US1057832A - Gas-muffle. - Google Patents

Description

J. A. Hmmm@ GAS MUFPLB. v

` APPLICATION FILED JULY 28, 1909. l Patented Apr.1,1m3.

5 SHEETS-SHEET 2.

J. A. HBRRIGK.

GAS MUPPLE.

APPLIGATION FILED JULY 28, 1909.

Patented Apr. 1, 1913.

5 SHEETS-SHEET 3.

m -www @Vi/immo@ J. A. HERRICK.

GAS MUIPLE.

APPLIGATION FILED JULY 28, 1909.

Ll, Patented Apr.1,1913.

5 SHEETS-SHEET 4.

Fig; 4-

J. A. HERRICK.'

GAS MUPPLE. APYLIOATLON' FILED JULY 28, 1909.

Lf. l Patented Apr. 1, 1913.

5 SHEETS-SHEET 5',

Figi 6- features V of construction, combinations of UNITED sTATEs PATENT oEEIcE.

JAMES A. HERRICK, OF NEW YORK, N. Y.

GAS-MUFFLE.

To all whom t may concern Be it known that I, JAMEsA. HERRiCiL residing at New York city, in the county'otl New York and State of New York, have 1nvented certain new and useful Improvements in Gas-Mutlles, of which the following is a specification.

This invention relates, to improvements in that class'of furnaces-known as muffles, and one of the objects there9f is to provide new and improved apparatus of the above character designed jto provide 1ncreased heat eiiilciency, and economy in fuel consumption.

' Another object of the invention is to provide apparatus employing gaseous fuel of such construction as will provide for uniform heat within the muftle.

Another object is to provide apparatus of this character which will take up a greater quantity of the heat generated bythe burning gases than has been done in similar apparatus and which will absorb, for purposes of regeneration, a greater quantity of the heat present in the products of combustion.

Other objects will be in part obvious and in part pointed out hereinafter.'

The invention accordingly consists in the elements and arrangement of parts, which will be exemplified in the constructionhercinafter described, and the scope of the application of which will be indicated in the following claims. y

In the accompanying drawings wherein is illustrated several of various possible embodiments of the invention: Figure'l is a vertical, sectional view taken through the center of the preferred embodiment of my improved muiie; Fig. 2 is al horizontal sectional view taken substantially on the line 2 2 of Fig. 1; Fig. 3 is a similar view taken partly on the line 3 3 of Fig. 1 and partly o-n line 4-4 ofFig. 1; Fig. 4 is a vertical -sectional view taken substantially Aon line 4 4of Fig. 3; Fig. 5 is a vertical sectional view of a different embodiment of the invention; Fig. 6 isa vertical sectional view on line 6 6 of Fig. 5 in the direction of the arrow. p

Similar reference characters refer to similar parts throughout the various figures of the drawings. v

Referring now to the drawinofs, and particularly to the embodiment illustrated lin Specication of Letters Patent.

Patented Apr. 1, 1913.

Application led July 28, 1909. Serial No. 510,094.

Figs. 1 to f1 inclusive 1 indicates air passage ways which extend lengthwise of the apparatus and 2 is an air regenerative chamber which is preferably filled with spaced blocks or checkers 3, asv shown. 4 indicates gas passage ways which extend lengthwise of lthe apparatus and 5 isa gas regenerative chamber which is also filled with checkers 6.

7 indicates air passage ways similar to those shown at 1 above which is arrangedl an air regenerative chamber 8 containing checkers 10. Gas ,passage ways 40 similar to those shown at 4 are adapted to deliver gas to the gas regenerative chamber 11 which is also lilled with checkers 12. Chambers 2 and 5 constitute one pair of air and gas regenerative chambers, and chambers 8 and 11 constitute a second pair of air and gas regenerative chambers.

