US1351281A - Furnace construction - Google Patents

Description

B. E. BROADWELL. FURNACE CONSTRUCTION. APPLICATION FILED MAR. I9, 1919.

Patented Au 31,1920.

7SHEETS-SHEE1 l.

muentoz Liar Mun,

Patented Aug. 31, 1920.

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5] n ml 11 oz BLE/BROADWELL. FURNACE CONSTRUCTION.

7 SHEETS-SHEET 3.

0 2 9 1 3 A d m P w R A M w. N 0 H A W H P A 1 8 2 I, 1 5 3 1 B. E. BROADWELL. FURNACE CONSTRUCTION.

I APPLICATION FILED MAR; 19,1919. I v 1,351,281; I Patented Aug. 31, 1920.

7SHEEISSHEE15.

vwemtoz 8. E. BROADWE LL. FURNACE CONSTRUCTION.

APPLICATION FILED MAR. 19. 1919.

Patented Aug. 31, 1920.

7 SHEEIS-SHEE1 6.

B. E. BROADWELL FURNACE CONSTRUCTION.

APPLICATION FILED MAR. I9, 1919. 1,351,281.

- Patenfied Au 31,1920.

7 SHEEISSHEE1 7.

7 glvwentoz a second BARTLEY n. BROADWELL, or NIAGAnArAnLs, NEW YORK.

FURNACE CONSTRUCTION.

Specification of Letters Patent, Patented fi 31 Application filed- March is, 1919. Serial No. 233,4?0. 7

To all whom. it may concern: 7 a I Be it known that L-Ban'rnnr E. BROAD- WELL, a citizen of the United States, residing at Niagara Falls, in the .countyof Niagara and State of New York, have in ventel certain new and useful Improvements in Furnace Construction; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being hadto the accompanying drawings, forming part ofthis specification. This invention relates to what is known as ring type furnaces, which consists of a series of baking chambers so arranged that in the heating of one ofthe chambers the hot waste gases will warm up the chambers in advance and at the same time the chambers on the other side of the chamber being heated will warm up,'in their cooling, the air which is to be burned'in' the chamber now under firc,'thus permitting a constant or ring action of the furnace as a whole, all the chambers of the furnace being successively heated in turn. i The objects of the present invention are to improve the method of circulating the gases in such a furnace and to provide means whereby complete observation of each individual chamber is permitted in order to closely regulate the heat therein and the time of baking. The method of circulating the gases is distinct from'previous practice in furnaces of this type in that, instead of passing such gases in a generally horizontal direction, as is common in ring furnaces of known types, 1 cause the major portion of the gases to pass through the flues of an oven being warmed up or preheated, first directly upward the entire height of the oven, then downwardly beneath a baffle in the flue on either side of the oven, then upwardly through a central chamber and over baffle, and thence downwardly again through the front chamber to ports leading to the next vertical duct or flue, which is located directly in front of the oven being preheated, thus giving the major part of the gases (about three-fourths in volume) a generally verti'caltravel up and down about the walls of the oven. The path of the air around an oven being cooled is the same as that through a similar oven being heated, so the saving of fuel in my improved furnace is very material.

A complete survey of the interior of the furnace fines is permitted by arranging an observation hole'immediately over the point at. which the fuelgas meets the stream of strongly heated air,xa second hole directly in the center, .both laterally and longitudinally of the middle: chamber .in which the flame ascends, and a third observation hole directlyyagainst the front Wall of the flue directly over the last portof emission from the gas flame.

. Other ob ects of this inventionare to prove generally furnaces of this type and to alter the constructionof details of the same inorder to increasethe ease of'operation' thereof.

In the drawings;-

Figure'l is a plan vlew of a portion of a rin type furnace embodying the features of my invention.

V Fig.- 2 is a sectional elevation on the line 22 of Fig. 1, showing a vertical section through one of the pits in which thearticles to be heated or baked are placed.

