US1932415A - Method of and apparatus for producing cellular aggregate - Google Patents

Description

T. E LLOYD Oct. 31, 1933.

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11, 1931 4 Sheets-Sheet 1 INVENTOR. 4741 5.

A TTORNEYS.

Oct. 31, i933. T. E. LLOYD ,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11, 1931 4 Sheets-Sheet 2 746W 5' ZZVENTOR. 7

BY M'v- I ATTORNEYS.

Oct. 31, 1933. E, LLOYD 1,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11, 1931 4 Sheets-Sheet 5 7: 6, ZEVENTOR. BY 2 i zQq A TTORNEYS.

Oct. 31, 1933. T. E, LLOYD 1,932,415

METHOD OF AND APPARATUS FOR PRODUCING CELLULAR AGGREGATE Filed April 11, 1931 4 Sheets-Sheet 4 M ZVE/VTOR.

ATTORNEYS.

Patented Oct. 31, 1933 UNITED STATES METHOD OF AND APPARATUS FOR PRO- DUGING CELLULAR AGGREGATE Thorne E. "Lloyd, Stanhope, J assignor to Dwight & Lloyd Sintering Company, New York, N. Y., a corporation of Delaware Application April 11, 1931. Serial No. 529,533

11 Claims.

This invention relates to a process and ap paratus for heat treating material and provides for successively treating layers of said material to produce a light weight cellular aggregate. The invention is particularly applicable 1 to the burning of material, such as clay, shales, argillities and similar rocks which preferably have a relatively extended softening range, rather than a sharp melting point. The process is so carried out that the various layers are each completely heat treated before the next successive layer is applied thereto and the product comprises a cellular cake which is substantially homogeneous and in which the various'layers are joined together as an integral unit. The heat treatment may be carried out by applying hot gases to the various layers or by drawing the gases through the layers as they are successively passed through a heat treating ap .paratus.

The invention also consists in certain new and original features of construction and combinatio'ns of parts hereinafter set forth and claimed.

. Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, andthe manner in which -it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which i Fig. 1 isa side elevation of one form of apparatus for carrying'on the improved process;

Fig. 2' is a plan view of the roof of the apparatus showing the arrangement of the apertures;

Fig. 3 is a sectional view taken on the line .3-3 ofFig. 1;

Fig. iris a side elevation of a modified form of apparatus for practicing the invention; and

Fig. dis a section taken on the line 5--5 of Fig. 4. I

. Like reference characters denote like parts in the several figures of the drawings.

In the following description and in the claims, various details will be identified by specific names for convenience, but'they are intended to be as generic in their application as the art will permit.

The present process for manufacturing light cellular aggregate consists in heat treating a thin layer of raw material by passing therethrough gases heated to the proper temperature moved through chamber 25.

to-bring the particles into the state of incipient fusion whereupon the particles are spun out into cellular form. A fresh layer of -material is then applied which coolsthe first layer and causes it to retain its cellular form. The second layer is itself heated to the required temperature and the process is repeated until a bed of desired thickness has been built up whereupon it is discharged from the heating apparatus and may be crushed and screened to'the desired size.

Referring to Figs. 13 an apparatus for carrying on this invention is shown which comprises a framework 10 carrying track 11 on which a plurality of movable pallets 12 are mounted. Said pallets are propelled along track 11 by driving wheel 13 operated by a source of power '14 through a gear train 15. Pallets 12 are prefervsaid pallets and is connected by suction pipe 23 to a suitable source of suction (not shown).

Hinged doors 24 are provided for purposes of inspection or cleaning. v

Supported on frame 10 and mounted above pallets 12 is a heating chamber 25 comprising roof 26, sides 27 and bottom members 28 which overhang the sides 20 of said pallets a sufiicient distance to shield said sides from the intense heat of said chamber. Said bottom members 28 are preferably arrangedsufiiciently close to said pallets to form an effective seal and prevent leakage of gases. A further seal may be effected, if desired, by flexible members 30 which are secured to said side members and engage the sides of said pallets.

