Abstract: The objective is to provide a process and an apparatus for the continuous production of mineral wool nonwovens, by means of which a stable flow pattern is created in the chute, thus facilitating a clearly defined, homogeneous layer of deposited mineral wool.According to the invention, at least one backflow region (24, 25) is generated in the chute (9) outside the fibre flow (23), which backflow region (24, 25) is sufficient for such a large-volume backflow with such a low mean velocity that appreciable upward fibre transport is avoided. In this connection, a portion (32) of the process air entrained with the fibre flow is deflected upward in the backflow, and another portion (34) of the process air is extracted.

Abstract: A process and apparatus for the continuous production of mineral wool nonwovens in which the objective is to provide a process and an apparatus for the continuous production of mineral wool nonwovens, by means of which a stable flow pattern is created in the chute, thus facilitating a clearly defined, homogeneous layer of deposited mineral wool in which at least one backflow region (24, 25) is generated in the chute (9) outside the fibre flow (23), which backflow region (24, 25) is sufficient for such a large-volume backflow with such a low mean velocity that appreciable upward fibre transport is avoided. In this connection, a portion (32) of the process air entrained with the fibre flow is deflected upward in the backflow, and another portion (34) of the process air is extracted.

Abstract: An apparatus and a process for the continuous production of mineral wool nonwovens in the nonwoven formation process on the drums of the accumulating conveyors arranged at the lower end of a chute. Several fiberization units (1, 2, 3, 4) communicate with a chute (9) for the formation of a nonwoven (14). The fibres are deposited under the influence of suction pressure onto the curved surface of the accumulating conveyor (10, 11). At least one of the drum-shaped accumulating conveyors (10) is designed to swivel around a pivot (23) essentially arranged perpendicular to the flow direction (22) of the mineral wool such and to the extent that a discharge gap (21) can be adjusted to a width corresponding to the thickness of the nonwoven (14) to be formed.

Abstract: In the continuous production of mineral wool nonwoven fabrics, fiber/gas/air mixtures (3, 4) produced by several shredding units (14 to 17) are directed onto collecting conveyor units (19, 21) with suction surfaces (c, d) running in a curve and being under suction pressure for the formation of a wool nonwoven fabric (25). In this case the arrangement is such that an imaginary suction surface, increasing in its size in the conveying direction, is assigned to each fiber/gas/air mixture formed by the individual shredding units (14 to 17), actually d is larger than c. As a result it is possible, in a space-saving method of construction and per collecting conveyor unit to produce mineral wool nonwoven fabrics from rock wool with constant suction pressure with bulk densities even under 25 kg/m.sup.3 in good product quality. By series connection of several units or an oscillating deposit of an individual nonwoven fabric multilayer felt webs can further be formed.

Abstract: By combining two measures, namely by using rock wool fibers with a particularly low fiber thickness, and by adding an avivage agent with an unusually high viscosity, it is possible to needle a rock wool felt, without adding any other fibers, to produce a needle felt with high strength and good bendability. If the needle felt is subsequently relaxed with heat treatment, and the avivage agent is also expelled during this treatment, the needle felt is then available as a pure rock wool needle felt, free of any organic additives.

Abstract: In a process for the manufacture of an exhaust silencer for motor vehicles, the advantages derived from employing mineral fiber mouldings are extensively retained while at the same time greatly reducing expenditure on shape-stabilization and transportation. To this end the silencer casing itself is divided in the meridian plane and the mineral wool is supplied and inserted directly into the original silencer casing in the form of precisely dimensioned prefabricated elements which have been impregnated with a suitable fluid, for example pretreated with synthetic resin, but not cured. This enables fast and reliable positioning of the impregnated and manually compressed prefabricated elements around the periphery of the exhaust pipe and the internal component containing the exhaust pipe inside the original silencer casing; once the silencer casing has been closed, the silencer is ready for installation. Curing, hardening or some other time consuming method of shape-stabilization is not necessary.

Abstract: A process of melting silicate raw materials includes the steps of using the tank exhaust gases to heat the combustion air, using the tank exhaust gases to preheat a mixture of raw materials, removing acid gaseous aggressive media from the tank exhaust gases, then using the tank exhaust gases to preheat the combination air. Because the acid gaseous aggressive media are removed from the tank exhaust gases before the tank exhaust gases are used to preheat the combustion air, more heat can be withdrawn from the tank exhaust gases than was heretofore possible, since there is no danger of acid condensation even when the tank exhaust gases are cooled to near ambient temperature.