Fig. 3 is a sectional elevation on .the line 3-3 of Fig. 1, showing a'vertical section through the center of one of the gas flues.

Fig. 4 is a horizontal sectional view on line 4; 1 of Fig. 3, showing particularly the passageways under the gas flues and pits.

Fig. is a'horizontal sectional view on line 5'-5 of Fig. 3, showing particularly the chambers into which the gas flues are divided. I

Fig. 6 is a vertical section taken on' line 66 of Fig. 1, showing the Vertical ducts in the head walls which separate the several sets of gasflues and pits, and also the cross section of one of the flues.

Fig. 7s a section on line 7-7 of Fig.1, showing the ducts in the head walls.

Referring now to Fig.1 of the drawings, wherein is shown a typical section of a ring type furnace embodying my invention, 7

represents the central: fuel gas main which extends the entire length of the furnace,

being. provided with a number of ports 8, 8, from any one of which fuel gas may be led into the inlet ports 9, 9, of the gas fines of the respective setcorresponding to such port 8 by means of a removable pipe 10 having connections 11 with each of the gas inlet ports 9 of such a set of parallel flues, such connections 11 each being provided with a manually controlled valve 12 for regulating the supply of gas into the individual flues. The pipe 10 is intended for use with each of thedifferent sets of fines and-is supported as best shown in Fig. 6 by means of the yoke 13 and chains 14 from a trackway (not shown) extending around the furnace above the pits. The ports 8 when not in use for supplying fuel gas to the flues'are closed by covers 15, and the inlet ports of all of the remaining gas flues 9 are likewise closed by covers (ilwhen firing of that set is completed.

Arranged transversely on either side of the gas main 7 and at right angles thereto are headwalls 16 extending from the gas main to the waste main 17, these heads serving to separate the pits and fines into sets, each set consisting of five pits and six fiues alternately arranged parallel to the gas and waste mains. The head walls 16 are provided with a vertical duct 18 for each pit, each duct ending in a chimney 19 extending above the level of the top of the pit 20, and such ducts are connected at their upper section about on the same level as the fuel gas main, that is, just below the top of the pits 20 by a transverse horizontal passageway 21 opening into each duct and extendingon either side of the end ducts as far as the side gas flues 23 and 2 1. The upper wall of the head is perforated. centrally of each of gas fines 22 forming a vent 25 in line with an orifice 26 in the end wall of the gas line, thus permitting gases to pass from the vertical ducts 18 to the gas flue 22. Each gas flue is divided into three approximately equal chambers 27 by means of a baflle 28 extending a little more than one-half of the way down from the roof or crown 29 and a similar baliie 30 extending an equal distance upwardly from the floor 31 so as to be somewhat higher than the bottom of the baffle 28, this construction being best shown in Fi 3.

abservation holes 32, 33 and 3 1 are provided in the roof 29 of each gas fine in the longitudinal center line thereof, the forward observation hole being located at the extreme front, closely adjacent the front wall of the flue, which wall does not join the head 16, but is spaced therefrom so as to provide a dead air space 37 which serves as an expansion joint and prevents displacement of the head by the expansion of the gas flue whenheated. A similar expansion joint 38 is provided between the rear wall 39 and the adjacent head wall 16. The rear observation hole 32 is arranged as close as possible to the gas inlet 9, in order to see more clearly the combustion flame, and the middle observation hole is arranged centrally of the middle chamber 27, making the distance between the observation holes 32 and 33 the same as the space between the observation hole 32 of one gas flue and the observation hole 341- of the next gas flue.

