Patent GB-962409-A (GB)
Title: Pressure seal
IPC: D06B23/18
Filed: 1962-08-21
Abstract: 962,409. Sealing pressure vessels. AMERICAN CYANAMID CO. Aug. 21, 1962 [Dec. 18, 1961]; No. 32124/62. Heading D1L. A pressure sealing device which permits elongate material 21 (e.g. yarn, fabric, rope, film and the like) to pass between two zones maintained at different pressures (e.g. a zone below opening 19 and another above opening 20) comprises a hollow chamber 11 filled with a liquid and containing at least one pair of rollers 23, 24 and 23<SP>1</SP>, 24<SP>1</SP> between which the material passes. The rollers are rotated such that their surface speed is substantially equal to the forwarding speed of the material. In the embodiment shown the bottom wall 17 of the device which is in the form of a flange Has an opening 19 which registers with the inlet or outlet of a pressurized treating vessel in which the material (e.g. a filament of a polymer or copolymer of acrylonitrile) is subjected to e.g.high temperature wet steam. Two pairs of sealing rollers 23,24 and 23<SP>1</SP>, 24<SP>1</SP> are provided, the rollers 23, 23<SP>1</SP> being mounted on stationary shafts 76, 76<SP>1</SP>while the rollers 24, 24<SP>1</SP> are mounted in shafts 41, 41<SP>1</SP> the ends of which are so mounted that the rollers may move towards and away from the stationary rollers along arcs centered on a shaft 61. The rollers 24, 24<SP>1</SP> are urged towards rollers 23, 23<SP>1</SP> respectively by a pneumatic cylinder and piston 50, 51 which acts on the ends of their shafts through a suitable linkage. Sealing shoes 27, 27<SP>1</SP> which co-operate with the rollers 24, 24<SP>1</SP> are mounted on sleeves 36, 35 respectively to be rotatable about the spindles 61, the sleeves being so linked to the shafts 41, 41<SP>1</SP> respectively that each shoe 27, 27<SP>1</SP> remains in the same position relative to its associated roller irrespective of the position of the roller. The shoes 27, 27<SP>1</SP> have curved outer surfaces slidably associated with curved blocks 28, 28<SP>1</SP> to maintain effective sealing during movement of the shoes. Stationary sealing shoes 26, 26<SP>1</SP> are associated with the stationary rollers 23, 23<SP>1</SP> to prevent recesses in the vessel such as those at 98, 98<SP>1</SP>, 104, 104<SP>1</SP> being blocked with waste, liquid is introduced through inlets 99, 99<SP>1</SP>,105, 105<SP>1</SP> and flows outwardly past sealing strips e.g.101,102; liquid is also caused to flow outwardly between the end faces of the rollers and the sides of the vessel. This intake of liquid replaces that which escapes from the vessel through either pair of rollers. The rollers are driven from shaft 61 by a suitable arrangement of gears on the ends of their shafts, the drive to rollers 24, 24<SP>1</SP> being such that it is not affected by their movement. The surface speed of the rollers is arranged to be equal to the linear speed of the material so that the rollers exert no force along the length of the material. Observation posts 115 may be provided and if filamentary material is being worked guide bars 114 are provided to prevent the material running off the ends of the rollers.