US3372012A - Fiber attenuating burner - Google Patents

Description

March 1968 w. F. PORTER FIBER ATTENUATING BURNER Filed June 7, 1965 v 5 Sheets-Sheet 1 R. ER w v w FWEA M W M K A March 5, 1968 w. F. PORTER 3,372,012

FIBER ATTENUATING BURNER Filed June 1965 5 Sheets-Sheet 2 W/LL/AM EPO/PTER INVENTOR.

A TTORNEY March 5, 1968 w. F. PORTER FIBER ATTENUATING BURNER Filed June 7, 1965 3 Sheets-Sheet 5 W/LL MM F PORTER INVENTOR. 8% all.

A TTORNEY 3,372,012 Patented Mar. 5, 1968 3,372,012 FIBER A'ITENUATING BURNER William F. Porter, Roselle, Ill., assignor to United States Gypsum Company, a corporation of Delaware Filed June 7, 1965, Ser. No. 461,994 3 Claims. (Cl. 65-14) ABSTRACT OF THE DISCLOSURE Apparatus for manufacturing fibers including a fiberizing rotor and an encircling gas burner having a combustion chamber to Operate at superatmospheric pressure, with a plurality of inlets on the downstream side of the burner and radially remote from said rotor, and a refractory liner on the upstream wall of the burner opposite the inlets so that incoming pressurized gases are directed against the refractory. A gas supply manifold is spaced downstream of said burner on rigid supports and is connected to the inlets by flexible conduits which occupy a minor portion of the circumference of the manifold.

This invention relates to an internal combustion ring burner and more particularly to an improved ring burner especially adapted for use in formation of glass fibers with a centrifugal fiberizing rotor.

In forming glass fibers through the use of a centrifugal rotor having a perforate wall, it is well known to employ burners to surround the rotor with a high temperature environment in which the fibers are formed. Frequently, the rotor is operated on a hollow vertical shaft through which glass melt is supplied and the burner or burners occupy a substantial portion of the remaining space above the rotor. When employing glass fibers to make non-woven batts, insulation and thev like, a number of advantages are realized during the felting process if the rotor shaft can be in a horizontal position or nearly so. Turning a spinner with a vertical shaft on its side does not solve the problem, as the glass melt cannot be fed satisfactorily through a hollow horizontal shaft and the bulky burners of the prior art so obscure the rear of the rotor that it is awkward and inconvenient to feed the glass directly to the rotor.

It is an object of this invention, therefore, to provide' a burner which is especially suitable for'use with a rotor operating on a substantially horizontal shaft. It is a further object of this invention to provide a burner which renders substantially all of the rear. of the rotor accessible during the fiberizing operation. It is a still further object of this invention to provide, a burner whose structure is substantially all radially outward of the fiberizing rotor,

It is an object of this invention to provide a burner and its fuel and oxidant supply means which permit access to the rear face of substantiallyall the rotor during the fiberizing operation.

These and other objects and advantages of this invention will be more fully understood when'reference is made to the :detailed description thereof which follows and to the accompanying drawings in which FIG. 1 is a partially sectioned View showing a rotary fiberizing rotor surrounded by the burner of this invention with its associated gas supply apparatus, FIG. 2 is an enlarged sectional drawing illustrating in detail the construction of the burner and FIG. 3 shows another embodiment of the invention, also sectioned to reveal its interior.

In general, the advantages and objects of this invention are realized through the provision of an enclosed burner combustion chamber having a refractory lining in which fuel is burned under pressure. The metal walls of the combustion chamber are cooled with a fluid such as water or steam. Combustion products are conveyed from the burner chamber by a discharge means having fluid cooled metal Walls and which have no refractory lining. The fuel and oxidant are preferably premixed outside the burner and are admitted to the combustion chamber at a location remote from the discharge means.

