That’s where the water bath classifier or stationery trommel with water bath (float tank) comes in (see photo above).

The brand we’ve used is a Wittco stationary screening plant with a 6000 gallon water bath. As shown in the photograph, the process begins at the hopper.

A mix of wood and rock (dirty material) is loaded into the hopper. A conveyor, or feed belt then carries the product into a 28 foot long trommel screen which rotates. Different size screens can be installed into the trommel and the screens which are located at the bottom of the trommel determine the size of the product that is produced. As the wood, dirt and/or rock products pass over the screens, that which is small enough drops through, and the large pieces of wood and rock are carried through the trommel and drop into a 6000 gallon water bath (float tank).

The water bath which is attached to the trommel encompasses two conveyor belts which are partially positioned beneath the surface of the water. The wood will float, be picked up by the upper conveyor (wood belt -see photo on left), carried out of the bath and disposed of in front of the classifier. The rock and/or heavily saturated wood products will sink to the bottom of the bath and will be carried out by the lower belt (rock belt -see photo on right) and dispensed to the rear of the classifier (behind the bath).

The wood which is expelled from the bath can then be picked up with a piece of machinery, taken back to the tub or horizontal grinder and be reground into wood chips. The rock can often be reused in other parts of the recycling operation, or be sold.

The classifier runs on either a diesel or electric powered engine. The controls for the trommel are located in a tower directly across the bath in line with the trommel. In the event any product gets hung up inside of the trommel, the classifier operator can stop the trommel with the flip of a switch.

The classifier can also be used for blending products such as compost and topsoil, creating a topsoil blend enriched with nutrients. It’s perfect for resizing bark products, as well.

In our wood recycling operation, learning how to separate wood from rock involved a lot of experimentation until we purchased the stationary classifier with trommel and water bath (float tank). Not only did our production increase, but we were able to reduce labor and heavy equipment costs, plus eliminated all other screening equipment.

Need more information on the Wittco trommel with flotation tank? Just drop a comment or use the contact form.

As mentioned in  “What Can Be Recycled”, the wood products that are recyclable are tree branches, brush, stumps, small trees, and clean scrap wood from new construction. Some wood products that are the result of a building being demolished can also be ground up and recycled.* Larger trees are usually limbed and sold as timber** or cut up for firewood.

*Although many of these products can be recycled and/or reused, great care must be given to the handling of hazardous materials which may be generated from demolition jobs. Hazardous materials can include surfaces covered in lead paint or mold, asbestos, wood products treated with preservatives and/or containing glue, just to name a few. Hazardous material must be disposed of in accordance to local, State and Federal laws.

**When cutting down trees which will be sold for timber, check with your local US Forest Service for their reporting requirements. Timber that is sold to others may be subject to a Federal (and possibly a State) timber tax. If in doubt, consult your attorney.

When new construction, land developing and/or the demolition of buildings occurs, wood wastes are generated.

Common wood waste would include:

Tree trimmings, branches, stumps, and the logs, themselves

Pallets or wooden shipping containers

Scrap wood from new construction, such as 2x4s or plywood

Wood products generated from the demolition of older buildings.*

*Although many of these products can be recycled and/or reused, great care must be given to the handling of hazardous materials which may be generated from demolition jobs. Hazardous materials can include surfaces covered in lead paint or mold, asbestos, wood products treated with preservatives and/or containing glue, just to name a few.