US1889993A

US1889993A - Furnace construction

Info

Publication number: US1889993A
Application number: US214570A
Authority: US
Inventors: Herbert V Leahy
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-08-22
Filing date: 1927-08-22
Publication date: 1932-12-06
Anticipated expiration: 1949-12-06

Description

Dec. 6, 1932. H, v LEAHY ,889,993

FUBNACE CONS TRUCTION Filed Aug. 22, 192'?l 4 sheets-sheet 1 Dec. 6, i932, H. v. LEM-:Y

FURNACE CONSTRUCTION Filed Aug. 22., 1927 4'sneets-sneet 2 www idf Dec. 6, 1932. H. v. LEAHY FURNACE CONSTRUCTION Filed Aug. 22., 1927 4 vSheets-Shea?I 4 zo b l Fatented Dect-6, i932 unire LSSSLQQ HERBERT v. LEAHY, or Los ANGELES, CALIFORNIA FURNAGE CONSTRUCTION Application led. August 22, 1927. Serial No. 214,5?0.

rl`his invention relates tofurnace construc-4 tions and an object, in general, is to secure lincreased fuel economy.

A very important obj ect is to provide a 5 unit burner construction that readily lends itself to multipli-cation of burner units so that .the furnace may be built in larger .or smaller sizes, as desired.

An important object is to support a group of burner tiles in such manner that the entire group can be installed and removed at one time.

' Another object is to make provision for supporting the individual burner tiles in such manner that any one of them is readily removable so that it can be replaced, if broken or otherwise damaged. e

Another obj ect is to provide a construction 2U in which the fuel supplying manifold, the

mounted for independentinstallation and removal. i

Another object is to insure that the fuel as it leaves the gas nozzles is whirled against plete combustion of the gas'within said tiles.

Another object is to provide a construction in which the burner tiles are of a shape and are banked in such'manner as to provide air ports between the tiles for the preheating of j the air and for the cooling of the burner tiles.

Another object is to provide eiiicient cooling of the furnace Hoor and preheating of the air for combustion. These results are 0bnace Hoor in combination with the gas distributor.

Another object is to provide for support of the front Wall of the furnace above the burner unit so as to prevent sagging of said Wall when it becomes heated. This is one of the most difficult things to accomplish in furnace gas distributor and the burner tile holder are y walls of the burner tiles so as to insure cominvention..

tained by providing-an air loop in the fur the advantage of maintaining a. high temperat-ure zone adjacent to the oil and gas burners.

` construction that will enable the gas burner l units to be installed or repaired While the furnace is operating on oil fuel. 60

Another object is to feed the hot or cold air around the oil burner tube so as to keep the burner comparatively cool.

Another object is to rovide a door construction that Will admlt of the oil burner being pushed through the door opening in inf stallingand removing said burner.'

Anotherobject is-to improve the air admission door-control device.

Another object is to improve the burner construction. Further. objects and advantages will ap- 4 pearin the subjoined detailed description.

The accompanying drawings illustrate the Figure 1 is a longitudinal section of a furnace constructed in accordance with the provisions of this invention.

Figure 2 is a broken front elevation, partly in section, ofthe furnace shown in Figure l.

Figure is a front elevation of one of theburner units, the pilot light supporting member being shown partly in section. One of the tile holders and some of the tiles are omitted as are alsothe oil burner and some of the gas burners and manifolds.

Figure 4 is a rear view of one of the burner units, some of the burner tiles being omitted.

Figure4 5 is an enlarged sectional detail on i D v the line indicated by 5 5, Figure 2. 0

Figure 6 is an enlarged'sectional detail of the lower front portion of the furnace, -showing on an enlarged scale some of the parts shown in Figure 1. v

Figure 7 is an enlarged sectionaldetail illustrating, in part, the mounting.I of the tile holders and the gas distributor.

Figure 8 is an enlarged-sectional detail also illustrating in part the mounting of the gas distributor. loo

Figure 9 is an enlarged fragmental elevation, partly in section, from the line indicated by 9-9, Figure 1. l

Figure 10 is a side elevation of one of the burner holders and burner tiles supported thereby.

