Patent ID: 6197093
Filing Date: 2001-03-06
Classification: B01D,Y02A

Abstract:
A method for the purification of waste gas of a drying apparatus of a wood-drying plant, comprising pre-washing, during a first process step, the waste gas in washing water of a washing apparatus having a first washing water circuit to remove predominantly solid matter particles, whereafter subjecting, during a second process step, the prewashed waste gas to an activated sludge treatment including a second washing water circuit to remove gaseous contaminants, wherein the temperature of the waste gas is reduced for the activated sludge treatment in order to reduce its point of condensation by a reduction of its absolute humidity, wherein the pre-washed waste gas is led for said activated sludge treatment through a trickling filter device which is sprayed with sprayed water, wherein the sprayed water is led from the trickling filter device to an activated sludge basin and thereafter recirculated from the activated sludge basin for spraying of the trickling filter device, and wherein the washing water of the washing apparatus is recirculated with a first part amount of the washing water, after leaving the washing apparatus, being led back via a pumping device directly to the washing apparatus and being injected into the washing apparatus by a first pressure, and with a second part amount of the washing water, after leaving the washing apparatus, being led via said pumping device to a solid matter removing apparatus and from there back to the washing apparatus into which it is injected by a second pressure in a finely divided state to increase the surface area of the washing water, the first part amount of the washing water being larger than the second part amount of the washing water, and the first pressure being lower than the second pressure.