US1773011A - Kiln - Google Patents

Description

ug. T930.

H. M. ROBERTSON KILN Filed Mal;r 9. 1928 3 Sheets-Sheet 1 WHMMM.

fuit/- Aug. 12, 1930. H. M. RoBERTsoN KILN 3 Sheets-Sheet 2 Filed Ma;\r 9, 1928 fr G. 5. 40

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31a/vanto@ 5m@ @my abkomwq Au@ l2, 1930. H. M. ROBERTSON 1,773,011

KILN

s sheets-sheet zs Filed May 9, 1928 Patented Aug. 12, 1930 Parar caries HARRY M. ROBERTSON, OF CLEVELAND, OHIO KILN Application led May 9, 1928.

This invention relates to a kiln of the continuous type for heat treating or burning various kinds of ware or products. ln the illustrated application of the invention l have shown a kiln of this type adapted for burning ceramic products', more particularly where the same are glazed, but the invention in its broaderv sense maybe applied to the treating of other products as well as ceramic products not requiring glazing.

One object of the invention is to construct a continuous kiln in which a draft inducing means is connected therewith at or beyond the discharge end of the heating chamber, whereby air and hot gases are caused to flow through the kiln in the same direction as the ware or products move.

Another object of the invention is to construct a continuous kiln in which a draft inducing means is connected therewith at or bethe draft inducing means, flows through the kiln in the same direction as the products or ware move.

Another object of the invention is to provide in a continuous kiln having a preheating chamber, a firing or heating chamber and a cooling chamber, means at the inner end of the cooling` chamber for drawing heated air therefrom, and a separate suction means inwardly of the air drawing oif means to induce a draft through the preheating and heating chambers in the direction in which the products move therethrough.

Another object of the invention is to provide an improved continuous kiln capable of rapidly and economically glazing ceramic ware or products.

Other objects of the invention will be apparent to those skilled in the art to which my invention relates from the following description taken in connection with the accompanying drawings, wherein Fig. 1 is a horizontal section showing diagrammatically a kiln embodying my invention.

Figs. 2, 3, 4, 5, 6, 7 and 8 are sections en- Serial No. 276,306.

larged, on the lines 2 2, 3 3, 4 4, 5 5, 6 6, 7 7, and 8 8 of Fig. 1.

Fig. 9 is a fragmentary vertical section.

Fig. 10 is a section on the line 10-10 of Fig. 3.

In the drawings, 1 indicates a bed formed of suitable material, such as reinforced concrete. The bed is shown more or less diagrammatically, but it may be of any desired construction capable of supporting the kiln structure.

The kiln comprises vertical side walls 2 reinforced by spaced uprights 3 secured at their lower ends in the bed 1 and tied at their upper ends by rods 4. Each wall 2 comprises an inner portion 211 formed of suitable refractory material, an outer portion 2b and an intermediate portion 2C formed of suitable insulating material. The inner and outer portions are constructed of slabs or bricks. 5 indicates caps or base members extending along the upper ends of the wall portions 2, 2, and supported thereby and ledges 2b on the inner surface of the wall portion 2b. The caps 5 form bases or abutments for the opposite side edges of the roof G, which is preferably arch shaped. The construction of the roof 6 will be later described. 7 indicates benches eX- tending longitudinally of the kiln and forming between them the passage or traversing space for suitable trucks or carriers A (Fig. 8) which support the products or ware. The trucks or carriers may be of any desired construction and arranged to run on tracks 7 (the tracks being omitted from F ig. 1 for sake of clearness). Any suitable means may be provided for moving the carriers through the kiln and returning them to the inlet end thereof.

The kiln comprises generally a preheating chamber 8 in which water smoking7 of the products B takes place, a heating chamber 9 in which oxidizing and vitrifying temperatures are maintained, and a cooling chamber 10, these chambers being in contiguous rela- 9 tion so that the loaded trucks or carriers A may pass successively through them. The receiving or outer end of the preheating chamber 8 may have an extended section 11, its open end being closed by a door (not shown),and the discharge end of the cooling chamber 10 may be provided with an eX- tended portion l2, having at its exit a suitable door (not shown). The section l2 may also be provided with a supplen'iental cooling means 13, suchas banks of pipes through which air is circulated in any well known manner.