Figure 11 is an enlarged longitudinal section of one of the gas burner tips.

Figure 12 is a perspective View of the gasdirecting bushing.

Figure 13 is a front elevation' of'a multiple gas burner tip.

Figure 14 is a vertical section on the line indicated by 14-14, Figure 13.

Figure 15 is a longitudinal section of a modified f orm of gas burner tip.

Figure 16 is a vertical section on the line indicated by 16-16, Figure 15.

Figure 17 is a perspective View of the gasdirecting bushing shown in Figures 15 and 16.

Referring to the drawings, the furnace comprises a rear wall 21, a front wall 22, side walls 23, a top 24 and a floorv composed'of spaced upper and

lower sections

25, 26. These together form a combustion chamber. The space between the

floor sections

25, 26 is divided vertically, by a longitudinally extending partition 27, into `horizontal lower and

upper air passages

28, 29, respectively. The

passages

28, 29 connect at their rear ends to the lower ends of

vertical passages

281, 291 in the rear wall 21. The upper ends of the

passages

281, 291 communicate through a port 30. Lower draught control doors 31 are mounted at the front end of the passage 28 to control the inflow of cold air.`

The

air passages

28, 29, l281, 291 and port together form an air loop in the furnace floor and rear wall for the purpose of preheating the air and cooling the floor and rear wall. The forward end of the passage 29 communicates with one or more burner units,

. indicated in general by the character 32, and

constructed as follows: Each burner unit comprises a sheet metal box or case having a top 33, a bottom 34 and ends 35 and open front and rear. The bottom 34 is provided with an opening 36 that extends almost from front to rear and end -to end of the bottom 34. Through this opening the air passes into the interior of the case. The iloor 34 is provided from end to end thereof with an upwardly projecting ilange or shoulder 37 and detachably secured against the front face of said flange are tile holders 38. To secure the tile holders 38 to the flange 37, said flange is provided with forwardly projecting studs 39 that pass through holes 40 in the tile holder 38, the forward ends of the pins 39 being provided with cotter pins 41. The tile holders 38 at their upper ends rest against shoulders 42 that project downwardly from the case top 33. Projecting downwardly from the top 33 hence forwardly are studs 43, each of which passes between adjacent tile holders 38 and through ahole in a member 44 that overlaps the edges of two adjacent tile holders 38. rlhe forward ends of the studs 43 are provided with cotter pins 45. rIhe rear faces of the tile holders 38 are formed with pairs of shoulders or flanges 46. The shoulders 46 of each pair are at the opposite sides of the tile holders. Burner tiles 461 are positioned between adjacent pairs of flanges 46 and these tiles, in this instance, are hexagonal in cross section and are positioned so that the tiles in adjacent vertical rows are in contact on their straight faces. The tiles may be made of any suitable material. This results in the upper and lower faces of the tiles extending aslant to the horizontal and the shoulders 46 also extend aslant to the horizontal so that the slanting faces of the tile will be engaged by the shoulders 46 in order to securely, but removably, support the tile. The edge portions of the tile holders' are cut away adjacent to the flanges 46 so as to form air ports 47 between each four adja' cent tile and air ports 48 between each two adjacent tiles along the case. Also the tile .holders arev spaced so as to form air ports 49 between each two adjacent tiles along the top and bottom of the case.

Detachably connected with the tile holders 38 are gas distributors 50. For this purpose the tile holders have forwardly projecting` upper and lower bosses 51. The bosses of the endmost tile holders are provided with forwardly extending studs 52 which pass through the associated gas distributors and are provided in their forward ends with cotter pins 53. The remainder of the bosses 51 are provided with forwardly projecting dowels 54 which engage in holes 55 in the gas distributors. Each gas distributor is provided with a port 56 and into the ports project the branch tubes 57 of a gas supply manifold which is indicated in general by the character 58. Each branch tube`57 is provided with a cock 59. A valve 60 on the manifold 58 controls the flow of gas thereto.

