Screw Feeder to Meter Ingredients for Animal Feed Blocks

General Description

Animal feed blocks are consumed by livestock and provide essential nutrients, vitamins, and supplements needed for healthy, productive animals. The block supplements use a combination of dry and liquid ingredients in a highly specialized manufacturing process.

The dry ingredients, including but not limited to, dried distillers grains, minerals, and vitamins, are pre-mixed in this unique manufacturing process. The pre-mix is then discharged from a batch mixer where it must be conveyed horizontally and elevated by an inclined screw feeder to a block forming line.

An animal feed block manufacturing company had an existing screw feeder in place; however, this screw feeder was undersized for the current production rate causing a bottleneck in production. KWS was contacted to engineer and manufacture a new screw feeder capable of handling the increase throughput. KWS has provided screw feeders for thousands of similar applications and easily met the requirements.

Design Parameters

1. Product Type: Mix of Dry Granular Ingredients
2. Material Density: 45-60 Lbs. per Cubic Foot
3. System Capacity: 890 Cubic Feet per Hour

KWS Advantages

Because there was an existing screw feeder in place, the end user wanted to keep the number of modifications required to other existing equipment and structure at a minimum during the upgrade. KWS engineers traveled to the plant to view the existing screw feeder, observe the plant layout, and gather critical dimensional information that would be needed to design the new screw feeder.

The upgraded KWS screw feeder was larger in diameter than the existing screw feeder in order to meet the increased production demands. KWS collaborated with the contractor and end user to ensure that the larger screw feeder would fit in the existing space. KWS provided detailed drawings so that any modifications to the existing equipment and structure could be made ahead of the screw feeder’s delivery which aided in a shortened installation schedule.

Special Features

Approximately every two days the old screw feeder had to be shut down to remove buildup of bulk materials from the screw flights. This perpetual downtime was another key contributing factor for screw feeder replacement. As a solution to the buildup and constant cleaning issues, KWS polished the screw welds, pipe, and flight surfaces to a 150-grit (42 Ra) finish. The polished surface finish increases the release properties of the steel and eliminated the buildup problem on the screws.

The new KWS inclined screw feeder utilized UHMW trough liners to reduce the clearance between the screw flights and trough/housing. The reduction in clearance minimized bulk material fall back caused by gravity and increased the efficiency of the screw feeder. The UHMW liners also have a very low coefficient of friction and any sticking of bulk materials in the trough was eliminated.