A plurality of burners 31 communicate with ports 32 which extend through sides 27 of said chamber. Said burners may be controlled by valves 33'and are fed through a header 34 in any convenient manner. that any suitable fuel, such as oil or gas, maybe employed and the ports are preferably located a sufficient distance from the pallets to permit complete combustion before the gases come in contact with the bed of material. Valves 33 permit the regulation of the various burners so that control of the heat distribution within chamber 25 may be obtained. j

Roof 26 is provided with a plurality of transverse apertures 38 which are arranged to distribute charge over the pallets 12 as they are The apertures in' the various rows may be staggered, so that the It is to be understood charge to said roof.

through onto the pallets.

piles of material dropped through any one row will not fall directly upon the piles dropped from the adjacent holes. A hopper 39 may be mounted in a convenient position to apply the A plurality of movable rabbles 40. mounted on an endlessbelt ll are adaptedjto engage said charge and distribute the same along said roof whereby it is applied to the various apertures and caused to fall'there Said belt 41 may be operated from power source 14 by any convenient drive such as belt 42. Side members .43 "are mounted on roof 26 to confine thelayer :of material to the area above the apertures .38.

It is to be understood that the size of theapertures 38 may be varied to control the amount of material fed therethrough, for example, by the use of cast plates 60 having openings ofvarioussizes which may be selectively positioned in saidapertures.

Hoppers mis also mounted on frame lfl -inza position to discharge material to pallets 12prior: to-their passage through heating chamber 25. v

In'the operation of the-above-described appa ;;ratus the interior of theheating chamber is keptfilled with flame and-hot combustion products .by' the fuel burners; A thin layer of prepared charge isfed onto the pallets from hopper and is burnedby the flame which is drawn through the.

3o charge into wind box 22. The first row of aper era-blycrushed sufficiently fine to pass a charge in this form is droppedthroughthe aper- ,spreadinto, acomparatively uniform thin layer screen and is moistened and thoroughly mixed to reduce the charge to small pelletsa'preiterably gradingfrom A to down insize. .Asthee.

tures onto thelayer of -material already in. the pallet, it tends to spread. out, even though-- dropped in a series of small piles, this tendency being-increased by the generation of steam which- ,throws the pallets about violently .whenthey are first subjected to the highly heatedgases. In

consequence, even-though the charge is dropped" on.-the layer-at a few points spaced acrossv its width, within-a brief period'of time .-it willhave oven. the entire. width ofthe pallet.-

The second layer is applied immediately after the-first. layer has. fused and expanded; and before the material thereof has. run together and lost itscellular condition. The second layer accordingly cools thefirst layer and causes it to remainin a cellularcondition andialsoit is; quickly heated to'thefusion point and caused to firmlyadhere to the first layer so that the final- ,=product..comprises a homogeneous cake of con siderablethickness and without cleavage planes or lines of. fracturebetween the individual layers.

A. modified form of apparatus for carrying on therinvention is shown in Figs. 4 and -5.- Inthis apparatus the frame 10, pallets 12, driving-mechanisn1..1l,,hopper 45 and heating chamber-25 are similar .in constructionto that of Figs.'13 and have been 1 given similar reference. numerals. In this formofuapparatus,however, roof 26 is pro vided with a plurality of. transverse slots 50, each of which communicates with a feed hopper 51. Said feed hopper is provided with a discharge apparatus, such as rotating drum 52, by which a regulated quantity of material may be removed from the hopper and applied through slots 50 to thepallets. Shields 53-maybe provided to prevent escape of gases frornslots 50 as material is being applied thereto. The discharge apparatus maybe driven by suitable gearing 54 which isconnected to the driving motor 14 as by belt 55, and suitable gates 56 may be provided for controlling'the amountof discharge from hopper 51.

The operation of this form of device is similar to that above described with the exception that thphargeis--fed.from the various hoppers 51 through slots 50. This form of apparatus may be preferable in certain instances where an independent controloftherate of feed of the various layers is required.

A considerable variation in the product may be secured by suitable control of temperature-and time of treatment given the'charge; With-high. temperatures and rapidtreatment aproduct is obtained having larger ceilabut being somewhat,

ess strong than that made withlcwer temperw tures. It will be understood that-the most suit able grade otaggregate Will :depend upon the particular use to which it is put and the various: grades may be produced bypropencontrol-of. the-operating conditions. For: example, an-ag gregate of maximum hardness will be desirable: for making partition blocks, which require com.- paratively lowstrength, whereasvawstrong and somewhat heavier aggregate may berdesirable :1

for use in wallsand floors which supporta-com siderable load. 7 r

The herein described process for makinglight a weight aggregate is rapid in operation, economi.-.-

cal requires but little labor-and acomparatively i:

small amount of fuel, makes an aggregate which ugg is exceptionally light and extremely :uniformcinj character and may be readilycontrclledfor pro ducing aggregate materials of various-degrees of. lightness and strength.

