Coffee, Tea & Cocoa - Spray drying is the most economic method of
producing soluble coffee.
Niro is strongly associated with the technologies of liquids and solids
processing of instant coffee, tea and cocoa. Our core competences include:
- Extraction
- Concentration
- Centrifugal separation
- Filtration
- Aroma preservation
- Drying
- Agglomeration/granulation
- Powder handling
- Special expertise is offered within the supply of plants for manufacturing
heat sensitive aroma-based consumer products.
For more than 50 years, Niro has been developing its coffee technology, and
great emphasis has been placed on maintaining a leading position within coffee
processing.
More than 160 plants have been delivered world-wide for instant
coffee alone.
The Fast Instant Coffee, or Battery FICTM
extractor The latest double extraction technique features in the
Niro coffee processing system. With this system, water is introduced at two
different stages so as to decrease the overall extraction time while producing
two completely separate extract fractions (aroma and hydrolysis). It is a
continuous process featuring batch operated multi-extraction percolators. With
the design and operation of the double extraction plant, a superior aroma
profile is achieved. This also makes it ideal for canned coffee production.
The total extraction time is 1½ - 2 hours, compared with conventional
extraction systems where the total extraction time is typically 3 - 4 hours.
Concentration of the coffee extract is done in lenient processing
conditions in equipment designed specially for coffee. Technologies available
are freeze concentration, evaporation and membrane filtration.
Lower view of a Fluidised Spray Dryer - FSDTM, producing
spray dried instant coffee
Spray drying is the most economic
method of producing soluble coffee. The feed to the spray dryer is a mixture of
concentrated aroma and hydrolysed fractions, with the preserved aroma
components added. In order to maximize aroma retension, drying of the extract
takes place under conditions that maintain low powder temperatures. Different
types of spray dryers can be used for drying of instant coffee. Bulk density
and colour control is possible by means of in-line gas mixers. Inert gas is
injected into the feed system just prior to the nozzle atomizer used in the
spray drying system.
In cases where spray dried powders require further
agglomeration, an additional process stage is used involving powder wetting,
afterdrying and cooling. Control of weeting is carried out with water and/or
saturated steam in an agglomeration chamber equipped with a rotating impacter.
The agglomerates are then dryed and cooled in the attached fluid bed, followed
by sieving and packing. Fines and oversize fractions are reprocessed within the
agglomeration plant.