Patent EA-000274-B1 (EA)
Title: Man-made vitreous fibre products and processes and apparatus for their production
Inventor: TONDER FLEMMING WEISS
IPC: D04H1/736
Filed: 1996-05-14
Abstract: 1. Apparatus for making MMVF products comprising - a centrifugal spinner 1 having a front end, a first rotatable rotor 43 or a set of rotatable rotors consisting of a first rotor 43 and one or more subsequent rotors 44, 45 and 46 wherein the or each rotor is mounted for rotation about a substantially horizontal axis in front of the front end whereby melt poured onto the first rotor is thrown off as fibres or, in a set of rotors, is thrown onto the or each subsequent rotor in sequence and is thrown off the or each subsequent rotor and optionally off the first rotor as fibres, and primary air supply means 53, 54, 55 and 56 at least in the outer peripheral regions of the spinner associated with the first rotor 43 or, in the set of rotors, with each subsequent rotor 44, 45 and 46 and optionally with the first rotor 43 for blasting primary air substantially axially forwards across the surface of the or each rotor with which the primary air supply means are associated, and motor means 50 for rotating the or each rotor, - and a chamber 2, which comprises a collecting portion 3, having part 4 of the spinner adjoining the centrifugal spinner 1 and which protrudes forward from the spinner 4 edge characterised in that the chamber also comprises a spinner portion 5 which has a rear end 6 which is substantially open to the atmosphere and a front end 7 which opens into and merges with the collecting portion 3, and a substantially tubular duct 8 which extends between the front end 7 and the rear end 6, - the collecting portion 3 of the chamber is substantially closed to the ingress of air except for air forced through the spinner 1 and air which is sucked through the tubular duct 8 and, optionally, a lesser, non-interfering, amount of air sucked or forced through supplementary air passages in the spinner end 13 of the collection portion 3, - the front end of the spinner 1 and the front end 7 of the spinner portion 5 together define a substantially open annular collar a between them; - at least 50% of the cross-sectional area of the front end 7 of the spinner portion is open to the flow of air sucked through the spinner portion by the suction means 19; and - the spinner 1 and the tubular duct 5 are constructed to provide substantially steady air flow conditions through the collar. 2. Apparatus according to Claim 1 in which the spinner is a cascade spinner comprising a housing which is substantially closed to the free axial flow of air through the spinner and which has a front face and a rear end and a substantially tubular wall which extends between the front face and the rear end, a first rotor and one or more subsequent rotors each mounted in the housing for rotation in front of the front face about a substantially horizontal axis and arranged such that melt poured on to the first rotor is thrown on to the or each subseguent rotor in turn and is thrown off the or each subseguent rotor (and optionally off the first rotor) as fibres, and primary air supply means associated with the or each subseguent rotor (and optionally with the first rotor) for blasting air substantially axially forward across the surface of the or each rotor at least in the outwardly facing regions of the or each rotor and motor means for driving the rotors and located within the housing or substantially behind the rear end. 3. Apparatus according to Claim 2 in which the total cross-sectional area of the first and subsequent rotor or rotors is 40 to 95% of the maximum cross-sectional area defined by the housing. 4. Apparatus according to Claim 3 in which the total cross-sectional area of the first and subsequent rotors is 50 to 90% of the maximum cross-sectional area, defined at a front portion of the housing being 10 cm. long. 5. Apparatus according to Claim 3 or Claim 4 in which the housing has substantially parallel sides leading from the front face to a position at or near its rear end. 6. Apparatus according to any of Claims 3 to 5 in which the total cross-sectional area of the first and subsequent rotors is 55 to 85% of the maximum cross-sectional area defined by the housing. 7. Apparatus according to any preceding Claim in which the motor means comprise a motor for each rotor substantially coaxial with that rotor. 8. Apparatus according to Claim 7 including means for adjusting individually the speed of rotation of one or more of the rotors separately from one or more of the other rotors. 9. Apparatus according to any preceding Claim including secondary air supply means for blasting air axially forward for carrying fibres from the spinner towards the collector. 10. Apparatus according to Claim 9 in which the secondary air supply means are in the spinner. 