PharmTech's monthly newsletter, Equipment and Processing Report, reviews the Editor's Picks for the April 2011 edition from ACS Valves and L.B. Bohle.
Rotary feeder improves conveying efficiency
The ACS Valves Aero-Flow series of rotary feeders is designed to convey pharmaceutical ingredients efficiently. Air enters the feeder through its two endplates. As the air circulates around the endplates, the air pressure increases and prevents the ingredients from getting into the feeder’s seals and bearings.
Air passes through a slot in the bottom of each endplate into the feeder housing and mixes with material being conveyed by the 10-vane rotor. The feeder thus aerates the material and helps it to flow freely. The aeration also helps to keep sticky or abrasive ingredients away from the feeder housing, endplates, and rotor, thus reducing wear on the unit.
In addition, the rotor design prevents material from building up inside the feeder. The precision tolerance of the 10-vane rotor design inside the unit prevents excess air from passing through the valve.
Cone mill increases throughput
L.B. Bohle’s BTS high-speed cone mill has a new impeller design intended to help manufacturers increase throughput by more than 50% on low-density materials, compared with traditional mills. Standard impeller designs consist of a straight bar that relies mostly on its own centrifugal force and the static pressure of the material above. Bohle’s impeller consists of two flat bars curved into the direction of rotation. The curved impeller pushes material into the screen, and this forced movement helps to increase the rate at which the material moves through the screen, says Martin Hack, the company’s vice-president and general manager.
Bohle provides a simple tool to allow users to remove the mill’s screen and impeller. The entire mill head also can be removed and cleaned in an autoclave. The mill is delivered with a mobile, height-adjustable cart that allows the machine to be docked easily with containers of various sizes.