W'hile certain novel-features of the invention 1269 material by drawing externally heated gaseslggr.

therethrough and substantially completing the treatment of each layer before thesucceeding layer is applied thereto. V

2. The continuous process 'of heat treating ma terials which comprises passing a layer of' said' 'l35- material through a heating chamber, drawing externally heated gases through said materialf' thereby effecting the desired heat treatment and applying additional layers of said material at spaced points in said chamber while continuing 149? the heat treatment with externally'heated gases" so that each layer is completely heat treated before the next succeeding layer is applied thereto.

3. The method of heat treating materials which said layer as it advances-through:saidheatingrwm chamber whereby the successive operations are successively subjected to said preheated gases.

4. The method of heat treating materials which comprises passing said material in a thin layer through a heating chamber and drawing preheated gases through said material to bring said layer to the state of incipient fusion and applying a second layer of material to said first layer before said first layer has melted and run together, said second layer serving to cool said first layer and maintain the same in its cellular condition and itself being heated to the fusion point by said gases and adhering to said first layer to form a uniform mass and repeating the operation with the addition of successive layers to form a mass of the desired thickness.

5. A heat treating apparatus comprising a heating chamber, a movable support, means for progressively passing said support through said chamber and means for applying layers of material to said support at spaced points as it is passed through said chamber and means for passing externally heated gases through said material whereby heat treatment of said layers is progressively effected.

6. An apparatus for heat treatingmaterials comprising a heating. chamber, a plurality of pallets having perforate bottoms, means for applying a layer of said material to said pallets and passing'said pallets through said chamber, means for passing externally heated gases downwardly through said layer in said chamber and means for superimposing successive layers ofsaid material thereon as said material advances through said chamber.

7. An apparatus for heat treating materials comprising a heating chamber, a plurality of pallets having perforate bottoms, means for applying a layer of said material to said pallets and passing said pallets through said chamber, means for passing externally heated gases downwardly through said layer in said chamber, means for superimposing successive layers of said material thereon as said material advances through said chamber, and means for regulating the thickness of each of said layers whereby the heat treatment thereof may be controlled.

8. In an apparatus for heat treating materials, a heating chamber, means for passing a layer of material through said chamber, burners for introducing hot gases to said chamber and causing complete combustion of said gases out of contact with said material and uniformly applying the heated gases over the surface of said material, means for drawing said hot gases through said material and means for superimposing successive layers of material as said material-pas'ses through said chamber at spaced points.

9. In a heat treating apparatus, a heating chamber, means for applying preheated gases thereto, a movable support for passing a layer of material through said chamber, a plurality of feeding means spaced along the roof of said chamber and adapted to apply successive layers of material to said support, and means for draw ing said preheated gases through material passing through the preheated chamber on said movable support.

10. A heat treating apparatus comprising a heating chamber, a plurality of movable supports, means for passing said supports through said chamber, means for applying a charge ofmaterial to said supports and causing said charge to form a thin layer thereon, said heating chamber being provided with a roof having a plurality of transverse openings therein, means for applying a charge of material to said roof and meansfor spreading said material along said roof whereby it is caused to fall through said openings and to be applied to said movable supports in a plurality of successive thin layers.

11. A heat treating apparatus comprising a heating chamber, a plurality of movable supports, means for passing said supports through said chamber, means for applying a charge of material to said supports and causing said charge to form a thin layer thereon, said heating chamber being provided with a roof having a plurality of transverse openings therein, means for applying a charge of material to said roof, means for spreading said material along said roof whereby it is caused to fall through said openings and to be applied to said movable supports in a plurality of successive thin layers, said spreading means comprising a plurality of movable rabbles mounted on an endless belt and adapted to engage said charge and spread the same along said roof.

TI-IORNE E. LLOYD.

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