Stainless Steel Screw Feeders for Baking Ingredients

General Description

General Mills, one of the world’s largest food companies, needed to replace three existing screw feeders that were a constant cause of downtime and excessive maintenance. The existing feeders would get clogged up in the discharge and would require a maintenance worker to beat the outside of the trough with a hammer to get the product to start flowing. They were also having problems keeping product contained in the existing screw feeders. Product leakage created a maintenance headache and reduced process capacity. The different products metered by the screw feeders are ingredients used in baking breakfast cereals, breads, and snack bars.

Design Parameters

KWS Advantages

Engineers at KWS analyzed the problem of product clogging at the discharge of the screw feeders. By designing screws to promote mass flow, the trough loading was reduced at the discharge and the product flowed easily to the next process. General Mills required that the screw feeders be completely sealed and dust tight so no product could escape. KWS utilized a non-split tubular trough design to meet this requirement. The new equipment had to fit within the existing plant layout and there were several obstructions to design around. KWS engineers modeled the screw feeders to directly replace the existing screw feeders in the same amount of space while giving them the dust tight construction required. Since the screw feeders were metering food products, KWS relied on their extensive experience in the food industry by providing completely polished stainless steel screw feeders with food grade shaft seals.

Special Features

One of the screw feeders utilized a right angle drive and needed to bolt to an existing large rectangular hopper flange. KWS designed this special inlet transition to eliminate a potential bridging problem and to fit within the space constraints. The length of each screw feeder was also constrained by existing equipment. KWS was able to incorporate purgeable food grade shaft seals and allow room for maintenance and still fit within the allotted space. Another screw feeder had a special inlet transition from a large diameter down to a long rectangular inlet. KWS was able to make this transition perfectly. Each of the feeders had stainless steel food grade air purged shaft seals on both the drive end and non-drive end to contain the product. KWS polished all product contact surfaces to 180-grit finish. No pits or crevices were permitted since the products being metered were used as food ingredients.