On-line viscometer maximizes yield in spray-drying process
An on-line process viscometer from Hydramotion Ltd. is reducing losses and maximizing yield in the production of milk powder at the H.J. Heinz plant in Kendal, Cumbria (U.K.).
Milk powder is produced by the process of “spray drying,” which is widely used in the food industry for making products as diverse as baby foods, coffee and soup mixes. The process involves:
Pre-concentrating the liquid improves the efficiency of the relatively expensive drying stage and thereby increases productivity. The liquid product concentrate is pumped to the atomizer, which reduces the liquid to a spray of droplets of a controlled size, generally from 10 to 500 micrometers depending on the type of product. The droplets are sprayed into a stream of hot gas, which is usually dried air, unless the liquid is oxygen-sensitive or a flammable solvent such as ethanol, when nitrogen is used. The tiny droplets lose moisture very rapidly in the drying air, after which the dry powder is separated from the moist air in cyclones by centrifugal action.