Abstract:
A melt for use in the production of man-made vitreous fibres may be formed in a circulating combustion chamber (20) by melting particulate material. The material is collected in a base region (26) of the combustion chamber, where it can be heated using submerged heating means (40). The submerged heating increases the homogeneity of the melt within the melt pool (30), the increase in homogeneity being encouraged by a relatively long average residence time for mineral material in the chamber (20) of at least 15 minutes.
Abstract:
A melt for use in the production of man-made vitreous fibres may be formed in a circulating combustion chamber (20) by melting particulate material. The material is collected in a base region of the combustion chamber (26), where it can be heated using submerged combustion apparatus (40). The submerged combustion process is controlled to ensure that the proportion of Fe(2+) based on total Fe within the melt extracted from an outlet of the chamber is greater than 80%.
Abstract:
The invention provides a method of manufacture of man-made vitreous fibers (MMVF) comprising: providing a fiberizing apparatus, wherein the fiberizing apparatus comprises: a set of at least three rotors each mounted for rotation about a different substantially horizontal axis; wherein each rotor has a driving means; rotating the rotors; wherein the first rotor rotates to give an acceleration field of from 25 to 60 km/s2 and the second and third rotors each rotate to give an acceleration field of at least 125 km/s2, providing a mineral melt, wherein the melt has a composition comprising the following, expressed by wt of oxides: SiO2 in an amount of from 33 to 45 wt %, Al2O3 in an amount of from 16 to 24 wt %, an amount of K2O and/or Na2O, an amount of CaO and/or MgO, wherein the ratio of the amount of Al2O3 to the amount of SiO2 is in the range 0.34-0.73, wherein the ratio of the total amount of K2O and Na2O, to the total amount of CaO and MgO, is less than 1; pouring the melt on to the periphery of the first rotor; wherein melt poured on to the periphery of the first rotor in the set is thrown on to the periphery of the subsequent rotors in turn and fibers are thrown off the rotors; and collecting the fibers that are formed. Man-made vitreous fibers (MMVF) can thus be formed having a median length of 100 to 300 μm, a median diameter of not more than 2.5 μm, and wherein the ratio of the median fiber length to median fiber diameter is 25 to 500.
Abstract:
A melt for use in the production of man-made vitreous fibres may be formed in a circulating combustion chamber (20) by melting particulate material. The material is collected in a base region of the combustion chamber (26), where it can be heated using submerged heating means (40). The submerged heating increases the homogeneity of the melt within the melt pool (30), the coherence of which is maintained by the use of a siphon (50) to extract melt from the combustion chamber.
Abstract:
The invention relates to a melt composition for the production of man-made vitreous fibres and man-made vitreous fibres comprising the following oxides, by weight of composition: SiO239-43 weight % Al2O320-23 weight % TiO2up to 1.5 weight % Fe2O35-9 weight %, preferably 5-8 weight % CaO8-18 weight % MgO5-7 weight % Na2Oup to 10 weight %, preferably 2-7 weight % K2Oup to 10 weight %, preferably 3-7 weight % P2O5up to 2% MnOup to 2% R2Oup to 10 weight % wherein the proportion of Fe(2+) is greater than 80% based on total Fe and is preferably at least 90%, more preferably at least 95% and most preferably at least 97% based on total Fe.