Abstract: A method for the reduction of the velocity of dispersions of fine particles in gas is described, in which the dispersion is divided into a plurality of mass flows M which are conveyed each to a subsonic diffuser to reduce the velocity from V.sub.1 to V.sub.2, wherein the product of mass flow M and density velocity ration S.sub.1 V.sub.1 /S.sub.2 V.sub.2 is less than 10 kg/sec.The method is particularly useful in the manufacture of mineral wool, where the mineral wool fibers are first obtained being dispersed in a high velocity gas stream.

Abstract: A drawing nozzle for finely dividing melts according to the nozzle blasting process, wherein(a) the contour of the nozzle inlet from the upper edge of the nozzle passes initially inside a radius R.sub.1 =40% of the narrowest cross-sectional dimension d of the drawing nozzle and then runs parallel to, or diverges by up to 2.degree. from the drawing nozzle axis up to a depth below the upper edge of the drawing nozzle which is not greater than the narrowest cross-sectional dimension d of the drawing nozzle;(b) the nozzle inlet is immediately adjoined by the drawing-out part, the upper cross-sectional dimension of which is from 1.5 to 2.4 times as wide as the narrowest cross-sectional dimension d of the drawing nozzle;(c) the drawing-out part widens over a length of at least 6 times the narrowest cross-sectional dimension d of the drawing nozzle with a widening angle of from 1.degree. to 2.4.degree.