US2153739A - Apparatus for and method of forming mineral wool from fusible solids - Google Patents

Description

April 11, 1939. c. R. BUSS 2,153,739

APPARATUS FOR AND METHOD OF FORMING MINERAL WOOL FROM FUSIBLE SOLIDS Filed Dec. 10, 1956 jw'roenbr Patented Apr. 11, 1939 PATENT- OFFICE APPARATUS FOR AND METHOD OF FORMING MINERAL WOOL FROM FUSIBLE SOLIDS Charles Richard Buss, Thorold, Ontario, Canada, assignor to Spun Rock Wools, Limited, Thorold, Ontario, Canada, a company Application December 10, 1936, Serial No. 115,169

12 Claim.

This invention relates to the disintegrating of rock, slag and other fusible solids into the fibrous state. The process and apparatus at present used for the manufacture of fibrous material of this kind is very unwieldly and requires the use of a large amo t of building space.

The objec \gigthe present invention is to devise I apparatus which is very compact in comparison with the present apparatus, and which at the same time will be very efiicient in operation and economical in use.

The. formation of fibers from molten rock, slag and the like is generally termed blowing." The present process relates to that general type of spinning which involves the formation of drops or small masses of the viscous fluid which are projected away from their place of formation with the pulling of a. thread or fiber from the drop or mass. The drop or head of the thread solidifies, due to loss of heat, and it produces so-called shot. The production of the sho is unavoidable according to this method of producing the fibers. Also it appears that some of the shot are formed under circumstances resulting in little if any drawing of fiber from or by them. However, the presence of the shot in the finished flbers is undesirable because the shot add very greatly to the weight without any compensating utility.

According to the present invention the drops or small masses by and from which the threads are drawn are formed and projected by the engagement of a stream of the molten rock, slag and the like with the peripheral portion of a coned and grooved spinning disc running at a high velocity. The spinning disc breaks up the viscous fluid into the required drops or masses and projects them with sufilcient kinetic energy to draw the desired thread. The head and thread continue to remain attached so long as the head is molten and viscous, but as soon as the head loses its molten condition, it should be broken 0133 the thread. The problem then is first to assist in the breaking off the heads or shot when possible and separation of the heads or shot from the threads. According to the present invention Iv have provided a classifier which works on the combined action of suction and inertia to cause not only separation of the heads from the fibers but also classification and segregation of the same.

The way I do this is more fully described hereafter, but, in general, it consists in establishing a definite flow or air downward in a zone around the spinning disc. This zone is defined by a circular wall outside of which is a relatively quiet zone which provides a receptacle for the shot.

The flow of air in the first zone is in practice secured by drawing or sucking the air by means of a fan or blower.

The action is as follows: The drops or small masses projected from the disc have suflicient kinetic energy or inertia of motion to carry themselves through the zone of flowing air without material deflection. But the thread or fiber which 10 is being drawn presents so great a hold to the moving current of air that it is carried by the current of air and tends to be broken off of the shot. Thus whereas the shot succeed in passing through the zone of moving air into the recepl6 tacle for shot, the threads or fibers are drawn away by the current of air before they escape. These fibers as fast as they are formed are then conveyed by the current of air to a second classifier.

Someof the fibers are produced by drops or masses which are so small to begin with or are so much depicted by the drawing oi. the threads that they do not have the necessary inertia left to carry through the moving current of air and, 25 therefore, are carried along with the fibers by the suction of the fan. As the fibers pass through the fan, the action tends to break ofl? some of the heads or shot from threads. The fan delivers all the fibers, both those without heads and those 3 having heads attached, under considerable velocity of movement in a moving current of air which is projected against a wall which is preferably the bottom wall of a pan or classifier. There the current of air is sharply deflected, but the heavier 35 particles impinge upon the bottom wall of the pan. The light fibers tend to follow the flow of air and are likewise deflected, i. e., up and over the edge of the pan. The heads of the fibers or any adherent solid particles being more compact 40 and heavy tend to strike against the wall. and are thereby broken off of or loosened from the fibers, and much of the shot that escapes the first classiflcation at the spinning cone is detached and trapped at this stage. The second classifier is preferably arranged to trap the detached heads and allow the fibers to escape into a suitable receptacle. This action of the separation or the solid particles is accomplished by deflecting the solid particles and by allowing them to gravitate into a pocket or trap where they are out of the line of impingement by incoming fibers and shot.