The heating of the chamber 9 is effected by combustion of fuel in a plurality of'primary combustion chambers or bones14 formed in each wall 2. As shown in Fig. 8, each lire chamber leads inwardly from the cuter side of the wall 2, its inner upper end connecting with a secondary combustion chamber 15 above and extending longitudinally ofthe adjacent bench 7 Each secondary combustion chamber comprises a rear refractory wall 16, a frontcheckered wall l? 4both eX- tending upwardly approximately to the height of the loads B on the carriersA., 8) and a top 18 formed of refractory material and resting on the walls 16 and 17 As shown in Fig. 1, I provide in each wall 2 three primary combustion chambers lli (which may be termed the main primary combustion chambers) and also shown in this view I provide a supplemental primary combustion chamberv 19 betweenthe preheating chamber 8 and the heating` chamber 9. In this arrangement of the primary combusv tion chambers the heating of the products may be effectively controlled and any one or more may be shut down whenV desired. I have shown the chambers 14 and i9 as adapted for burning coal,coke or other form of.

The means 20 may be of any suitable formA to effect burning of salt (sodium chloride) the effect of which is to generate and supply tothe traversing passage the necessary atmosphere for glazing the surfaces of the product. The means 2O shown for illustration purposesv comprises a combustion chamber 20iprovidedin one wall 2 or (by prefer-V ence) each of said walls 2 in opposed relation. Each combustion chamber herein shown consists of a fire box and a `grate for the combustion of fuel, the salt 'being mixed with the fuel or thrown .on the fire bed in suitable quantities. As the fire boxes or combustion chambers 20 are open exteriorly of the walls 2, the'salt may be supplied thereto from time to time as desired.

Each combustion chamber 20 communi-v cates with the passage for the products through an'opening 20, the outer side wall of which is inclined toward the traversing passage so that the glazing atmosphere may be readily collected by the induced draft (to which reference will later be made) flowing toward the discharge end of the kiln and carried along therewith to insure glazing of the products B. The products herein shown consist of piping formed from clay and are preferably set on end on the carrier and on each other.

V21 indicates headers disposed opposite each other on the benches 7 at a point in the traversing passage beyond the opening 20". These headers are formed with chambers 22 into each of which leads a discharge port 23 extending` through its inner end wall.V From each of the chambers 22 leads a discharge pipe 24 connected at its outer end to an `eirhaust flue 25. The iiues 25 are connected to the inlet port of a suction mechanism, such as a power driven fan, indicated generally at 26, driven by a motor 27. The fan 27 serves to set up a draft through the kiln from its inlet end to the headers 2l and hence causes a `flow of the heated air discharged into the preheating chamber and the hot gases and products of combustion from the econdary combustion chambers through this portion of the kiln, as indicated by the arrows in Fig. l.

28 indicates lateral recesses formed in the walls 2 in opposed relation to each other. As shown, the recesses 28are disposed between the .fire box 20 or opening 2Oa and the discharge headers 2l. The recesses 28 serve as reservoirs into which the mixed air, gases and glazing atmosphere may expand or circulate to retard their iiow and also change the direction of their iiow (see arrows in Fig. l) so as to insure a circulation thereof in. around and into the products B being treated. The outer side walls of the recesses 28, that is, the side walls toward the discharge end of the kiln, are disposed in a converging relation to guide the gaseous products into the traversing passage. y

In the construction herein disclosed I provide means for heating air and conveying such air to the preheating chamber S, into which-it is discharged, preferably at spaced pointsthroughout its length, for preheating the products before they ent-er the heating chamber and effect a removal. of moisture therein; this heating being known water with the headers 30 and 32, the pipes of each l series are supported KA,by spaced piers 33, the

pipes extending through the latter, as shown in Fig. 6. The lower ends of the headers 32 are connected with conduits 34 which in turn are connected to a main conduit 35 extending transversely of but below the bed l. The conduit 35 leads to a pipe 36, which is connected to the inlet port of a power driven fan or blower 37, which serves to set up a suction and hence draws air through the pipes 3l to the headers 32.V As `willbe understood the products B are heated in the heating chamber to relatively high temperatures according to the'kind of clay used for the manufacture of the products, first to an oxidizing temperature and then to a vitrifyingtemperature whereby the 'silica in the clay on the exposed surfaces of the products is melted so that it may combine chemically with the sodium in the salt, and as the products B pass through the cooling chamber l0, the heat radiating from the products is utilized to heat the air flowing through the pipes 3l.