The middle tile holder 38 has an enlarged opening 61 near its upper end and no burner tile is positioned in alinement with the opening 61 as through said opening projects an oil burner which is indicated at 62. The oil burner 62 may be of any'suitable construction and its oil supply tube 63 is surrounded by an air tube 64 provided with numerous ports 65 in its intermediate portion. Air that enters the case that holds the burner tiles is free to enter the ports 65 and said air surrounds the burner tube 63 and keeps the same cool and said air flows forwardly and around the tip of the oil burner 62 so as to supply an additional amount of air for combustion.

There is no gas distributor for the middle column of burner tiles and gas is supplied to the central burner t-ile of the middle colmessage into said openings 67 are screwed gas burn` ers 68, the tips of said burners being adjacent to the forward ends of the burner tiles. The burners 68 are preferably of special construction, as will be hereinafter described, in order to throw the gas outwardly into contact with the walls of the burner tiles. v

011e of the screw threaded holes 67 is in the branch 66 so that the associated bur-ner tip 68 is axially alined with the central burner tile of the middle column. lt will be seen that so far no provision has been made for supporting a gas burner in axial alinement with the lowermost burner tile of the middle column. l'n this position is a pilot light 69 which is supported by being screw-threaded into an opening 7 O in an arm 71 that extends laterally from one of the gas distributors, the one selected in this instance being that immediately on the left of the middle column of tiles. as shown in Figure 3. The arm 71 is blanked andcommunicating with the pilot light 69 is a separate gas supply tube 72.

From the foregoing it will be readily seen v that the burner unit may be duplicated as many times as desired so as to supply diiferent sizes of furnaces with the requisite number of gas and oil burners. Since each burner unit comprises a number of burner tiles, gas distributors, and gas burners all mounted within a case, the units may be built up in the Shop and shipped to their destination and readily installed and the units may be placed end to end or one above another. lf any one or more of the burner tiles become broken or otherwise damaged, it may be readily removed by simply slipping it rearwardly out of engagement with the flanges 46. No other portion of the burner unit need be disturbed. If any of the gas distributors require cleaning or repairing, it may beidetacbed without disturbing any other parts of the burner unit. Likewise, the manifold 58 and tits branch tubes 57 may be readily detached from the gas distributors 50 without disturbing any other parts.

The forward end 'of the tube 64 is provided with a swingingdoor 73 which has its hinge 74 arranged with its axis horizontal.v

The door 73 has a slot 75 to accommodate the tube 63. In installing the oil burner 62, it

-will simply be thrust against the door 7 3l which will swing inwardly to permit the burner tip to pass into the tube 64 and said door will then automatically swing closed. Also in removing the oil burner, the door 73 will swing outwardly to permit the oil burner tip passing out of the tube 64.

Projecting inwardly from the inner Aface of the front wall 22 is an air deector 76 which, in this instance, is in the form of an. arch extending from side to side of the furnace just above the level of the burner unit or units. rlhis air dede'ctor prevents the cool air, that enters the furnace adjacent to the burner unit, from rising to theboiler which is indicated at 77, thus preventing cooling of the front end of the boiler since the cold air will be' deflected rearwardly and be raised in temperature by the hotter lower zone of the furnace. rlFhis tendency for the cold air to How upwardly and strike the boiler is especially prevalent when only oil is being used as the fuel, since there is a. How of air through the inter-tile ports 47. By j orovid-` ing this air deflector, it also maintains a high temperature zone adjacent to the oil and gas burners, thus facilitating combustion of the fuel.

The hottest zone of combustion is, of course, adjacent to the front wall 22 of the furnace and it has always been practically impossible to prevent deterioration of the furnace front walls and sagging thereof and, accordingly, it has heretofore been necessary to frequently rebuild such front walls. The re-building operations, of course, puts the furnace out of commission. To prevent deterioration and sagging of the front wall, l place longitudinally in said wall, just above the burner units, a metallic support 78 in the form of an open ended box or tube. In this instance, said metallic support comprises two parallel 1- beams, the space 79 between said I-beams constituting an air passage which' communicates with the atmosphere at both ends through openings 80 in the furnace walls. lThe air passage 79 is connected by downwardly extending duct or ducts 81 to the interior of the burner unit case. In this instance, fourl such ducts are employed, as clearly shown in Figure 2.

