The Dieffenbacher SWISS COMBI ecoDry system is a new solution to clean the exhaust of OSB & PB-drum dryers.
The energy generation and the exhaust gas cleaning is combined to completely avoid the VOC’s ( volatile organic compounds ) and the wood dust in the emissions.
As usual, the wet material is fed into the dryer via an airlock. After the dryer the dried material is separated from the exhaust gas stream by means of a cyclone.
The exhaust gas stream is then heated up in a heat exchanger to reach the necessary dryer inlet temperature and returned to the dryer inlet. Approx. 25% of the total air volume is taken out of the loop and fed into the heat energy system.
Besides the steam the dryer exhaust also contains wood dust and VOC’s, which are created by heating up the wood in the dryer. The VOC’s are responsible for the typical smell near dryers and up to now can only be controlled with an expensive RTO.
There the emissions are heated up to more than 850 deg C for at least 2 seconds and thus completely combusted. The hot gases created in the combustion are taken to the heat exchanger to reheat the dryer gas stream. The ash in the exhaust from the combustion can be removed with a electrostatic filter.
The SWISS COMBI ecoDry system solves environmental problems in a very cost effective manner.

• No contact of combustion gas with the flakes or wood particles
• Lower emissions of VOC’s / blue haze
• Lower emissions of CO – carbon monoxide
• Almost complete freedom of odor
• Gentle drying for optimum product quality
• Minimum energy consumption
• High energy recovery potential
• No working costs of a WESP/RTO filter (gas, water, sludge, neutralization)
• Reduces fire and explosion risk due to the steam drying with very low oxygen content
• Less wearing caused by ashes in the dryer
• No ash in the product