Screw Feeder and Conveyors for Alternative Fuel System

General Description

Sawmills produce a large amount of sawdust and scrap as standard board sizes are cut from logs. Many mills choose to use these wood byproducts as an alternative fuel source, ensuring that every portion of a log is utilized without waste. Heat generated from burning wood byproducts can be routed to a number of areas within the plant.

One common use for wood byproducts in a sawmill is fueling kilns to dry freshly cut lumber to desirable moisture levels. Without the use of a kiln, cut boards are dried under varying ambient conditions leading to inconsistent drying. This results in board warpage, and ultimately, increased scrap rates.

With sawdust in abundance, the sawmill needed a method to convey it into the kiln. The sawdust is gathered and stored in a bin equipped with a walking floor. KWS designed, manufactured, and delivered a conveying system to feed the kiln.

Screw Feeder is Designed with Additional Torque to Handle Head Load of Material

Design Parameters

Product Type: Sawdust
Material Density: 10 to 30 Lbs. per Cubic Foot
Conveyor System Capacity: 400 Cubic Feet per Hour
Duty: 24 Hours per Day, 7 Days per Week

KWS Advantages

The existing walking floor discharged a large volume of sawdust at once, completely filling the screw feeder with a head load of material approximately 10-feet high. KWS designed the screw feeder with additional torque to handle the head load and sheer through the bulk material and discharge as intended. The drive unit was sized to handle the worst-case conditions. Similarly, each transfer screw conveyor was designed with a torque rating that exceeds full motor torque by a factor of 5-to-1 to remove the risk of mechanical failure.

KWS Special Features

KWS provided a very economical solution by utilizing CEMA stock components where possible. The screw feeder was engineered for the application using variable pitch flighting to evenly meter the sawdust from the hopper and walking floor.

Each of the transfer screw conveyors utilized heavy duty helicoid screws with continuous welds on both sides of the flights for added strength. Stock formed flange troughs were chosen to create a very cost-effective, dust tight system. KWS keeps a large inventory of stock CEMA standard screw conveyor parts that are available for immediate shipment.