From the foregoing it will now be readily understood that the metallic support 78 is kept cool by the air that passes through it and that the air is drawnthrough the member 78 by reason of the furnace draught.

Partially forming the front wall 22 of the furnace is a sectional plate comprising upper, intermediate, and

lower sections

82, 83 and 84. The draught doors 31 are hinged at85 lon the outer face of the plate section 84. The

sections

83, 84 could be integral. There is an advantage in having the

sections

82, 83 indevlllll? pendent of one another and this is that it en tween said seats.

or their equivalents. Each member 87 is provided with a concave seat 90 and the associated member 88 is also provided with a concave seat 91 and the pipe 86 is clamped'be- The bolts 89 also secure the clamps to the plate section 82. The

pipes

86, 861 connect with the burner tube 63 and said

pipes

86, 861 are provided with

valves

92, 921, respectively. The shut ofi' Valve for the burner 62 is shown at 922.

The plate section 83 may be removed wthout disturbing the plate 82 and oil line and the plate section 82 is provided with lower openings 93 and upper openings- 94. The lower openings 94 may be closed by lower doors 95 which are, hinged at 96 to the plate section 83. The openings 94 may be closed by upper doors 97 which are hinged at 9 8 on the plate section 83.

The

doors

95, 97, when open, adm't air to the interior of the burner box or case and a means is provided for simultaneously controlllng and holding the

doors

95, 97 as will now appear. A door control is also provided for regulating the opening of the doors 31. The door controls for the

doors

31, 95 are alike and, therefore, only one of them need be described in detail as follows: A shaft 99 constitutes the hinge pin and a pa'r of the doors is fixed to said shaft. Also fixed to the shaft 99 is a U-shaped 0r bifurcated arm 100 for turning said shaft. Between the furcations of the arm 100 is a block 101 which is securedto the associated plate section. The

block 101 is provided with a curved eccentric face 102, said face being'eccentric to the axis of the shaft 99 and the distance between said face and the axis of said shaft increasing from top to bottom of said eccentric face. A screw 103, constituting one form of abutment, is screwed through the arm 100 in position to engage the eccentric face 102 so as to hold the arm 100 in any position to which it may be adjusted, the eccentric face preventing the screw 103 from slipping downwardly. The

screw 103 is provided with a knurled handle 104 whereby said screw may beeasily turned.

The door control for the doors 95 is also connected to the doors 97 so as to simultaneously control the doors 97 as well as the doors 95. To effect this the shaft 105 that constitutes the hinge pin of the doors 97 is provided at its opposite ends with arms 106 and the shaft 99 is provided at its opposite ends with arms 107. The arms 106 are connected with the arms 107 by links 108 which are pivoted at 109 to said arms. One of the arms 106 is provided with an extension forming an operating handle 110. The handle 110 may be raised without loosening the screw 100 and the screw 100 may then be turned into engagement with the eccentric face 102 so as to support the

doors

95, 97 in the position to which they have been raised.

From the foregoing it will be readily seen reeaees that While the burner is in operation it is possible to remove the plate section 83 and the parts mounted thereon so as to have access to the burner box for making whateverre air or replacement is required.

en the gas is under comparatively high pressure a gas nozzle of the type illustrated in Figures 6, 11 and 12 will be employed and is constructed as follows: A hollow cap 111 is provided axially thereof with an orifice 112 and said cap is screw threaded onto a coupling 113. The burner tube 114 is screwed into the couplin 113. Thecap 111 is provided in its interlor with an annular shoulder 115 and the inner face `of the cap 111 extends aslant from the shoulder 115 to the wall of the orifice 112 so ,that that portion of the cap chamber 116 that lies between the shoulder 115 and the orifice 112 is reduced toward said orifice. The coupling 113 is provided interiorly with a shoulder 117 spaced from the shoulder 115 and between said shoulders is clamped the flange 118 of a cyclone jet forming member 119.H The face 120 of the member 119 that is turned `toward the orifice 112 is concave and extending from end to end of the member 119 are gas passages 121 which extend aslant circumferentially of the member 119. This construction results in the gas being given a whirling motion in the nozzle and when it leaves said nozzle, thus entailing that the gas be thrown outwardly against the inner face of the burner tile that is axially alined with said nozzle. After the furnace is in operation, the burner tiles are highly heated and, accordingly, the gas thrown against the inner `faces of the burner tilesl comes into contact with highly heated surfaces, and, said gas being mixed with air, is subjected to substantially perfect combustion within the burner tiles.

