GB1072517A - - Google Patents

Abstract

1,072,517. Making filter medium. JOHNS-MANVILLE CORPORATION. Oct. 12, 1964 [Jan. 2, 1964], No. 41478/64. Heading BIT. [Also in Division Dl] In a process for producing a felted body from attenuated glass fibres, a stream of hot gases carrying the fibres is separated into two parts of which one comprises a substantial proportion e.g. 45% of the gases but a small proportion of the fibres, whilst the other comprises a substantial proportion e.g. 99% of the fibres. A heat-curable binder is then introduced into the latter stream, and the fibres in it are collected to form the body. As shown, glass is melted in a chamber 10, drawn into primary filaments 12, and attenuated into fine fibres 15 by a blast of hot gas from the burner 14. The fibres are carried by the gas into and through the tube 35, which is bent so that the fibres are deflected as shown. Part of the tube 35 is surrounded by a heatexchanger 11, to cool partially the gas stream. A divider 72 divides the outlet into two parts 74 and 76. Part of the gas and substantially all of the fibres emerge at 74 and are sprayed with liquid binder, e.g. a phenol-formaldehyde resin, from a nozzle 46. The fibres are collected on a foraminous belt 38 with the aid of a suction box 41. Gas from the diversion discharge nozzle 76 contains few fibres and passes to chamber 77 where heat may be recovered from it. The fibres in it are removed by a cyclone device 75. The mat 40 of fibres is removed from the belt 38, passed through an oven 52 to cure the binder and rolled up. In other embodiments; (Fig. 2, not shown) the tube 35A is divided near its outlet end, from one arm part of the gas and most of the fibres emerge and are collected as in Fig. 1, the few fibres passing into the other arm are removed by a foraminous belt and collected in a bin; (Fig. 3, not shown) the discharge nozzle 74B for the fibres is above the diversion tube 76B and empties into a chamber 90, the few fibres in this stream fall to the bottom of the chamber, and can be collected; (Fig. 4, not shown) a rotating foraminous member 100 is placed in the tube 35C, diverted air is drawn off through it, any fibre fines collected on it are blown off by cold air and so returned to the main stream of fibres; (Fig. 6, not shown) air is discharged into the tube 35D at its first inflexion to obviate friction between the fibres and the wall of the tube; (Fig. 8, not shown) several burners may be mounted side by side, with a conveyer tube 35 for each, feeding the fibres to a common collection belt; (Figs. 9 and 10, not shown) the divider 72 is adjustable to vary the relative volume of air to be diverted; (Fig. 11, not shown) the divider 72A has ports through which air is blown to remove any fibres that may collect upon it; and (Fig. 12, not shown) the divider 72B is a cylinder rotated either by the air stream or by external means so that any fibres that may collect on it are projected back into the main fibre stream. More than one separation point may be incorporated.