EP0045303A4 - Procede et appareil de production de produits cellulaires vitreux. - Google Patents
Procede et appareil de production de produits cellulaires vitreux.Info
- Publication number
- EP0045303A4 EP0045303A4 EP19800901280 EP80901280A EP0045303A4 EP 0045303 A4 EP0045303 A4 EP 0045303A4 EP 19800901280 EP19800901280 EP 19800901280 EP 80901280 A EP80901280 A EP 80901280A EP 0045303 A4 EP0045303 A4 EP 0045303A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- rollers
- kiln
- silica
- charge
- raw material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/02—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces
- F27B9/021—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces having two or more parallel tracks
- F27B9/025—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces having two or more parallel tracks having two or more superimposed tracks
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B19/00—Other methods of shaping glass
- C03B19/08—Other methods of shaping glass by foaming
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C11/00—Multi-cellular glass ; Porous or hollow glass or glass particles
- C03C11/007—Foam glass, e.g. obtained by incorporating a blowing agent and heating
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B33/00—Clay-wares
- C04B33/32—Burning methods
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
- F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
- F27B9/24—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor
- F27B9/2407—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor the conveyor being constituted by rollers (roller hearth furnace)
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/28—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity for treating continuous lengths of work
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/12—Travelling or movable supports or containers for the charge
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/12—Travelling or movable supports or containers for the charge
- F27D2003/124—Sleds; Transport supports
Definitions
- This invention relates to the production of cellular vitreous slabs or shapes having a substantial part of the volume composed of gases enclosed in the cells, and is particularly concerned with the process and apparatus to produce cellular vitreous refractory material in prescribed shapes and products therefrom of lighter densities than con ⁇ ventional brick or tile, and more impermeable.
- the kiln for the above described commercial process was made of graphite slabs which acted as resistance heaters. The charge was carried in graphite pans pushed in a train through the kiln. The process was not successful, as I understand the matter, because it was too expensive and the graphite slabs and pans would not last. My process avoids expensive grinding to fine particle size and the use of
- Such dense clay mixtures produced by dry pressing or damp pressing have usually contained from about 5% to 8. moisture and have been subjected to from about 1000 psi to about 5000 psi. In the prior art extrusion of clay mixtures, the moisture content of the clay mixture is usually higher, namely in the neighborhood of from 15% to 20%; however, very substantial pressure is still necessary.
- Each of the resulting dense mixtures must be dried quite slowly over an extended period of time so as to permit the gradual migration of the moisture through the clay. If such a procedure is not followed, the clay may -crack or ex ⁇ plode during drying.
- the resulting sintered clay is quite dense and holds its original shape without cracking or crazing.
- the sintering is at a temperature below the fusion temperature of the clay which is employed. I use a mix which is low in moisture and is pressed at low pressures. This enables the rapid heating of the charge which may crack on sintering but such cracks are later healed.
- the cellulation of clay materials have been carried out. For example, Ford, in U. S. Patent No.
- 2,485,724 taught that by using flux, low temperature foaming of a special Albany slip clay could be carried out using an oxygen containing agent and carbon in the form of carbon black. Ford also taught that urea, sugar, dextrose or molasses could be substituted for the carbon black to produce bodies having densities of from 10 to 20 lbs. per cubic foot. The firing temperature was in the neighborhood of 1500°F to 1800°F.
- the process of the present invention eliminates the expense, trouble and hazards of using a flux and has thus produced a foamed product having a higher melting point and more resistant to water and chemical agents.
- U. S. Patent No. 2,337,672 discloses the manufac ⁇ turers of multicellular glass by heating a charge from glass, oxide of arsenic, zinc or cadmium and carbon powder to pro ⁇ quiz a reaction between the oxide and the carbon.
- Another object of the present invention is to pro ⁇ vide a process and apparatus for producing a foamed mineral material and the material, itself, which has a high struc ⁇ tural strength capable of forming load bearing walls and roof decks with wide spaced supports and can be produced in large sheets.
- the process of the present invention employs low pressure for the compacting of a clay, carbonaceous material and moisture, mixture charge followed by rapid heating to dry the clay charge and the progressive firing of the shaped charge, above the fusion temperature, on rollers without the necessity of carrier plates to produce a preshaped cellular vitreous impervious lightweight refrac ⁇ tory.
- the movement of the charge through the firing zone is slow; however, no appreciable sagging of the ribbons of charge take place, due to the high viscosity of the molten clay in ⁇ volved. Any cracks occurring during drying or preheating are healed by the bloating of the clay.
- a parting or re ⁇ leasing agent is in some cases applied to the bottom and perhaps sides of the ribbon.
- the apparatus of the present invention includes a plurality of juxtaposed sets of damp pressing rolls, each of which is supplied from a hopper with a mixture of clay and/or shale whose carbonaceous material content and moisture con ⁇ tent has been adjusted. Each set of rolls also co-extrudes a releasing or parting agent around the sides and bottom of the ribbon of clay raw material which is extruded. Nozzles introduce glaze or engobe to the top of the ribbon. .
- the force of the rolls feed the ribbons along parallel horizontal vertically spaced paths to the first warming or preheating chamber of the kiln and, thence, into the firing chamber along the upper surfaces of rollers.
- the ends of the rollers protrude outwardly of the walls of the kiln, the end portions being supported on circumferentially spaced idler wheels and can be rotated simultaneously by a common belt.
- Fuel and air are supplied, via headers, to the burners disposed in staggered relationship in opposed paralle rows along the sides of the kiln in the firing chamber.
- Exhaust ports are disposed opposite to the nozzles, the ports leading to manifolds which feed to the exit portion of the preheating chamber of the kiln.
- Exhaust blowers discharge the flue gases from the entrance portion of the preheating chamber. In the preheating chamber, sintering of the ribbons usually takes place.
- Foaming of the sintered clay ribbons takes place at above about 2000°F in the firing chamber as the ribbons are progressively moved along the rollers in the firing chamber.
- the ribbons, emerging from the exit of the firing chamber, are in the form of impervious cellulated refractory streams and are passed into an annealing lehr where the temperature thereof is rapidly reduced to annealing tempera ⁇ ture and then -annealed.. Thence, these products are fed to conveyors where they. are cut into rectangular blocks.
- a charge of silica, carbonaceous material and water is produced in a heated low pressure press.
- a plate, formed from aluminum foil or other release agent and a layer of pitch and coke or coal is produced on the lower surface of the charge, at the same time the charge is being pressed.
- This compacted silica charge on its plate, is fed through the kiln end-to-end and is preheated and foamed in the manner previously "described for clay. Cellular fused silica blocks are formed.
- the third embodiment includes two stage extruders, each having three feed rollers to feed a charge as a ribbon from hopper horizontally to the kiln.
- the parting agent is sprayed from below onto the ribbon and the glaze or engobe from above.
- the kiln of the third embodiment has muffle plates to produce vertically spaced chambers above and below the ribbons, the chambers exhausting into the drying or pre ⁇ heating zone of the kiln.
- the kiln is depicted as ram fed with preassembled pans containing charges of green or raw silica.
- the sections of the pan are either preassembled to receive a hand rammed charge or respectively provided with pressed charges which upon melting form a monolithic or uni ⁇ tary fused product.
- Fig. 1A is a schematic vertical sectional view of one embodiment of an apparatus for producing cellulated refractory material according to the present invention, the apparatus being shown as processing clay charges;
- Fig. IB is a continuation of the view of the apparatus shown in Fig. 1A;
- Fig. 1C is a continuation of the view of Fig. IB;
- Fig. 2 is a vertical sectional view taken substan ⁇ tially along line 2-2 in Fig. 1A;
- Fig. 3 is a vertical sectional view taken substan ⁇ tially along line 3-3 in Fig. 1A;
- Fig. 4 is a vertical sectional view taken substan ⁇ tially along line 4-4 in Fig. IB;
- Fig. 5 is a vertical sectional view taken substan ⁇ tially along line 5-5 in Fig. IB;
- Fig. 6 is a vertical sectional view taken substan-- tially along line 6-6 in Fig. 1C;
- Fig. 7 is a vertical sectional view taken substan ⁇ tially along line 7-7 in Fig. 1C;
- Fig. 8 is a vertical sectional view similar to Fig.
