US2317895A - Means for and method of manufacturing mineral wool products by the "dry" process - Google Patents

Description

D. c; DRILL 2,317,895 MEANS FOR AND METHOD OF MANUFACTURING MINERAL WOOL April 27, 1943.

PRODUCTS BY THE "DRY" PROCESS Filed March 3, 1941 4 Sheets-Sheet 1 v Qm Dam-J c. mm

7 INVENTOR.

ATTORNEY.

Aprnl 27, 1943. c. DRlLL MEANS FOR AND METHOD OF MANUFACTURING MINERAL WOOL PRODUCTS BY THE "DRY" PROCESS Filed March :5, 1941 4 Sheets-Sheet 2 IN VEN TOR.

l. 6 Q Dania! C, Dr iil ATTORNEY.

A nl 27, 1943. D. c. DRILL 2,317,895

MEANS FOR AND METHOD OF MANUFACTURING MINERAL WOOL PRODUCTS BY THE "DRY" PROCESS Filed March 3, 1941 Daniel C. Drill INVENTOR. I 6 6 MW ATTORNEY.

D. C. DRILL April 27, 1943.

. 2,317,895 MEANs FOR AND METHOD OF MANUFACTURING MINERAL wooL PRODUCTS BY THE "DRY" PROCESS Filed March 3, 1941 4 Sheets-Sheet 4 Daniel c. Drill ATTORNEY. K

Patented Apr. 27, 1943 UNITED STATES PATENT OFFICE 2,317,895 f MEANS FOR AND :METHOD OF MANUFAC-"j TURING MNERAL WOOL PRODUCTS BY THE DRY PROCESS Daniel 0. Drill, Wabash, Ind., assignor-to American Rock Wool Com, Wabash, Ind., a corporation of Indiana Application March 3, 1941, Serial No. 381,556.

" (cum-27) pulp. The wet mixture is then compacted, dried,

14 Claims.

This invention generally relates to a mineral wool felted product having a low "shot'? and nonfibrous content and to means for and methods of manufacturing the same by the dry process.

In the conventional method of manufacturing mineral wool felted material by the dryprocess now generally employed by the industry, a

. stream of suitable siliceous materials is disintegrated by the shredding blast-not into portions alone-but into a stream or glass-like slugs, slivers, and shot, to the last of which there are appended the true mineral wool fibers. These fibers provide substantially all "of the heat insulating and acoustical properties, the

fibrous mass .of

and bonded together in water with wet paper and cut to form a batter the like.

The present'inven'tionhas for its object the provision of improved apparatus and'methods 3 whereby thevshot and non-fibrous portions may be, to a large extent, separated from the fibrous portions before the fibrous'portions become deposited on the movable floor or conveyor of th blow chamber. a

, Afurther object of the invention is the provi- 1 sion ofways and means whereby substantially shot free batts may be continuously and economi- Cally Produced. 1 H

A further object is the provision of an improved tensile strength, and the resilience of the finished '15 settling c a b r Which h gases d th 3- Pr d ct The Slugs. slivers and shot, however, bers of the chamber are withdrawn in amanner are of no value whatever in the felted mineral .adapted to provide. a more efiicient feltedgstrip wool blanket or batt, but materially impair its of fi s n the movablefioorvof the blow ch mquality and readily stick into-0r perforate the r r r hands of the operators who handle the product er objectis the prov ways, n in preparing it for shipment nd in applying t means whereby substantially all of the gases in in the structures which are to be insulated or to a blow chamber of the character described may be made more sound absorbent. be withdrawn-through: the felted strip; forming In the conventional manufacturing operation, o t e o v yor of the blowchamber-anda D0 the disintegrated mass of fibers, shot, slugs and tion of these withdrawn gases may b blown ac slivers are all blown by the blast into the settling nto t e Settling chamber to aid h elimina'e chamber where they become felted together on tion of much of the shot inthe'finished batt, to a continuously movable floor of the settling chamaid in maintaining the setting chamber at the ber upon which they form an elongated blanket desired p e, and to aid in producing a which is continuously withdrawn from the setmore Perfect bath J 1 tling chamber and thereafter compacted and out A' furth r object s t provision f w s and into the desired blanket sections, pads, batts or mean wh r y stream 's -m y 'be' irec ed wall boards, hereinafter referred to as batts.', aga nst 93 fa llngstream of fibers to aid in obtain- Since the beginning of the mineral wool indusing an even distribution of said fibers 'on the try, the inclusion of .the shot and other non-fimovable floor-or conveyor of theblow chamber brous portions has been recognized as an unmitiupon which the mineral wool strip is being gated evil and manyefiorts have been made by formed. v those skilled in the art to eliminate these non- A further object is the provisionof ja gblow fibrous portions from the unfinished material. chamber having-two movable floors or conveyors One method is to granulate the wool by turn- 40 upon one of which the feltedstrip is formed and bling the disintegrated mass and passing it over removed'fromthe chamber and upon the other a rotating screen through which a large part'of of-which the shot is deposited and removed fromthe shot and other non-fibrous portions become the blow, chamber. l