The wool or fiber so produced is so much freed of shot that it is greatly superior toany mineral W001 heretofore produced in respect to fineness, weight, and insulating qualities.

I attain my object by means of the apparatus hereinafter described and illustrated in the accompanying drawing in which- Fig. 1 is a diagrammatic view showing the improved apparatus;

Fig. 2 a plan view of the disintegrator;

Fig. 3 a cross section through the disintegrator; and

Fig. 4 a plan view of the apparatus, parts being shown in section;

Fig. 5 an enlarged detail illustrating the shape of the ribs on the disintegrator.

In the drawing like numerals of reference indicate corresponding parts in the different fig- H ures.

The apparatus comprises broadly three main parts, a furnace for melting the material, disintegrating means and collecting means.

I indicates a reducing furnace, which may be of any ordinary type and heated in any suitable manner and provided with the discharge spout 2.

Adjacent the furnace is a spinner chamber 3 where the disintegration is effected. On a vertical shaft 4 is mounted the spinner 5. This shaft is provided with a drive pulley 6 by means of which it is driven from an electric motor, gasoline engine, or other means not shown. This spinner is formed with a flat central disk portion 6 and an outwardly and downwardly inclined peripheral portion 6 and the upper surface of this inclined peripheral portion is provided with annular ribs 6, forming between them annular grooves. As will be seen from Fig. 5, these ribs are formed with a narrow inner wall and a wide outer wall, and the top of the rib is above the level of the groove at the inner side of the rib. The ribs therefore have a tendency to collect and carry the film of molten material around with the spinner before overflowing to the next groove. A considerably greater spread of the film is thus obtained before it is discharged from the spinner under centrifugal action. It will be noted from Figs. 1 and 3 that the spout 2 is arranged to discharge on to this ribbed inclined peripheral portion of the spinner.

The upper edges ofthe ribs which separate the grooves form definite edges from which the material is thrown off and the depth of the'groove serves to define the mass of the drops or masses thrown off by centrifugal force. Thus, simultaneous spinning from the upper edges of a plurality of ribs is carried on, greatly increasing the yield of wool.

The material is disintegrated by discharging it in the molten condition from the furnace on to this inclined peripheral portion 6' of the spinner, while the latter is being rapidly rotated.

With a spinner approximately twelve inches in diameter I find that best results are attained by driving the spinner at approximately 3600- 4000 revolutions per minute, but it will be understood that the spinner may be larger or smaller and the speed of rotation may vary with the diameter of the spinner.

The molten material from the spout 2 is, as before stated, dropped on or directed against the upper part of the inclined peripheral portion 6 of the spinner while the latter is rapidly rotated, and due to the centrifugal force, is discharged outwardly from the spinner. Due to the inch-'- iiation of the molten material receiving surface,

, the deposited material has a tendency to also spread downwardly over said inclined surface thus thinning the film of molten material before the latter is thrown off, thus facilitating the disintegration or breaking up of the material. This thinning or spreading" of the material is further helped by the corrugating or ribbing of the deposition surface.

The stream of molten material from the spout 2 in running upon the coned and grooved portion of the disc 5 tends to fill one or more of the grooves. That is to say each groove will accept only a certain fiow or quantity of material and any excess tends to be received. by the next succeeding groove or grooves. The edges of the ridges separating the grooves act like retaining flanges from the rims of which the material is flung in drops or masses. The size of the grooves which are emptied by centrifugal force tends to control the size of the drops thrown off.

These molten viscous drops in being projected by the disc tend to leave behind them a thread or fiber which is pulled, drawn, or spun from the body of the drop while it is sufficiently fluid. The drop forms a head from which the fiber or thread streams backward. When the headsolidifies, the drawing of fiber ceases and the head tends to separate from the fiber because the fiber has much greater friction with the air than the head has. The heads freed from the threads or from which no threads were formed are like small pellets or shot and are generally termed shot.

These pellets or shot particles, due to their greater weight, are thrown further from the spinner than the fibrous material and are thus naturally separated from the latter. I therefore provide means for taking advantage of this natural separation to retain the shot separate from the fibrous material.