The burner may be designed to operate with the fuel and oxidant supplied at super-atmospheric pressure of from 1 to about 10 pounds per square inch gauge and preferably about 5 pounds per square inch gauge so that the combustion products are discharged therefrom at a temperature of about 2200 to about 2500 degrees Fahrenheit and at a velocity of 1100 to about 1500 feet per sec 0nd or more. The temperature and velocity of the combustion products may be controlled by adjusting the fueloxidant mixture fed to the burner and also by changing the pressure at which these gases are supplied.

Referring now to FIG. 1 of the drawings, there is illustrated a shaft I mounted at a slight angle from the horizontal and adapted for high speed rotation by means not shown. Mounted on the shaft is a centrifugal rotor having a side wall 2 with a working area in which are located a large number of fiber forming orifices 3. Surrounding the rotor is a ring burner 4 having a combustion charnher 5 in which fuel and oxidant are burned at super-atmospheric pressure. Mounted from the burner and coaxial with it is a gas supply manifold 6 which is secured by brackets 7. Flexible supply lines 8 convey the gas from the manifold to the burner. To supply additional heat to the interior of the rotor a supplemental burner 9 may be employed.

In operation, the rotor 3 is rotated rapidly and brought to near operating temperature through the combined action of the ring burner 4 and a supplemental burner 9. When the rotor is at near operating temperature, the stream of glass melt 10 from a supply not shown is introduced to the rotor from the accessible rear side. Centrifugal force causes the glass melt to pass through the orifices 3 and to form fibers 11. As these leave the working area on the wall of the centrifuge, they pass through the hot gases issuing from the discharge means 12 where the action of the hot, high velocity gases attenuates the fibers and carries them downstream to a collection means not shown.

In the embodiment of the invention shown in detail in FIG. 2, the rotor shaft is again shown at 1. The rotor is shown with its side wall 2 and the orifices 3 substantially surroundedby the burner.

The burner itself is comprised of metal walls 20 which have associated with them companion walls 21. The space between them constitutes a passage for fluid coolant. Spacers 23 secure the walls to each other and prevent distortion due to the combined action of the high pressure of the fluid coolant and the elevated temperature encountered when the burner is functioning. The combustion chamber 5 has a refractory lining 25 which becomes incandescent when the burner is operating so that it accelerates the ignition of the incoming fuel and oxidant and promotes its more rapid combustion. A bushing 26 is fitted to the burner inlet 27 and secures the burner tip 28 through which premixed fuel and oxidant are admitted. Similar fittings, one of which is shown at 35,-are employed at spaced intervals around the burner and are supplied through flexible hoses 29 secured by fittings 30. The bracket 7 secures the gas manifold to the burner, although other supporting means could, of course, be employed.

The combustion products are discharged across the working surface 2 of the rotor through an orifice or discharge slot 31. This discharge slot as well as the passage leading to it are defined by metal walls 32 and 33 which have no refractory lining and which are cooled by fluid.

As shown in this embodiment, this fluid cooling means may be a continuation of that employed on the burner chamber but it should be understood that separate cooling means may also be employed.

FIGURE 3 shows another embodiment of the burner with the combustion chamber 46 sectioned and with the burner located in an operating position relative to a fiberizing rotor 41 mounted on a shaft 42. The combustion chamber walls 43 are protected from the combustion flame by a refractory lining 44. They are further protected by a cooling medium circulating through the cooling passages 45 which are formed by the combustion chamber walls and an outside shell 46 which is located by spacers 47. Premixed fuel and air are supplied from a manifold not shown through a plurality of conduits 48, in this instance 18 in number, equally spaced near the outer edge of the burner and on the down-stream side. Burner tips 49 are located at the entrance to the combustion chamber by appropriate nozzles 50 and further distribute the combustion gases and prevent flame flash-back into the supply conduits.

Discharge means 51 includes fiuid cooled walls 2 which define an annular slot 53 adapted to direct the combustion products over the wall 54 of the fiberizing rotor 51.

