GB176614A - Improved method of and apparatus for drying or otherwise treating sheet material - Google Patents

Abstract

176,614. Minton, O. Feb. 1, 1921. Drying materials in long lengths.- A method of sealing the inlet and outlet openings of a vacuum chamber through which sheet material is passed to be dried or otherwise treated consists in forcing a fluid such as mercury, water, air, or steam, which has no deleterious effect upon the material, through the openings under sufficient velocitv to prevent admission of air into the chamber. Fig. 1 shows the method applied to apparatus for drying paper in which the web of paper is passed between felts 8, 9 over heated rotary drums 2, 3 within the vacuum chamber 1. The inlet seal comprises a housing 11 containing the fluid and communicating through a passage 13 with the chamber which is connected by a pipe 31 with a barometric seal 30. The fluid is circulated through the housing and seal by a, pump 34 actuated by a motor 35 to maintain a low level of fluid in the chamber. The outlet seal comprises a housing 14 containing the fluid and formed with nozzles 41 communicating through a narrow passage with an enlarged opening 46, the fluid being circulated through the nozzles and housing by the pump 43. In a modification, the inlet and outlet seals comprise a combination of those previously described. In another arrangement, the passage 51, Fig. 5, is formed with nozzles 52 through which the fluid is circulated by the pumps 55 which are driven through gearing 69 from a motor 67. In a further modification, the passage 75, Fig. 6, is formed with nozzles 76 and enlargements 82 through which the fluid is circulated by the pumps 80. In a further arrangement, the seal is vertical and is maintained by the static head of fluid in the housing 110, Fig. 8, the addition to the circulation of the fluid by the pump 120.