US2275816A - Flowable heat insulating material and method and apparatus for forming the same - Google Patents

Description

March 10, 1942. R. ERlcsoN '52,275,816

FLOWABLE HEAT INSULATING MATERIAL AND METHOD AND v APPARATUS FOR FORMING THE SAME Filed March 14, l938 2 Sheets-Sheet 1 'www ff flat/wl fav@ im l March 10, 1942. A R ERlCsON '2,275,816

FLOWABLE HEAT INSULATLNG MATERIAL AND METHOD AND APPARATUS FOR FORMING THE SAME Filed March 14, 1938 2 Sheets-Sheetl 2 I Patented Mar. l10, 1942 ,//FLOWABLE HEAT INSULATING MATERIAL AND METHOD AND APPARATUS .FOR

FORMING THE- SAME ammira Ericson, chicago, nl., assigner to United States Gypsum Company, Chicago, Ill., a corporation ot Illinois Application March 14, 1938, Serial No. 195,831

9 c1sims. (ci. 154-28) for example as mineralvl wool, into particles of My invention relates to heat insulating materials and to methods and apparatus for producing the same. More particularly, the invention relates to the manufacture of owable heat insulating materials of a fibrous character and has for an object the provision -of a product, process, and apparatus of this type.

In the insulation of buildings and other similar structures it is now common practice to intro'duce into the hollow wall spaces thereof granular types of insulating materials so as to decrease the iiow of heat therethrough. Various attempts have heretofore been made to increase the owability of granular fibrous materials so as to duplicate the owability of other types of granular insulation such, for example, as ground cork, pop corn slag, or expanded vermiculite, but so far as I am aware none of these attempts have been entirely successful.

One method of treatment which is now common in the art, is to pass the fibrous material through nodulating or granulating` machines so as to roll the material into small irregular shaped particles to facilitate blowing or pouring the material into a space to be insulated. The fibrous insulating material thus formed is more spreadable than ordinary fibrous particles not so. treated, but it cannot be considered as flowable. In other words, While the material c'an with some difculty be spread out between joists to a fairly uniform thickness, considerable difficulty is encountered when it is attempted to pour the material into a hollow wall space or into similar voids of appreciable depth.

- `An examination of the fibrous particles now sold on the market as nodulated or granulated wool indicates that the-exteriorsurfaces of the particles consist of extending threads -of fibers which interlock with similar fibers on adjacent particles, thus preventing free fiowability of the material. It will also be found that fibrous particles thus formed are composed of fibers which have broken considerably during the process of nodulating or granulating. It will thus be apparent that something is yet to bedesired in fibrous insulating materials of this character,

and accordingly it is a further object of my in- -vention to provide an improved method and apparatus whereby a granular fibrous insulating material may be provided having a high degree of owability due to the fact that the exterior surfaces of the resulting nodules or particles are substantially free from projecting fibers.

In carrying out my invention in one form I iirst form the fibrous linsulating material, such predetermined size Aand treat the particles so as to remove the projecting fibers from the exterior surfaces thereof. More particularly, the particles after being formed to a predetermined size are subjected to a rollingy action to form substantially spherical particles which are then subjected to4A a surface-treating operation to remove the projecting fibers. This surface-treating operation may be accomplished by heating the spherical'particles suiiiciently to fuse the external surfaces thereof and remove the projecting fibers while forming a slight incrustation on the surface, or a similar incrustated surface may be provided by coating the'v exterior surfaces of the spherical particles with a suitable adhesive material so as to bind the projecting fibers together and form an incrustation or coating.

Itwill of course be understood that the nodules thus formed may be of various desired sizes and shapes,` and a very eiiective iiowable'heat insulating material may be obtained by intermingling nodules of several diierent'sizes, the nodules of each particular size being formed in accordance with my invention lto provide incrustated or smooth surfaced particles.

As a further aspect of my invention I provide an improved apparatus for subjecting -the particles to a rolling action so as to provide a spherical coniiguration, and in some cases it may be desired to apply the coating material to the particles prior to the rolling action.

