Inclined Shaftless Conveyor for Conveying and Elevating Industrial Wastewater Sludge

General Description

Clear Path Recycling recycles over 280 million pounds (over 5 billion bottles) a year of PET (Polyethylene terephthalate) plastic bottles. As part of the process, a caustic water wash is used to remove labels and residue from the bottles. Clear Path Recycling uses a very high volume of water and they have a wastewater reclamation process onsite so they can reuse their water or provide suitable water back to their municipality. The resulting sludge from the washing process needs to be removed from the wastewater via a centrifuge. For this project, Clear Path Recycling required a solution for transferring sludge from a decanter centrifuge to a dumpster. KWS designed and manufactured an inclined shaftless screw conveyor to move the sludge from the centrifuge to a dumpster so it could be taken to landfill. The recycling plant is a joint effort by two companies: Shaw Industries, the largest carpet manufacturer in the world, and DAK Americas, the second largest PET resin producer in the Americas. KWS worked with engineers and managers of both companies to provide a successful solution.

Design Parameters

KWS Advantages

Clear Path Recycling contacted KWS after reviewing our qualifications on our website and by emailing a request for quotation to our Engineered Sales department. The KWS website is superior to any other company in the screw conveyor industry and we constantly upgrade the website to provide our customers with the latest and best information. The Customer was so certain of our qualifications and through a past relationship they saw fit to identify KWS as the only screw conveyor manufacturer named in their specification. Because of the high quality and technical expertise evident in KWS products, we are named in many engineering specifications in a variety of industries. KWS manufactures shaftless spirals with a hardness of 340-Brinnell (BHN). The KWS-340 spiral is the most robust and longest-lasting spiral in the industry. Clear Path Recycling wanted a conveyor that would provide a limited footprint on their plant floor and move the sticky, sluggish product effectively. KWS engineers analyzed the existing plant machinery and layout to fully understand the Customer’s concerns, needs and goals. Working closely with the Customer, KWS was able to provide a successful and effective shaftless conveying solution.

Special Features

KWS engineers designed a special 9-inch diameter shaftless screw conveyor about 27-feet long on a 15 degree incline to obtain the proper elevation to discharge to the dumpster. The KWS-340 shaftless screw conveyor was the best option to convey damp, abrasive and sluggish sludge from the centrifuge. The KWS shaftless conveyor design has the advantage of having tight clearances so all the sludge could be fully captured and conveyed with very little left behind. KWS engineers selected 316-stainless steel for the materials of construction because of the high acidity present in the sludge. The conveyor was also designed with a spray nozzle system so the conveyor could be flushed with cleaning solution. The unit was also equipped with an emergency pull cable stop system as a safety device. The drive unit for the inclined conveyor was sized for upset conditions to prevent stalling under heavy load. KWS provided all necessary connecting chutes and structural supports so the unit could easily interface with adjoining equipment and be installed very easily. KWS engineers modeled the system in 3D Autodesk Inventor making it very simple to provide structural load locations and values for the Customer’s installation crew.