Inasmuch as the apparatus now to be describedis duplex but one side thereof may be'specifically described in orderto impart a clear understanding of the invention. The air after passing thro-ugh the-regenerative chamber 2 is discharged through a portfl shown in dotted lines. (a similar po-rt 14 being shown in full lines leading from chamber 8,) and flues 15 to a combustion or firing chamber 16 which extends underneath a muiie 17. The gas from the chamber 5 is discharged through the port 18 chamber 21 which extends longitudinallyof the second muiiie 22. Muflie 17 which eX- tends longitudinally of the apparatus is provided with an arched Hoor 23 and an arched dome 24 above which, and spaced therefrom is a wall 25, the space provided between the muiie and the inner surface of said wall constituting a flame space 26.

Spaced blocks or kickers 27 may be interposed between the mutlie and the inner surface of wall 25, as shown, such construction aiding in holding the walls of the mufles in place andproviding for a free passage way for the Haine. These blocks 27 are arranged in the form of independent vhorizontally spaced piers 27', which extend upwardly to the spring lof the mutlie arch, and divide the ame space into a series of spacesI I of openwork construction, for viewing and Ventilating purposes, and to allowA of expansion. The reason for graduating the size of the spaces between piers is in order that more flamemay be directed toward the door end of the Inutile, where the spaces are largest, than to the back end, where the s aces are smaller. Ports as at 28 are pro-- vided between chamber 16 and the Hama space 26 through which dames may pass about the muiile. v

Arranged midway between mutlles 17 and '22 isv a. wall 30, said wall comprising a plurality of alternately arranged U-shaped portions 31 and 32 clearly shown in Fig. 2 of the drawings, the construction being such that alternate U-shaped portions '31 and 32 are disposed respectively beneath the dame spaces 26 and 33 of muflies 17 and ,22. 1t

Awill be seen that 'this construction not only permits the passage of Haine from one flame space to the other but also permits the direct passage of liames from the combustion chamber 16 of mutlle 17 to the flame space 33 of mulile 22 and vice versa. 1f desired, small openings as at 34 may be provided in this wall to permit of the passage of a small quantity of the fiame directly from one combustion chamber to the other. e

Referring now to Fig. 4 of the drawings 35 indicates a Vconduit adapted to deliver gas to the apparatus and 36 indicates a similar conduit through which air may be delivered; the'passage of the gas and air through said conduits being controlled as by means of valves 37 and 38. The conduit 37 communicates with the gas passage ways 4 and 40 respectively which extend underneath the gas regenerative chambers around either side of the 'apparatus and the air conduit 36 similarly communicates with'the air passage ways 1 and 7. The direction of flow of gas and air may be controlled 4as by means of valves 41 and 42 shown in Fig. 4. These valves are adaptedto deflect the gas and air to one side of the apparatus to the exclusion of the other, and at the same time open the air and gas passage ways upon the side of the apparatus from which the air and y gas is excluded, to a flue 43 which leads to Y a stack 44.t 1t will be seen therefore that when gas and air enter through one side of the apparatus the lopposite side thereof is Vopen to the Hue and stack so that the prod ucts of combustion may be discharged therethrough as will be hereinafter more fully eX- plained.' A valve as at 45 may be provide in due 4,3.

Las by means of the t meanest Having thus described the construction of this embodiment of my invention the operation thereof may now be understood.' 'llhe valves 41 and 42 being properly positioned, the gas and air pass through .the passage ways 4 and 1 to the regenerative chambers 5 and 2l and then pass upward through said regenerative chambers between. checkers 6 and 3 which will be heated, as will be hereinafter described and which will giveup a part lof said heat to said ingoing gas and air; The gas and air will then be delivered ports 18 and 13 and tlues`20 and115 to the combustion chamber 16, through the apertured partition 100 whichseparates the regenerative chambers fromythe combustion chambers. The gas and air mixing at this point, burst'into flame just above ports or lues 20 and 15, and at this point, it may be noted that these flues have a greater cross-sectional area at the front or door end of the mutlie, than at the rear and decrease regularly in 'crosse vsectional area from front to rear of the apparatus.I IThis construction provides for a greater amount of flame at the front part of the apparatus. The ports 28 which lead from the combustion chamber 16 to the llame space 26 are `similarly constructed so that a greater portion of the `flame will pass about the front end of the mulile. This lconstruction is desirable for the reason that, owing to the fact that the` front or. door of the inutile is opened frequently for the insertion andremoval of the material to be treated,