- Fig. 9 is a vertical sectional view similar to Fig.
- Fig. 10 is a vertical sectional view of the front portion of a second embodiment of the present invention show ⁇ ing a press assembly for forming successive rectangular charges to be fed to the kiln;
- Fig. 11 is an enlarged fragmentary side elevational view showing the drive for the horizontal feed rollers of the kiln of Figs. 1A; IB and 1C;
- Fig. 12 is a view similar to Fig. 11 but showing the drive for those feed rollers which are spaced apart more than the rollers of Fig. 11;
- Fig. 13A is a vertical sectional view similar to Fig. 1A but showing a third embodiment of apparatus for pro uc ng ce u ate re rac ory ma er a ;
- Fig. 13B is a continuation of the view shown in Fig. 13A;
- Fig. 13C is a continuation of the view shown in Fig. 13B and showing the glaze applicators and the annealing lehr;
- Fig. 14 is a vertical sectional view taken substan ⁇ tially along line 14-14 in Fig. 13A;
- Fig. 15 is a vertical sectional view taken substan ⁇ tially along line 15-15 in Fig. 1A;
- Fig. 16 is a vertical sectional view taken substan ⁇ tially along line 16-16 in Fig. 13A;
- Fig. 17 is a vertical view taken substantially along line 17-17 in Fig. 13B;
- Fig. 18A is a vertical sectional view similar to Fig. 1A and Fig. 13A showing a fourth embodiment of my inven ⁇ tion;
- Fig. 18B is a continuation of Fig. 18A.
- Fig. 19 is an exploded perspective view of abutting sections forming a first pan for receiving an unpressed charge of sand or brickettes;
- Fig. 20 is an exploded perspective view of several abutting sections forming a pan, the sections being shown after being pressed with their respective portions of the total charge;
- Fig. 21 is a perspective view of the assembled pan of Fig.20, without the charge.
- Fig. 22 is a fragmentary plan view of a portion of the pan of Fig. 20 and 21 with its charge within the kiln of Fig. 13A, 13B and 13C, the sides and vertical alignment rollers of the kiln being shown in cross-section. DESCRIPTION OF THE PREFERRED EMBODIMENTS
- numeral 10 in Fig. 1 denotes a vertically dispo hopper having parallel triangular end walls 11 joined by downwardly converging side walls 12 which terminate in a rectangular opening at the bottom portion of the hopper.
- set of damp pressing rollers is carried at the opening of hopper 10.
- This set includes a pair of opposed compressio rollers 13 carried by brackets 14 for rotation about space parallel, horizontally disposed, axes or axles 15 rotated opposite directions for compacting and feeding the materia or charge contained in the hopper 10 into a curved conduit 16 having a rectangular cross sectional area.
- End rollers 19 disposed along axes or axles perpendicular to axles 15 cooperate with rollers 13 for compacting and driving the material into conduit 16.
- the rollers 13 and 19 thus extrude a rectangular ribbon 20 of the raw material or charge in a vertical down ward path into the upper end portion of the conduit 16.
- the curved contour of the conduit 16 progressively alters the course of the ribbon 20 from a vertical path to a hori zontal path, the lower end portion 17 of the conduit 16 protruding in a horizontal direction outwardly from the co duit 16 to provide a slide plate along which the ribbon 20 progressively moves.
- the upper surface of the slide plate is aligned with the upper periphery of a plurality of parallel disposed, infeed, conveyor rollers 18 which are formed either of steel or ceramic material.
- the infeed rollers 18 are rotated in synchronization so as to form a live deck for the conveyance of the ribbon 20 into the entrance port 9 in the front or entrance end 26 of a kiln, denoted generally by the numeral 25.
- the ribbon 20 forms a continuous charge of rectangular cross section whi is moved through the kiln 25 from the entrance end 26 to t exit end 27 of the kiln 25.
- a U-shaped partition 23 separates the two compartments 21 and 22.
- partition 23 includes opposed truncated, triangular shaped, downwardly converging, parallel, side walls 24, joined by their forward edges to the side walls 11. The rear edges of the side walls 24 are respectively joined to the edges of a transverse rectangular partition plate 26a.
- a U shaped secondary or parting agent ' compartment 22 is defined by a portion of hopper 10 and the partition 23 which also surrounds three sides of the main charge receiving chamber
- a parting or releasing agent is fed into the compartment 22.
- This parting or • releasing agent can be any of a variety of agents which are employed for preventing sticking of surfaces in a mold. I prefer, in order to keep the rollers 35 and 36 clean, to use a damp mixture of fire clay and fire clay grog which has the double function of separating the extruded ribbon 20 of clayey material from the rollers in the kiln 25 and also confine the width of expansion of the ribbon 20, transversely. Further ⁇ more, the parting or releasing agent around the sides and bottom of the ribbon 20 may be made strong enough to resist breaking off in case of a sticky spot on the rollers 35 and 36 caused by an inadvertent contamination.
- An alternative parting agent mixture of silica sand bonded with moist clay to about 8 to 20% clay may be used, to give adequate bond to substantially hold the parting layer through the green and dry stages. This would give a stronger bond upon firing, except that the sudden expansion of the sand grains at about 1073°F largely breaks the bond. Then in case of a sticky spot of molten material on the rollers, the sand grains are given up to the spot until the stickiness is covered.
- the parting agent should be pitch bonded carbonaceous material .such as coke or coal.
- a pitch or tar bonded coke or coal is to be used as the parting agent
- the press 202 includes a vertically disposed double acting hydraulic or air cylinder 204, the piston rod of which reciprocates in a vertical path a rectan ⁇ gular flat metal press plate 205.
- the heated rectangular platen 203 is disposed in a fixed position in registry below the plate 205.
- a vertically moveable border supporting plate 206 which carries an upstanding border member 207 surround ⁇ ing the edge portions of the platen 203.
- a ram 209 reciprocates the plate 206 and hence bor ⁇ der member 207 in a vertical path from the position shown in broken lines to the position shown in full lines in Fig. 10.
- a ram plate 211 mounted by the piston rod of a horizon ⁇ tally disposed ram 213.
- a slide plate 213 on the side of platen 203 provides a deck over which successive charges 220 are fed from press 202 into the oven or kiln 225 for processing.
- the plate 205 is retracted and the border member 207 raised around the platen 206.
- the charge which may consist of an aluminum sheet, a carbonaceous material and a binder on the sheet as a thin layer, and the silica charge thereover, is placed in. the bo ⁇ der member 207 on the platen 203.
- the material is then pressed by plate 205 through actuation of the press cylinder 204 and then the plate 205 is retracted. Thereafter, the border member 207 is stripped downwardly and the ram 213 actuated to move ram plate 211 over the platen 203 and urge charge 220 into kiln 225. Successive charges 220 form a ribbon entering kiln 225 where it is then treated in the same manner as ribbon 20 in kiln 25.
- the low pressure press 202 is normally used to exert a pressure of from about 50 psi to about 1000 psi and can be used in place of the rollers 13 and 19 for forming clay charges with or without a parting agent along the bottom sur ⁇ face or bottom and side surfaces of the clay charge.
- a drying heater 28 Disposed above the slide plate 17 is a drying heater 28 the function of which is to dry the upper surface of ribbon 20 as it emerges from the conduit 16 in a horizontal path.
- the heater 28 can, if desired, be an electrical resistance heater or a gas heater or any of a variety of heaters which would supply sufficient heat for simply drying the upper sur ⁇ face of the ribbon 20.
- the ribbon 20 is travelling in a horizontal path and has a releasing agent along its bottom and side surfaces and a glaze or engobe along its upper sur ⁇ face.
- a second hopper 110 which is identical to the hopper 10 is disposed adjacent to hopper 10 for providing a second ribbon 120 for entry into the kiln 25.
- This second hopper 110 includes rectangular downwardly converging side walls 112 and truncated triangular walls 111 forming a rectangular down ⁇ wardly converging hopper.
- the hopper 110 also includes opposed feed rollers 112 rotating on axles 115 and supported by brackets 114.
- the hopper 110 includes side rollers 119 which cooperate with the feed rollers 113 in creating a downwardly directed stream or ribbon 120 which is received within the curved conduit 116.
- Conduit 116 gradually alters the path of the ribbon 120 from a vertical downwardly directed path into a horizontally directed path.
