SPRAY COOLING
Spray cooling (alternatively spray congealing) is a process by which a melt is formed into particles of spherical shape by spraying the melt into a cooling chamber. The cooling is performed by air introduced at sufficient low temperature. The melt can be atomized or prilled by a rotary atomizer equipped with a special designed wheel, or be atomized by pressure nozzles or 2-fluid nozzles. Spray cooling has applications in the chemical, food, and pharmaceutical industries. It is a convenient method of transforming melted feed stocks into free-flowing particulates of controlled particle size.

Importance of melt properties
When a spray of melt droplets contacts a cool air environment, the melt cools first to the solidification temperature. For a pure substance the congealing then takes places at a constant temperature during release of the product's heat of solidification.

Not all products have a clearly defined solidification point. The phase change may take place over a range of temperature or the product may go from a melt phase to solid amorphous form without the release of all the heat of solidification, since a non-crystalline formation occurs. The droplets may also sub-cool below the solidification temperature. Data on the physical properties of the melt and behaviour during solidification are important to size the cooling chamber, select the method of atomization, and determine whether the cooling should be conducted in cocurrent or countercurrent gas flow. An additional second stage cooling may also be found advantageous.

PRODUCTS

Encapsulated materials Fats Glycerides Hydrates Inorganic/organic melts Quaternary ammonium compounds Fatty acids Waxes

DESIGN SELECTION BASED UPON THE SOLIDIFICATION PROPERTIES OF THE MELT
The most suitable second-stage cooler is a fluid bed supplied with cooled ambient air. Alternatively, a pneumatic transport system with cooled conveying air might be suitable.

Typical products from Nozzle atomization and Rotary atomization

UTILIZING CLOSED CYCLE SPRAY COOLING ENABLES OPTIMIZATION OF COOLING ENERGY REQUIREMENTS AND PRODUCT QUALITY
Plant operation in warm and humid climates will normally require the ambient air supply to the spray cooler to be dehumidified and cooled. To reduce the extra energy consumption involved, it is common practice to recycle the process air, thereby minimizing the load on the dehumidification/cooling unit.

The recycle system is designed to permit a bleed of air from the system, enabling an intake of ambient air in cases, where there is a degree of evaporation associated with the spray cooling. The multi-way damper incorporated in the recycle system also allows the plant to run in open cycle without the dehumidification/cooling unit in operation during the colder and dryer seasons of the year. This reduces operational costs.

PARTICLES

Design selection is based upon particle size requirement, from fine to coarse and extra coarse products.

PLANTS
Over the years we have supplied a number of plants specially designed for spray cooling and / or congealing of various products. The majority of the plants have been specially designed for individual needs of the clients.

It is our intention to meet the special demands and needs in this area of processing .