Process and apparatus for the production of very fine mineral fibers, in particular glass fibers

摘要

The streams of melt issuing from the melt outlet apertures (18) at the bottom of a melting crucible (14) are broken up into fibers in a drawing nozzle by means of a blast medium directed substantially parallel to the streams of melt. The blast medium is produced by a pressure gradient in the drawing nozzle and sucked in at the drawing nozzle inlet (7). In the drawing nozzle (16), the flow velocity is reduced in a downstream diffuser after the drawing process. The blast medium is supplied in the form of a hot gas between the underside of the crucible and the top edge (15) of the drawing nozzle from opposite broadsides of the melt distributor (14) in excess to the total quantity of gas stream sucked in at the drawing nozzle inlet (7). The hot gas consists of a mixture of combustion gases and air and is at a temperature from 600 DEG C. to 1500 DEG C., preferably from 800 DEG C. to 1400 DEG C. The flow velocity of the hot gas is adjusted to a value below 100 m/s, preferably 50 m/s, in the region (13) between the drawing nozzle (16) and the melt distributor (14). Gas burners (1) provided for producing the hot gas are arranged with their combustion chambers (3) situated laterally between the melt distributor (14) and the top edge (15) of the debiteuse. The combustion chambers (3) are connected by bores (6) to air chambers which are under an excess pressure. In the combustion chambers (3), the combustion gases are homogeneously mixed with the air introduced.