High Capacity Screw Feeder for Mississippi Lime Ste. Genevieve, MO

General Description

Limestone is a sedimentary rock consisting of high levels of calcium, magnesium carbonate, and dolomite. Limestone is mined from quarries and underground mines all over the world. Lime products are derived from heating limestone at very high temperatures. The heating process is called calcining. Quicklime is created during the calcining process. Water can be added to quicklime to create hydrated lime. Building materials, cement and concrete, aggregate for the base of roads, white pigment or filler in products such as toothpaste or paints, are just a few many different applications for limestone and lime products.

Being such a diverse and multi-purpose product, the demand for lime products is huge. Mississippi Lime operates the largest lime facility in the Americas and mines some of the purest limestone reserves in the world. Mississippi Lime supplies a variety of lime products including high-calcium quicklime, hydrated lime, and calcium carbonate products.

In order to keep up with this high demand, Mississippi Lime is always upgrading conveying and processing equipment. KWS has worked with Mississippi Lime for over 25 years by providing heavy-duty equipment to meet application requirements. KWS recently provided a mass-flow screw feeder for metering granular lime from storage to further processing.

Design Parameters

1. Product Type: Granular Lime
2. Material Density: 55 to 60 Lbs. per Cubic Foot
3. Capacity: 7,272 Cubic Feet per Hour
4. Duty: 24 Hours per Day, 7 Days per Week

KWS Advantages

KWS engineers recreated the existing equipment using 3D parametric modeling. Mississippi Lime wanted the new KWS screw feeder to be upgraded in design with the expectation that the lifespan would greatly increase. KWS is unique among equipment manufacturers and able to utilize finite element analysis (FEA) to perform stress loading on the screw feeder and identify areas with a higher tendency to fail. With engineering analysis complete, KWS provided a superior design that would last an extended lifetime over what Mississippi Lime was expecting.

Special Features

The new KWS screw feeder utilized extra heavy-duty construction to withstand the large capacity requirements. The screw feeder was equipped with a 125-horsepower motor in order to handle full 100-percent trough-loading over the full length of the unit. The drive and intermediate shafts were designed to handle the tremendous torque output of the drive unit. The feeder section utilized variable pitch in order to meter and convey the limestone accurately from the hopper above.

Due to the long length of the screw feeder, an intermediate hanger with additional support features was designed to handle the weight of the long spanning screws and was equipped to account for thermal expansion presented by the 200-degree F lime.

KWS shaft guards were also supplied with the equipment to accommodate MSHA guidelines for safety. The screw feeder was equipped with a zero speed sensor to monitor for low or zero speeds of the screw.