- the hopper 110 includes a partition 123 so that the ribbon 120 is provided with a releasing agent along its bottom surface and side surfaces.
- the upper surface of the ribbon 120 as it emerges in a horizontal path is supported by a slide plate 117 and is heated by a heater 128 adjacent to its upper surface.
- a glaze applying nozzle assembly 129 is provided for spraying glaze onto the heated and dried, upper surface of the ribbon 120.
- the rib ⁇ bon 120 enters the kiln 25 through a rectangular opening or port 109 spaced vertically above the rectangular entrance por 9 for the ribbon 20.
- the ribbons 20 and 120 are dis ⁇ posed and go through the kiln 25 from the entrance end 26 to the exit end 27 along parallel horizontal vertically spaced paths.
- the kiln 25 or at least the lining of the kiln, is formed of refractory material. It is generally rectangular in shape throughout its length.
- a vertical partition 30 which separates the interior of the kiln 25 into a drying and preheating chamber 31 and a firing chamber 32.
- the chambers 31 and 32 are disposed in tandem along the longitudinal path which is traveled by the ribbons 20 and 120.
- the partition 30 has two vertically spaced openings or ports 30a and 130a through which the ribbons 20 and 120 pass.
- Ports 9, 30a and 60 are horizontally aligned ports; 109, 130a and 160 are in horizontal alignment above ports 9, 30a and 60.
- All burners 40 heating the kiln 25 are preferably in the firing chamber 32, the drying and preheating chamber 31 receiving the exhaust, flue or stack gases from the firing chamber 32.
- the kiln 25 and particularly the firing zone or chamber 32 is made of or lined with refractory material which will withstand temperatures in the neighborhood of 2300°F and up to 3300°F in some instances.
- Chamber 31 is less critical in that it is always at a lower temperature than chamber 32, but refractory material should be used for lining this chamber 31.
- the rollers 35 and 135 in the preheating chamber 31 and the rollers 36 and 136 in the firing chamber 32 are of suitable refractory material, such as high alumina or fused silica.
- the rollers 35 and 36 are disposed along a horizontal path and extend transversely of the kiln 25, the ends of each rollers 35 and 36 protruding outwardly. through appropriate holes on opposite inner side walls 37 and 38 and outer side walls of the kiln 25.
- the upper peripheries of the rollers 35 and the upper peripheries of the rollers 36 are disposed along a common horizontal plane and are adapted to receive and support by its lover surface, the ribbon 20.
- the rollers 135 and 136 protrude outwardly through appropriate holes in the side walls 37 and 38 and provide upper peri ⁇ pheries which are in a common plane and receive the bottom surface of the ribbon 120 for supporting the same.
- the plane of rollers 135 and 136 is parallel to and above the plane of rollers 35 and 36.
- the firing chamber 32 I have provided a plurality of spaced laterally directed fuel, i.e., oil or gas, combustion nozzles or burn ⁇ ers 40 which protrude through the walls 38 defining the chamber 32.
- the nozzles 40 on one side of the chamber 32 are staggered with respect to the nozzles 40 on the other side wall 38 of the chamber 32.
- O-.-IPI flames from the nozzles 40 are introduced laterally in alternate directions both over and under the ribbons 20 and
- each side wall 38 has three vertically spaced rows in which there is alternately a discharge port 42 and a nozzle 40 equally spaced, longitudi ⁇ nally.
- Each nozzle 40 directs its flame transversely across the firing chamber 32 so that a substantial amount of combus ⁇ tion gases travel through the opposed port 42 and out of the chamber 32.
- Each nozzle 40 is disposed longitudinally equi ⁇ distant between two adjacent rollers 36 and 136 and protrudes through and are supported by the side wall 38.
- Combustible gas such as natural gas is supplied from a gas header 43 through individual branch lines 43a to the nozzles 40.
- An air header 47 supplies air under pressure through lines 44a so as to present air for mixture with the gas at the nozzles 40.
- the headers 43 and 44 are disposed on opposite sides 48 of the firing chamber 32. A similar arrangement may be made for burning oil or other fuel.
- the kiln 25 is provided with outer walls 44 which are spaced outwardly of and parallel to inner side walls 38.
- Upper and lower horizontal walls 45 and 46 join the upper and lower edges of walls 44 to their respective inner side walls 38 to form horizontally extending channels or passageways 47 on opposite sides of the inner side walls 37.
- End walls 56 which are parallel to rear end wall 27 closes the downstream ends of channels 47.
- the walls 44, 45, 46 define manifolds which en ⁇ close all of the exhaust port 42 so that they communicate, on their respective sides, with the horizontally extending channels 47. Spaced blocks 57 below walls 46 provide support for these manifolds.
- the walls 44, 45, 46 extend in an upstream direction over the opposite side walls 37 of the upstream end portion of the chamber 31 to terminate at end walls 58.
- inlet ports 59 are pro ⁇ vided in the end portions of side walls 37, as seen in Fig. IB, so as to communicate with the channels 47, as shown best in Fig. 4.
- channels 47 conduct all flue gases from the firing chamber 32 and introduce them laterally through ports 59 on opposite sides of chamber 31 both above and below the ribbons 20 and 120 in the downstream end of chamber 31 and such gases pass in an upstream direction, as indicated by the arrows being received by discharge ports 48 disposed in the walls 37 adjacent to the front 26 or entrance end of chamber 31.
- the transversely opposed discharge ports 48 communi ⁇ cate with opposed, upwardly extending suction ducts 55 communicating with exhaust manifolds 49 disposed exteriorly of kiln 25 adjacent the walls 37. These exhaust manifolds 49 lead upwardly into an intake duct 50 which is connected to the intake ports of an exhaust blower 51 driven by a motor 52 through belt 53. The fan or blower 51 discharges through a stack 54 to the atmosphere.
- Individual controls for nozzles 40 including strategically located pyrometers and valves (not shown) which enable an operator to control the transverse heating zones of the firing chamber 32 so that the heat in the firing chamber 32 may be maintained within quite ' close tolerances.
- the transverse flow of these gases, both above and below the moving ribbons 20 and 120 enable the firing chamber 32 to be maintained at an appropriate temperature for progressively firing and foaming or cellulating of successive increments of the clay ribbons 20 and 120, as they move along the firing chamber 32.
- the proportion of air to fuel is maintained in various zones, as desired, for oxidizing neutral, or reducing conditions.
- the cellulated or expanded vitreous clay denoted by the numerals 20a and 120a, progressively and continuously emerge through discharge ports 60 and 160 in the rear end 27, onto support rollers 61, 161.
- the upper surfaces thereof can, if desired, be treated with additional surfacing material, such as a dry granular fritted glaze 62.
- additional surfacing material such as a dry granular fritted glaze 62.
- the glaze or coating material 62 is retained in a hopper 63, adjacent one side of kiln 25.
- the bottom portion of hopper 63 is provided with a transversely extending, hollow, distribution cylinder 65 carrying a horizontally disposed screw conveyor 64.
- the distribution cylinder 65 communicates at one end with hopper 63 and is provided, at its lower side with a plurality of axially spaced holes 66.
- a means for cooling both the coating material 62 and the cylinder or trough 65 is provided.
- This means for cooling includes a hollow central shaft 67 for conveyor 64, through which water under pressure is directed.
- the shaft 67 and the screw conveyor 64, which is attached to shaft 67, are rotated by a motor 68 and chain drive 69.
- Water' is fed to the shaft 67 by pump 70 through a pipe 71, shaft 167, pipes 72 and 73, from a tank 74.
- a return line 75 delivers the cooling water back to tank 74.
- Shaft 167 is identical to shaft 67 and carries a screw conveyor 64 in a cylinder or trough 165 of a hopper 163 driven by motor 168 and chain 169 for feeding fritted glaze 162 through holes 166 onto the upper surface or ribbons 120a.
- the cylinder 165 extends transversely over ribbon 120a.
- fritted glaze 62, 162 is delivered to the hot upper surfaces of ribbons. 203, "* 120a.
- the glaze immediately becomes molten to provide- a glazed surface thereon.
- rollers 35, 36, 135, 136 protrude outwardly through appropriate holes in walls 37, 38, 44, 237, 238, 244 of the kiln 25 and 225.
