Patent GB-952999-A (GB)
Title: Apparatus for irradiating webs of material, ribbons or threads
IPC: G21K5/02
Filed: 1960-09-12
Abstract: 952,999. Irradiating ribbons or threads. HEBERLEIN & CO. A.G. Sept. 12, 1960 [Sept. 12, 1959; Jan. 30, 1960], No. 31358/60. Heading H5R. An installation for the treatment by electromagnetic radiation of material in the form of ribbons, threads, and the like, comprises guide members for guiding such threads &c. past the radiation source, and a protective housing surrounding the apparatus. The radiation source is constituted by a number of parallel horizontal aluminium tubes 2, arranged closely one above the other in a hollow containing body 1. These tubes contain radioactive material producing X-rays or γ-rays. In the operative position, this container 1 is disposed within a system of rollers over which the threads or web of material to be treated is conveyed (Fig. 4). This system comprises a lowermost set of six driven rollers 30 of hollow steel tubing, arranged in downwardly converging V-formation. Uppermost is a further set of similar driven rollers 32, arranged in a vertical line. Directly above and below the container 1 are two sets of inner non-driven rollers 34, 33, arranged in opposed V-formation as shown. All these rollers are mounted on an iron framework 44. The web of material enters the roller system as shown by entry arrow 6 (Fig. 4) and is drawn over the various rollers as shown, so that it runs six times past each side of the radioactive material container in alternating direction of movement, the runs being spaced only a few millimetres from each other. Finally the web passes over a driven roller 31 and leaves the roller system (exit arrow 6). The irradiation process takes place within a protective concrete housing 9, Fig. 2, having a zinc bromide filled inspection window 11. The housing has in its floor a shaft 8, which can be filled with water, and into which the radiation source can be lowered by a travelling crane 7. The web of material 6 is unwound from a supply roll 16, enters the housing through an angled slot 10 in the wall thereof, and, after passing through the roller system 3, leaves the housing again through a similar angled slot 10<SP>1</SP>, on to a take-up roll 27. When preparing the apparatus for use, the container 1, enclosed in an outer lead enclosure 26, is introduced through a door 20, and carried along by the crane 7 until it can be lowered to the bottom of shaft 8 (position 26<SP>1</SP>). The enclosure 26 is then removed, and the container 1 secured to a support 35 (Fig. 11). The roller system is installed in position, and the web of material drawn through. Finally the support 35 is lifted by a hoist 41 until the container 1 is in operative position within the roller system. In the modification of Fig. 14, the tubes 102 containing the radioactive material are arranged on each slope of a ridge-shaped carrier 101 of triangular section, with a roller system such that the web is carried three times along each slope. In a further modification (Fig. 15, not shown), the carrier 101 is of parabolic section. When the installation is not operating, the radiating member is lowered once more into the shaft 8.