US1746860A - Process of manufacturing cellular aggregate - Google Patents

Description

Patented Feb. 11, 1930 UNITED STATES PATENT OFFICE RICHARD L. LLOYD, OF NEW YORK, N. Y.,' ASSIGNOB TO DWIGHT @JLLOYD METAL- LURGIGAL COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF NEW JERSEY PROCESS OF MANUFACTURING CELLULAR AGGREGATE 1T0 Drawing.

This invention relates to cellular aggregate, and more particularly, to a process for manufacturing a light-Weight, sulphur-free, cellular aggregate from Waste material.

The invention more specifically relates to a cellular aggregate suitable for use as a filler in concrete floors, road-bed ballast and such analogous conditions where a light, strong material is required, and to a method of manufacturing the same from a cheap Waste product such as residue from burned fuel.

Cellular aggregate used as above should '1 be strong, porous and light, and, if used with eral original features of iron or steel reinforcing, should preferably .be comparatively free from sulphur inasmuch as that element would attack the metal reinforcing.

By the present invention it is possible to convert the entire ash product of burned fuel into a superior material which is highly cellular and porous and is light in weight and at the same time is strong and rigid. The product is furthermore substantially free from sulphur and is of a uniform quality.

This is accomplished by spreading ash which may or may not contain some unconsumed carbon, together with the required amount of fuel, in a uniform, thin layer. The surface of the layer is then ignited and the zone of combustion caused to pass progressively through the entire mass. As each zone of the layer becomes fused, the force of the gases themselves serves to froth or spin the fused portion into a cellular structure which is immediately cooled as the zone of combustion passes onward, forming the desired cellular aggregate. The heat of combustion is suificient to expel any sulphur which may be present, leaving the entire mass substantiall sulphur-free.

T e invention further consists in the new .and novel features of operations and the new and original arrangements and combinations of steps in the process hereinafter described and more particularly set forth in the claims. The invention also consists in forming a product having the general characteristics, the new and useful applications, and the sevutility hereinafter set fortlr and claimed.

Application filed January 18, 1927. Serial No. 161,962.

In the following description and in the claims, specific names are employed for convenience, but they are intended to be as One method by which this invention may be carried out consists more specifically in shghtly moistening ashes containing some unconsumed carbon or other fuel and mixing them together into a uniform, permeable mass which may be spread on a pervious support in a substantially even layer in depth slightly more than the thickness of the cellular cake it may be desired to obtain. Obviously, if the material is in the proper condition to permit progressive combustion, the preliminary moistening may be omitted.

One surface of the layer may then be ignlted, as by the temporary application of a flame, and combustion of the fuel in the mixture may be continued internally of the layer by causing currents of combustion-supporting gases such as air to pass therethrougk from the surface initially ignited to the opposite surface. The combustion thus initiated at one surface will progress in an approximately uniform zone through the layer to the opposite surface.

The heat developed by this internal combustion raises the particles in a given zone momentarily to the point of incipient fusion, and during this moment the currents of gases passing through the layer cause the fused particles to be frothed or blown and spun into thin walls and filaments, which are immediately chilled and frozen by the 0001 gas currents as the zone of combustion moves on through the layer. At the same time any sulphur in the ashes is oxidized and carried away by the gases.

Thus, when the zone of combustion has passed completely through the layer, the entire layer has been converted from small, loose particles into a cellular, thin-walled, honey-combed cake,which is exceedingly light in weight compared to its bulk, but which is I at the same time rigid and strong, and which is free from sulphur.

The above process may be made continuous by using a heries or train of supports for the,

ash mixture to be treated, and causing such supports to be moved through a zone where currents of combustion-supporting gases may be passed through the layer of material on the supports, one surface of the layer on each support being ignited as the support enters the treatment zone. The internal combustion within the layer may then be carried on as heretofore described while the support passes through the treatment zone. After completion of the treatment, the finished cake may be removed by inverting the support or by other suitable means and the cycle repeated.

Where it is desired to employed currents of combustion-supporting gas of high velocity, it is preferable to prevent agitation of the particles among themselves which might be occasioned by the gas currents or by other means and which might prevent the formation of a coherent cake. This may be accomplished by enclosing the layer of material between two screens or pervious supports in order to prevent movement during combustion. If desired, however, a single support may be employed and the gaseous v currents caused to pass downwardly through the layer of material and out through the pervious support on which the material rests. The pervious support in this case serves as a screen to prevent agitation of the particles as well as a support therefor.

Ashes obtained from ordinary coal-fired furnaces have been found to contain sufiicient unconsumed carbon for supporting combustion, but it will of course be understood that material which contains in itself insufficient fuel to develop the required degree of heat I may be used by adding suflicient fuel, such as fine coal, sawdust or other combustible material. This is thoroughly mixed with the material and the mass spread in a uniform layer and burned as described above.

In some cases it may be desirable to mix with the material being treated some fluxing material which will reduce the melting point of the mixture. For example, to ashes which are highly siliceous, suitable proportions of limestone dust or fine iron-bearing material may be added.

The material may be found to contain more than the small amount of fuel necessary to furnish the necessaryheat (generally from five to ten percent), and in such cases a suitable quantity of fuel-free material, such as clay, sands, crushed rock or the like may be added, thereby increasing the output at little or no increased cost.