- the rollers 35 for example, which support the charge prior to sintering and are in the drying and pre ⁇ heating chamber 31, can be spaced apart from each other by greater distance than the spacing of the rollers 36. With such greater spacing, each end portion of the rollers 35, outwardly of the kiln is confined by three circumferentially spaced idler ⁇ vheels 70a, 70b, 70c.
- the idler wheels 70a, 70b, 70c are supported for rotation by stub shafts 71 which project into the outer walls 44. The axis of each lowermost wheel 70c is vertically below the roller 35 which it supports.
- a continuous steel belt 72 passing between, each wheel 70c and its associated roller 35, to the next and then to the next provides synchronized for all rollers 35.
- the same belt 72 also passes beneath all rollers 36, as seen in Fig. 11, being received between the end portion of each roller 36 and its associated wheel 73c which is there beneath.
- rollers 36 are closer together, they can share an additional wheel 73b which is between them and rides against the peripheries of the adjacent rollers 36 above the axial plane of such rollers 36. Such wheels 73b aid the belt 72 in synchronizing rotation of rollers 36.
- the outboard roller 36 has an outer idler wheel 73a circumferentially spaced from wheels 73b and 73c for that roller 36.
- Belt 72 passes round appropriate drive or guide rollers 74 outboard of the rollers 35 and 36.
- a motor (not shown) may drive belt 72.
- Rollers 135, 136 have a similar drive.
- Lehr 80 is provided with a similar drive for its or lehr to drive one or both end portions of the rollers.
- rollers 35, 36, 135, 136 At locations along the path of travel of the ribbons 20, 120, if there is expansion or contraction of the ribbons, it may be found desirable to permit one or several of the rollers, such as rollers 35, 36, 135, 136 to idle. This can easily be accomplished by shifting the appropriate associated wheel or wheels 70c and/or 73c laterally inwardly or outwardly so that they are out of alignment with belt 72.
- the ribbons 20a and 120a pass into an annealing lehr denoted generally by the numeral 80.
- the annealing lehr 80 like the kiln 25, is separated into compartments, the first being a cooling chamber 81 and the others annealing chambers 82a, 82b, 82c.
- the lehr 80 includes a front wall 83, intermediate partitions 84a, 84b, 84c, 84d and a rear A ail 85. In addition, it has front side walls 86 and rear side walls 87 as well as a top 8S and a bottom 89.
- Rollers 87 and 187 form horizontal conveyors for the ribbons 20a and 120a in the first chamber 81.
- Rollers 88 and 188 form horizontal conveyors in the second chamber 82.
- the front wall 83 is provided with ports 90 and 190 through which the respective ribbons 20a and 120a pass into the chamber 81.
- the partitions 84a, 84b, 84c, 84d are provided with ports, such as ports 91 and 191, through which the ribbons 20a and 120a pass from the chamber 81 into the successive chambers 82a, 82b, 82c, 82d.
- the rear wall 85 is provided with ports 92 and 192 through which the ribbons 20a and 120a emerge from the lehr 80.
- Additional transverse rollers 93 and 195 form hori ⁇ zontal conveyors for the cooled ribbons 20a and 120a which emerge from the lehr 80.
- a forced draft circulating air system 119 For rapidly cooling the ribbons 20a, 12Ca in the cooling chamber 81, a forced draft circulating air system 119 is provided.
- This system 119e includes three transversely extending metal baffles 95, 96, 97 and a bottom plate 98 dis- posed in the chamber 81.
- Plate 95 was disposed above ribbon 120a; plate 96 below the ribbon 120a and rollers 187; plate
- Plates 96 and 97 were formed of transverse valleys and ridges to accommo ⁇ date the rollers 87 and 187. Plates 95, 96, 97 and 98 are perforated or foraminous.
- the plate 95 and the top of the lehr 80 formed an upper plenum, plates 96 and 97 a middle plenum and plates
- plenums are connected to the discharge side of a blower 100 through a branch duct 101a and a manifold 101 so that cooling air is forced into the plenums and directed against the upper and lower surfaces of the ribbons 20a and 120a as shown by the arrows in Fig. 7.
- Exhaust air is taken out of the chamber 81 via ducts 102 leading from the opposite side of the lehr 80 at the level of the ribbons 20a, 120a. These ducts 102 l.ead to an exhaust manifold 103 which communicates with a header 104. A common exhaust duct 105 is connected by a branch duct 106 to. the header 105.
- a cross-over duct 107 leads from header 104 via tee 108a to the intake of blower 100.
- the other duct 108b con ⁇ nected to tee 108a opens to ambient air.
- the damper 108, in tee 108a the ratio of ambient air to recirculated air is manipulated for cooling of the ribbons 20a, 120a in chamber 81.
- the annealing oven is made up of a series of chambers 82a, 82b, 82c, 82d, similar to chamber 81, respec ⁇ tively having individually controlled circulating air systems 119a, 119b, 119c, 119d identical to the system 119e described. All headers, such as header 104, discharge, to the common duct 105, the heat therefrom being used for heat as needed in the plant, or as preheated air to burners.
- the ribbons 20a and 120a are transversely cut during their path of travel so as to produce rectangular slabs. These slabs are on the order of 4 feet to 8 feet wide, cut to length as ordered. Trimming of edges, planing of surfaces, and cutting into . ⁇ - cated with interlocking joints.
- a kiln 225 which is identical to kiln 25 except that it has vertical guide roller 280 and drives therefor.
- the kiln 225 included inner walls 238, outer side walls 244, horizontal walls 245, 246, roof 241 and bottom 242 and rollers 235, 236, 335, 336 which receive and transport the ribbons 220 and 320 through the preheating chamber 231 and firing chamber 232.
- Fuel is supplied in the firing chamber 232 through nozzles 240.
- rollers 280 there are a plurality of longitudinally spaced opposed, pairs of vertically disposed guide rollers 280 in kiln 225, projecting up between the ad ⁇ jacent horizontal rollers 235, 236, 335, 336.
- the function o such rollers 280 is to guide the charges 220 and 320 in their longitudinal path through kiln 225.
- the ends of rollers 280 protrude through appropriate holes in top 241 and bottom 242 of kiln 225.
- the bottom portions of vertical rollers 280 are received and journalled by thrust bearings 281.
- the upper en portions of rollers 280 pass through bearings 282 and protrud outwardly therefrom.
- rollers 280 receive sprockets 283 around which passes a continuous chain 284 which drives the opposed pairs of rollers 280 in opposite directions at approximately the same peripheral speed of the rollers 235, 236, 335, 336.
- rollers 280 The spacing of the rollers 280 is a matter of choice; however, they should be sufficiently close to prevent appre ⁇ ciable lateral movement of the charge 220 or 320.
- the lehr 80 and the kiln 25 can be equipped with such vertical rollers, as rollers 280, if desired.
- the third embodiment depicted in Figs. 13A, 13B, 13C, 14, 15, 16 and 17 has multistage extruders formed of rectangular vertically disposed hoppers 310 and 410 having downwardly converging side walls 312 and 412 joined by triangular end walls 311 and 411 and compression rollers 313, 313a, 313b, 319, 413, 413a, 413b and 419.
- the power driven compression rollers 313, 313a are disposed on opposite sides of the mouth of hopper 310 and, with end rollers 319, compress and feed the charge as a rectangular compacted stream, downwardly.
- the axles 315 of these rollers 313, 313A and the axis of rollers 319 are disposed in a common horizontal plane.
- the second stage power driven compression rollers 313b is disposed below roller 313 with its axis parallel to the axles 315 of rollers 313, 313a.
- the rollers 313 and 313b cooperate to squeeze and feed, as a stream, the charge hori ⁇ zontally.
- the sheet 317 extends from adjacent the inner periphery of roller 313a to adjacent the inner periphery of roller 313b and functions as a guide means to guide the outer surface of the stream.
- rollers 313 and 313a give the clay charge an initial squeeze feeding the stream downwardly and the rollers 313, 313b a second and subsequent squeeze, feeding the stream horizontally.
- Additional opposed rollers can constitute subsequent stages for cooperating with rollers 313, 313a, 313b in shaping, compressing and feeding the charge as a rectangular ribbon 320 of indeterminate or continuous length fed horizontally onto a receiving slide plate 317a arranged outwardly adjacent to the upper periphery of roll 313b.