it is necessary t-ol supply a greater amount of heat through the front portion of the mutlle. For the same reason the flame space 26 is preferably of greater cross-sectional area at the front end of the mulile than it is at the rear end; and the openings in the checker-work are also preferably somewhat larger at the front end than at' the Lrear end of the'air and gas generative chambers.

The flame in the combustion chamber 16 divides, one part passing to the outside through ports 28 around the lower corner of the mulle up theside and' over the top thereof, fillingy the entire/space between the same and the surface of the outside walls. This flame passes entirely around the first muftlc from' left to right, and then drops down through/the dues 46 formed by the 'Ll-shaped portions 31 and '32 ofjwall' 30into chamber 21, which, when the flame is passing in this direction through the apparatus, may be termed a gathering chamber. The other part of the llames pass between the legs'of the U-shaped members thence through dues 47 and upward about the second muihe 22 whence they return through ports 48 to the chamber 21. From chamber 21 the dames pass down thrugh the dues 50 and ports 14 and 51 into the regenerative chambers 8 and 11 whence they pass through the passage scribed by means of the valves 41 and 42v which deflect same throu h the passage ways upon the opposite side o? the apparatus.

Suitable blocks as at 52 and 53 may be slidably mounted in lateral openings provided in walls 25 and 54. These blocks may be slid in and out to vary the size ofthe passage ways 28 and 48 throughpwhich the flames pass from the combustion 'chambers to the flame spaces about the muies, in order that the amount of flame required to properly heat any portion of the muile may be regulated.

When the apparatus has been in operation for some time the rear portion of the muiiie will be very much, hotter than the front portion, on account of the door`and the pull of the stack. In order to relieve this condition I may provide valve-controlled openings in the rear wall of the apparatus, so that communication may be established lbetween thc atmosphere and the fiame chamber and also between atmosphere and the interior of the muie, when desired. p

