Screw Conveyor for Conveying Wet Sugarbeet Pulp Amalgamated Sugar in Paul, ID

General Description

Amalgamated Sugar began making sugar back in 1898 and is the second largest producer and refiner of sugar from sugarbeets in the United States with over 180,000 acres of sugarbeet farms. Sugarbeets are a sustainable and environmentally friendly crop. Modern agricultural techniques reduce carbon dioxide emissions and produce higher crop yields. Amalgamated sugar is pure sucrose and is not chemically altered or bleached during processing. One teaspoon of sugar contains only 15 calories.

Screw conveyor are used throughout the sugar production process. Amalgamated Sugar had issues with existing screw conveyors at the facility in Paul, ID. Stainless steel screws were fatiguing and failing over time when conveying hot, wet beet pulp. Beet pulp is a byproduct of the process and is used as an additive for cattle feed. KWS worked with Amalgamated Sugar to understand their processes and offer long-term solutions to their screw conveyor problems.

Design Parameters

1. Product Type – Wet Sugarbeet Pulp
2. Material Density – 35 Lbs. per Cubic Foot
3. Capacity – 3,379 Cubic Feet per Hour
4. Duty – 24 Hours per Day, 7 Days per Week

KWS Advantages

Amalgamated sugar was experiencing fatigue failures of screw conveyors made from 304 stainless steel. The center pipe of the screw would fatigue and develop cracks over time leading to eventual failure causing interruptions to production. The main problem was a screw conveyor that received wet beet pulp from a dewatering screen. Since the beet pulp is a byproduct, carbon steel was acceptable for use in the new KWS screw conveyor.

KWS recommended using a larger diameter, heavy-wall carbon steel center pipe with stainless flights for the screw sections. The larger diameter, heavy-wall pipe would much stiffer and resistant to deflection under load. Carbon steel is also much more ductile than 304 stainless steel and more resistant to fatigue.

Special Features

Due to the length of the screw conveyor, one internal hanger bearing was required. Based on other areas of the plant, Amalgamated Sugar chose to use brass for the hanger bearing material. Brass is a unique material for a hanger bearing. Typically, bronze is a more common material for screw conveyor hanger bearings.Since KWS has full CNC machining capabilities, it was not a problem to machine the brass bearing.

Other than the center pipe of the screws, all of the construction of the new KWS screw conveyor was 304 stainless steel for corrosion resistance and ease of cleaning. The covers of the screw conveyor were bolted on 12-inch centers to prevent any leakage and for safety purposes.