GB1186091A - Electron Beam Heating Apparatus for Annealing Strip Material. - Google Patents

Abstract

1,186,091. Heat-treating strips. AIR REDUCTION CO. Inc. March 21, 1967, No.13213/67. Heading C7N. [Also in Division H1] In an electron beam furnace for continuously annealing metal strip, the strip 1, Fig. 6, is fed to a vacuum electron beam bombardment chamber 4 through a series of entrance seal chambers 3a, 3b, 3c maintained under progressively higher vacua and away from the vacuum chamber through a series of exit chambers 9a, 9b, 9c, maintained under progressively lower vacua, to a cooling chamber 10 maintained at atmospheric pressure. The various chambers are separated by dynamic roll seals each comprising a roll 14a, 14b, Fig. 9, on either side of the strip 1 with the lower roll 14a rotatable about a fixed axis and the upper roll 14b rotatable about an axis shiftable toward and away from the strip to allow for bumps in the strip. The dynamic seals and the chamber walls are water cooled. The upper roll 14b is downwardly biased by the differential pressure across the seal possibly augmented by spring pressure. In the vacuum chamber the strip passes under rows of electron guns 6, Fig. 6; radiant heaters may also be provided to supplement the electron beam heating. In the cooling chamber 10 the strip passes between opposed chill plates 11 and air or an inert gas, such as argon or nitrogen, may be circulated during cooling. Suitable specific pressures are given for the vacuum and seal chambers and the general pumping arrangement is described. The apparatus is described as useful for the annealing or bright annealing of stainless steel or titanium strip or of refractories.