Referring to the embodiment of my invention shown in Figs. 5 and 6 of the drawing, 55 denotes a gas regenerative chamber and 56 an air regenerative chamber corresponding chambers 57 and 58 being provided upo-n the right hand side of the apparatus. Air and gas are delivered to the regenerative chambers and 56 as by means of passage waysY 60 and 61; similar passage ways 62 and 63 being provided to deliver gas to the other side of the apparatus. Suitable valve mechanism (not shown) is provided for delivering air and gas to regenerative chambers at one side of the apparatusand for allowing the products of combustion to pass to the stack; the direction of flow of the gas through the apparatus being determined by the` position of the valves. Mounted above the regenerative chambers is the muiile 64 having the arched floor 65 and 55 the arched dome 66 about which is positioned an exterior permanent wall 67 leaving a space 68 between the muflle and wall which provides a 'flame space. Suitably spaced bricks or kickers are employed for supporting the lateral walls of the muiile. Extending longitudinally underneath mufile 64 is a palr'of chambers 70 and 71 respectively, separted by a wall 72 which, if deslred, may be provided with apertures as shown in dotted lines. Passage ways 73 and 74 lead from regenerative vchambers 55 and v56 to chamber 70 and similar passage ways 59 and 69 lead from the regenerative chambers 57 and 5 8 to chamber 71. The series of mouths of the two series of passage ways upon two sides of the apparatus which lead from the regenerative chambers to the chambers 7 O and 71 are preferably arranged in alternation. 72 and 731 are `auxiliarygas conduits leading direct from the gas regenerative chamber to the flame space 68. Leading from chamg bers 70 and 71 to the flame 'space 68 are lateral passage ways 7 fl and 7 5', said passage ways allowing flame to pass upward about the dome of the muflie to the flame space 68. The exterior wall of the apparatus may be provided with'suitable apertures at any desired point in which may be'mounted slidable'blocks as at 76. These blocks when slid inwardly or outwardly are adapted for vary-l ing the size of the various flues. In the operation of this embodiment of my invention the gas and air passing upward through the regenerative chambers 55 and 56 mix in the chamber 70 'where they' are ignited. The flame then passes through passage way 74, thence upward about the dome lcf the mufile through the flame space 68, then downward about the mutlie, partl thereof then passing through passage way 59 into the chamber 57, and part thereof passing downward through the passage way 69 into the gas regenerative chamber 58. Thus it will be seen that some of the flame entering chamber 57 may pass downward into air regenerative chamber 58 and some through passage Ways 59y and 73l into the gas regenerative chamber 57. These chambers, as in the first above described embodiment, are filled with 'checkers' 77 which-operate to absorb the heat present in the products of combustion, so that when the direction of flow of air and gas through the apparatus is reversed such heat will be used in preheating such gas and air, the dis-v charging products of combustion operating to replenish the heat in the checkers located in the other pair of regenerative chambers. It will be obvious that some of thegas will pass upward through either of the tubes 7 3 to meet thc fiame passing through the lateral openings 74 and 75 which lead from the' chambers 70 and 71 to the flame space 68. For relieving an overheated condition of the back of the mulile, I may provide suitable valve-controlled passages in the back wall of the apparatus, as indicated at 68', whereby communication may be established between the back of the flame space 68 and atmosphere. And similarly, to cool the `back of the muffle itself when desired, I may provide similar passages 64', to establishcommunication between the back of the mufiie and atmosphere.

Accordinglyit will be seen that I have. provided constructions well adapted among others to maintain all the ends and objects pointed out in an entirely simple yet ecient manner.

. The various regenerative' chambers and the passage Ways leading therefrom to the chambers underneath the mutlles and the yflame spaces which surround them are vso arter contained in the rabove description orv shown in the accompanying drawings shall be interpreted as illustrative and not in al limiting sense. It is also tobe understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which as a matter' of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is: 4

1. In apparatus of the class described, a muHle having asurrou'nding flame-space, a combustion chamber communicating with said flame space, regenerative .chambers communicating with said combustion chamber for delivering heated air and gas thereto, and an apertured rpartition between said regenerative chambers and the combustion chamber.

2'. In apparatus of the class described, a pair of muies, a wall about eachv of said mufles and spaced therefrom, a chamber underneath each of said muliles, a wall separating said chambers and provided With iame passage Ways, and a pair of regenerative chambers located beneath each of said first mentioned chambers.

3. In apparatus ofthe class described, a pair of inutiles, a Wall about each of said mutiles and spaced therefrom, a chamber' underneath each of said muffies, a Wall separating said mufliesand provided, with flame passage Ways, an air and a gas regenerativev chamber yarranged beneath each of said first mentioned chambers, and partitions provided with gas and air passage ways posi-l tioned between said 'regenerative chambers and said irst mentioned chambers.y

4. In apparatus of the class described, a

pair of mufiles, a wall about each of said muffles and spaced therefrom, a chamber underneath each of said muflies, a wall sepai rating said chambers, said wall providing passage ways from the space surrounding one mufe to that surrounding the other, an

an air and a gas regenerative chamber arranged beneath each of said chambers, each noevgeaa of said. last mentioned chambers being provided with a series of ports, the ports of the two series being tion.