11. Apparatus according to any preceding Claim in which the spinner is mounted so that the vertical separation between the lowermost subsequent rotor and the lowermost part of the tubular duct of the spinner portion is at least 1.5 times the vertical separation between the top of the first rotor and the uppermost part of the tubular duct. 12. Apparatus according to any preceding Claim in which the spinner is suspended in the spinner portion from the sides and/or upper parts of the tubular duct. 13. Apparatus according to any preceding Claim in which there are means for oscillating the spinner relative to the spinner portion about a substantially vertical axis through an oscillation angle of 5 to 30 degree . 14. Apparatus according to any of Claims 1 to 12 including means for oscillating the spinner with the spinner portion about a substantially vertical axis through an oscillation angle of 5 to 30 degree . 15. Apparatus according to any preceding Claim including means for pivoting the spinner about a substantially horizontal axis which is substantially parallel to the axes of rotation of the rotors. 16. Apparatus according to any preceding Claim including means for oscillating the spinner about a substantially horizontal axis which is substantially perpendicular to the axes of rotation of the rotors. 17. Apparatus according to any preceding Claim in which there are guides at or near the front end of the spinner portion each for imparting a non-axial movement to an axial segment of air flowing through the front end of the spinner portion into the collecting portion. 18. Apparatus according to Claim 17 in which the guides are located on the inner face of the tubular wall and are shaped or adjustable to provide different non-axial movement to different axial segments of air flowing through the front end of the spinner portion. 19. Apparatus according to Claim 17 or Claim 18 in which the guides are positioned to provide an outward substantially conical component to air flowing from the front end of the spinner portion into the collecting portion. 20. Apparatus according to any preceding Claim in which the collecting portion of the chamber is substantially closed to the ingress of air except for air forced forward from the spinner and air sucked through the open area in the front end of the spinner portion. 21. Apparatus according to any preceding Claim in which there is a substantially parallel-sided substantially annular passage defined between, externally, the substantially tubular duct of the spinner portion and, internally, the centrifugal spinner and this passage leads from the substantially open rear end to the collar. 22. Apparatus according to any preceding Claim in which the collector is positioned in the collecting chamber at an angle of 60 degree  to 120 degree  to the horizontal. 23. Apparatus according to Claim 21 in which the horizontal distance from the bottom of the lowermost subsequent rotor to the collector is 0.3W to W, where W is the maximum width of the open end of the spinner portion. 24. Apparatus according to any preceding Claim in which the collector has a width of 1.1W to 2W where W is the maximum width of the open end of the spinning portion. 25. Apparatus according to any preceding Claim in which the sidewalls of the collecting chamber, or air guide baffles within the sidewalls, diverge outwardly substantially conically from adjacent the open end of the spinner portion and the top wall of the collecting portion extends substantially conically upwardly from the open end of the spinner portion. 26. Apparatus according to any of Claims 1 to 22 including at least two of the said cascade spinners each positioned within its associated spinner portion, and wherein the spinner portions are arranged substantially parallel to one another and each opens into the spinner end of the collecting portion. 27. A first apparatus according to any of Claims 1 to 26 comprising also at least one second apparatus according to any of Claims 1 to 26 arranged in side-by-side relationship with the first apparatus. 28. A process for making MMVF products using apparatus according to any of Claims 1 to 27 comprising pouring melt onto the first rotor while the rotor or rotors are spinning, forming fibres off the first or, in a set of rotors, off the or each subsequent rotor and optionally the first rotor while forcing primary air through the primary air supply means, and collecting the fibres as a web on the collector while applying suction through the collector and carrying the web out of the chamber on the collector, and sucking air through the collar under substantially steady flow conditions and with a mean axial velocity of 5 to 40% of the mean axial velocity of the primary air as it is forced out of the primary air supply means. 29. A process according to Claim 28 in which the mean axial velocity of the air sucked through the open cross-sectional area is 5 to 50m/s, and the axial velocity of the primary air as it is forced out of the air supply means is 60 to 170m/s. 30. A process according to Claim 28 in which the axial velocity of the primary air as it is forced out of the air supply means is 70 to 120m/s, and the axial velocity of the air sucked through the open cross-sectional area is 10 to 30%