摘要:
Extraordinarily low ranges of error, with respect to yarn adhesion and uniformity, in dry spinning yarns are achieved when the spinning gas in the upper part of the shaft blasts the yarns radially from the inside to the outside in an apparatus designed for this purpose, the velocity of the radial flow of gas, dirctly below the spinning nozzle, transverse to the running direction of the yarns and within a spacing of 10 mm from the nozzle, increasing from 0 to at least from 0.2 to 1 m/s.
摘要:
In a process for the production of mineral wool fibers according to the jet blast process, comprising issuing at least one melt stream from at least one opening in the base of a melting crucible into a converging-diverging drawing nozzle, flowing a gaseous blasting medium into the nozzle substantially parallel to the melt stream so as to separate the melt stream into fibers, the blasting medium being drawn into the nozzle by suction due to a drop in pressure produced between the nozzle inlet and outlet, and passing the fibers and spent blasting gas into a diffuser connected downstream of the nozzle to reduce the gas rate of flow, the improvements which comprise effecting(a) a maximum drop pressure in the inlet of the drawing nozzle;(b) a minimum drop pressure in the diverging portion of the drawing nozzle over a maximum length without separation (transition) of the laminar boundary layer;(c) the subsequent pressure conversion initially with a shock at a constant cross-section of the drawing nozzle and subsequently in a subsonic diffuser.
摘要:
A process for finely dividing melts according to the nozzle drawing process is described wherein the pressure gradient of the gas flowing into the inlet opening of the drawing nozzle is increased by the provision of obstacles to that flow of gas. The obstacles may be streams or jets of gas directed a traverse of the flow of gas.
摘要:
In a process for the production of mineral wool fibers according to the jet blast process, comprising issuing at least one melt stream from at least one opening in the base of a melting crucible into a converging-diverging drawing nozzle, flowing a gaseous blasting medium into the nozzle substantially parallel to the melt stream so as to separate the melt stream into fibers, the blasting medium being drawn into the nozzle by suction due to a drop in pressure produced between the nozzle inlet and outlet, and passing the fibers and sent blasting gas into a diffuser connected downstream of the nozzle to reduce the gas rate of flow, the improvements which comprise effecting(a) a maximum drop pressure in the inlet of the drawing nozzle;(b) a minimum drop pressure in the diverging portion of the drawing nozzle over a maximum length without separation (transition) of the laminar boundary layer;(c) the subsequent pressure conversion initially with a shock at a constant cross-section of the drawing nozzle and subsequently in a subsonic diffuser.
摘要:
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. and,(d) in the intermediate cross section between the lower edge of the nozzle inlet and the upper edge of the drawing-out part, there are provided propulsion jet nozzles, the axis of which is inclined by from 5.degree. to -2.degree. to the drawing nozzle.
摘要:
In a process for the production of mats made of organic or inorganic fibres, comprising dispersing fibers in a flowing gas so as to issue together from a channel, depositing the fibers on a perforated conveyor belt for the formation of the mat, and removing the gas by suction below the conveyor belt, the improvement which comprises(a) disposing the conveyor belt so as to form an angle of about 90.degree. to 150.degree. with the direction of gas flow at the outlet of the channel;(b) deflecting the gas flow on one side of the channel in the direction of the conveyor belt such that the gas flow is deflected in the direction of the conveyor belt by the Coanda-effect after issuing from the channel;(c) the deflected gas flow entraining ambient air or recirculated gas from the surroundings in the direction of the conveyor belt downstream of the deflection;(d) on the opposite side of the channel ambient air flowing into the region of the fiber deposit between the conveyor belt and the lower edge of the channel in the direction of movement of the conveyor belt, at an angle of about 45.degree. to 90.degree. to the direction of gas flow at the channel outlet; and(e) removing the total flow by suction on the conveyor belt such that the gas carrying the fibers takes an S-shaped path to the conveyor belt with a double deflection, whereby the direction of flow is at an angle of from 0.degree. to about 30.degree. with the conveyor belt at the turning point.
摘要:
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.
摘要:
In the production of fibers by blast drawing in which primary filaments are produced from a liquid stream, reduced to fibers and drawn on passing through a draw nozzle by drawing gas streams flowing substantially parallel to the primary filaments, the improvement which comprises surrounding the drawing gas streams over at least part of their length and inside the draw nozzle in the direction of flow by parallel boundary gas streams having at most the same flow velocity as the drawing gas streams. Advantageously the parallel boundary gas streams are formed by that part of a circular flow produced on both sides of the drawing gas stream which is in contact with the drawing gas stream, the flow velocity of the parallel boundary gas streams amounts to between about 60 and 80% of the velocity of the drawing gas streams, the drawing gas streams having a velocity of from about 360 to 500 m/s, the volume flow of the parallel boundary gas streams amounting to between about 20 and 60% of the volume flow of the inlet stream, the drawing gas streams and the parallel boundary gas streams being driven by a pressure gradient generated by power jets in the draw nozzle. A corresponding novel draw nozzle is provided. The inner walls of the nozzle do not undergo the erosive/abrasive wear characteristic of other draw nozzles.
摘要:
A rod-shaped medical tampon for releasing an active substance, including (a) a tampon core of compressed fibers selected from the group consisting of cellulose fibers, cotton fibers, and acetate fibers; (b) a tampon cover surrounding said tampon core and being firmly bonded to one another by a glue, the tampon cover comprising a hardened collagen foam or a hardened gelatin foam impregnated with a retardant including a dissolved active substance to be released; and (c) a retrieval string connected to at least one of said tampon core and said tampon cover.
摘要:
In a process for the production of mats made of organic or inorganic fibres, comprising dispersing fibers in a flowing gas so as to issue together from a channel, depositing the fibers on a perforated conveyor belt for the formation of the mat, and removing the gas by suction below the conveyor belt, the improvement which comprises(a) disposing the conveyor belt so as to form an angle of about 90 to 150.degree. with the direction of gas flow at the outlet of the channel;(b) deflecting the gas flow on one side of the channel in the direction of the conveyor belt such that the gas flow is deflected in the direction of the conveyor belt by the Coanda-effect after issuing from the channel;(c) the deflected gas flow entraining ambient air or recirculated gas from the surroundings in the direction of the conveyor belt downstream of the deflection;(d) on the opposite side of the channel ambient air flowing into the region of the fiber deposit between the conveyor belt and the lower edge of the channel in the direction of movement of the conveyor belt, at an angle of about 45 to 90.degree. to the direction of gas flow at the channel outlet; and(e) removing the total flow by suction on the conveyor belt such that the gas carrying the fibers takes an S-shaped path to the conveyor belt with a double deflection, whereby the direction of flow is at an angle of from 0 to about 30.degree. with the conveyor belt at the turning point.