- live rollers 318 feed the ribbon 320 into the horizontal kiln 325 through opening or entrance port 309 in front or entrance end 326 to subsequently emerge as a hot cellulated product from the exit opening or port 360 in the exit end 327 of the kiln 235.
- the hopper 310 receives a premixed raw or green charge formed of a mixture of clay, water and carbonaceous material, as described above.
- the hopper 410 has identical end walls 411, side walls 413, rollers 413, 413a, 413b, 419, curved sheet 417, slide plate 417a and heater 428 for discharging a compacted horizontal ribbon 420 of green clay charge, identical to and above ribbon 320.
- Ribbon 320 is fed next to a coating zone where glaze or engobe is sprayed onto the upper surface of the ribbon 320 by a nozzle assembly 329 having a horizontal header 329a carrying a plurality of spaced downwardly directed nozzles 329b.
- a nozzle assembly 329c group of nozzles 329d carried by a transversely extending header 329e.
- the nozzles 329d discharge a parting or releasing agent onto the bottom perhaps the sides of ribbon 320.
- the parting agent is preferably a slip formed of raw, high temperature, fire clay and water and sufficiently fluid to pass through the nozzles 329d.
- Nozzle assemblies 429 and 429c similar to nozzle assemblies 329, 329c, are .provided for ribbon 420.
- the power driven rollers 318 and 418 feed the ribbons 329, 420 through ports 309, 409 into kiln 325.
- Horizontal power driven or live rollers 335 receive ribbon 320 and horizontal power driven rollers 435 receive the ribbon 420.
- the upper peripheries of rollers 335 and 435 form parallel horizontal conveyors which feed the ribbons 320 and 420 at uniform rates through the kiln 325, the rollers 335, 435 being driven as illustrated in Figs. 11 and 12.
- the kiln 325 is provided with a plurality of horizontally disposed muffle plates 330a, 330b, 330c, 330d which partition the kiln 325, throughout its length into a plurality of alternately spaced combustion chambers and muffle chambers, the combustion chambers being the longitudinal extending ' chamber 347a, 347b and 547c.
- the upper chamber 347a is above the top ribbon 420; the intermediate chamber 347b is between upper rollers 435 and lower rollers 335; and the lower chamber 347c is below the rollers 335.
- combustion chambers 347a, 347b and 347c The purpose of the combustion chambers 347a, 347b and 347c is to separate the ribbons 320 and 420 from the combustion gases so that the ribbons will be in a reducing or neutral atmosphere, at least during the period in which the temperature of the ribbons is above about 800°F ' .
- the muffle plates 330a and 330b thus define, there ⁇ between, a tubular upper muffle chamber 431 and the plates 330c and 330d, the lower muffle chamber 331 within which are the rollers 435 and 335 and the ribbons 420 and 320.
- Baffles or muffle plates 330a and 330c are inclined slightly so that the latter portion of chambers 331, 431 progressively widen gradually toward the exit ports 360 and 460 and corresponding portions of chambers 347a and 347b progressively narrow 7 toward the end 327.
- the muffle plates 330a, 330b, 330c, 330d preferably formed of sheets of fused silica which i ⁇ ill permit tempera ⁇ tures within the kiln 325 of up to about 2700°F.
- the silica charge for the kiln 525 should be provided with a silica or sand glaze along the upper sur ⁇ face and then after firing, the glaze thus formed should be sawed off of the foamed remaining product.
- a succession of fused silica sheets disposed transversely side edge to side edge in the kiln will make up each of muffle plate 330a, 330b, 330c, 330d.
- the sheets When installed, the sheets should be heated initially to about 2300°F. At that temperature, the sheets will slowly devitrify to produce cristobalite crystals which have less tendency to sag at higher temperatures. Thereafter, the higher temperatures, up to about 2700°F, can be used.
- rollers 355 and 435 protrude through the side w r alls 344 of the kiln 325, the end portions thereof being supported by w ⁇ heels or rolls 370a, 370b, 370c and driven by belts 372, as described above for the preceding embodiment.
- Staggered fuel nozzles 340a disposed in about the last half, direct an ignited air and gas mixture transversely across the upper chamber 347a for heating it, while similar staggered nozzles 340b and 340c do the same for the central o intermediate chambers 347b and 347c, respectively.
- Air lines 300 supply air through branch lines 301 to the nozzles 340a, 340b, 340c while gas or oil fuel lines 302 and branch lines 303 supply the fuel, thereto.
- an exhaust assembl or means which is identical to the exhaust assembly of Fig. 1, is provided. It includes a motor 52 driving, through belt 53, a blower 41 for drawing the products of combustion from the discharge ends of chambers 347a, 347b, 347c, through port 348a, 348b, 348c and manifolds 349, and discharging the same through exhaust stack 354.
- the ribbons 320a and 420a after being bloated or cellulated, are fed beneath the glaze applicators 363 and 463 and thence to annealing oven or lehr 380 having successive chambers provided with air systems 419a 419b, 419c, 419d, the lehr being identical to lehr 80.
- a rectangular kiln 525 having parallel juxtaposed, freely rotating, rollers 535, and live or driven rollers 536.
- Rollers 535 receive, from a ramp or platform 510, a charge 520 carried in a tray or pan 521.
- This pan 521 is rammed, by a reciprocating hydraulic ram 522, through entrance opening 509 in front wall 526, into the firing chamber 531 of the kiln 525.
- Pan 521 is received on the roller hearth, formed by horizontal idler rollers 521, and is moved thereon by bein pushed by successive similar pans 521, with their charges --.--.u, as such pans are successively fed by the ram 522 into the kiln
- the kiln 525 is heated by fuel burners (not show ⁇ n) as in the preceding embodiments and the products of combustion exhausted by blower 551 through stack 554, the suction being drawn through exhaust ports 548.
- the pan 521 thus eventually reaches the line rollers 536 at the exit end within the kiln 525 which, when actuated, discharge the pan through momen ⁇ tarily opened exit port or opening 560 (aligned with open 509) when the vertically slideable door 561 on the kiln 525 is raised by a ram 562 to the position shown in Fig. 18B in broken lines.
- a motor (not shown) drives, through a unidirectional drive, all rollers 536, so that some resistance to feed along rollers 536 is encountered. This applies a back pressure which keeps the juxtaposed tandem arranged pans 521 on rollers 535 and 536 in abutting relationship.
- a pivoted finger or switch arm 563 connected to switch 564 as shown in Fig. 18b acts as an electrical control means for both the motor (not shown) for rollers 536 and ram 562, so that the door 561 is opened when the arm 563 is moved toward door 560 by the cellulated charge 520a, and the rollers 536, thereafter, actuated so as to discharge one tray 521 from the oven or kiln 525. Then the door 561 is closed and another cycle can commence.
- Fuel nozzles (not shown) but similar to nozzles 40 and 340a, 340b, 340c, heat the kiln 525.
- pans 620 and 720 may be intermixed.
- the sections tray or pans 620 include a pair of opposed end segments 521 and a plurality of intermediate segments 622. Segments 622 are each channel members having flat rectangular bottom plates 623 and
- the end sections are also channel members having rectangular base plate 625 and side plates 626. One end is closed by a rectangular end plate 627.
- the sections 624 and 625 are assembled by simply being placed edge to edge, on platform 510 to form pan 620, closed on its sides and bottom.
- the silica charge of ra sand, water and carbonaceous material is hand packed or ramme into the pan 620 and the ram 522 is used to push each pan 620 successively into the oven.
- the panels or plates 623, 624, 625, 626, and 627 are formed from sheets of refractory material, i.e., pressed carbon, such as coke fines or charcoal granules.
- Pitch o ⁇ tar may be employed as a binder for the coke or charcoal and as a adhesive to join the appropriate edges together.
- a second form of segmented or sectional pan 720 includes a plurality of abut ⁇ ting flat rectangular intermediate bottom plates 723 and end plates 723a which are each provided with a pressed or com ⁇ pacted right prism or rectangular block 724 of silica charge.
- a conventional press (not shown) can be employed to compact each block 724 onto its associated bottom plate 723 or 723a, or the blocks may be pressed separately and then placed on the base.
- the outer or side ends 725 of the block 724 should terminate inwardly of the end edges 726 of bottom plate 723.