Fora more complete understanding of my invention reference should now be had to the drawings in which:

Figure l is a somewhat diagrammatic representation of a preferred form of apparatusembodying my invention for producing, by my im- '.proved process, granular heat insulating mate-l rials embodying my invention;

Fig. 2 is a fragmentary view of a modified form of apparatus embodying my invention;

Fig. 3 is a diagrammatic'representation of a still further form of apparatus which may be utilized in carrying out my invention;

Fig. 4 is a fragmentary view of va portion of the apparatus used vwhen it is desired to apply the coating material to the particlesprior to the A rolling operation;

Fig. 5 is a disassembled detail view of a portion of the rolling means illustrated generally in Fig. l; and

Fig. 5 is another disassembled detail view of a portion of the rolling means illustrated generally in Fig. 1.

embodiment of my invention illustrated in Fig. l a body of brous material I0, such for example as mineral wool, glass wool, etc., is continuously fed, as. for example by a conveyor II, to aA a rotating trommel I6 for closely grading the particles; The trommel IS'is of a type well known in the art and includes a plurality of screens of various sizes, the smallest screen being adjacent the inlet end of the trommel and the largest screen being adjacent the discharge end from which .end oversize particles are returned to the' disintegrator through a duct Il, only a portion of this duct being shown.

As shown, the trommel I discharges the closely graded particles into a plurality of funnel-like conduits I8, the lower end of each of the funnels I8' communicating with a rolling device for reducing the particles to asubstantially'spherical i shape. Each rolling device, as shown, consists of a stationary disc or plate I 9 arranged in face-to-face engagement with a rotating disc 20, the disc 20 being' keyed to a rotatable shaft 2| which may be driven by any suitable means, not shown, and the stationary disc I9 being rigidly mounted, as` for example by a bracket 22, and being provided with a suitable aperture through which the rotating shaft 2| loosely extends.

As shown best in Figs. 5 and 5e, the stationary disc I9 is provided with a substantially circular groove 23 in one face thereof and the corresponding face of the rotatable disc 20 is provided with a cooperating groove 24, so that when the discs are arranged in face-to-face engagement i brous nodules of several different sizes.

the grooves 23 and 24 form a passageway which is substantially circular in cross section. Adjacent its upper end the stationary disc I9 is provided with an inlet 25, and a similar outlet passageway 251s provided in the disc I9 adjacent its lower end.

It will 'thus be apparent that when the closely graded Y particles are introduced into the inlet passageway .25 in the various rolling devices, rotation of the rotatable discs 20 will effect movement of the particles through the passageways formed by the grooves 23 and 24 and will subject e the particles to a rolling action so as to impart thereto a substantially spherical shape before the particles are discharged through the outlet 26. It will of course be understood that the grooves 23 and 24 in the various discs I9 and20 are so formed as to provide passageways corresponding in size to the size of the graded particles supplied thereto.

From the outlet passageways 2B of the rolling devices the fibrous particles which are now substantially spherical in form are discharged into a' suitable conduit 21 or other suitable conveying means, and are thereby introduced into a separating chamber 28 which may, if desired, be sirn-` ilar in construction to the separator I5. While any suitable means may be provided for conveying the particles from the disintegrator I2 2,275,816 Referring now to the drawings, in the preferred through the various portions of the apparatus, I prefer to provide a closed system of the type shown and to convey the particles pneumatically through the apparatus by means of suction, which may be accomplished by connecting to the conduit 29 at the top of the separator 28 suitable suction applying means not shown.

The lower vend of the separator 28 is provided with a discharge opening 30 as shown, from which the particles drop by gravity through a treating chamber 3| in which the surfaces of the particles are so treated as to remove the extending fibers therefrom and form a surface incrustation thereon so as to form a free flowing heat insulating material of the character described above.

It will be apparent that during passage through the duct or conduit 21, the separating chamber 28, and the treating chamber 3I, the various size particles discharged from the rolling means comprising the discs I9 and 2|! are thoroughly intermingled vand accordingly the flowable heat insulating material as it reaches the sacking bin 35 consists of intermingled, smooth-surfaced, fi- If desired of course the nodules of each particular' size may be separated as they leave the rolling devices and may be separately treated thereafter to provide a final product made up entirely of nodules of similar size. Ordinarily a more closely packed insulation will be obtained by employying a material made up of intermingled nodules of several different sizes.

