Wood chip drying system for drying wood chip and associated method for drying wood chip

Abstract

The invention relates to a wood chip drying system for drying wood chip (18) comprising a furnace (12), a drier (16) for the wood chip (18) and a recirculation apparatus (56) for the recirculation of exhaust vapors (34) into the drier (16), wherein the recirculation apparatus (56) has an exhaust vapor heater (42), and wherein the wood chip drying system (10) is designed to reduce organic compounds present in the exhaust vapor (34) prior to the recirculation into the drier (16). The exhaust vapor heater (42) comprises a regenerative and / or catalytic heat exchanger which is arranged downstream after the drier (16) and which is designed so as to heat up the exhaust vapor (34) to a temperature which is high enough to oxidize at least a majority of particles present in the exhaust vapor (34).

Description

technical field [0001] The invention relates to a sawdust drying system for drying sawdust, comprising: a combustion device, a sawdust dryer and a feedback device for returning residual steam to the dryer, the feedback device has a residual steam heater, The wood chip drying system is configured to reduce organic compounds in the vapor prior to returning it to the dryer. [0002] According to the second point of view, the present invention also relates to a wood chip drying method, comprising the following steps: (a) conveying flue gas from a combustion device to a dryer; (b) drying the wood chips in the dryer to generate residual steam; (c) returning at least a portion of the residual vapor to the dryer. Background technique [0003] Wood dust is usually burned in a combustion unit of known wood chip drying systems, and the resulting hot flue gases are fed into a mixing chamber where they are mixed with steam (also called return steam). The temperature of the resulting dr...

AI Technical Summary

Problems solved by technology

[0013] DE 29 26 663 discloses a method for cooling the vapors so that water and entrained terpenes condense, the disadvantage of which is that the cooling of the vapors is expensive

[0014] WO 01 / 59381 discloses a wood chip drying system that can return a part of the residual steam to the combustion chamber. The disadvantage is that a part of the terpenes contained in the returned residual steam may be deposited on the material to be dried, so that Wood chips have a higher VOC content after leaving the dryer

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