GB1333319A - Apparatus for heating fluent solid materials - Google Patents

Abstract

1333319 Rotary drum dryers; heating granular material H BRANDT and A KRITZLER [trading as APPARATEBAU ROTHEMUHLE BRANDT & KRITZLER] 23 Dec 1971 [28 Dec 1970 20 Aug 1971] 60163/71 Heading F4G and F4U Apparatus for heating (e.g. drying) pulverulent rock material comprises an inclined stationary array of heating tubes 1 supplied with heating medium and surrounded by a rotatable drum 4 provided with longitudinal lifting blades 19b, material being fed in at the top of one end of the drum 4 and discharged at the bottom of the other end, the longer leg S2 of each blade 19b extending radially or up to 30 degrees from the radius of the drum 4 and two (or three) shorter legs Sl, Z extending from the longer leg S2. The tubes 1 are lenticular in cross-section, and are supported in a rectangular pattern by being fastened to end walls 2 of end caps 3 and having each alternate row of tubes supported by crosspieces 70, so as to promote vibration. The rotatable drum 4 is sealed to each stationary end cap. 3 to prevent escape of hot gases by sealing rings 51, 52 biased together by a spring 62, and an expandible sleeve 65. The flange ring 53 is prevented from rotating by three rods ball-jointed to the flange ring 53 and the end cap 3. The sealing rings 51, 52 are replaceable, and stops limit their wear. The apparatus is mounted on the chassis of a semitrailer. The bogie of the chassis is removable so the chassis is supported on jacks for inclining the apparatus to between 3 and 8 degrees. The drum is rotated (at between 5 and 9 r.p.m.) by a chain drive from a gear unit driven by an adjustable V-belt drive from an induction motor. In another embodiment, Fig. 15, an automatic burner 87 is arranged on a burner muffle 88 connected via a mixing chamber 89 with the gas inlet to the drum 4. Freshly combusted gases are mixed in the chamber 89 with exhaust gases drawn from the gas outlet duet 97 and recirculated by fan 95 through ducts 93 and 92. A perforated metal plate 90 assists mixing and shields the tube array from the burner. Material is fed in at 15 and discharged at 16, the drum 4 being inclined downwards from 15 to 16. The sealing rings 51, 52 are shielded against the ingress of material by short cylinders disposed within the rings 51, 52, the cylinder at the material inlet end being secured to the end cap 3 and projecting into the drum 4 while the cylinder at the material outlet end is secured to the drum 4 and projects into the end cap 3. In the annular spaces between the cylinders and the drum 4 and end cap 3, one or two rings or helical sealing members are fixed to the drum 4 and end cap 3. The helical members urge material away from the sealing rings 51, 52.