- the sides 727 of each block 723 should end in alignment w ⁇ ith the side edges 729.
- the outer edges 729a of end blocks 724a should terminate inwardly of the outer edges 729a or end plates 726a.
- the plates 723, 723a, when assembled have perimeter portions which receives thereon longitudinal spaced parallel side bars 730 and spaced parallel transverse end bars
- the pan 720 When assembled, the pan 720 has the individual blocks 723 and 723a abutting each other. These blocks 723 and 723a fuse together as the silica charge, formed by blocks 723, 723a, fuses and cellulates, while passing through the oven or kiln 525.
- vertical idler rollers 580 dis ⁇ posed at spaced intervals within the kiln 525, guide the pans, such as pan 720, through the kiln 525, the rollers 580 prevent ⁇ ing appreciable outward movement of side bars 730 and the bars
- a small press (not shown) can be used to process a very long cellulated fused silica product.
- the trays 620 and 720 are inexpensive and expendable. It is expected therefore that one, two or three uses is all that they would withstand. Being of carbonaceous material or carbon, they may be consumed by oxygen and water vapor. Hence, they function to assume a reducing condition around the charge and when the hot trays and charges are discharged to the atmosphere, they may be consumed by the ambient air.
- the trays and expendable permits the burning of fuel, such as gas, oil or solid fuels, i.e., wood or coal, within the kiln to generate products of combustion, such as water vapor. These products of combustion are con ⁇ sumed by reacting with the carbon of the trays.
- fuel such as gas, oil or solid fuels, i.e., wood or coal
- the speed of the feed through the kiln should be such as to leave the charge in the kiln from about 10 minutes to about 60 minutes, depending on the thickness of the charge.
- a 3/8 inch thick charge should be moved at about tw-o feet per minute to remain in th kiln for 20 minutes while a five inch thick charge should mo at about one foot per minute.
- the spacing of the rollers in the kiln should be such " as to preclude appreciable sagging, particularly after the charge has been fused and is in a relatively viscous condition. Thus, in the latter part of the kiln, care shoul be taken to provide the rollers at spacings of less than abo five inches on center. Thus too will vary with the thicknes of the charge. If the charge is thin, i.e., about 3/8 inch, the rollers should be arranged at about 1-1/2 inches apart, on centers, and if the charge is thick, for example, five inches thick, the rollers should be about four inches apart, on center.
- the ribbons are sufficiently self-suppor ing for the rollers to be from about six inches to twenty fo inches apart, on centjer.
- the rollers should, however, be sufficiently numerous to support a segment of a pan by two or more rollers at all times.
- the kiln is built of fused silica, as a rule, in any part subjected to not more than about 2700°F, and support wall sections on the cold sides. Solid or cemented layers do not crack off due to differential expansion. It is noted that in the usual operating temperatures in the hot zone, the fused silica.will tend to devitrify in time, converting to cristobalite which has a disruptive thermal expansion below about 600°F.
- the kilns are normally operated for months at full temperature, and it is simple in this case and in many other operations to maintain the devitrified parts above 600°F by a small holding fire.
- One charge whic can be satisfactorily processed to a foamed or bloated clay product is made up by weight of 100 parts clay, from about 6 parts to about 15 parts water, and from about 1/20 part to about 2 parts available carbon in carbonaceous material.
- the clays which I have found useful as a raw materi include surface clays, ball clays, kaolin, shale, and bentonite.
- Other clay-like materials are useful for my process, the essential quality being the small ultimate particle size of the material and the ability to sinter into an impervious mass.
- clays and clay like materials whic have a mean particle size of less than 2 microns are particu ⁇ larly useful in my process.
- Such clays are found in nature in rock like form; they should be crushed to a granular form, typically to pass through a 6 mesh screen.
- Another charge which can be processed to a foamed fused mineral is made up of silica, carbonaceous material and water.
- a useful silica raw material is a sedimentary quartzite occurring naturally in massive form, having an average crystallite diameter of about 10 microns and less, preferably between 5 and 10 microns, and containing negligibl inter-crystalline material.
- a preferably useable silica raw material contains at least 99% SiO ⁇ , on an oxide basis. Such a silica raw material may be found, for instance, in
- the quartzite material is crushed after removal from the mine, typically to pass through about a 6 mesh screen. If a purer form of silica is desirable, a silica flour obtained by fine grinding quartzite sand or gravel should be used. The addition thereto of colloidal silica improves the surface area of the quartzite, as will be ex ⁇ plained, hereinafter.
- the charge is formed by admixing 1000 parts silica and from about 1/2 part to about 4 parts available carbon in soluble carbonaceous material and sufficient water to provide for the thorough distribution of the soluble carbonaceous material and the colloidal silica, if present. Hence, from about 50 to about 100 parts water is recommended.
- the silica charge must be placed on plates which are fed end to end through the kiln 25 in place or ribbons 20, 120.
- silica raw material is diatomaceous earth w r hich is a very porous form of silica and foams quite readily. It is not, however, a pure form of silica and its lack of resistance to acids detracts from its usefulness.
- the charge is compacted using either a low pressure press or rolls, such as rollers 13 and 19.
- the clay charge will extrude into the ribbons 20, 120.
- the silica charge may require carrying plates or carriers 200 along its bottom surface.
- the carrying plate 200 is expendable and if a carrier plate is used it is made in the same press where the charge is compacted.
- the plate 200 is formed of a binder and carbon material. It is preferably composed of a binder and carbonaceous material such as pitch and coke fines or pitch and coal dust, as is practiced in the carbon forming arts.
- the plate 200 is produced on an aluminum foil sheet or other parting agent 201 in press 202 so that it does not stick to the heated platen 203.
- the aluminum will melt in the kiln 25 and burn up.
- silica sand corresponding in purity to the silica of the interior may be placed on the upper sur ⁇ face of the silica charge (without a blowing agent) to form a glaze, when fired.
- the plates 200 are to be removed from the ribbon of fused silica, once the cellulated fused silica has cooled.
- the charge When the charge enters the kiln 25, regardless of whether it is a silica charge or a clay charge, it is sub ⁇ jected to about a 600°F temperature and is progressively sub ⁇ jected to increasing temperatures so that, as it reaches the end of its travel in chamber 31, the charge is being sub ⁇ jected to environmental temperatures of from about 50°F to about 200°F less than the temperature of the gases of the firing zone or chamber 32.
- the charge then enters the firing chamber 32 where the temperature should be maintained, for example, as follows: For surface clay charges and bentonite charges
- the temperature and turbulence which determine the heat transfer characteristics, should be such that there is not more than about 150°F temperature differ ⁇ ential between the surface temperature of the charge and the lowest temperature in the interior of the charge.
- Sintering of the charge usually takes place when the charge is about 100°F to about 500°F below the melting point of the clay or the silica in the charge. Thus, sinter ⁇ ing may take place largely in the preheating chamber 31.
- the charge pro ⁇ gressively swells or bloats as cellulation takes place and upon emerging from the chamber 32, the foamed or cellulated raw material has a density of 8 lbs. per cubic foot to about 100 lbs. per cubic foot and has a glassy, vitreous, cellular structure of mostly non-innerconnecting cells.
- the raw material is silica so that a foamed fused silica product is produced, it is not necessary to feed the product to the annealing lehr or oven 80. Instead it must be cooled rapidly to about 2000°F and then as rapidly as is convenient.
- the product must be fed to the annealing lehr 80 and therein progressively cooled.
- the annealing curve for each product should be established experimentally.
- a curve similar to that of 1/4" thick plate glass gives good results.
- the speed of the ribbons or plates through the kiln 25 and lehr 80 is from about 3" per minute to about 72" per minute and the spacing of the rollers 36, 136 toward the dis ⁇ charge end of chamber 32 is from about 1" to about 6" on centers.
- the viscosity of the material during cellulation is from about 4.8 x 10 poises to 5.2 x 10 poises, and the material does not sag between rollers.
- the atmosphere has an excess of air or oxygen and is, therefore, an oxidizing atmosphere.
- One or more surfaces of the ribbons 20 and 120 are kept in this oxidizing condition from just before fusion of the ribbon or plate until discharge to the cooler temper ⁇ atures.