3S indicates a motor for driving the fan or blower 3T. 39 indicates an outlet connected to the outlet port of the fan or blower 37. The outlet 39 is connected to a chamber 40 provided on the roof of the cooling chamber l0. rEhe. outlet 39 is provided with a branch 39a which leads to the atmosphere or is connected to a chimney (not shown). The outlets 39, 39, are provided withdampers 4l, 41a, respectively, so that the supply of heated air to the chamber 40 may be regulated at will. rllhe chamber. 40 is formed by the arch wall 6a and side, end and top walls 6b. The inner side wall 6b is formed with a plurality of ports 6l which register with the inlet ends of a plurality of supply conduits 42 formed in and extending longitudinally of the roofs 6 for the heating chamber 9 and preheating chamber 8. At itsopposite end each conduit 42 is provided with a branch 42a (see Fig. l0) connected to a header 43 mounted on the adj acent benches 7. 'As will be understood from l, there area plurality of headers 43 along each bench 7, each thereof being opposite a similar header on the other bench; the outermost conduits 42y are connected to the innermost headers 43, the remaining conduits bein respectively connected to the headers in successive order toward the inlet end of the chamber 8. To provide for the conduits 42, each of the roofs 6 for the chambers 8 and 9 consists of an inner arch shaped wall 6c on which are placed rows of blocks or brick 61 of suitable refractory material, the spaces between the rowsyforming the conduits 42, and an outer arch shaped wall 44 of suitable refractory material mounted on the bricks 6 and cooperatingwith the wall 6c to complete theconduits .42. To prevent loss of heat the roofs 6 may be covered with insulation material 45. Each header 43 is provided with a damper or valve 46 and its inner side the roof walls 6C to raise the temperature ofA the air flowing through the conduits as wel as to keep it circulating therethrough.

ln my construction of kiln, a draft inducing means is provided at or beyond the end of the heating chamber and where means are provided for generating a glazing atmosphere, the draft inducing means is provided at a point beyond such generating means, the

object being to cause a flow of all gases, including free or supplied air in the kiln, to flow in the direction in which the products B move therethrough and to draw from the kiln all of such gases before entering the coolchamber l0, so that the products B moving through the latter chamber will be unaffected by the heat of these gases and the air flowing through the pipes 31 may be utilized to absorb heat from the products to cool them. By causing the hot gases to flow through the kiln with the products B they are heated to the desired temperatures in an economical manner and at the same time these hot gases are prevented from entering the pre heating chamber and heating the products before the moisture is evaporated or water smoked therefrom; and by heating air by the heat radiated from the products dueV to cooling thereof and conducting it to the preheating chamber, the products B are heated sufficiently therein to effect removal of their moisture content before entering the heating chamber. f

As the heatrequired for the pre-heating chamber is derived from the heated products, cost of operation is reduced. The temperature of the preheating chamber is preferably maintained at approximately 300 degrees F. As the products B move through the heating chamber 9 they are heated to that temperature which will melt the silica in the material ofthe surfaces of the products. The salt which is burned in the fire boX 20 is reduced into its component parts (chlorine and sodium), the chlorine passing oli" with the hot gases and products through the headers 2l and pipes 25, whereas the sodium vaporized and combines with the silica to form on the surfaces of products B sodium silicate, which constitutes the glaze thereon.