if sifted out. In this operation, thewoolis rolled A further object is the provision of amineral into the small balls, pads, or pellets which are wool settling chamber having means whereby known to the industry as granulated wool. These substantially all of the loose shot may. be autofibrous balls, pads, or pellets, however, ar not matically removed :frOm the settling chamber. suitable for forming batts or 'the'like by the dry" The other objects and purposes of this inv'eriprocess because these balls, pads, or pellets do tion ,will appear from thefollowing description, not readily felt to each other and the resulting s, a d accompanying w n s. 1 ff batts have little or notensile strength. When .In. the drawings: I y it is desired to use this granulated wool to make 7 Figure 1 is a partly side ,elevational and'partly felted material, the granulated wool is first mixed cross sectional view of a preferred formof the apparatus of my invention,

.iled form .of myinvention.

:be used'in carrying out my invention, but I wish it to be understood that other suitable forms of apparatus may also be employed in manufacturing mineral wool products .in accordance with the ,teachingsand methods of .:my invention.

In Figure vl there is shown a cupola or melt- .ing .means ,2 in which suitable raw materials :may :be melted :in a manner adapted to provide a continuouslyflowing stream 3 of suitable molten materials -of a type adapted to provide mineral awool' ilbers.

the same figure have also shown a blow chamber 4 which is particularly adapted to be used in carrying out my invention. This chamber preferably includes-a rear wall .3, .side walls .8 and 1.0, a roof I2. a rearwardly-movable shot .removing .conveyor 14 and an adjacent upwardly inclined and forwardly movable conveyor 10.

The shot receiving conveyor. l4-is provided with a foraminous continuously movablebelt l8 which is.adapted to move the .separatedshotzand other non-fibrous particles deposited. "thereon backwardly out of the blow chamber .anditodischarge these particles into any suitable receiving means,

such as a hopper-20, having" a downwardly extending conduit 22 through which theshot and other non-fibrous portions maybe discharged into a truck or the like by opening a slidinggate .The upwardly inclined conveyor l8 includes a yccntinuonaly movable belt 23 upon which the mineral wool fibers may-be deposited fromgaseous suspension in a manner adapted to form an,

elongated blanket ll of mineral wool which, in operation, continuously moves forwardly under a compacting roller 23, and then out of the blow chamber where the blanket is. cut into sections to provide felted mineral wool products, such asv rolled strips, heat insulating abatts, and acoustical pads.

Each of these conveyors are, of course, provided I with suitable driving means (not shown) whereby the conveyors may be driven at the desired operatin'g speeds. The shot removing conveyor may be moved at any desired speed. The forwardly movable conveyor should, however, be driven by somesuitable variable speed drive means (not shown) at a speed preferably determined by the "thickness of the blanket to be produced and by the rate at'which the mineralwool is deposited .on this conveyor.

Ihave also provided a blowerconstruction which is adapted for withdrawing the steam and .air .or other gases from the blow chamber through the foraminous upwardly inclined conveyor belt 26,;for. discharging a desired part of the withdrawnyapor and gases into the outer atmosphere and for feeding the remaining portion of the withdrawngases back intothe blow chamber-for purposes which will become more apparent as thespecification proceeds. l

This blower construction may be made-in any 'Figure2isa section taken .along the lines 2-2 suitable form, but I preferably employ the conmunication with theoutside atmosphere, and it I may be advantageously provided with a suitable damper means 42 whereby the flow of the gases and vapor through the discharge conduit may be controlled as desired. This blower 32 is operatively connected to the intake side of the blower 34 by any suitable conduit 44 which may also beprovided with an adjustable damper 46 for the purpose of controlling the rate of flow of the gases which pass through the blower 34. This blower 34 preferably has two discharge conduits 48 and 50, the first of which is operatively con- 'nected to a pan 5| which may be operatively associated with the foraminous shot removing belt [8 between its upper and lower portions substantially as shown. Each of the conduits 48 and 50 is preferably provided respectively with dampers 52 and 53 whereby the flow of the fed back vapors and gases through these conduits may be controlled.

y Y The discharge conduit 50 (see Figures 2, 5, and 6) is connected at its upper end to a preferably rectangular funnel-like discharge member 54 (see Figures 1, 5, and 6) connected andse- .cured around an open portion 55 in the lower central portion of the rear wall 6. This discharge member may be advantageously provided with two pivotally mounted andsubstantially parallel dampers 58 and 60 having crank handles 52.