- the temperature just before sintering and during firing is sufficiently high that the carbon in the surface area of the charge is burned out to a limited depth from the surface of the clay.
- a shell of high melting point material is created partially or completely around the ribbon 20 or 120 or the plate.
- this releasing or parting agent upon heating in the kiln is more inert than the clay itself and thus does not stick to the surfaces of the rollers. Furthermore, this releasing agent or parting agent, if supplied on three sides, creates a cradle beneath and on the sides of the ribbons 20 and 120 so as to confine the charge during the period in which it is foamed or cellulated.
- the proper amount of gas is formed to give the desired density. Adjustment of the moisture and degree of pressing gives a clay ribbon strong enough to pass over the rollers, but not so dense as to require a long drying time at low temperature.
- the carbon reduction of the iron oxides and other oxygen rich compounds in the clay is possible at lower temperatures; however a substantial part of the reaction is delayed until the melting of the charge. It is an essential part of my process that the carbon coating is deposited on each minute ultimate particle in the interiors of the large agglomerated particles of the clay as mined or crushed. Thus when the clay melts and molecular diffusion becomes faster, the physical meeting of the iron oxide and the carbon is over a very short distance and the reaction takes place promptly. This phenomenon acts as a built-in control to produce gas after sintering but promptly upon melting.
- Some porous rocks of compacted quartz crystallites are formed with crystallites or particles almost as small as the ultimate particles in clay lumps.
- Diatomaceous earth als is silica of fine ultimate particle size but less pure than the purer sands.
- These silicas, such as quartz crystallites or diatomaceous earth have larger specific surface areas tha pulverized sand and, therefore, larger interfaces. This is another way of saying that a thinner layer of carbon covers a lesser depth of silica and thus the molecular diffusion is quicker due to a shorter path.
- the carbon reacts with the silica to produce silicon carbide which subsequently upon further heating reacts with more silica to produce silicon monoxide and carbon monoxide which are the gases in a silica body or in a high temperature aluminum
- the silica flour has a particle size of about 15 microns equivalent diameter while colloidal silica is approxi ⁇ mately 1000 times smaller. This means that the surface area of a given mass of colloidal silica has 1000 times the surface area of the same mass of silica flour.
- I use approxi ⁇ mately two parts by weight colloidal silica to 100 parts by weight silica flour and thereby increase the effective surface area of the silica flour by about 20 times. This proportion ⁇ ally increases the area of interface for reaction between the carbon and the silica.
- Cellulated vitreous fused silica product can also be made from crushed silica rocks, such as quartzite rock or diatomaceous earth, to provide agglomerates of less than 1/2 inch in diameter. These crushed rocks are admixed with colloidal silica sol and a soluble carbon compound, which will char upon heating, dissolved in water. The solution will penetrate the agglomerates and coat its small particles there ⁇ in. The subsequent heating will drive off the moisture, leaving the colloidal silica and carbon uniformly distributed on the particles. Continued heating will cause a reaction between the carbon and the available silica and between the carbon and available oxygen to cause cellulation as the silica fuses. Suitable foamed materials can be produced accordin to my invention from surface clays, shales, bentonites, diatomaceous earth, and silica. Surface clays and shales obtained from brick, roof tile and flower pot plants in
- Swelling bentonite from Wyoming and South Dakota and non-swelling bentonite from Mississippi and California are also useful for producing foamed material according to t present invention. All of these clays (shale and bentonite being referred to as a clay) have been successfully processed in the following manner:
- organic materials containing carbon are well distributed in the clay and presen no particular problem except that they must be considered. Thus, in some instances, it is not necessary to add carbonaceous material to the clay. In some instances, where extremely high organic material content is contained in the clays, they should be admixed with other clays so that the resulting charge has about 2% by weight organic material in the mixture. If more than about 2% organic material is con ⁇ tained in the mixture, overblowing and irregularities in the cellular structure will occur. When less blowing or foaming is desired, the organic material in the charge is reduced accordingly. This can be done by admixing with other clays of low organic- content.
- the resulting foamed or cellulated clay will be more uniform and less densely cellulated.
- impermeable cellulated pieces of good uniformity were obtained in all cases, except where an excess of organic material was contained in the charges.
- a 12" square tile was formed by pressing at 100 psi, to about 1" thickness.
- the tile was introduced into a 700°F atmosphere for 15 minutes, thence into a controlled atmosphere whereby the tile was substantially sintered without burning out the carbon derived from the sugar, as the temperature w r as raised to about 2000°F in a reducing atmosphere.
- the tile was passed over rollers at about 12" per minute for 20 minutes in an oven at about 2100°F in an oxidizing atmosphere.
- the rollers were clean and new before this run and the tile passed over w ⁇ ithout being stopped by sticking to the rollers. There was no evidence of sagging between rollers.
- the tile had expanded to about 16" by 16" and had a reddish brown skin due to the skin oxidation.
- the interior was greenish dark gray and cellulated to about 30 lbs. per cubic foot.
- Green tiles from Example 1 were painted on the bot tom and sides with an engobe of ⁇ aw r and calcined high temper ature fireclay, after preliminary drying.
- Example II These tiles were fired as in Example I and showed less tendency to cause sticky spots on the rollers, but wher a sticky spot existed there was still a tendency to pull off the engobe and oxidized skin, which could build until the conveyor would become inoperable.
- the tile expanded later ⁇ ally to about 16" x 16".
- Example I A mixture of 60 parts calcined fireclay to 40 parts raw fireclay and 10 parts water was spread over the bottom of a die cavity and patted up on the sides. The die was then filled with the clay charge from Example I and tiles pressed otherwise as in Example I.
- Example I Example I and cellu ⁇ lated to about the same density. It was noted that while the tile had expanded laterally to about 16" x 16" in Example I and II, the tile of this example expanded in thickness rather than laterally.
- a parting agent was made by mixing 12 parts raw fireclay to 88 parts silica sand and 10 parts water. This mixture was used to make the bottom coating of the tile of Example I and processed as in Example II. When tile w ⁇ ith thi bottom coating was passed over the rollers in firing, the sand, exposed to a sticky spot, was pulled off only as it was ex ⁇ posed, until eventually the sticky spots on the rollers were well covered. In subsequent runs these rollers were then able again to receive the clay charge w ⁇ ithout the charge sticking.
- Example II Tile similar to Example I were made with Wyoming bentonite instead of clay and the sugar addition was reduced to about 2 parts per 1000 parts of bentonite. At a firing temperature of about 2300°F similar results were obtained as in Examples I, II and III.
- the carbon plates were then cooled and loaded with a charge about -8" x 8" x 1" by placing a form on the plate and filling the form and hand ramming.
- Example VI the charge was Mississippi M ⁇ D ball clay, mixed with sucrose and water as in Example I.
- the sample was fired on one of the carbon plates, going directly from room temperature into the kiln at about 2800°F, w r here it was fired for about 20 minutes. Temperature was adjusted by trial and error to achieve good cellulation.
- Example VI This was a repeat of Example VI, except that crush diatomaceous earth was substituted for the clay.
- the temper ature was adjusted by observation of the melting and cellula tion, and was judged to be about 3100°F.
- the sucrose addi ⁇ tion was about 2 parts per 1000.
- Good cellulation was obtained at about 20 pounds per cubic foot, and the product did not break when brought from the kiln temperature into cold air.
- Example VII The procedure of Example VII was repeated except that porous quartzite rock (see Table I) was crushed and use in lieu of the diatomaceous earth.
- the firing temperature was about 3200°F. Quick cooling was successful and cellulation was good after about 30 minutes firing.
- Example VII and VIII The procedure of Example VII and VIII was followed except that the charge was a purer quartzite silica, princi ⁇ pally a purchased 325 mesh silica flour, 99.8% pure silica.