The above described process may also be applied to natural materials, such as carboniferous shales, or to waste materials in general, such, for example, as those found in mine culm banks. The carbon content of the mass may be controlled by adding a suitable amount of combustible material, or of fuelfree material. Furthermore, the proper basic and acid content of the resultant aggregate may be obtained by the addition to the raw material of proper fluxes, such as clay, limestone, sand, etc.

If pieces of aggregate smaller than the cake formed as heretofore described are desired, the cake may be broken to the desired size by any desired means. And by using formed supports or molds for the layer to be treated, cakes of any desired shape may be obtained.

This invention provides a simple and eco nomical method for converting a material which is at present a waste product into a highly useful and desirable commodity. The process may be carried out on well-known apparatus, requiring little labor or attention. The product is exceedingly light in weight, is strong and rigid, is uniform and of a highly superior character.

Although certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the several steps of the process and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. A process of manufacturing cellular aggregate from waste materials inherently containing combustible matter which comprises causing momentary combustion of said matter whereby incipient fusion is produced and passing gases therethrough whereby the material is spun into a thin, uniform texture, and subsequently cooling said material to produce a strong, light, cellular aggregate.

2. The process of manufacturing cellular aggregate from ash which comprises forming said ash into a thin layer, causing momentary combustion of each portion thereof whereby incipient fusion is produced, and spinning said ash while in a fused condition into a porous mass.

3. The process of manufacturing cellular aggregate from ash which comprises forming the ash into a thin layer, progressively burning said layer whereby each portion is momentarily heated to the point of incipient fusion, spinning the fused ash into a porous mass and chilling said mass to form a strong, light, cellular structure.

4. The process of manufacturing cellular material inherently containing combustible matter from waste material which comprises mixing material therewith to produce the dematerial containing unconsumed fuel which consists in moistening and mixing the material to a permeable mass, spreading the mass in a uniform bed on a pervious support, igniting the combustible constituent atone surface of the bed, passing currents of combustion-supporting gas through the bed fromthe surfaceinitially ignited to the opposite surface to cause combustion of the fuel internally of the bed whereby the material is brought to the temperature of incipient fusion, and simultaneously blowing the heated particles into a coherent thin-walled, cellular structure which is cooled by the gaseous currents.

6. The process of manufacturing lightweight cellular material inherently containing combustible matter from material which consists in adding a small proportion of solid fuel in the form of small particles thereto, moistening and mixing the materials to a permeable mass, spreading the mass in a uniform bed on a pervious support, igniting the combustible constituent at one surface of the bed, passing currents of combustion-supporting gas through the bed from the surface initially ignited to the opposite surface to cause combustion of the fuel internally of the bed whereby the material is brought to the temperature of incipient fusion, and simultaneously blowing the heated particles into a coherent, thin-walled, cellular structure which is cooled by the gaseous currents.

7. The process of manufacturing lightweight cellular material from waste material inherently containing combustible material which consists in mixing with the waste material suitable fluxing materials, spreading the mixture in a uniform, permeable bed on a pervious support, igniting the combustible constituent at one surface of the bed, passing currents of combustionsupporting gas through the bed from the surface initially ignited to the opposite surface, causing a zone of combustion to progress through the bed to heat the particles of material while in the zone of combustion to a temperature at which the flux material will react with the waste material to form a thin, semi-plastic layer which is blown by the gaseous currents into thinwalled cells, and chilling the cells by the cooling action of the subsequent gaseous currents as the zone of combustion advances, whereby the entire bed of material is converted to a homogeneous, cellular, rigid cake.

8. The process of manufacturing light- I weight cellular material from waste products inherently containing combustible material which consists in bringing the content of combustible material to the desired value, spreading the mixture in a uniform, permeable bed on a pervious support, igniting the combusti: ble constituent at one surface of the bed, pass ing currents of combustion-supportin gas through the bed from the surface imtlaily 1gnited to the opposite surface, causing a zone of combustion to progress through the bed to heat the particles of material while in the zone of combustion to the temperature of incipient fusion and form a thin, semi-plastic layer which is immediately blown by the gaseous currents into thin-walled cells, and chilling the cells by the cooling action of the subsequent gaseous currents as the zone of combustion advances, whereby the entire bed of material is gradually converted to a homogeneous, cellular, rigid cake.

9. The continuous process of manufacturing light-weight cellular material from,

tional external heating, progressively heating the particles of waste to the temperature of incipient fusion and immediately blowing them, while hot, into thin-walled cells, and then chilling the cells by the cooling action of the gaseous currents, whereby a homogeneous, cellular, rigid cake is formed in each support.

10. The continuous process of manufacturing light-weight cellular material from waste inherently containing combustible matter which consists in mixing with the waste small proportions of fuel, spreading the mixture in a permeable, even bed on a series of movable, pervious supports, adding a flux to reduce the melting point of the mixture, advancing the supports through a treatment zone in which combustion-supporting gases are passed through the bed, igniting the fuel at one surface of the bed immediately upon reaching the treatment zone, and continuing combustion of the fuel internally of the bed without additional external heating, progressively heating the particles of waste to the temperature of incipient fusion and immediately blowing them, while hot, into thin-walled cells, and then chilling the cells by the cooling action of the gaseous currents, whereby a homogeneous, cellular, rigid cake is formed in each support. 1

In testimony whereof I have hereunto set my hand.

RICHARD L. LLOYD.