When low pressure gas is to be employed, it is preferable to employ a multiple jet nozzle of the type illustrated in Figures 13 and 14. The parts of this nozzle that functionately correspond to those described above are indicated by the same reference characters with the addition of the letter a.

In this instance, the'tubes 114, of which therel may be any desired number, are screwed into the front wall of a chamber 122 and screwed lll into the chamber 122 is a tube 123 by which of a fewer number of parts. ffhe parts that function the same as those described above in connection with Figures 11 and 12 are indicated by the same reference characters with the addition of the letter b. In this instance, the cyclone jet forming members 1195 Lacasse The nozzles shown in Figures 13 to 16 inclusive each throws a multiple of whirling jets into the burner tile and against the inner face of said tile.

in operation, Jthe temperature of the furnace may be lowered by closing the doors 31 and opening the

doors

95, 97 and, conversely, the temperature may be increased by closing

thedoors

95, 97 and opening the doors 31 to permit a greater volume of air to be preheated in the air loop vof the floor.

rlhe temperature may be controlled to some extent by regulating the dampers 124 which are positioned at the ends of the air passage 79, as clearly shown in Figure 2.

rlhe gas passes through the manifold 58 into the diil'erent gas distributors 50, thence into the burner nozzles and combustion takes place, as stated above, within the burner tiles.

l claim: 4

i. A furnace construction comprising a metal case with an opening, a plate section closing said opening, tile holders detachabl mounted in the case and removable throughI the opening, gas distributors detachably connected with the tile holders and removable through the opening burner tiles detachably supported by the holders and removable through the opening, and gas nozzles projecting from the gas distributors in axial alinement with the tiles.-

A furnace construction comprising a metal case with an opening, a plate section closing said opening, tile holders detachably mounted in the case and removable through the opening, burner tiles detachablyi supported by said holders and removable through the opening, gas distributors detachably connected with the tile holdersand removable through the opening, gas nozzles projecting from the gas distributors inaxialalinement with the tiles, and a gas manifold provided with branch tubes detachably connected with the gas distributors.

3,. A furnace construction comprising ametal case, tile holders mounted 1n the case,

and provided with rearwardly projecting iianges extending aslant to the horizontal,

hexagonal burner tiles positioned in vertical rows,the tiles iii adjacent rows being in -contact and the upper and lower faces of the tiles engaging the flanges, and gas nozzles positioned to project gas into the burner tiles.

4. A furnace construction comprising burner tiles positioned in vertical rows with their axes horizontal, said tiles constructed and arranged to form air ports therebetween, arlid burner nozzles axially alined with the ti es. f

5. A furnace construction comprising burner tiles positioned in vertical rows with their axes horizontal, each tile having more than four sides and the tiles in adjacent rows being in contact and the upper and lower faces of the tiles extending aslant to the horizontal, there being air ports between the upper and lower faces of adjacent tiles. U

6. A furnace construction comprislng open-ended burner tiles, and gas nozzles posif tined in axial alinement with the burner tiles adjacent to one end thereof and spaced from the burner tiles to leave air passages into the tiles around the nozzles, each of said nozzles 4provided with a means to impart a whirling motion to the gas to cause said gas to be thrown outwardlyy against the inner face of the tile. [l

' 7. A furnace construction comprising tile holders, burner nozzles detachably connected with the tile holders on one side of said holders, and open-ended burner tiles detachably mounted on the other side of said holders in axial alinement with the nozzles.