These handles are operatively connected by'connecting bars 64 and to a motor driven variable speed drive means 61 in' a manner whereby each of the two dampers may be simultaneously swung to and fro in'a preferably horizontal plane to direct the stream of gases'blown through the conduit 50' to and fro over the shot removing conveyor and toward the forwardly movableconveyor on which the mineral fibers are being, deposited.

The roof l2 of the settling chamber preferably, although not indispensably, includes a raised rear roof portion 68 and a, substantially lower front portion 10 which may be connected. to-

gether by a wall portion 12. a

In the raised roof portion 68 I have provided a preferably circular open portion 14 upon which is mounted a blow tube 16 which is preferably in the form of a hollow truncated cone. This blow tube may be operatively connected to the blow chamber in any suitable manner, but it is preferably supported in position by an out-,

wardly extending peripheral flange 18 which may be rigidly secured to the upper roof portion 68 by any suitable means such as, for into any suitable blast fluid supply means, for instance, a steam generating plant (not shown).

The periphery of the central open portion 85 is defined by a cylindrical wall portion 92 and a lower truncated cone-like wall portion 94.

This cone-like wall portion is provided with a plurality of preferably downwardly and inwardly 'eral wool fibers) are therefore quickly decelerated and placed in atmospheric suspension while the sings, and unattached shot imme- "diately fall upontheshot removing-conveyor.

extending conduits or nozzle orifices 96 whereby' the blast fluid may be directed in a plurality of streams downwardly and at an angle on the lava stream. These blast streams disintegrate A large part of such shot as remains attached to the "mineral wool fibers continues onits downward course and is therefore torn or pulled apart from the real mineral wool fibers and falls upon the shot removing conveyon: ;The fibers,

the lava stream, as has been before mentioned,

into mineral wool fibers and non-fibrous portions such as slugs and shot.

This blast nozzle construction may,'if desired, 1

be provided with a peripheral flange 98wh'ereby the blast nozzle means may be supported upon the open upper portion I of the blow tubesubstantially as shown. The nozzle orifices 96 may be formed in a plurality of spaced apart rings 91 in a manner adapted to direct the jets of the shredding fluid around the lava stream at different vertical levels in order that this lava together with the small amountof shot which still remains attached -to the wool, are blown toward the forwardly moving conveyor where they are drawn-downwardly and deposited'on thisfconveyor by reason of'the'stream of gases being "drawn downwardly through this conveyor by the blower-32. -While the fibers are being drawntoward this "conveyor, "the stream of fed back gases issuing'from the conduit Sllgls'constantly movinglaterally to and fro across this conveyor in a manner adapted to distribute these suspended fibers above that portion of the conveyor immediately above the suction pan 36.

stream may be more thoroughly shredded by the action of the shredding blast.

The blow tube 16 is preferably provided with some suitable liquid spray or injection means upon the conveyor.

This transverse movement of the gases, of course, serves to distribute the fibers more or less evenly Should the fibers, however, be deposited on one portion of the conveyor more than on an adjacent portion, this condition is whereby liquid or molten adhesives may be sprayed upon and intermixed with the newly formed fibers in the blast of fiber formation. One such means N12 is shown in Figure 1 and includes a supply conduit I04 which is adapted for operative connection to any adhesive sup-- desired in the finished mineral .wool product.

This conduit is operatively connected to a fluid nozzle construction I08 which includes an an nular conduit H0 having a plurality of spaced apart and inwardly inclined spray tubes H2 which are adapted to discharge a plurality of adhesive sprays or streams through the open portion H3 in the blowtube and into the comingled blast of steam or air and newly formed fibers a short distance below the blast nozzle means.