In .the embodiment of my invention here shown, this surface treatment of the particles is accomplished by fusing the exterior surfaces to such an extent as to remove any projecting fibers and form a slight incrustation. Thus the treating chamber 3| is provided with a plurality of burners 32 which may be gas, oil, or powdered coal burners, and which discharge directly into the chamber 3l so as to provide a heating zone inthe chamber, the gases of combustion passing upwardly through the chamber 3I and out of the top thereof. As the particles pass downwardly through the combustion 'chamber 3| in counter-current relation to the hot gases, the external surfaces thereof are fused andthe temperatureproduced in the combustion chamber by the burners 32 is so'controlled with respect to the character of. the fibrous particles and to the length of time that the particles remain in the chamber, as to 'cause only the surface of the particles to be fused.

As the resulting smooth-surfaced nodules pass through the portion of the chamber 3| below the burners 32, they are cooled by any suitable means,

., as for example by air introduced through suitveyor means may be provided for conducting the fibrous nodules to the sacking bin 35.

Although I prefer to use a treating chamber, `such as the chamber 3|, for fusing the spherical particles after they are discharged from the separator 28,' it will of course be understood that my invention is not limited to this particular treating means, and in Fig. 3 I have shown a. somewhat different arrangement for fusing the external surfaces of the particles to provide an inorustated surface. In this embodiment of my invention a low the outlet passageway 30 of the separator 28, and a battery of burners 38 of any suitable type is disposed beneath the vibrating screen for fusing-the particles as they move downwardly along the inclined screen 31. Vibrating screens 'of the' type here shown are of course well known in the art, and any suitable means may be provided for accomplishing the desired movement of the screen 31. For purposes of illustration I have shown the screen as pivoted at its lower end on a link 39 which is in turn pivotally mounted on a xed support 40, the upper end of the screen 31 being pivotally connected to a crank arm 4I the opposite end of which is connected as shown-to a rotatable crank disc 42. 'Ihis disc 42 may, of course, be driven from any suitable source of power and it will be apparent that as thedisc '42 rotates the screen 31 will bereciprocated or Vibrated, whereby movement of the fibrous particles downwardly along the screen 31 Vand over` the battery of burners 38 will be assured. Suitable conveying means, not shown, are of course provided adjacent the lower` end of the screen 31 for conveying the resulting smooth-surfaced particles or nodules to a suitable sacking bin or storage chamber.

In some cases it may be desirable to coat the exterior surfaces of the fibrous particles withV a suitable adhesive so as to bind the projecting particles Ytogether and form an incrustation or coating on the surface of the particles. While various organic glues may be used for this purpose, I prefer to utilize inorganic binding materials because of their non-combustible nature. Thus, suitable binding materials or adhesives which may be employed, for example, are water soluble silicates, clays such as highly colloidal bentonite, cementitious materials such as Portland cement, magnesium oxysulfate and chlorides, lime, calcined gypsum, pozzolan cements, fusible silicate mixtures which can be applied when heated, aridother fusible materials such as borax.

While the adhesive or coating material can of course be applied to the particles in any suitiibrousparticles, assists in the rolling of the flbers into spherical particles provided ..thatthe slurry is in a fluid condition. A-sticky or thick vmass of clay-would of course interfere with prop-v er rolling of theparticles.

- After the clay-coated particles have been sub- Jected to the proper rolling action, the clay surface or incrustation may then be dried or baked by passing the particles through a suitable treatine` chamber such as the chamber 3|.