l5. In apparatus of the class described, a

'pair of mules, a wall positioned about each of said inutiles and spaced therefrom, a chamber underneath each of said muiiies, a wall separating said chambers, said Wall lbeing so formed as to provide passage ways between the spaces formed between the inutiles and said first mentioned walls, an air and a gas regenerative chamber arranged beneath eaeh ofsaid first mentioned rchambers,.each of said last mentioned chambers being providedy with aseries of ports,

the 'ports ofsaid two series being arranged in alternate relation,A and a passage way common to said ports for conducting a mix'- ture of air and gas to said first mentioned chambers. v

6. In apparatus of the class described, a pair of mu'tfles, a Wall aboutea-ch of said inutiles and spaced therefrom, a combustion chamber' beneath each said muftles, a wall separating said chambersl and so formed as to connect the spaces formed between the same and said muiies, and a gas and an air regenerative chamber disposed beneath each of said irstmentioned chambers.

7. In apparatus of the class described, a pair of mufdes, a' gas andan air revenerative chamber located beneath each of said mufdes, a wall provided with as and air ports located above each of sai regenerative chambers, means for directing a dame first about one of said inuiiies and then about the other, and means for introducing air and gas into one pair of regenerative chambers and for allo-wing the products of combustion to be discharged from the other air of regenerative chambers, said means being. adapted to reverse the direction of How of air and gas and the discharge of the products of combustion through said apparatus,

8. yIn apparatus of the class described, a)

arranged in alternate rela-l may pass firsthorizontally and then up- A wardly about the mules, one portion of the {lamepassing about one muiiie and the other portion thereof about theother mtime', a pair of regenerative chambers for delivering a` mixture of gas and air to one' of said chambers, anda second' pair of chambers through which productsof combustion may pass.

9. In apparatus of the classl described, a

pairofgas fired muffles, eachv of which is provided with a combustion chamber below the same, Walls surrounding said mutiies and spaced therefrom to rov-lde flame spaces. flues connecting the said chambers, iues connecting the spaces. above the muifles, means for introducing a mixture of gas and air into one of said chambers and for Withdrawing the products of combustion from the other of said chambers, means for causing the flame to divide so that part thereof will pass about one muiile and part about the other muie, and means for reversing the direct-ion of said flow of flame about said mufiles. v

10. In apparatus of the class described, a pair of mulfles each of which has a surrounding flame space and a firing or collecting chamber disposed beneath the same, a pair of chambers arranged below each of said first mentioned chambers, one pair of said last mentioned chambers being adapted to deliver a mixture of gas and air to one of said rst mentioned chambers and the other pair of said mentioned chambers being adapted to receive the roducts of com bustion from the other o said first mentioned chambers and to store the heat remaining in said products of combustion.

11. In apparatus of the class described, a pair of -mullles each of which is provided -With a combustion chamber beneath the same and a. surrounding flame space, passage Ways connecting said flame spaces, passage Ways connecting said chambers, a pair of chambers disposed beneath each of said first mentioned chambers and connected therewith by means of passage Ways, each pair of last mentioned chambers comprising a gas regenerative chamber and an air regenerative chamber, means for introducing air and gas into one pair of said last mentioned chambers, and means whereby passage of gas, air and products of combustion through said apparat-us may be reversed, each pair of said last mentioned chambers being provided with means for absorbing heat present in the products of combustion and for delivering said heat to the ingoing gas and air.

l2. In apparatus of the class described, a mufile, a .Wall positioned about the same to provide a flame space, a chamber underneath said mufile and extending the entire length thereof, an air regenerative chamber located beneath said muffle, a gas regenerative chamber located beneath said muie, each of said last mentioned chambers being provided With a series of fiues and the fiues of said series being arranged in alternate relation, and a series of flues terminating in the bottom of said first mentioned chamber which connects the same with the flues leading from the air and gas regenerative chambers.

