PROCESS AND DEVICE FOR CONDITIONING BULK MATERIAL

• Main Authors: HILLEBRAND, WOLFGANG, HEDERER, HARTMUT, KREFT, MANFRED
• Format: Patent
• Language: English; French
• Published: 22.10.1991
• Edition: 5
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CONVEYING; DRYING; DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM; HANDLING THIN OR FILAMENTARY MATERIAL; HEATING; LIGHTING; MECHANICAL ENGINEERING; PACKING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PNEUMATIC TUBE CONVEYORS; SHOP CONVEYOR SYSTEMS; STORING; THEIR RELEVANT APPARATUS; TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING ORTIPPING; TRANSPORTING; WEAPONS

Bulk material such as lignite, hard coal, peat, waste wood, clarifier sludge, waste sludge, contaminated earth, catalysts, zeolites and filter cake containing vaporizable ingredients, is conditioned by means of a vibrating plate conveyor divided into a heating zone and a drying zone, using an indirect heat exchange. The aim of the process is to condition bulk materials composed of particles of different sizes, ensuring a low energy consumption and minimizing the need for the required equipment. The bulk material is heated in the enclosed heating zone in the presence of the remaining steam pressure and at the final temperature under withdrawal of the vapour from this zone. In the downstream enclosed drying zone, the content of the vaporizable fractions contained in the bulk material is further reduced by indirect heating under the vapour withdrawal. The bulk material is separated several times into coarse and fine fractions, the fines being remixed with the coarse fractions which has a higher water content. The bulk material is mixed several times while being heated in said zones. The device required for the above process is a vertical vibratingplate drier (1) which has a plurality of horizontal double-wall plates (2) and an external enclosure. A particular feature of said device is that some of the plates (6) in the drying section 8 have at least one slotted grid (21) required for separating the fines from the coarse fractions. Said process and device are suitable for drying hydrous bulk material such as crude lignite, the water content of which is reduced from 58 to 18%.