Spray drying involves the atomisation of the dyestuff and pigment feedstock into a spray of droplets, and bringing the spray into contact with drying air. Feedstocks can be in solution, suspension or paste form.

Within this industry Niro offers a broad range of technical solutions and tailor-made applications to meet the specified product property requirements, such as free-flowing characteristics, powder granulometry, low dustiness and redispersion characteristics.

The range of plant concepts includes spray dryers, FSD dryers, IFD dryers, fluid beds for agglomeration / granulation and mechanical granulation.

TYPICAL SPRAY DRIED DYESTUFFS AND PIGMENTS:

Acid dyes Azoic dyes Barium sulphate Basic dyes Cadmium carbonate Cadmium sulphide Calcium carbonate (and Ceramic colorants Disperse dyes Dyestuff intermediates Iron oxide (black, red, yellow)

Kaolin Lead chromate (chrome yellow) Lead molybdate Lithopone Phthalocyanines Reactive dyes related fillers Titanium dioxide Zinc chromate Zinc potassium chromate

The recipe of many dyestuffs and pigments includes hazardous organic ingredients representing risk of fire and dust explosion or environmental pollution due to toxic or active emissions.

Today's environmental restrictions require a more complex design depending on the type of product, powder form, residual moisture content in the final dried product and/or toxicity properties.

Niro has successfully developed and supplied a number of process plants designed to meet the requirements of our customers and the local authorities requirements such as:

• Open, environmentally friendly plants with highly effective components ensuring exhaust of clean process air
• Semi closed plants utilising low oxygen combustion gas as process air
• Semi closed plants, selfinertised and featuring incineration of exhaust air
• Closed cycle concept with Nitrogen purged process gas circuit

Cleaning-in-place (CIP) systems, semi- or fully automatic, are available for all Niro plants.