In my construction of kiln the products to be glazed are moved through the successive chambers in batches or charges mounted on carriers A, the latter being introduced sucdescription herein are purely illustrative and arenot intended to be in anysense limit- What I claim is.:`

l. In apparatus of the class described, the combination of a preheating chamber and a heating chamber, said chambers being' `disposed in contiguous relation toy form a passage for product bearing carriers, heating means for said heating chamber, means having connection with said passage at a point beyond said heating means and serving to induceaovv ofthe hot gasesthrou'gh saidk passage in the direction of movement of the carriers, and a lateral chamber -tormed in the wall of said passage between' said heatingk means and the connection for said iow inducing means.

2. In apparatus of the class described, the combination of a preheating chamber having supply lports anda heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, heating means for said heating chamber, means having connection With said lpassage at a point beyond said heating means and serving to induce a flow of the hot gases through said passage in the direction of movement of the carriers and discharging them exteriorly of said chambers, and means for supplyingy heated Watersmoking atmosphereto said supply ports.

3. In apparatusof the class described, the combination of a preheating chamber having supply ports and a heating chamber, said chambers being disposed in contiguous relation to form a passage-for product bearing carriers, heating means for said heating chamber, means having connection With said passage at a point beyond said heating means vand serving to induce a liovv of the hot gases through said passage in the direction of movement of the carriers and discharging them eXteriorly of said chambers, means for conveying air through a portion of said passage beyond said flow inducing means and conducting the heated air to said supply ports.

4. In apparatus of the class described, the combination ofa preheating chamber lhaving supply-ports in spaced relation lonthrough said passage in the direction ofV movement of the carriers, and means for supplying heated Water smoking atmosphere to4 said supply `ports. r

5. In apparatus of the class described, the combination of a preheating chamber having a supply port and a heating chamber, said chambers being disposed in con tiguous relation to form a passage for product bearing carriers, heating means for said heating chamber, suction means connected with said passage at a point beyond said heating means and arranged to induce a floW of the hot gases through said passage in the direction of travel of the carriers and to draw hot gases and air mixed therewith from said passage, a conduit formed in the roof of said Aheating' chamber and extending longitudinally thereof and connected with said supply port, and means for supplying 'i air to lsaid conduit. Y

6. In apparatus of the class described, the combination of a preheating chamber having supply ports disposed in spaced relation longitudinally thereof and a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, heating means for said heating chamber, suction means connected With said passage at a point beyond said heating means and arranged toinduce a ow of the hot gases through said passage inthe direction `of travel of the carriers and to drawl hot gases and air mixed therewith from said passage, conduits formed in the roof of said heating chamber and extending longitudinally thereof and leading to one or more of said supply ports, and means for supplying air to each of said conduits. Y

7. In apparatus of the class described, the combination of a preheating chamber and a heating chamber, said chambers being disposed in.k contiguous relation to form a passage for productbearing carriers, heating means 4for said heating chamber, suction means having connection with said passage at a point beyond said heating means and serving to draw air and hot gases through said passage in the direction of travel of the carriers, and a lateral chamber formed-in the side Wall ofsaid passage between said suction means vand said heating means and arranged to retard the flow of air and hot gases through said passage.

8. In apparatus of the class described, the combinationof a preheating chamber having supply ports disposed in spaced relation 1ongitudinally thereof and a heating chamber,

loo

said chambers beingr disposed in contiguous relation to form a passage for product bearing carriers, heating means for said heating chamber, suction means connected with said passage at a point beyond said heating means and arranged to draw hot gases and air mixed therewith from said passage, conduits forme-c in the roof oi said heating chamber and leadto one or more of said supply ports, means iior supplying air to each ot' said conduits and a lateral chamber formed in the side wall of said passage between said suction means and said heating means and arranged to retard the iiorv of air and hot gases through said passage.

