Evaporation and Drying


Evaporation and Drying

Gemak design and manufacture falling film and plated type evaporators for the concentration of dairy and fruit juices along with spray dryers for drying and powder (milk and whey) production.


Gemak evaporating plants are designed either as falling film or plated principle depending on the product and required level of evaporation. The number of stages and effects are also determined at the initial requirements stage. It is intended for evaporation of whey and both skimmed and whole milk and fruit juices. 

The plant is of the once-through type which means that the product is concentrated from initial to final concentration while passing through the plant without being recycled which provides for a good quality of the product. The evaporation capacity is determined by the required flow rate, % total solids at the inlet and required total solids % at the outlet. Gemak evaporators are available from 1000 l/h to 30,000 lt/h inlet capacity with an efficiency of increasing inlet dry solids from %8 to %55 at the outlet.

Spray Dryer:

 Gemak designs and manufacture spray dryer models with pressure nozzle atomisation designed to produce powder (milk and whey) with final residual moisture of 3%. The scope of plants includes a feed balance tank to the discharge point of powder from the fluid bed cooler. Feed material enters a balance tank from where it is pumped to the top of the spray dryer (via high-pressure pump) before atomising into a heated chamber.

In contact with the hot air, particles forms and fall by gravity down the inside of the chamber. Moisture is removed from the particles down to 3%. Powder/product temperature from the spray dryer discharge would be 75°C. A vibratory fluid bed then reduces the temperature of the finished powder to less than 30°C. The fluid bed discharge is fitted with a rotary valve.

Provisions are made to start and stop the plant on the water to reduce the possibility of product burn on in the atomiser feed tube. Similarly, an air sweep is employed at the top of the dryer to reduce powder adhesion to the neck of the incoming hot air. Burst membranes are employed for explosion relief ducted to the atmosphere and covered with polystyrene covers for sanitary protection.