special low-temperature drying method. The liquid feed is frozen, then the 'ice' is broken (or 'granulated') into smaller pieces that are dried on trays or a conveyor by sublimation without melting. This is done in a vacuum chamber using indirect heating by means of radiation with infrared light or microwaves. The evaporated water is condensed as ice.
Due to the low temperature level, the drying is very lenient. Due to the high investment and running costs it is a relatively expensive drying method.
It is used only for high-quality, high-priced products (or products difficult to dry by other methods). Typical examples are: premium coffee-extract, fruit juices and frozen, sliced or cut vegetables.

OTHER PROCESSES

• Freeze concentration: is a new technology for concentrating natural products at freezing points by means of crystal formation and following separation of the ice crystals in a washing tube.
• Filtration: Reverse osmosis (RO), nano-, ultra-, and microfiltration are used for special liquid separation requirements where liquid components have to be separated or solids content increased without any product reduction.
• Homogenisation: results in micronization of fluids under high pressure to form stable dispersions. This is an essential process in the chemical, dairy, food and pharmaceutical industries.