| 摘要 |
The aim of the invention is to obtain larger granules with reduced residual moisture during the drying of sticky sludge that is difficult to dewater, with low expenditure in terms of equipment and energy. To achieve this, a centrifuge is integrated into a dryer housing of a combined dewatering and drying device, in such a way that at least the solid dropping zone of the centrifuge lies directly in the dryer housing and after multiple deflections, the moist particles of the centrifuged solid spray-mist from the centrifuge, which are spatially well distributed, collide directly with the dry particles of the surrounding circulating fluidised bed. The residence time in the spray zone of the particles that are enlarged by agglomeration granulation and are simultaneously dried is adjusted by the speed of the heating gas. The flow of the heating gas is influenced in a targeted manner by guide and impact elements that are installed in the dryer chamber, in order to cause a uniform distribution of solids and gas, to prevent dead space and to guarantee an intensive contact between the heating gas and the moist, continuously enlarging solid particles. According to the invention the mechanically pre-dewatered and finely dispersed, moist sludge particles are uniformly distributed in a continuous process in the drying gas containing solids and are thus prevented from making premature contact with the dryer walls, the fine dry particles are enlarged by agglomeration granulation and the centrifuge dryer remains free of incrustation even in the presence of sticky products, without back-mixing or pre-treating the sludge. |