A burner similar to that shown in FIG. 2 was constructed having a combustion chamber with an outside diameter of approximately 32 inches. The chamber walls were fabricated from A1 stainless steel plate and the refractory lining 25, approximately inch thick, was cast into place. For this purpose a castable refractory sold under the trademark TACOR by Charles Taylor and Sons of Cincinnati, Ohio was used. The cooling chamber outer walls 21 were fabricated from ordinary mild steel. Twelve bushings and burner tips were spaced equally about the burner. The gas discharge slot 31 was about A inch wide and about 12 inches in diameter.

Natural gas having a heating value of 1,000 B.t.u. per cubic foot was mixed with air at a volume ratio of about 1 to 10 and fed to the burner at about 7 p.s.i. Water was supplied to the passages 24 as a coolant. Gas was supplied to the burner at a rate of 2,000 cubic feet per hour which, with the air, made available about 1600 pounds per hour of combustion products. They issued from the discharge slot 31 at a velocity of 1100 to 1500 feet per second and a temperature of about 2500 F. A bright glow was visible through the discharge slot but no flame appeared outside the burner. The discharge slot did not distort under operating conditions and the coolant proved so effective that after hundreds of hours of operation, the machine marks were not eroded from the metal walls.

The burner proved highly efiicient and capable of ejecting a high temperature, high velocity blast across a confined working area of small dimensions while, at the same time, leaving the large area accessible within the burner ring.

I claim:

1. In apparatus for producing fibers including a centrifugal spinner rotatable about its axis, an annular burner coaxial with and encircling said spinner, said burner having walls defining a substantially closed combustion chamber to operate at superatmospheric pressure and including opposed upstream and downstream walls substantially normal to the axis of the spinner, and discharge means connected to said downstream wall and defining a passage adjacent said spinner to lead the combustion products in a high temperature high velocity blast adja- 4 cent the periphery of the spinner, the improvement comprising a plurality of inlet means for pressurized fuel and air through said downstream wall and radially remote from said spinner, and a refractory liner on said upstream wall and opposite said inlet means, said inlet means being positioned to direct the incoming gases against said refractory liner in areas radially remote from said discharge means.

2. In apparatus for producing fibers including a centrifugal spinner rotatable about its axis, an annular burner coaxial with and encircling said spinner, said burner having walls defining a substantially closed combustion chamber to operate at superatmospheric pressure and including opposed upstream and downstream walls substantially normal to the axis of the spinner, and discharge means connected to said downstream wall and defining a passage to lead the combustion products in a high temperature high velocity blast adjacent the periphery of the spinner, the improvement comprising a plurality of inlet means for pressurized fuel and air through said downstream wall and radially remote from said spinner, a gas supply manifold spaced downstream from and coaxial with said burner, rigid supports to align the manifold with said burner, and flexible conduits between the manifold and burner to convey the pressurized gases to the inlet means, said supports and conduits occupying a minor portion of the circumference of said manifold and said burner to permit substantially unimpeded induction of air around said peripheral wall by such a blast issuing from said discharge means.

3. In apparatus for producing fibers including a centrifugal spinner rotatable about its axis, an annular burner coaxial with and encircling said spinner, said burner having walls defining a substantially closed combustion chamber to operate at superatmospheric pressure and including opposed upstream and downstream walls substantially normal to the axis of the spinner, and discharge means connected to said downstream wall and defining a passage adjacent said spinner to lead the combustion products in a high temperature high velocity blast adjacent the periphery of the spinner, the improvement comprising a plurality of inlet means for pressurized fuel and air through said downstream wall and radially remote from said spinner, a refractory liner on said upstream wall and opposite said inlet means, each of said inlet means being positioned to direct the incoming gases against said refractory liner in an area radially remote from said discharge means, a gas supply manifold spaced downstream from and coaxial with said burner, rigid supports to align the manifold with said burner, and flexible conduits between the manifold and burner to convey the pressurized gases to the inlet means, said supports and conduits occupying a minor portion of the circumference of said' manifold and said burner to permit substantially unirnpeded induction of air around said peripheral wall by'such a blast issuing from said discharge means.

References Cited McCoppin 65-6 I DONALL H. SYLVESTER, -Prim'ary Examiner.

R. L. LINDSAY, Examiner. i

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