'Itwill of course be understood that the apparatus and the various processes described above are simply illustrative, and that myinvention is not limited to the detailed apparatu's'and steps spe- `cically described. For example, in place of the disintegrator I2 any suitable means may be provided for initially reducing the fibrous material to particles, one suitable arrangement being the able manner, I prefer to apply the adhesive by l s spraying the particles as they fall through the treating chamber 3| or as they pass down the vibrating screen 31. Thus in Fig. 2 I have shown -an embodiment of my invention in which suitable spraying nozzles 43 are provided adjacent the upper end of the treating chamber 3| for spraying the fibrous particles with a suitable coating. or adhesive material as the particles pass through During their passage j the treating chamber. through the chamber 3| the particles are baked and dried by the combustion gases traveling upprovision of means for forming a thin continuous bat of brous material, which bat is then sliced into thin strips, the strips rolled, and the long tubular strip thus formed cut into lengths of desired size. Furthermore, my invention is not limited to an arrangement in which the particles are exposed directly to the products of combustion in the heating chamber, since the chamber 3| may obviously be indirectly heatedy by means of a conventional rebox surrounding the lower end of the chamber 3|.

Bybrous insulating materials I intend to include any type of fibrous material used for insulating purposes, such for example as glass, mineral rock, or slag wool, and certain types of asbestos bers. In general, I have found that a shorter length fiber rolls more readily than longs er bers and that rock wool rolls better than glass wool, but it should be understood that the rollability in each case depends upon the 'chemicalcomposition, the Ifiber lengths, the' diameter of the particles, etc.

that I do not Wish to be limited thereto since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention. y

Having thus described my invention, what lI claim and desire to secure by Letters Patent is:

1. A ,flowable heat insulating material comprising nodules of fusible mineral fibers the surfaces of which are fused to provide an incrustation thereon.

2. A fiowable heat insulating materialcom-- vprising mineral wool nodules the exterior surfaces v."of which-are fused to provide an incrustation thereon. y

wardly through the chamber in counter-current relation to the movement ofthe particles,land

the incrustated particles or nodules are discharged from the bottom of the treating chamber 3| by suitable conveying means, such for example as the conduit 35 described above in connection with Fig. l. i

As a further embodiment of my invention I have also found that it is sometimes desirable to apply a fluid water-clay mixture or other suitable slurry to the fibrous particles before they are subjected to a rolling action between the discs I9 and 20. This may be accomplished, as shown in Fig. 4, simply by introducing a suitable huid slurry into the l,conduits i8, as Vfor example through a suitablesupplypipe 44.1 Theaddition of a slurry at point lin thejtreatment of the 3. The process .of forming ilowable heat insulating material which comprises forming fusible fibrous mineral material into nodules of predetermined size and fusing the exterior surfaces of u said nodules to remove projecting fibers.

4. The process of forming owable heatv insulating material which comprises forming mineral wool into particles of predetermined size, subjecting said particles to a rolling action to form substantially spherical nodules, and fusing the exterior surfaces of said nodules to remove projecting bers therefrom.

5. The process of forming iiowable heat insulating material which comprises forming mineral wool into particles of predetermined size, subjecting said particles to a rolling action to' form substantially spherical nodules, and passing said nodules through a zone in-countercurrent relation to a stream of hot gaseous medium to fuse the exterior surfaces of said nodules.

6. In a process for improving the ilowability of mineral wool nodules adapted for use a's insulating material the step which comprises fusing the exterior surfaces of said nodules to remove prO- jecting fibers therefrom.

7. Apparatus for forming owable fibrous insulating materials of fusible mineral fibers com-` prising means for forming vsaid fibers into particles of predetermined size, means for rolling said particles to form nodules having a substantially spherical shape, means for heating said spherically shaped nodules to fuse vthe exterior surfaces thereof, and 'means for agitating said nodules during said fusingoperation.

8. Apparatus for forming fiowable brous insulating materials of -fusible mineral fibers comdifferent sizes.

prising means for forming said iibers into particles of predetermined size, means for rolling said particles to form nodules having a substantially spherical shape, a, treating tower having inlet means adjacent one end thereof for said spherical nodules, and heating means in said tower for fusing the exterior surfaces of said spherical nodules as they pass through said tower.

9. The process-of forming owable heat insulating material which includes the steps Aof forming fusible mineral bers into nodules of several selected sizes, fusing the exterior surfaces of said nodules to remove projecting fibers therefrom and intermingling the nodules to form a mass of smooth surfacedbrous nodules of said selected RICHARD ERICSON.

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