SE313243B - - Google Patents

Abstract

1,124,966. Rollers. WIGGINS TEAPE RESEARCH & DEVELOPMENT Ltd. 15 Sept., 1966 [11 Nov., 1965], No. 47953/65. Heading F2U. In a heating or cooling, rotatable, hollow, heat-exchange cylinder in paper making, textile and plastics materials processing machines, the peripheral temperature is controlled by a circulating heat exchange fluid, e.g. a vapour, gas, liquid metal or liquid such as oil, at least in part applied to the interior surface of the cylinder via axially spaced delivery conduits 16 communicating with a common supply conduit 10 coaxial with the cylinder, and the rate of flow through the delivery conduits is controlled by valves 18 included one in each delivery conduit and controlled by adjusting means traversed lengthwise interiorly of the cylinder into register with any one of said valves. As shown, the cylinder comprises an outer shell 1 and an inner shell 7, the space between which is divided into communicating circumferentially extending passages. The passages may be parallel circular passages provided with intercommunicating ports or the passages may form a helical passage continuous from end to end of the cylinder or, as shown, helical passages 5 of opposite hand and continuous from opposite ends to the centre. The passages are formed by internal webs 2 secured to or integral with the shell 1 and tapered pieces 4 clamped by screws to the shell 7. Brackets 8 secured to the cylinder ends are mounted for rotation with a hollow shaft 9 which houses nested supply and main return conduits 10, 11 connected, via a rotary union 14, to supply and return pipes 12, 13. The rotary union for the pipe 13 may be disposed at the opposite end of the conduit 11 to that shown. Fluid is supplied from the supply conduit to the passages 5 through a central main duct 15 and through delivery conduits provided respectively with a valve 17 and the valves 18. Return conduits 19 co-operating with corresponding delivery conduits each connect the passages 5 with the main return conduit 11 and are provided with valves 20. Fluid not removed through the conduits 19 returns to the conduit 11 through return ducts 21. In the case of a single continuous end-tooth-end passage, main and return ducts 15, 21 are disposed at opposite ends of the cylinder. The valves 17, 18, 20 are operated by traversing valve operating gear, one form, Fig. 6, being described below. The shell 1 is “ inch to ¢ inch thick for small paperdrying cylinders or 1 to 2 inches thick for " MG " paper-drying cylinders, and is of copper, copper alloy, aluminium, or aluminium alloy. By flow regulation the temperature of the cylinder along its length may be controlled, and, to reduce restriction to heat flow in a boundary layer, e.g. a condensate film, turbulence may be provided in the passages 5. In Figs. 4, 5 (not shown), the supply conduit 10 is housed in a stationary hollow shaft 9. The cylinder comprises a thin shell provided with end plates and is rotatable about the shaft 9. The delivery conduits 16 extend through the shaft 9 and have portions (16a) substantially concentric with the interior surface of the shell 1 and provided with series of nozzles (16b) disposed close to and directed towards said interior surface. Delivery conduit valves 18 are operable by the traversing gear. Return fluid is collected in the bottom of the shell and removed by a pump through a pipe coaxial with the supply conduit 10. The velocity from the nozzles (16b) is such as to break down any boundary layer. A traversing valve-operating gear, Fig. 6, for the above embodiments comprises a worm 38 axially slidably keyed on a shaft 26 journalled in arms 28 which are rockable about a lead screw 24 journalled in the cylinder end plates 22. In operation, the screw 24 is rotated through a gear 25, as by a reversible electric motor, to align the worm 38 with a selected one of valvecontrolling worm-wheels, a lever 29 is actuated by air cylinders or solenoids 30 to rock the shaft 27 about the lead screw to mesh the worm with the selected worm-wheel and the shaft 26 is rotated through gears 34, 32, 31, as by a reversible electric motor, to adjust the selected valve.