In operation the lava stream is poured from the spout or lip H4 of the cupola 2 and falls in the close vicinity of the blast nozzle where it is drawn centrally into the open portion I00 of this nozzle by reason of the suction of the air drawn quickly remedied by reason of the fact that the resistance to the suction of the gases through the thicker portion of the felted strip isgreater thanthe resistance offered to the gases through the thinner portions. A-larger proportion of the gases will, therefore, be drawn through these thinner portions until the fibersare evenly deposited'on that part of the conveyor.

This ability of my apparatus to evenly distribute the fibers on the conveyor is considered an important'feature'of my invention. 'At the present time the tendency of both the consumers. and the buyers is to become more and more insistent that felted mineral wool products have a uniformd'ensity. This is, of -course,'due to the fact that when one portion of the product has asubst antially lower density than other portions,

the overall heat insulating value of the product is substantially reduced because the flow of heat through this open portion by the force of the suction blast. As the lava stream passes through the nozzle it is, of course, shredded by the action of a plurality of shredding blast jets issuing from the nozzle orifices 96. a

-As has been previously mentioned, the shred-- ding blast unfortunately does not shred the lava stream into mineral wool fibers alone but also into non-fibrous portions such as, for instance, shot, slugs and the like.

These disintegrated portions, of course, are

first blasted or blown down rapidly by the force of the shredding blast and are hurled with a high velocity against the relatively stationary least resistance.

Another important feature of the apparatus of my invention is believed to reside in the fact that i the drawing of a gaseous streamthrough the forwardly movable conveyor belt 26 exerts a resilient oscillating pressure downwardly upon each individual fiber as soon as it is deposited on the forming blanket and thereby forces the fibers to move into closer contact with the adjacent fibers and become more thoroughly felted in the forming blanket. This, of course, causes the product to have a greater tensile=strength than it would I ket by any suitable means such as a suction'means otherwise have. This is especially true when adhesives are employed because it brings the adhesively treatedsurfaces of' the fibers closer together, and holds them in this close relationship until they have passed under the compacting roller 28 after which the adhesives are cooled by the relatively cold air of the atmosphere outside the blow chamber which may, if desired and often is, rapidly drawn through the felted blan- (not shown) which may include asuctionpan, conduit and blower (not shown) of any type adapted to draw cold air through the felted blanket after it has passed under the compacting roller 28.

Another feature of my apparatus is that the force and rate at which the gases are withdrawn and fed back into the blow chamber may ber j damper 42, 28, 52, 53 provided in the conduit 30 of my blow chamincreased or decreased by suitablygmoving the l its discharge side to the atmosphere outside of said blow chamber.

3. A mineral wool blow chamber having a roof portion, a wall portion, a base portion, and an purpose of exemplification and'not limitation since numerous modifications maybe made in the apparatus and methods disclosedherein without departing from the spirit of our invention or the scope-of the claims appended hereto. instance, it is obvious that any suitable perforated baseportionand anysuitable horizontally extending forwardly moving conveyor maybe re- For spectivelysubstituted for the rearwardly moving a base portion which is provided with a'screened horizontally extending conveyorbelt l24.- This modifiedv form of theblow chamber, of course, is

provided with some suitable, suction blower construction I26 whereby the gases=may=bewith-.

drawnfrom the blow chamber through the forwardly movable conveyor and then fed back into the blow chamber throu h the hopper or discharged into the outer atmosphere in any desired proportion.-

I claim:

1. A mineral wool blow chamber having a roofportion, awall portion; a base portion, an open a portion adapted to" receive ablast of mineral wool fiber'formation and a suctionvblower means, an upwardly extending blow tube operatively con-- nected to said open portion, anda fluid blast nozzlemeansmount'ed on, said blow tubein a manner adapted to direct a shredding blast down- ,wardly; through said blow tube into the interior I qc'onveyor I4 and forwardlymovable conveyor l6.

Such a modified form ;is shown inFigure'Z and ingludesany suitable .blowv chamber IZO- having hoper l2! and a perforated forwardlymovable open portion adapted to receive a blast of mineral woolflber formation and a suction blower means, said baseportion including two endless foraminous. conveyor belts movably mounted in substantial alignment with each other and being provided with driving means to drive one of said belts in one direction and the other of said belts in an opposit direction, said suction blower means beoperatively connected to each of said belts in a manner adapted to withdraw gases out of said blow chamber through one of said'conveyor belts and to feed back at least a portion of the withdrawn gasesinto said blow chamber through the other of said belts and including a blower having an intake side and a discharge side and being operatively connected on its intake side to the iimer surface of one of said belts and being operatively connected ,on its discharge side 'to the innerside of theother of said belts, said blower being also connected on its discharge side to the atmosphere'outside of said blow chamber, said blower being provided with a plurality of conduits and a plurality of damper means in said conduits v whereby any desired proportion of the withdrawn gases may be either fed back into the blow chamber ordisoharg ed into the atmosphere outside said blow chamber.