Under each pit 20 are located a pair of longitudinal channels 40 separated by a parthree larger ports 43 at the forward end of the pit, each of these ports 42' and 13, extending completely under the adjacent gas fine 22 and communicating with the chamber 27 immediately above the same, that is, each of the ports 42 opens vertically upward into the rear chamber 27 immediately below the gas inlet 9 and each'of the ports 1-3 communicates with the forward chamber 27, the

front port l3 being directly under observation hole 3e. 7

The pits, it will be noted, are open at the top as the term denotes, and are closed on the side by the walls of the gas lines which, as will be seen from Fig. 6, do not rise flush with their bases 51, but form a ledge 52, which, with the partition 11, forms a support or piers for the lire bricks 53 which bridge the parallel longitudinal channels 10 and form the floor a l of the pit. The ends of the pit are closed by the head walls 16, which are at this place practically hollow chimney structures since the ducts 18 are nearly as wide as the pits. These walls 16, however, extend as solid masonary from the wall of one flue to the wall of the next, except for the'upper portion where they are pierced by the transverse passage 21 and its communicating short vents 25.

The tops of the fines are capped by blocks 56 extending from one wall 50 to the other, and forming the roof or crown 29 of the gas'flue, the upper surface of which is about a foot or more below the ground level in my preferredconstruction, the observation holes, gas inlets, and chimneys all being. raised to such level by shafts or casings as shown, so that, the entire roof structure may be covered with sand or other heat insulator, when it is so desired.

A slot 57 is provided between the head wall 16 and the rear wall 39 in which slot is placed a damper 58 to close the exit formed by the vent 25 and orifice 26. This damper can be handled directly from the surface by moving back the tile 59 which rests on the top of the head wall 16 and acts as a seal over the slot 5? whether the damper 58 is in the slot or not. The damper may be of refractory material, sheet metal, paper or fabric, provided that such paper or fal ric possesses a compactness suliicient to yield a low enough porosity to prevent the leak age of any appreciable amount of gas or air through it. Tn case paper is used, it is tacked on a frame and dropped into the slot, and when it is desired to openanother pit, and therefore move the damper farther per 65, fits over along the furnace, it is simply necessary to knock a hole in the paper of the one to be eliminated, and the direction of hot gases is changed and will in a short duration of time burn out the remainder of the paper.

The waste gases, when deprived of the greater part of their heat by through five or more sets of units (each set consisting of eleven parallel units, as heretofore described) is passed out the chimneys 19 to waste main 17, by means of a removable pipe 60 swung from an overhead track (not shown) by means of chains 61. A main connection G2 fits over the port 63'of the main 17 I and other smaller connections 64, each provided with a manually controlled damthe chimneys 19, the covers 66 of which are removed for such purpose. it has been found unnecessary to connect all the chimneys with the waste gas main and I find it sufficient to only so connect each alternate chimney of the set. U V

I will now describe the operation of my improved furnace in its preferred construction, consisting of twenty-eight sets of eleven units each, arranged compactly with a battery of fourteen such sets on either side of the centrally disposed fuel gas main, the two waste gas mains lying on the outside of the batteries and being connected in the usual way to a stacker exhaust not shown, but of the usual construction. are connected to the adjacent unit of the battery opposite by fines and passageways as nearly like the connections between adjacent units as possible so that, numbering the sets in order in the sequence denoting the passage of gas from a lower to higher numbered set, the hot or cold gases would pass from No. 28 to No. 1 in just the same manner (except for distance) as in passing from No. 1 to No. 2.

Considering now that set No. 12 is under fire, and that l los. 13 to 17 are being heated by the burned gases, Nos. 7 to 11 are being cooled by the air being drawn into No. 12, and lies. 1 to 6 are available for unloading and loading. The operation is as follows: ljovers -66 of chimneys 19 of the head in advance of the set (No. 6) of pits being empied is removed and air is either drawn or =orced through the hrough vent 25 orifice 26 through the -ext gas fine 22 (set No. 7) passing partly ownward through the ports42 into the lon- .-'itudinal channels 40 and partly through he three chambers 27 and thence into the channels 40 through the forward ports 43 am thence upwardly through the next ducts 18 (No. 8), and so on, through the successive units to be cooled, finally arriving at the head wall 16 at the rear of the set being fired (No. 12), and the now heated the flow of.