8. A furnace construction comprising a bank of burner tiles positioned in vertical rows withtheiraxes horizontal, a gas distributor mounted in front of each vertical row of tiles, and burner nozzles projecting from the gas distributors in axial alinement with the burner tiles, the tips of said nozzles being adjacent to the front ends of the tiles.

9. A furnace construction comprising a combustion chamber, an open ended metal box extending longitudinally in the front wall of the combustion chamber and communicating with the atmosphere through a wall of said chamber, and a burner unit in the front wall of the combustion chamber below the metal box, said front wall provided with a duct connecting the box with the burner unit. l f

10. A furnace construction comprising a combustion chamber, parallel I-beams ex'- tending longitudinally in the front wallof the combustion chamber and forming therebetween anfair passage, said passage communicating'fwith the atmosphere through a wall of sa1d'chamber, and a burner unit in thefront'fwall of the combustion chamber belofwthe'I-beams, said front wall provided with aduct connecting the air passage with theburner unit. j

11. A furnace construction comprising a combustion chamber, the front'wall of said chamber partially formed by a sectional plate, the plate sections being independently detachable, an oil supply line secured to the upper plate section, an oil burner connected with said oil supply line, another of the plate sections provided with an opening, gas burner nozzles rearwardly of said opening, a door mounted on the second mentioned plate section and controlling the low of air through said opening, and a gas supply manifold passing through the second mentioned plate section and connected with the nozzles.

12. A furnace construction comprising a lio interior communicating with the 4through said ports, burner tiles mounted in burner unit including a tube having air ports therein, an oil pipe extending through 'the tube, an oil burner on one end of the oil pipe, a case supporting the tube and having its tube with a curved eccentric face and the distance between said face and the axis of the shaft increasing from top to bottom of said face, and a screw threaded through the arm in position to engage the eccentric face.

14. A furnace construction comprising side walls, a front wall, a rear wall, a top, a floor, a burner unit mounted in the front wall, the floor provided with a double air passage communicating at its front end with the atmosphere and with the burner unit, the rear wall provided with a vertical double air passage communicating with the rear end of the floor passage, the front wall provided above the burner unit with a transversely extending air passage having one end open to the atmosphere, the last mentioned air passage communicatingwith the burner unit.

15. A furnace construction comprising side walls, a front wall, a rear wall, a top, a fioor, a burner unit mounted in the front wall, the floor provided with a double air passage communicating at its front end with the atmosphe-re and with the burner unit, the rear wall provided with a vertical double air passage communicating with the rear end of the floor passage, the burner unit including a case, and burner tiles positioned along the rear of the case and provided with horizontal openings therethrough, the front wall provided above the burner unit with a transversely extending air passage communicating with the casein front of the tiles.

16. A furnace construction comprising a combustion chamber, the front wall of the combustion chamber provided with a longitudinally extending air passage open at one end to the atmosphere, and a burner unit in the front wall of the combustion chamber below the air passage, said front wall provided with a duct connecting the air passage with the burner unit.

17. A furnace construction comprising a combustion chamber, a burner unit in the front wall of the combustion chamber, an air deector projecting inwardly from the inner face of the front wall above the level of the Aburner unit, said burner unit including a separate ,detachable burner positioned at the upper portion of the unit and including other burners located at the sides and underneath 18. A furnace construction comprising a metal case providing with an opening, a plate section closing said opening, title holders detachably mounted in the case, burner tiles detachably supported by said holders, a gas distributor detachably connected with the tile holders, said tile holders provided with openings in axial alignment with the tiles and provided with flanges holding the tiles in position, means on the tile holders detachably holding the gas distributor, and gas nozzles connected with the distributor and positioned to project gas through the first mentioned opening and into the burner tiles.

19. A furnace construction comprising a metal case provided with an opening, a plate section closing said opening, tltle holders detachably mounted in the case, burner tiles detachably supported by said holders, gas distributors detachably connected with the tile holders, said tile holders provided with openings in axial alignment with the tiles and provided with flanges holding the tiles in position, means on the tile holders detachably holding the gas distributors, gas nozzles connected with the distributors and positioned to project gas through the first mentioned opening and into the burner tiles, and means to independently supply gas to each of the distributors.

