GB794292A - Improvements in or relating to the manufacture of glass - Google Patents

Abstract

794,292. Glass manufacture. PENBERTHY, H. L. March 9, 1956 [March 9, 1955; May 3, 1955], No. 7480/56. Class 56. In the treatment of molten glass, gas bubbles 34, 36, 38 are released from at least three spaced points 26, 28, 30 in the floor 24 of the container, the points forming a closed configuration so that the streams of bubbles rising therefrom co-operate with one another to produce a steady rising stream 40 of glass which fans out at 42 and continuously breaks the surface of the molten glass. Fig. 3 shows the points at the corners of a triangle ; when more points are used they may be arranged at the corners of a square, or at the corners and within polygous, or around the circumferences of concentric circles of different radii. The points are preferably spaced from one another by a distance equal to approximately twice to four times the diameter of the bubbles at the time of their release. The bubbler tube may be of an erosion-resistant refractory e.g. zirconium aluminate which may extend into the glass or it may be of metal e.g. platinum or molybdenum which may terminate flush with the base of the glass container which may then be formed with a refractory insert around the tube. The tube may have a cooling jacket and may be provided with a heating chamber to facilitate the removal of the tube from the container by melting the glass in the annulus in the base around the bubbler tube.