KWS Manufacturing

Conveying Solid Waste at Liquid Environmental Solutions in Houston, TX

General Description of the Application

Liquid Environmental Solutions is the nation’s largest, exclusive, non-hazardous waste collection and recycling company. Waste is collected from a wide variety of sources such as grease traps at restaurants, grit separators at car washes and auto lube facilities, as well as industrial and manufacturing processes. Used cooking oil is also collected for further treatment. The waste is collected by vacuum trucks and transported to fully permitted waste disposal sites where it is processed using industrial centrifuges. The liquids are recycled and the solids separated for transportation to landfills.

The solid waste is very abrasive with a high moisture content. Screw conveyors are used in the existing process for conveying the solid waste from centrifuges to waste containers. The “load out” screw conveyor at the Houston facility, based on the original OEM specifications, was wearing out every 6 to 8 months. KWS worked with a local power transmission distributor, BK Power Solutions, to provide a cost-effective, long term solution to the problems with the existing screw conveyor.

Design Parameters of Application

  1. Bulk Material – Non-Hazardous Waste
  2. Material Density – 40 to 50 Lbs. per Cubic Foot
  3. Capacity – 150 Cubic Feet per Hour
  4. Moisture Content – 40 to 50 Percent Wet
  5. Duty – 16 Hours per Day, 5 Days per Week

Advantages Provided by KWS

KWS reviewed the application with BK Power Solutions and the Customer to determine the exact needs of the plant. Dimensional information was gathered from the existing equipment. The screw conveyor components were examined to determine causes of premature wear and failure. A new design was recommended which would handle their current requirements while providing additional reliability. Based on all the information gathered, KWS performed calculations and redesigned the load out screw conveyor to improve the life of the system.

Special Features of KWS Design

The existing load out screw conveyor was not designed for the harsh application. KWS designed the new replacement screw conveyor with 1/4-inch thick abrasion resistant (AR235) flights welded to a schedule 40 center pipe. AR235 is a special abrasion resistant steel that is much harder and tougher than standard mild steel and typically outlasts mild steel by a factor of 8-to-1. The existing UHMW screw conveyor trough liner was pulling loose and rolling out of the conveyor due to liquid sometimes being present and the abrasiveness of the waste product. KWS replaced the UHMW liner with a weld-in AR235 liner. The new screw conveyor has now been in service over 4 months. A recent inspection revealed no noticeable wear.

Testimonial

"The new KWS screw conveyor with the AR235 liners is performing GREAT! I would like material specifications because we are recommending another plant of ours to use the same solution to our challenging conditions!"

David L. Everett, Vice President Centralized Waste Treatment Plants – Liquid Environmental Solutions

Conveying Solid Waste at Liquid Environmental Solutions in Houston, TX - KWS

Existing Screw Conveyor Was Very Inefficient

Conveying Solid Waste at Liquid Environmental Solutions in Houston, TX - KWS

Existing Flights Were Worn Down

Conveying Solid Waste at Liquid Environmental Solutions in Houston, TX - KWS

New KWS Screw Conveyor with AR235 Liner

Conveying Solid Waste at Liquid Environmental Solutions in Houston, TX - KWS

Transferring Solid Waste to Trailer

Solid Waste

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