Furthermore, the suction means which I provide facilitates the separation or breaking of the heads from the fibers to produce separate fibers and shot, by pulling the fibers downwardly as the heads thereof travel laterally. This tends to release the heads from the tails or thread-like fibers and allow them to travel on as shot. If the heads are not separated from the threads, they are pulled with the threads or fibers by the current of air and later subjected to a second separating action. Within the spinner chamber 3 is provided a deep pan or receptacle 1 having an open top. This receptacle 1 is of such a size that its wall is so placed that the fibrous material falls inside the receptacle, whereas the shot or heavier material is thrown outside the receptacle.

The fibrous material is drawn from the receptacle 1 through a conduit 8, a suction fan 9 being provided in the conduit for this purpd'se. The suction due to the operation of the fan 9 has a tendency to draw down any fibrous material which might tend to pass over the top of the wall of the receptacle I.

This drawing down of the air in a zone surrounding the disc 5 and inside the walls of the chamber'l presents a novel and effective action.

The current of air tends to draw the fiber or thread downwardly much more than it does the head or shot because the head or shot presents much less surface for a given mass. A a result, by the downward pull of the air upon the thread or fiber not only is the thread pulled down into the-receptacle I, but this action tends to pull or break the threads off of and away from the heads or shot and out of the path in which the heads or shot are projected.

Thus, by projecting the spun material heads or shot and the fibers transversely across-the curarcane angle is with the bottom wall l2. The solid par- I rent of air, it is possible to secure a very good classifying action due to first that the heads or shot having a higher ratio of volume to surface to retain'a greater inertia and are projected to a greater radialdistance than the threads or fibers. Second, the transverse current of air draws the threads sidewise (i. e., down in Figure 1) relative to the path in which the material is projected. Hence, alarge part of the heads or shot are removed in this operation, while the fibers largely freed of heads or shot are drawn off and discharged through conduit 8:

This conduit 8 leads to a receiver "I, preferably of woven wire or similar openwork construction to permit air to pass therethrough while collecting the fibrous material. A small percentage of heavy or shot material will cling to the fibrous shot laterally to trap the same in the lower material and drop into the reseptacle I, and is drawn off through the conduit 8, which it is desired to separate as far as possible from the fibrous material.

This shot comprises some heads which are still integral with their fibers, which heads were not broken off by the air flow in the zone lying around the disc 5 and inside the receptacle 1. To some extent these heads may be freed as shot by the actionof the fan and the travel 01' the.ma terial through the conduit 8-8. However, I provide a further action in the' second stage of treatment where I provide means for breaking off and separating as shot those heads which still are attached to threads. This second stage of treatment also classifies and separates such loose shot as was not removed by the action in the first classifier 5-1-3 and such as has been freed from the threads or fibers in passing from the first classifier 5'|3 to the second classifier. I therefore suitably support within the receiver lfl'apan H, and the conduit 8 is arranged to discharge into this pan .Il. The wall of this pan is inclined inwardly from the base of the pan, and then outwardly, thus forming a wide mouth to receive the material from the conduit, and a narrow neck portion which tends to trap any shot which has adhered to the fibres.

The bottom wall 'of the pan as shown is coned convexlyin order to direct impinging heads or outer corner of the pan, both by their inertia and by gravity. The product carried bythe particles, such as shot or fibers with heads. or-

shot adhering to them, have sufilcient inertia to actually impinge against the bottom of the pan.

This impingement tends to shake loose or break loose from the fibers any solid particles such as shot or heads. Thereby the breaking off and separation of the solid particles as shot is effected by an action different from that in the separator and classifier 5-1-3. The deflection and gravitation of the solid particles laterally and downwardly keeps them from getting in the way of the incoming current of air and air borne material.

The pan ll forms a pocket with an inclined wall, 1 e., specifically, a flat cone l2 against the apex of which the discharge end of the tube 8 directs theair borne current of material. The

bottom wall has an annular conical wall l3 of steeper inclination than the wall I! joined to the outer end thereof so as to form an acute dihedral ticles in ,the air borne current tend to impinge upon said conical bottom wall and by their in- -ertia, bounce, and gravity are deflected into the it further into the comer or trap l5.

annular .pocket 15. The inwardly coned wall l3 tends to deflect any solid particles which strike The upwardly and outwardly flared wall ll allows and directs an easy expansion of the reflex current of air carrying the light fibers so that they are wafted out of .the pan II and tend to settle in the receptacle or bin 10. Obviously, the structural form 'of the pocket constituted by pan ll may be wide y varied giving, however, the above mode of impacting and separating. The fibrous stock under the action of the air is carried outwardly towards the wall of the receiver and drops to the bottom thereof. The fibrous material is removed from the receiver and bagged or baled as desired for convenient handling.

