AT 10.47 pm., a fire and explosion occurred in a chipboard production plant. Shortly before the event, a switching valve ensuring the uniform filling of a dryer jammed. The wood-chips fed to the dryer were thus unevenly distributed, that is one tube bundle was fed with too much wood-chips whereas the second one was not fed with enough material. Consequently, the residence time of the chips in the almost empty running part of the dryer was too long and the wood-chips overheated forming so-called “smouldering nests” which ignited when fed to vibrating sieves and split up by the mechanical movement. The material damage were evaluated at 0.175 M euros. The protection of the dryers against explosion is assured by permanently maintaining the worm feeders filled, obtained by monitoring the filling level of the bunkers. At minimal level the feeding worm is stopped, maintaining the feeding worm and the silos filled. Blasting waves from or into the dryer are certainly stopped. The filling of the dryer will be effectively checked by remote monitoring of the regulating system. The plant operator is looking for effective fire detection.