of said blow chamber, said. base portion includ ing two endless foraminousconveyorbelts movably mounted in substantial alignment with each Y suction blower means being operatively connected to, each of said belts in a manner adapted to withdraw gases out of said blow chamber through.

one of said conveyor belts and to feedback at least a portion of thewithdrawn gases into said blow chamber through the other. of said belts.

2. A mineral wool blow chamber having aroof 4. A mineral wool blow chamber of the, character described, said blow chamber having a roof ed over the opening in sai d wall portion and being adapted when operatively connected to a fluid pressure supply system to disintegrate a stream of suitable molten materials into mineral wool fibers,

shot,and slugs and tohurl said fibers, shot and slugs. downwardly into the interior of said blow chamber toward said rearwardly movable conveyor and a suction means including a blower having a fluid inlet and a fluid outlet, a conduit operatively connected to said fluid inlet and to said forwardly movable belt in a manner adapted to withdraw the gases from said blow chamber through said forwardly movable conveyor and a conduit operatively connected to said rearwardly portion,.a wall portion, a base portion, and an foraminous conveyor belts movably mounted in substantial alignment with each other and being provided with driving means to drive one of said belts in one direction and the other of said belts movable conveyor adapted to feed back at least a portion of the withdrawn gases into said blow chamber through said rearwardly movable conveyor. v

5.. Amineralwool blow chamber of the char acter described, said blow chamber having a roof portion provided with an opening, a wall portion,

in an opposite direction; said suction blower said belts in a manner adapted to withdraw gases out of said blow chamber through. one of said conveyor belts and .to feed back at least a por-' 7 means'being operatively connected toeach of charge side and being operatively connected on its intake sideto-theinner surface of one of said belts and being operatively connected on its discharge side to the inner side of the other of said belts, said blower being also connected on a base portion including a forwardly movable foraminous conveyor and a rearwardly movable pressure supply system to disintegratea stream of suitable molten materials into mineral wool fibers, shot, and slugs and to hurl said fibers, shot, and slugs downwardly into the interior of said blow chambertoward said rearwardly movable .conveyor and a suction means including a blower havingafluid inlet and a fluid outlet, a conduit operatively connected to said fluid inlet and to said forwardly movable belt in a manner adapted to withdraw the gases fromsaid blow chamber through said forwardly movable conveyor and a conduit operatively connected to said rearwardly forwardly movable conveyor.

movable conveyor adapted to feed back at least a portion of the withdrawn gases into said blow chamber through said rearwardly movable conveyor, said suction means being also provided foraminous conveyor and a rearwardly movable foraminous conveyor, a blast nozzle means mounted over the opening in said wall portion and being adapted when operatively connected to a fluid pressure supply system to disintegrate a stream of suitable molten materials. into mineral wool fibers, shot, and slugs and to hurl said fibers, shot, and slugs downwardly into the interior of said blow chamber toward said rearwardly movable conveyor and a suction means including a blower having a fluid inlet and a fiuid outlet, a conduit operatively connected to said fluid inlet and to said forwardly movable belt in a manner adapted to withdraw the gases from said blow chamber through said forwardly movable conveyor and a conduit operatively connected to said rearwardly movable conveyor adapted to feed back at least a portion of the withdrawn gases into said blow chamber through said rearwardly movable conveyor, said suction means being also provided witha third conduit'operatively connected to the output side of said blower and to the wall portion of said blow chamber in a manner adapted todirect a transversely moving stream of the withdrawn gases over said rearwardly movable conveyor and toward and in the general direction of the movement of said forwardly movable conveyor.