9. in apparatus of the class described, the combination of a preheating chamber having a supply port, a heating chamber, a cooling chamber, the roots for said preheating and heating chambers being formed with a conduit connected at its outer end with said supply port, means for heating saidL heating chamber, and an air conduit extending longitudinallythrough said cooling chamber ind connected at its discharge end With said irst mentioned conduit, said connection including means for causing a flow of the air through said conduits.

l0. ln apparatus of the class described, the combination of a preheating chamber having a plurality of supply ports spaced longitudinally thereoi, a heating chamber, a cooling chamber, the'roois for said preheating and heating chambers being formed With a series ot conduits each connected at its outer end to one of said ports, means for heating said heating chamber, and a conduit extending through said cooling chamber and connected with said hrs-t mentioned conduits, said connection including means for causing a flow ot air through said seriesof conduits and said air conduit.

ll. In apparatus of the class described, the combination of a preheating chamber,a heating chamber, said chambers being disposed in contiguous relation to form apassage for Ware bearing carriers, combustion means in communication With said passage through said heating chamber for maintaining a vitrifying temperature therein, suction means connected to the discharge end ot said heating chamber for inducing a flow ot' air and hot gases generated by said combustion means through said chambers in the direction of move nent oit' the products, and means between said heatingmeans and said suction means for creating a glazing atmosphere.

l2. In apparatus of the class described, the combination of a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, combustion means in communication with said passage for heating the Ware as it moves through said heating cnamber, means in one Wall of said heating chamber beyond said heating means for creating a glazing atmosphere, and suction means connected to said passage beyond said glazing atmosphere creating means for inducing a lionv ot the hot gases through said t ge oi said heating chamber and of the a .rnospherc said passage inthe direction in r. i the carriers move. n

lo. in apparatus of the class described, the combination of a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, combustion means in communication with the passage through said heating chamber, means in one Wall of said heating chamber beyond said heating means for creating a glazing atmosphere, suction means connected to said passage beyond said glazing atmosphere creating means for inducing a flow of the hot gases and atmosphere in said passage in the directi-on in Which the carriers move, and alateral chamber in the Wall of said heating chamber disposed between said suction means and said glazing atmosphere creating means.

le'. ln apparatus of the class described, the combination oi' a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, combustion means in communication with the passage through said hea-ting chamber, means in one Wall ofsaid heating chambery beyond said heating means for creating a glazing atmosphere, means for supplying heated air to said preheating chamber and means beyond said glazing atmosphere creating means for drawing the atmosphere from the Ware passage and preventing flow thereof into passage through said heating chamber. l

l5. ln apparatus of the class described, the combination ot' a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, combustion means in communication With the passage hrough said heating chamber, means in one Wall or said heating chamber beyond said heating means for creating a glazing atmosphere, suction means connected to said passage beyond said glazing atmosphere creating means for inducing a flow of the hot gases and atmosphere in said passage in the direction in which the carriers move, and means for supplying heated air to said'preheating chamber. i

i6. ln apparatus of the class described, the combination of a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation-to i'orm a passage for product bearing carriers, combusti-on means in communication With the passage through said chamber to cause vitritication of the products, means arranged beyond said heatmg means tor creating' a glazing atmosphere luc in said passage, separate means for maintaining a water smoking temperature in said preheating chamber, and means for preventing the hot gases in said heating chamberfr-om flowing into said preheating chamber, and the glazing vatmosphere from flowing into the heating chamber.

17. In apparatus of the class described, the combination of a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation to form a passage for product bearing carriers, means for supplyingA heat into the passage through said pre-A heating chamber to effect water smoking of the products while kmoving therethrough, combustion means in communication with the passage through said heating chamber and maintaining a temperature suiicient to mature the products as they move through the exit portion of said chamber, and means arranged beyond the heating means for creating a glazing atmosphere in said passage.

18. In apparatus of the class described, the combination of a preheating chamber, a heating chamber, said chambers being disposed in contiguous relation vto form a passage for product bearing carriers, means for supplying yheat into the passage through said preheating chamber to eiect water smoking of the products while moving therethrough, combustion means in communication with the passage through said heating chamber and maintaining a temperature sulicient to mature lthe products as they move through the exit portion of said chamber, means arranged beyond the heating means for creating a glazing atmospherefandmeans connected with said passage ata point beyond the last mentioned means for drawing from said passage the hot gases and atmosphere contained therein.

In testimony whereof, I have hereunto subscribed my name.

p HARRY M. ROBERTSON.

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