13. In apparatus of the class described, a muffle, a wall about said muffle and spaced therefrom providing a flame space, blocks interposed between said mufile and said wall, a chamber arranged beneath said mulile and extending longitudinally thereof,

passage ways connecting said chamber with said flame space, a gas and an air regenerative chamber located beneath said muffle, each ofv said chambers having a series of ports leading therefrom to said first men- `tioned chamber, said ports being arranged in alternate relation.

14:. In apparatus of the class described, a pair of muifles each of which is provided vwith a surrounding flame space, passage ways connecting said llame spaces, a chambar arranged underneath each of said muflies and extending longitudinally thereof, a pair of chambers' arranged beneath each of said first mentioned chambers, one chamber of each of said first mentioned pair of chambers comprising -a gas regenerativel chamber and the other chamber of eachpair an air regenerative chamber, alternately arranged .passage Ways connecting the chambers of each pair to one of said first mentioned chambers, and means whereby gas and air may be introduced into said apparatus through one pair of regenerative-chambers and the products of combustion discharged through the other pair thereof.

15. In apparatus of the class described, a pair of mufiies each of which is provided with a surrounding flame space, passage Ways connecting said flame space, a chamber arranged underneath each of said mufles and extending longitudinally thereof, a pair of chambers arranged beneath each of said rst mentioned chambers, one chamber of each of said first mentioned pair of chambers comprising a gas regenerative chamber and the other chamber of each pair an air regenerative chamber, alternately arranged passage Ways connecting the chambers of each pair to one of said first mentioned chambers, means whereby gas and air may be introduced into said apparatus through one pair of regenerative chambers and the products of combustion discharged through the other pair thereof, and means in each of said last mentioned chambers for absorbing the heat presentv in the products ofcombustion.

16. In apparatus of the class described, a pair of mutlles, each of which is provided with a surrounding flame space and a lon'gi` tudinally' extending combustion chamber arranged beneath t-he same, passage ways connecting-the flame space of each of said muiiles and for connecting the combustion chamber of each mufile with its flame space, a pair of regenerative chambers located beneath each of said mufiles, means whereby al mixture of gas and ain may be introduced into the apparatus through one pair ofregenerative chambers and the products of combustion discharged through the other thereof, means in each of said regenerative chambers for absorbin the heatvpresent in the products of comustion, and means whereby the direction of ow of gas and air and the discharging of the products of combustion througlrthe Asame apparatus may be reversed.

- 17. In apparatus ofthe class described, a inutile provided with a surrounding flame space, a chamber arranged underneath said mulile and extending longitudinally thereof, passage ways connecting said chamber with said flame space, said passage ways uniformly decreasing in cross-sectional area from the front to the rear of the inutile, gas and air regenerative chambers arranged underneath said first mentioned chamber, and passage ways connecting saidn-egenerative chambers with said first mentioned chambers, said passage ways uniformly decreasing in cross-sectional area from the frontto the rearof said mufl'le.

18. In apparatus of the class described, a muffle provided with a surrounding flame space and having a longitudinally extending combustion or liringchamber arranged beneath the same, a series of passage ways connecting said chamber with said flame space, said passage ways increasing in cross- Sectional area from the rear to the front of the mulile, a pair of regenerative chambers arranged underneath said Inutile, each chamber being connected with said lirst mentioned chamber by a series of passage ways Which are arranged in alternation and which decrease in cross-sectional area from the front to the rear of the apparatus, and means in each of said last mentioned chambers for yabsorbing heat from the products of combustion and for givingotf said heat to the f ingoing gas or air.

19. In apparatus of the kind described, a Inutile, and a wall positioned about the same to provide a flame space Substantially coextensive with the mutle, the cross-sectional area of the flame space being greater at one end than at the other.

20. In apparatus 'of the class described, a muflle, a wall positioned about the same to provide a flame space substantially co-extensive with the Inutile, the cross-sectional area of the flame space being greater at one end than at the other, a combustion chamber below the mulile and opening into the flame space, and a chamber opening into said combustion chamber by way of a row of ports, the port at one end of the row being larger than the port at the other end.