While the applicant does not desire to restrict himself to any particular dimensions, he has found that witha spinner I2! in diameter good results are obtained if the spinner chamber 3 is approximately seven feet square and six feet high, the receptacle 1 approximately four feet in diameter. It will be seen therefore that the main disintegration and separation of the fibrous material from the shot is conducted within the chamber -3, which is quite small in size. Thereceiver l0 may be of any suitable size. The chamber 3 and receiver ID will, of course,-be provided with suitable openings through which access may be had to their interiors for removing the shot material or .other purposes.

The apparatus above described is intended particularly for the manufacture of rock wool. It is found that with the apparatus above described, the rock wool is formedwith considerably longer fibres and contains less shot or heavy particles. The wool also possesses greater resiliency than rock wool as made by the older processes, and has a lesser tendency to break down under vibration. A given quantity of wool when subjected to a given pressure weighs lighter than wool made according to the old methods, and therefore a given quantity of the wool by weight, will go considerably further than the old type wool, and possesses a higher insulating value.

It is found that the thickness of the fibres may be regulated by varying the speed of rotation of the spinner.

What I claim as my invention is:

1. In apparatus for forming mineral wool from fusible solids, the combination with a furnace, of a rotary member having a downwardly and outwardly inclined peripheral portion; said peripheral portion having a plurality of closely spaced small V-shaped annular ribs formed in its upper surface, the inner sides of said ribs being narrow with a slight upward inclination, and the outer sides of said ribs wide with a slow downward inclination; means for rotating said member; and means for depositing molten material from said furnace in a. small stream on to said inclined peripheral portion of the rotary member.

- 2. In apparatus for forming mineral wool from fusible solids, the combination with a furnace of a rotary member; means for depositing molten material from said furnace in a fine stream on to said rotary member; means for rotating said member to centrifugally discharge the deposited inner and outer compartments; suction means for withdrawing the mineral wool deposited in 'the inner compartment, and a receptacle having openwork walls for receiving material from said suction means.

3. In apparatus for forming mineral wool from fusible solids, the combination with a furnace of a rotary member; means for depositing molten material from said furnace in a fine stream on to said rotary member," means for rotating said member to centrifugally discharge the deposited material from said member; and a chamber for receiving said discharged material, said chamber having a partition dividing said chamber into inner and outer compartments; suction means for withdrawing the mineral wool deposited in the inner chamber; a receptacle having openwork walls for receiving material from said suction means; and a pan positioned in said casing into which the discharge from the suction means is directed, said pan having a restricted neck portion adapted to trap heavier particles of material.

4. A method of forming mineral wool from fusible solids which consists in reducing the solids to a molten state; discharging the molten material in a fine stream, then bringing the molten stream into contact with downwardly and out.- wardly inclined annular surface while rotating the latter at high speed, drawing oil, in a current of air, the fibres from the loose shot adjacent the point of formation as fast as they are formed,

discharging in said current of air the withdrawn fibres downwardly against the wall of a pocket to breakoff any shot adhering to the fibres, and raising the fibers out of the pockets by the current of air to separate the broken-01f shot from the fibres.

5. In combination, a spinning cone comprising a central bodyportion and a downwardly and outwardly tapered marginal portion, said tapered marginal portion having upon its upper face a series of closely spaced grooves separated by circular ribs forming circular spinning edges from which fibers are adapted to be spun, means for pouring upon the grooved surface of the cone adjacent its periphery a stream of molten viscous slag like material which supplies simultaneously a plurality of said grooves to produce multiple spinning from the corresponding spinning edges, a fiber receiving receptacle having its upper rim dis posed below the cone and substantially surrounding the cone, said cone being mounted upon a vertical shaft extending solely from the upper end of the cone whereby the space below thecone and in the receptacle is unobstructed by the shaft, and a suction pipe having means for sucking a current of air downward around the periphery of the cone and through the receptacle and suction pipe to remove the fibers as fast as they are formed.

