50 Kg./hr Polyurethane Foam, Wash, Rinse & Drying Pilot Plant

Argonne National Laboratory has developed a patented process for separating the PUF from the Auto Shredder Residue (ASR), and for cleaning the recovered foam to meet the specifications of the recycle market. The photograph shows the equipment during testing at Argonne prior to the field test conducted in the latter half of 1997. As shown in the picture above, the sized foam is conveyed into a hopper that meters the sized foam into the wash station. The wash station, located between the conveyor end and just on the other side of the two personnel on the steps, consists of two sections. The first section is basically a density separation for removal of heavy tramp from the sized foam. The foam floats and moves into the wash section via solution flow. In the wash section an indexed squeeze conveyor moves the foam forward to the rinse station while compressing and releasing the foam at about 20 cycles per minute. This ensures that any entrained oils and dirt are removed. The rinse station is the same design as the wash section of the wash tank. Clean foam which appears pale can be seen exiting the rinse tank as it is being fed into the linear dryer at the very top right of the photograph. The dryer is also a conveyor system with a series of rollers above the conveyor which compress and release the foam. This type of action is essential to accomplish drying of the PUF in any reasonable residence time. In a conventional rotary dryer, a residence time of about 4 hours is required. In the linear squeeze dryer designed by Argonne, the residence time is about 10 minutes.

The cleaned, dry foam is then conveyed to a horizontal baler to densify the foam for shipment to the customer as shown in figure 3. A horizontal continuous baler is used to produce bales that weigh about 300 pounds with dimensions of 2 feet by 2 feet by 5 feet.