GB985052A - Apparatus for producing fibres of glass and like heat-softenable mineral material - Google Patents

Abstract

<PICT:0985052/C1/1> In the formation of glass fibres by centrifuging a molten glass from a rotating spinner with a perforated wall concentric with the axis of rotation, a burner disposed within the spinner comprises a part annular shaped combustion chamber having a peripheral wall concentric with the perforated wall of the spinner, the wall having a restricted orifice from which the hot gases of combustion are projected towards the inner face of the perforated wall of the spinner. The stream 16 of molten glass from the foreheater 10 of a melting tank is fed by a blower 142 through a cooled tube 140 with an elbow portion 144 to direct the glass on to the perforated wall 44 of a spinner 42. The tube 140 is offset from the axis of the rotor which also includes a sleeve 40 of slightly larger diameter than the spinner 42 and to which the spinner 42 is removably secured by a band 100 and a keeper ring 110. Driving members 120 are retained in connected assembly with band 100 and spinner 42 by pins 138 on an annular member 130. The rotor is positioned in a housing 26 supported on the main frame 30 and having a liner 36 of brass or bronze. The rotor sleeve 40 is formed with an outwardly-extending flange 48 with a flat surface 50 in which are a large number of semi-circular recesses 52. The upper surface 54 of housing 26 and liner 36 is similarly shaped and the two surfaces 50, 54 converge at an angle of about two degrees at the outer line of contact 60, and there is a clearance 62 between the rotor sleeve 40 and the liner 36. The rotor is supported by a film of gas or fluid under pressure supplied to the clearance 62 through vertically spaced chambers 64, 66 and 68 and passages 76, 78, 80 from pipes 70, 72, 74 and is also rotated by the same fluid from chamber 64 passing upwardly through passages 82 which are arranged at an angle of about 45 degrees to the axis of the rotor so that the fluid is directed into the recesses 52. The burner 180 comprises a circular housing 182, inside and on the same axis as the rotor sleeve 40, cut away to accommodate the glass feeding tube 140 and provided with a mixture of fuel gas and air through pipes 196, 194 and 188. The mixture passes through a disc-like passage 218 and small passages 216 to the combustion chamber 210 which has an undulating orifice 226 through which the gases escape to impinge over the whole height of the perforated wall 44. The filaments 47 may be attenuated by a blast from annular blower 232 or alternatively the spinner may be rotated at such speed as to provide fine fibres. A radiant or flame heater may be provided outside the spinner to heat the fibres as they emerge. Such a heater may also be incorporated in the arrangement shown. The fibres are formed into a beam which is collected on a conveyer and, in passing through a hood, may have alternating blasts so as to form a more even and overlapping mat. To prevent the beam necking in below the spinner 42, an underpressure is fed downwardly through the spinner from orifices 270 in a pipe 264 fed from inlet pipes 266, the air being used also as a cooling means for the top of the burner housing 182. Coating or binding material may be blown on to the interior of the beam of fibres from passages in a nozzle secured below the housing 182 to a pipe 286, 288 extending through the burner pipes 188, 194 and projecting through pipe 196. Specification 985,053 is referred to.