Inclined Screw Feeder and Bucket Elevator for Metering and Elevating Abrasive Materials GMC Roofing

General Description

GMC Roofing & Building Paper Products manufactures the highest quality roofing underlayment and building paper products. Roofing underlayment is used as a secondary weather resistant barrier applied over the roof deck before installation of the primary roofing products. Building paper is designed for installation behind stucco or other exterior wall claddings as a secondary weather-resistant barrier. Both are asphalt-based products that require moderately abrasive specialty materials in the production process.

GMC Roofing contracted Dynamic Industrial Technologies (DIT) to oversee the project, determine equipment layout, and select equipment manufacturers. DIT approached KWS to design a screw feeder to meter material received from hopper bottom trailers to a bucket elevator. The bucket elevator lifts the material from the screw feeder to silos where it is stored before entering the production process. The inclined screw feeder and bucket elevator boot are located in a concrete pit below ground level, which allows trailers to be unloaded quickly and efficiently.

Design Parameters

1. Product Type: Top & Bottom Surfacing
2. Material Density: 80 Lbs. per Cubic Foot
3. Capacity: 1,250 Cubic feet per Hour
4. Duty: Intermittent

KWS Advantages

The KWS and DIT engineering teams collaborated to ensure the screw feeder and bucket elevator would fit within the constraints of the pit. KWS provided a full set of Autodesk Inventor 3D models during the review process to check for design and interference issues. Together, KWS and DIT were able to make adjustments to the incline angle of the screw feeder to minimize the size of the concrete pit. The finalized design allowed significant savings in overall project costs.

Special Features

Both the new KWS screw feeder and bucket elevator were designed for the abrasiveness and duty of the application. The screw feeder was designed with a single-piece variable pitch screw to evenly meter bulk materials from the hopper. To remove a maintenance component, the screw was designed to span the full length of the screw feeder without the use of an intermediate support/hanger bearing. Abrasion resistant AR400 plate was used for the screw flights for enhanced abrasion resistance. The center pipe was oversized to minimize screw deflection and increase torque rating.

Along with the screw feeder, KWS provided a heavy-duty centrifugal type bucket elevator. Since the bulk materials are moderately abrasive, the elevator boot and discharge section were lined with replaceable abrasion resistant AR400 plate for long life.

KWS supplied a specially designed bucket elevator head platform. KWS performed Finite Element Analysis (FEA) on the platform to ensure integrity of design. Head platforms allow access to the drive components and bearings for maintenance. KWS maintenance platforms incorporate handrails, toe boards, and an adjustable OSHA compliant, self-closing safety gate.