passing 7 The end unitsof each battery sired manner, for example,

ducts 18 and passes air passes up ducts 18 and out orifice 26 in close contact with the gas being admitted through inlet port 9 of'the flue being heated (set No. 12) forming a long flame which extends downwardly through rear chamber 27, thence upwardly through middle chamber 27 and finally downwardly again in the forward chamber 27 thence passing through the horizontal ports 42 to the duct 18 inthe next head wall 16, separatingthe set of pits and fines under lire (N0. 12) from the pits and fines (No. 13)

next successive set of serving to hcat the same preparatory to their being fired. The course of the heated gases is similar to that heretofore describer in con difference being that the waste gaseswhen deprived of their heat at the set (N0. 17)

of fines next behind the pits being loaded No. 18) are allowed to pass to the waste ectionwiththe cold air, the single gas main 17 by themeans previously de, v

1 are in place and the waste gas pipe 60 is connecting the chimneys of that wall with the main 17.

lhe tops of the pits are closed in any dewhen :the furnace is used to bake. carbon electrodes, the green rods are piled in the pits in the usual two opposite .a;

between Nos. 3 and V manner, and the entire charge is covered with a considerable thickness of carbon dust or other heat non-conductor which serves the dual purpose of retaining the heat and preventing oxidation of the electrodes by contact with air.

While I have described my invention in connection with a rectangularly arranged carbon baking furnace I wish it distinctly understood that the terms herein used are intended to cover annular furnaces, and kilns for other material than carbon.

Claims for the head arrangement illustrated herein are included in application No. 283A69, filed concurrently herewith'by Al bert G. Smith and myself and bearingsimilar title.

What is claimed is:

ljln a ring furnace,

their len th and connectin with one of said fines, and a vertical battle in one or more of the flues.

2. In a ring -furnace, the combination with a plurality of interconnected gas lines the combination, with a plurality of interconnected gas flues arranged longitudinally of said furnace, of

lines.

3. In a ring furnace, the combination with a plurality of interconnected gas flue. arranged longitudinally of said furnace, of pits arrange 1 parallel to said fines and in proximity thereto and having a passageway 7 extending hei'ieath same throughout their length and connecting with one of said fines, and vertical hailies in each of the dues.

in a ring furnace, the combination *ith a plurality of gas fines arranged longitudinally of said furnace, or pits arranged parallel to said dues and in proximity there to, a hollow head wall at the ends of each line, and passageways connecting the hollows of adjacent head walls, passing part of the gases through the dues and the remainder of said gases under the floor of said pits, lengthwise thereof.

5. In a ring furnace, a plurality 01" hollow head walls, pits between said walls, and

flues between said walls parallel to said pits and having a passageway therein caus ing the gases to travel in a path the vertical component of which is considerably'greater than its horizontal component.

6. In a ring furnace, a plurality of parallel series of gas flues, each series consisting of a plurality of interconnected lines each extending longitudinally of the furnace,

through each line connecting the adjacent lines of the series, guiding the gases up and dwnthrough the entire length of the'flue.

8. In a rir nace,a plurality of paral- I tlues, each series consist-i a plurality oiinterconnected Hues each extending longitudinally of the furnace, pits arranged between the series of nues and proximity thereto, and passageways under each pit connecting with the fines on eitherside or" the pit. I

9, in a ring furnace, a plurality of paral lel series of pits, each series consisting of a plurality of pits each extending long1- tudinally of the furnace, and as passagewa s extending under and, on either side of each pit.

1 In a ring furnace, a plurality of par allel series of pits, each series consisting of a plurality of pits each extending longitudi-' nally oi the furnace, gas passageways ere tending under and on either side of each pit, and vert'cal gas passageways at either end of each pit.

BARTLEY E. BROADNELL.

n. the series of fl'ues and 45

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