- Firing was on the carbon plate at about 3200°F for about 30 minutes. The sample was cooled quickly upon dis ⁇ charge from the kiln and the carbon from the plate trimmed off. Cellulation was good at a density of 18 to 24 pounds per cubic foot.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- Tunnel Furnaces (AREA)
- Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
- Glass Compositions (AREA)
Abstract
L'appareil comprend une pluralite de dispositifs d'extrusion (10, 110) qui produisent des rubans paralleles (20, 120) d'un materiau brut le long de rouleaux refractaires (35, 135) au travers de chambres successives (30, 32) dans un four et au travers d'un four a recuire (80) vers une zone de coupage. Les surfaces du materiau brut (20, 120) sont enrobees sur trois cotes avec un agent isolant et sur le cote a exposer avec un agent de lustrage ou bien laissees sans revetement. La chambre de cuisson (32) du four possede des rangees opposees de bruleurs (40) diriges vers des orifices opposes (42). Les rouleaux (35, 135, 36, 136) font saillie au travers de parois laterales et sont supportes sur des roues espacees circonferentiellement (70a, 70b, 70c). Les roues (73a, 73b) synchronisent les rouleaux. Un collecteur (56) connecte la chambre de cuisson (32) avec la chambre de prechauffage (30). Le procede utilise un melange d'une petite quantite d'un materiau carbone soluble et de l'eau avec soit une charge d'argile soit une charge de silice pour regler la composition. L'argile peut etre extrudee sous forme de ruban revetu avec l'agent isolant et l'agent de lustrage, puis mis a feu, prechauffe, au-dessus de 20000 F, et recuit. Les produits en argile vitreux cellulaires sont alors decoupes. Une charge de silice avec une surface de sable de silice peut etre comprimee avec un materiau pour former des plaques, puis cuite dans le four pour former un produit vitreux cellulaire. Des plateaux consommables, en section, sont egalement decrits.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US1980/000077 WO1981002196A1 (fr) | 1980-01-25 | 1980-01-25 | Procede et appareil de production de produits cellulaires vitreux |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0045303A1 EP0045303A1 (fr) | 1982-02-10 |
EP0045303A4 true EP0045303A4 (fr) | 1984-07-03 |
Family
ID=22154173
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19800901280 Ceased EP0045303A4 (fr) | 1980-01-25 | 1980-01-25 | Procede et appareil de production de produits cellulaires vitreux. |
Country Status (10)
Country | Link |
---|---|
EP (1) | EP0045303A4 (fr) |
JP (1) | JPS57500065A (fr) |
AT (1) | ATA913580A (fr) |
BR (1) | BR8009032A (fr) |
DE (1) | DE3050248A1 (fr) |
DK (1) | DK424081A (fr) |
GB (1) | GB2079743B (fr) |
NL (1) | NL8020249A (fr) |
NO (1) | NO813232L (fr) |
WO (1) | WO1981002196A1 (fr) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3311327C2 (de) * | 1983-03-29 | 1986-05-28 | M.A.N.- Roland Druckmaschinen AG, 6050 Offenbach | Vorrichtung zum Auftragen einer Schicht aus einer fließfähigen, feinkeramischen Masse auf einen Träger |
CH671954A5 (fr) * | 1987-04-16 | 1989-10-13 | Misag Ag | |
US9362546B1 (en) | 2013-01-07 | 2016-06-07 | Quantumscape Corporation | Thin film lithium conducting powder material deposition from flux |
ES2890654T3 (es) | 2013-10-07 | 2022-01-21 | Quantumscape Battery Inc | Materiales de granate para baterías secundarias de Li y métodos de fabricación y uso de los materiales de granate |
WO2016168723A1 (fr) | 2015-04-16 | 2016-10-20 | Quantumscape Corporation | Plaques d'enfournement pour la fabrication d'un électrolyte solide et procédés d'utilisation de celles-ci pour préparer des électrolytes solide denses |
US9966630B2 (en) | 2016-01-27 | 2018-05-08 | Quantumscape Corporation | Annealed garnet electrolyte separators |
WO2018075809A1 (fr) | 2016-10-21 | 2018-04-26 | Quantumscape Corporation | Électrolytes de grenat remplis de lithium ayant une densité de défauts de surface réduite et procédés de fabrication et d'utilisation de ces derniers |
US11489193B2 (en) | 2017-06-23 | 2022-11-01 | Quantumscape Battery, Inc. | Lithium-stuffed garnet electrolytes with secondary phase inclusions |
US11600850B2 (en) | 2017-11-06 | 2023-03-07 | Quantumscape Battery, Inc. | Lithium-stuffed garnet thin films and pellets having an oxyfluorinated and/or fluorinated surface and methods of making and using the thin films and pellets |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2010263A1 (de) * | 1970-03-03 | 1971-09-23 | Kurz F | Verfahren zur Herstellung von Schaumglas |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA532763A (fr) * | 1956-11-06 | Frokjaer-Jensen Axel | Procede pour la fabrication d'un produit a structure cellulaire pour fins d'isolation | |
US1723006A (en) * | 1928-03-05 | 1929-08-06 | Ray A Bennett | Ore-roasting retort furnace |
US1850221A (en) * | 1929-10-07 | 1932-03-22 | American Face Brick Res Corp | Furnace mechanism and process for bloating clay |
US2251150A (en) * | 1940-04-15 | 1941-07-29 | Cons Mining & Reduction Compan | Continuous ore converter |
US2485724A (en) * | 1945-12-21 | 1949-10-25 | Pittsburgh Corning Corp | Method of making lightweight cellular materials |
US2552553A (en) * | 1947-08-25 | 1951-05-15 | Heine Henry William | Acoustical tile composition and method of making acoustical tiles |
US2543549A (en) * | 1948-10-30 | 1951-02-27 | Norton Co | Refractory support for ware in a tunnel kiln |
US2702748A (en) * | 1951-04-05 | 1955-02-22 | Heine Henry William | Method for manufacturing ceramic products |
US2890173A (en) * | 1953-08-19 | 1959-06-09 | Pittsburgh Corning Corp | Production of cellulated silica |
US2890126A (en) * | 1957-04-11 | 1959-06-09 | Pittsburgh Corning Corp | Cellulated silica and the production thereof |
US2890127A (en) * | 1957-04-11 | 1959-06-09 | Pittsburgh Corning Corp | Method of making cellular silica |
US2955947A (en) * | 1958-03-17 | 1960-10-11 | Kimberly Clark Co | Porous ceramic products and method |
US2934789A (en) * | 1958-09-03 | 1960-05-03 | Heine Henry William | Manufacture of acoustic fireproof tiles |
DE1301009B (de) * | 1965-08-05 | 1969-08-14 | Wasagchemie Ag | Vorrichtung und Verfahren zur kontinuierlichen Herstellung von Schaumglas bzw. -keramik |
US3666506A (en) * | 1969-04-01 | 1972-05-30 | Corning Glass Works | Batch for producing cellulated glassy bodies from rock |
US4013403A (en) * | 1975-12-08 | 1977-03-22 | Pullman Incorporated | Support means for a roller hearth in a kiln |
-
1980
- 1980-01-25 JP JP55501513A patent/JPS57500065A/ja active Pending
- 1980-01-25 BR BR8009032A patent/BR8009032A/pt unknown
- 1980-01-25 EP EP19800901280 patent/EP0045303A4/fr not_active Ceased
- 1980-01-25 WO PCT/US1980/000077 patent/WO1981002196A1/fr not_active Application Discontinuation
- 1980-01-25 GB GB8128238A patent/GB2079743B/en not_active Expired
- 1980-01-25 AT AT0913580A patent/ATA913580A/de not_active Application Discontinuation
- 1980-01-25 DE DE803050248A patent/DE3050248A1/de not_active Withdrawn
- 1980-01-25 NL NL8020249A patent/NL8020249A/nl not_active Application Discontinuation
-
1981
- 1981-09-23 NO NO813232A patent/NO813232L/no unknown
- 1981-09-25 DK DK424081A patent/DK424081A/da not_active Application Discontinuation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2010263A1 (de) * | 1970-03-03 | 1971-09-23 | Kurz F | Verfahren zur Herstellung von Schaumglas |
Also Published As
Publication number | Publication date |
---|---|
NO813232L (no) | 1981-09-23 |
EP0045303A1 (fr) | 1982-02-10 |
JPS57500065A (fr) | 1982-01-14 |
NL8020249A (nl) | 1981-12-01 |
GB2079743A (en) | 1982-01-27 |
BR8009032A (pt) | 1981-12-01 |
DK424081A (da) | 1981-09-25 |
ATA913580A (de) | 1986-11-15 |
WO1981002196A1 (fr) | 1981-08-06 |
DE3050248A1 (en) | 1982-04-15 |
GB2079743B (en) | 1984-08-15 |
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