2l. In apparatus of the class described, a muflle, a wall positioned about the same to provide a fla-me space substantially co-extensive with the muffle, the cross-sectional area of the llame space being greater at one end than at the other, a combustion chamber below themuliie and opening into the flame space, and a chamber opening into said coma bustion chamber by Way of a row of ports,

romena thel port at one end of the row being largerY than the port at the other end, said last named chamber being filled with checkerwork, the openingsr whereof at one end of the chamber are larger than those at the other end.

22. In apparatus of the kind described, a longitudinally extending muffle having a surrounding flame space and a longitudinally extending combustion chamber beneath and in alinement therewith, a row of passageways along the length of the combustion chamber and connecting the same with the flame space, and means for varying the size of each one of said row of passageways, whereby the amount of flame required to properly heat any portion of the mufl'le may be regulated.

23. In apparatus of the kind described, a. closed inutile having a surrounding wall spaced therefrom to provide "a flame-space about the mulile and extending from front to rear thereof, there being a valved opening connecting the rear of the flame-space with the outer air.

24. In apparatus of the kind described, a closed Inutile having a surrounding Wall spaced therefrom to provide a llame space about the muflle=and extending from front to rear thereof, there being a valved opening in the rear wall of the inutile to the outer air.

25. In apparatus of the kind described, a closed mulile having a surrounding wall spaced therefrom to provide a flame space transversely about the mulfle and extending from frontl to rear thereof, the rear end of the flame space being defined by a Wall which is an extension of the rear wall of the Inutile, said wall having a valve-controlled opening into the rear of the flame I a mulile having an arched top, a wall positioned about the muffle tol rovide a flame space, and independent horizontally spaced piers between the mulile and the surrounding wall, each pier extendingsubstantially up to the spring of the muflle arch whereby vertically unobstructed passages are formed between adjacent piers.

27. In apparatus of the kind described, a Inutile having an arched top, a Wall positioned about the Inutile to rovide a llame space, and independent horizontally spaced piers between the muflle and the surrounding Wall, each pier extending substantially up to the spring of the mufile arch whereby vertically unobstructed passages are formed between adjacent piers, said piers being of openwork construction.

28. In apparatus of the kind described, a mulile having an arched top, a wall ositioned about the muile to provide av ame space, and horizontally spaced iers between the mule and the surroun ing wall, each pier extending substantially up to the spring of the inuflle arch, said piers provid:

. ing graduated-f spaces between them from` end to end of the inutile.

2S). ln apparatus of the kind described, a muflie having an arched top, a. wall positioned about the muffle to provide a flame space, and independent horizontally spaced piers ybetween the muflle and the surrounding wall, each pier extending substantially up to the spring of the inutile arch whereby vertically unobstructed passages are formed between adjacent piers, there being a flame port into the space between each pair of piers.

30. In apparatus of the kind described, a mutiie having an arched top, a wall positioned about the muflic to provide a iame space, and horizontally spaced iers be tween the maille and the surroun ing-Wall, each pier extending substantially up to the spring of the mutlle arch, there being a flame port into the space between each pair of piers, said flame ports being graduated as to size from end to end of the mutfle.

3l. In apparatus of the class described, a Inutile structure having a surrounding flame-space, a plurality of combustion chambers communicating with said flamespace at diii'erent points, a regenerative chamber for each ofsaid combustion chambers, and an apertured partition between each regenerative chamber and the corresponding combustion chamber.

82. In apparatus of the class described, a Inuttle having a surrounding namespace,

ka combustion chamber communicating With said flame-space, a regenerative chamber communicating with said combustion chamber, and an apertured partition between Said regenerative chamber and the combustion chamber.

In testimony whereof I aiiix my signature in the presence of two Witnesses.

JAMES A. HERRICK. Witnesses:

ADELE Homcsrsmc, BLANCHE WV. CoULDocK.

Images