Screw Feeders and Hoppers for Storing and Metering Silica Sand Nucor Steel in Plymouth, UT

General Description

Specialized Analysis Engineering (SAE) is an engineering firm dedicated to design and automation processes for various industries such as automobile, oil and gas, aerospace, food processing and steel making.

Specialized Analysis Engineering had a very specific application for storing and metering silica sand at a local Nucor Steel facility in Plymouth, UT. Bulk bags of silica sand were brought in to the facility and needed to be metered at a precise rate into the process. The sand was used at the end of a furnace melt cycle to create a slag plug in the crucible discharge. The sand plug stops the flow of molten metal. KWS designed and manufactured two bulk bag unloading hoppers with integrated screw feeders as part of a larger bulk material handling system and automation process for Nucor Steel.

Design Parameters

1. Product Type – Silica Sand
2. Material Density – 85 to 90 Lbs. per Cubic Foot
3. Capacity – 540 Cubic Feet per Hour
4. Service – Intermittent

KWS Advantages

Using 3D modeling techniques, engineers from SAE and KWS collaborated to determine the ideal solution for the application. 3D models of the furnace area were created with all the equipment exactly located. Maximizing the available space was very important to Nucor Steel as well as allowing access to each piece of equipment for maintenance. KWS has worked on hundreds of similar projects utilizing screw feeders and hoppers, making possible the success of the project.

Special Features

KWS provided two heavy-duty screw feeders with hoppers to Nucor Steel. Each screw feeder accurately metered the sand by utilizing a variable-pitch screw design. The pitch of the screw varies from shorter to longer as the screw progresses toward the discharge of the screw feeder. The variable pitch configuration allows the inlet section of the screw to have more available volume for addition of silica sand from the hopper. The screw flights were constructed from abrasion resistant AR400 steel for increased service life, reduced downtime and overall lower cost of ownership.

The hoppers were constructed from carbon steel and designed to hold approximately 50-percent more than a typical bulk bag. As bulk bags are lowered over the hopper, razor sharp bulk bag breaker bars contact the bottom of the bulk bags, cutting open the bags and discharging sand into the hoppers. With the KWS commitment to customer safety, wire mesh safety screens were welded to the inlet areas of the hoppers, preventing possible exposure to personnel. Also, integral to the hoppers were heavy-duty support structures and lifting lugs for easy movement.