Rotary Feeder for Controlled Metering of Solids to Debut at POWTECH

Although rotary feeders have become firmly established in process engineering for feeding and metering powders and granulars, this does not mean that the possibilities of this technology have been exhausted. For Frewitt, the rationale behind the development of a new rotary feeder lay not only in the continuous feeding of products but also in the capability of fulfilling several other criteria. Hence, increased service life, GMP compliance, process reliability and versatility in use became the stated objectives.   

Product trials demonstrated that the straight design of the blades was not leading to the desired outcomes. A series of test results were ultimately instrumental in the decision to bend the six blades mounted on the rotor axle slightly, in the lengthwise direction of the axle. The advantage being that greater resistance and torque could be achieved.

A special grinding process was used to achieve the Ra 0.4 fineness of the stainless steel surfaces (AISI 316L) contacting the product, thus ensuring a frictionless, residue-free product flow.  

The ProFi-Valve, as Frewitt’s new universal rotary feeder is called, can be easily mounted on the infeed hopper of the sieve mill by means of a Tri-Clamp DN 150 (ISO 2852). The delivery volume is as high as 400 kg per hour at a maximum speed of 20 rpm. Moreover, the operation is exceptionally quiet. The rotor can be dismantled quickly without any special tools. This, plus the modular design, makes cleaning easier. It should also be pointed out that the ProFi-Valve is designed for WIP, CIP or SIP. A mechanical drive, a gear motor with a frequency converter or a pneumatic drive can serve as a drive unit.   

The rotary feeder ensures that the product is gently processed and prevents the mill inlet from becoming stopped up, making the formation of product columns and bridges a thing of the past. The ProFi-Valve effortlessly processes products with very diverse properties (highly adhesive, poorly flowing, abrasive). Customers that process potentially explosive products were also considered and the ProFi-Valve can be equipped for operation in ATEX zones 1/21.

The ProFi-Valve passed every endurance test in the laboratory and in operation, thus fulfilling the criteria for market success.  

Frewitt will present the ProFi-Valve at POWTECH 2013, 23–25 April, Nuremberg, Germany, Hall 1, Stand 442.

Frewitt SA, +41 26 460 74 00, info@frewitt.com, www.frewitt.com.