Precision Blending International’s business consisted entirely of blending and milling dairy powders for food and dairy products until 2010, when a customer asked the company to produce an agglomerated blend of finely powdered raw material to improve its processability in food formulations. “Agglomeration was new for us and required a third process line,” says Dan Carlbom, owner and president.

While the opportunity meant more business for Precision Blending International (PBI), it also presented the challenge of fitting a new line, including equipment to moisturize, agglomerate and dry the material, in a 27,000-sq.-ft. plant. The process line involved a fixed length of machinery and, therefore, limited size options for the drying equipment at the end of the line.

Carlbom decided a fluid bed processing system would work most efficiently. He had two options. One was a conventional rectangular fluid bed dryer, which would have taken up a large amount of space due to its shape, structural elements and weight. The other was a circular fluid bed processing system, which could dry the resized protein powders efficiently and, with a 60-in. diameter, would take up far less floor space than a rectangular fluid bed system. He purchased the circular unit from Kason Corp.

Because the circular fluid bed processor is inherently more rigid than rectangular designs, the materials of construction can be downgauged, internal cross braces eliminated and gyratory motors downsized. Fewer weld seams and the absence of corners and internal cross braces also facilitate faster cleaning and changeover times.

The circular fluid bed processor can be integrated with a heater, blower, ductwork, spray line and control panel on a caster-mounted frame, allowing in-plant mobility and rapid setup.

The circular fluid bed processor at PBI is configured to moisturize, agglomerate and then dry the powders. Dairy proteins arrive at the plant in bulk bags and are discharged into the process through a grate that removes oversized agglomerates and foreign material.

Material enters the fluid bed processor through an intake port on the top of the unit via an auger feeder and rotary valve. The heater, blower and ductwork route hot air upward through the enclosed circular screen on which the continuous airflow and vibration separate and fluidize individual particles, maximizing the surface area of the material. The vibratory motion of the processor also conveys the material along a defined pathway for uniform processing on a first-in/first-out basis.

Liquids are added to the airstream at timed intervals to moisturize and agglomerate particles, and impart desired flow characteristics. “The powder starts out very fine, almost like talcum,” Carlbom says. As it moves through the process, the particle sizes increase, improving flow and solubility.

The hot air then dries the material to a preset moisture level. Once dry, the granules exit through the discharge port onto a conveyor, which transfers them to a packaging line for loading into 15 or 20kg bags. The process is continuous, although throughput varies by product. PBI has set points for different types of powder; process rates vary from 500 to 2,000 lb. per hr.

PBI purchased the fluid bed processing system from ABM Equipment Company Inc. of Portland, OR, a Kason representative. “Kason provided PBI with a laboratory unit for onsite testing, which confirmed our decision to order the larger unit for full-scale production,” says Carlbom.

He adds that the unit works reliably and meets a demanding production schedule of 12 hours per day, five to six days per week.

For more information: Henry Alamzad, Kason Corporation, 973-467-8140,