Spray Drying Spray Drying of Foods and Pharmaceuticals – A Process Worth the Powder
More than just instant coffee — Spray–dried powders are widely used throughout the food and pharmaceuticals industry. While these products are easy to use, the required processes are actually quite challenging: Production methods have to be efficient, easy to handle and fully hygienic. Therefore, plant operators will have to take a closer look at the properties of spray dryers…
Processes for pharma, food and nutraceuticals have to deal with sensitive and delicate materials. Furthermore, facilities have to meet regulatory and hygienic requirements while providing the necessary cost effectiveness. Summit Custom Spray Drying is a specialist for these difficult jobs: The GMP-compliant, FDA-registered facility produces powdered solid particles from solutions, slurries and emulsions for customers in lifescience, nutrition and pharmaceutical industries — be it flavours, fragrances, cosmetics, nutraceuticals or pharmaceutical grade materials.
To make sure that all particles meet the tight tolerances of the demanding customers, Summit uses a Kason vibratory screener. “When fully operational, three spray dryers will produce several hundred different spray dried powders for diverse customers,” says Kevin Kimmick, Summit Custom Spray Drying Director of Process Technologies. “Runs can be small as pilot studies, to as large as 68,100 kg at the production level for a major firm.”
Devleoping Spray Drying Processes for Sensitive Materials
“Although spray drying is based on scientific principles, our test procedures enable us to determine and control optimum conditions according to numerous variables,” he says. Before accepting an order for a new material, the company performs laboratory and pilot plant tests with the customer's raw materials and formulae. “This allows us to determine whether or not we can effectively spray dry the material,” he explains. “It also helps us to develop a cost estimate for the process. If the results of the tests are favourable, we transition directly into production.”
A typical order begins with the delivery of the raw materials which are then emulsified, if necessary. A feed pump metres the solution into the spray drying chamber, where solids and liquids are separated. “All the action happens in the vicinity of the atomiser, whether it is a centrifugal wheel or a nozzle,” Kimmick explains.
“Selecting the proper equipment and determining the optimum settings and adjustments are the keys to successful spray drying. For example, various sizes and configurations of the spray nozzle can be selected to control particle size and density. When choosing process temperatures, you need to strike a fine balance between overheating the spray particles and having them stick on the wall of the dryer.”