6. In the manufacture of mineral wool from a viscous molten material, the method "of separating shot from fibers which consists in projecting the molten material transversely to a current of air which is ineffective to deflect the shot but which draws the fibers transversely from the path of the shot as fast as the fibers are formed, and by said current of air convey the fibers as fast as they are formed and discharging them so as to impact them against a wall disposed within a pocket, said impacting tending to knock shot or heavy particles loose from the fibers and the current of air flowing out of the pocket wafting the fibers back out of the pocket.

7. The process of freeing solid particles from rock wool which comprises conveying a stream of the material to be separated in a current of air, discharging said current of 'air and air borne material against an inclined bottom wall of a pocket whereby the denser portion of the current of air borne material impinges against said inclined wall and breaks the solid particles loose from the fibers of the wool, said solid particles being deflected laterally and downwardly by said inclined wall by inertia and by gravity and the fibers are wafted up and out of the pocket by the reflected current of air escaping out of the pocket.

8. The combination of a pan having a coned bottom wall and a rim, said rim consisting of an annular wall forming with the bottom wall an acute angle to provide an annular pocket for trapping said particles which impinge upon the coned portion wall, and means for discharging an air borne current of fibrous material with adherent solid particles against said coned bottom wall, said means comprising a discharge tube directed axially upon the point of the cone.

9. The combination of claim 8 with an outwardly and upwardly flared conical wall joining the. upper margin of said annular wall and serving to form an expansion passageway for the refiex current of air which is discharged by said tube in the direction of said coned bottom wall.

10. Apparatus for forming mineral wool comprising the combination of a shaft joumaled for rotation on a vertical axis, a rotary spinning member mounted on the lower end of the shaft,

the space around and under the member being.

upon said marginal conlcalportion at a point remote from the center of the member and in sufiicient volume to cause the molten materialto spread upon the inclined surface simultaneously over a series of said grooves, said grooves and ribs tending to assist in the spreading of said material on the member, and means for rotating the member at high speed, whereby the molten material is spun into fine fibers from a plurality of said edges in multiple at the same time and under substantially the same temperature conditions by the operation of said spinning member.

11. Apparatus for spinning molten viscous ma terial into fine fibers comprising a rotating spinner consisting of a central body having a downwardly sloping conical margin, said body having a series of closely spaced circumferential grooves formed on said margin, said grooves being spaced apart by sharp ridges from the tops of which fibers are spun, a shaft joumaled for rotation on a vertical axis, said spinner being disposed on the lower end of the shaft leaving the space around the sides and under the spinner clear of obstructions whereby fibers spun from the periphery of the spinner may be removed, as fast as formed, by a current of air, means for providing molten viscous material to be spun, and means for depositing a stream of said molten material upon the conical margin remote from the center of the spinner in sufficient volume to supply directly a plurality of said grooves simultaneously with material for spinning, and suction means for continuously drawing the fibers downwardly and away to remove them as fast as formed.

12. Apparatus for producing mineral wool comprising means providing a supply of molten viscous mineral for spinning, a rotary spinner having on its upper surface a conical margin on which are formed a series of closely spaced circumferential grooves separated by narrow ridges from'the tops of which fibers are spun, a shaft journaled for rotation, the spinner being mounted on the end of the shaft leaving the space about and beyond the spinner clear of obstructions, means for depositing a stream of said molten material upon the grooved surface of the spinner at a point remote from its axis simultaneously into a plurality of said grooves whereby fibers are spun in multiple at the same time and under substantially the same temperature conditions from a plurality of said spinning ridges, means for driving the shaft and said spinner at high rotative speed to cause the aforesaid spinning of fibers by the rotation of the disc, a fiber receiving receptacle having a wall, particles of the material not drawn into fibers being adapted to be discharged beyond the edge of the wall, said receptacle being disposed adjacent the spinner in position to receive the fibers, and suction producing means for drawing a current of air through the space in which the fibers are spun and through the receptacle to carry the fibers into the receptacle and to remove the fibers from the receptacle in a continuous operation, the space in which the fibers are spun and the interior of the receptacle being free of obstructions whereby the fibers may be continuously removed as fast as they are formed.

CHARLES RICHARD BUSS.

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