7. A mineral wool blow chamber of the character described having a roof provided with an inlet opening, a wall having an opening in its rear portion, a base portion having a rearwardly moving conveyor and a forwardly moving conveyor in substantial alignment with and adjacent to each other, a downwardly directed blast n02- zle means mounted above said opening in said rear wall portion and operatively connected to a fluid pressure supply system to provide a downwardly directed blast disintegrating a stream of suitable molten materials into a stream of intermingled mineral wool fibers and shot and direct: ing said last mentioned stream downwardly toward said base and above said rearwardly moving conveyor and a driven blower means having a fluid discharge conduit operatively connected through said rear wall opening to direct a fluid stream laterally into said chamber against said downwardly directed blast to blow said fibers away from said rearwardly moving conveyor and on said forwardly moving conveyor, said conduit being provided with a driven laterally and reciprocally movable damper means whereby said fluid stream may blow said fibers to and fro transversely over said forwardly moving conveyor and thereby distribute the fibers in the form of a moving blanket more evenly upon said last mentioned conveyor. v

8. The method of making from a stream of suitable molten mineral materials, a mineral eral wool fibers said method comprising shredding said stream into a commingled blast of mineral wool fibers and shot with a gaseous. blast directed downwardly onsaid stream, directing upwardly and against said first-mentioned blast an upwardly moving gaseous stream to halt the downward movement of said fibers while allowing a continuation of the downward descent-of at least a substantial portion of said shot and collecting the fibers in the'form of a blanket oil set with respect to the lineof travel of said shot.

9. The method of making from a stream of suitable molten mineral materials, a mineral wool blanket of at least partially de-shotted mineral wool fibers; said method comprising shredding said stream into a commingled blast of mineral wool'fibers and shot'with a gaseous blast di rected downwardly on said'stream; directing upwardly and against said first-mentioned blast an upwardly moving gaseous stream to halt the downward movement of said fibers while allowing a continuation of the downward descent of at least a substantial portion of said shot, collecting said fibers in the form of a blanket off-set with respect to the line of travel of said shot and withdrawing the gases from said gaseous blast and ,said gaseous stream through said blanket during the formation thereof, r

10. The method of making from a stream of suitable molten mineral materials, a mineral wool blanket consisting at least of partially deshotted mineral wool fibers; said method comprisingshredding said stream into a commingled blast of mineral wool fibers and shot with a gaseous blast directed downwardly into a relatively downward descent of at least a portion of said shot and collecting the fibers in the form of a blanket oifset and moving away from the line of travel oi said shot.

11. The method of making from a stream of suitablemolten mineral materials, a mineral wool blanket consisting at least of partially de-shotted mineral wool fibers; said method comprising shredding saidstream into a commingled blast of mineral wool fibers and shot with a gaseous blast directeddownwardly into a relatively stationary atmosphere, directing upwardly into said atmosphere and in opposition to said commingled blast a gaseous stream to halt the downward movement of said fibers while allowing the downward descent of at least a portion of said shot, collecting said fibers in the form of a blanket ofiset and moving away from the line of travel of said shot, and moving said shot in a direction other than the direction of movement of said blanket. a

12. The method of making from a stream of suitable molten mineral materials, a mineral wool blanket consisting at least of partially de-shotted mineral wool fibers; said method comprising shredding said stream into a commingled blast of mineral wool fibers and shot with a gaseous blast directed downwardly into a relatively stationary atmosphere, directing upwardly into said atmosphere and in opposiiton to said commingled blast a gaseous stream to halt the downward movement of said fibers while allowing the down-- ward descent of at least a-portion of said shot, collecting the fibers in the form of a blanket offset and moving away from the line of travel of said shot and withdrawing said-gases in said 7 7 blast and said gaseous stneam through; said blanket during. theformation: thereofi'.

13.. The" method? of making: from. as stream of suitabl'e molten mineral materials; a mlnerallwool blanket consisting at least of. partially de-shotted mineral wool fibers; said method comprising shredding said stream into a commi'ngljed blast of mineral wool flbers; and shot. with" a gaseous blast; directed downwardly into a relatively stationary atmosphere, directingupwardly into said atmosphere andin opposition to said-scommingled blast a gaseous stream to halt the: downward V 14; The method-of making from a stream of suitable molten mineral materials, a mineral wool blanket consisting at least of partially asshotted mineral wool fibers; said method comprising shredding said streamintov a commlngled blast of' mineral wool fibers and shot with a gaseous blast directed downwardly into a relatively stationary atmosphere, directing upwardlyinto said atmosphere. and inopposition to said commingl'ed blast a gaseous stream to halt the downward movement of said fibers while allowing the downward descent of at least a portion ofsaidshot, collecting theflbers in the form of. a

blanket ofiset and moving away from the line" of travel of said shot, and feeding back a portion.

of the withdrawn. gases to supply said gaseous stream.

DANIEL C. DRILL.

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