Patent GB-356136-A (GB)
Title: Improvements relating to rotary retorts
IPC: C10B1/10
Filed: 1930-02-27
Abstract: 356,136. Rotary retorts for low temperature carbonization. WISNER, C. B., 308, Lawn Ridge Road, Orange, New Jersey, U.S.A. Feb. 27, 1930, No. 6517. Convention date, April 17, 1929. [Class 51 (ii) and 55 (i).] Relates to the carbonization of fuel in rotary retorts and more particularly to low temperature processes as set out in Specifications 217,554 and 275,602, [both in Class 55 (i), Coking &c.], and consists broadly in maintaining a flue velocity for the heating gases of at least 50 feet per second and in subjecting the fuel when beginning to become plastic to an increased heat by reducing the thickness of the fuel layer. The fuel is caused to flow through a rotating container near but not at the temperature for educing hydrocarbons, its flow is then retarded so that there is 5 lbs. per square foot of container wall surface during its softening and plastic stage and at the same time it is subjected to increased heat, and when the coke structure is hard the depth of the coke balls formed is increased to 10-15 lbs. per square foot, the temperature being maintained to remove all the hydrocarbons. Apparatus suitable for the application of the invention is described. The main cylindrical shell 20 contains a plurality of sector tubes 21, spaced apart, inward from the shell, and outward from an axial tube 24 by short angle flange slips 26 and bolts 26a. To the ends of the sector tubes and axial tube are welded radial bars and square plates which close the radial flues 23, the flues 25, and the core tube 24. Truncated cone-shaped extensions 29, 30 are secured to and communicate with the intake and discharge ends respectively of the sector tubes. The retort is rotated on a slightly inclined axis. A stationary hood 35 around the intake end of the retort has a gastight swivel joint 36 with one end of the shell. A short tubular neck 39, having a flange with a gastight swivel joint 42 with the hood 35, is carried by a rim ring 38 secured to the conical extension, and is closed at the intake end by a stationary head 40 having a fuel feed pipe 40a. A discharge tube 30b extends from the end of the conical extension 30 to a stationary discharge spout 46a. Around the discharge end of the retort is a rotary hood 43 attached to the cylindrical shell 20 and opening into a stationary drum 48 around the tube 30b, there being gastight swivel joints at 47, 49, 50. The sector tubes are extended at each end beyond the cylindrical shell, in order that the flues 22, 23, 25 may communicate with the hoods 35, 43. Heating gases are drawn into the chamber 45, through the flues of the retort, and into the chamber 37. In every case where there is a joint, one of the swivel-bearing members is supported by inclined links so as to press against the other member. The intake head 40, as shown in Fig. 6, is supported from below by inclined links 53 with adjustable balls 53<1> moving in bearings 53<11>. Springs act as cushions between the head and the retort. The swivel joint comprises annular flanges 54, 55 around the ends of the stationary and rotary members of the retorts, an intermediate abutment ring 56 having a cylindrical sleeve 57 which telescopes into the stationary member, and a flexible band of asbestos cloth 58 outside the sleeve, secured to the ring and flange by cables 58a. The ring 56 is suspended by inclined adjustable links 53a, so that the machined ends of the ring and flange 55 are pressed together. Coal flows from the intake chamber 29 through the sector tubes to the discharge chamber 30, and thence is conveyed bv lifters 30c and the spiral flange 30d through the discharge neck 30b to the drum 46 and discharge spout 46a. For preheating purposes a temperature of 450-600‹ F. is maintained in the fuel, and for low temperature carbonizing or coal-ball processes, up to 975‹ F. In a modified apparatus, of greater length, the flues are divided into two or more longitudinal sections by a cross partition welded to sectors and shell in the flues 22, 23, 25. An annular drum around the shell is divided by a ring partition into two annular chambers which communicate with one or other of two sets of the flues by slots in the shell. Heating gas may be circulated in the same or different directions. Baffles may be provided in the flues. The crosssectional area of the heating chambers at the ends and middle of the retort is not less than the area of the flues. In making coal balls, the fuel is caused to flow faster during the initial plastic stage until the balls are formed, by providing a spiral flange to act as a screw conveyer in each sector tube, one-third of its length from the intake end, and baffles 65, 66 near and at the discharge ends of the tubes. Specification 255,882, [Class 55 (i), Coking &c.], also is referred to.