20. A furnace construction comprising, a case, burner tiles mounted in rows in the case, gas distributors, means detachably mounting each of the distributors in the case in front of a row of burner tiles, gas nozzles connected with the distributors and positioned to project gas into the burner tiles, and almeans to independently supply gas to each of the distributors.

21. A furnace construction comprising, an oil burner, gas distributors on opposite sides of the oil burner, burner tiles in front of the distributors, other burner tiles below the oil burner, gas burners connected with the distributors and positioned to project gas into those tiles that are positioned in front of the distributors, one of said distributors provided with a lateral branch, a gas burner connected with said branch and positioned to roject gas into one of the second mentioned urner tiles, an arm extending laterally from one of the distributors, and a pilot light supported by the arm in position to project gas into another of the second mentioned tiles.

22. In a furnace construction, a metal case ,provided with an opening, burner tiles deopens to the free edge assaeea il? ed in the case in position to discharge fuel into theburner tiles and removable through said4 opening when the plate section is detached.

23. A furnace construction comprising a metal case provided with an opening, a plate section closing said opening and provided with an opening therein, an air distributor tube having one end supported by the plate section in alinement with the opening in said plate section, a door to close the opening in the plate section provided with a slot that of the door, a fuel supply pipe extending through the slot into the air distributor tube, and aburner attached to said pipe, said burner being larger than the slot and removable through the opening in the plate section when the door is open.

E24. A furnace construction comprising side walls, a front wall, a rear wall, a top, a floor, a burner unit mounted in one of the walls, the floor provided with air passages communieating with the atmosphere at one end -and with the burner unit, the wall portion above the burner unit being provided with a transversely extending air passage having one end open to the atmosphere, said last mentioned air passage communicating with the burner unit.

25. A furnace construction comprising a metal case provided With'an opening` a plate section closing said opening, tile holders detachably mounted inthe case and removable through the opening, burner tiles detachably supported by said holders, said tiles constructed and arranged to form airports therebetween, gas distributors detachably connected with the tile holders and removable through the opening, gas nozzles projecting from the gas distributors in axial alinement with the tiles, a gas manifold provided with burner tubes detachably connected with the gas distributors` and gas nozzles connected with the branch tubes and positioned to project gas into the burner tiles.

26. A furnace construction comprising a metal case. tile holders mounted in the case and provided with projecting flanges, burner tiles engaging said flanges and constructed and arranged to form air ports between said tiles,- and gas nozzles positioned to project fuel into the burner tiles.

27. A furnace construction comprising two members, one forming a casing and provided with an opening and the other hinged to close said opening, a mixing Chambertin the casing, a burner positione to discharge fuel into the mixing chamber` a block mounted on one of said members and provided with a curved eccentric face,.and an abutment on the other member for the eccentric face to rest against, the block and abutment being relatively adjustable, so as to regulate the degreeof opening of the hinged member.

Q8. A furnace construction comprising a combustion chamber provided 4with an opening in one of its walls, a burner unit in said opening,y said burner unit including a separate detachable burner and including other burners located on opposite sides and underneath the first mentioned burner and ar` rangedin. rows, a plate closing the opening, Y

and a means detachably supporting the first Amentioned burner from they plate.

29. A furnace construction comprising a combustion chamber, a burner unit in the wall of the .combustion chamber, an air deflector projecting inwardly from the inner face of said wall above the burner unit, said burner unit comprising a wall of refractory material having a plurality of substantially horizontal passages therethrough, a. plurality of gas discharge nozzles positioned to discharge gas` through some of said horizontal passages, an a liquid fuel burner projecting into said combustion chamber through one of said horizontalpassages at least a part of the air for combustion of fuel issuing from said liquid fuel burner entering said combustion chamber through said horizontal passages.

30. A furnace construction comprising a combustion chamber, a burner unit in the wall of the combustion chamber, said unit comprising an oil burner removably positioned in the upper part thereof and other burners located at the sides and underneath said oil burner, said unit provided with atv least two air passages admitting air into said unit at approximately right angles to each other, and said unit being provided with further air passages leading into'said combus tion chamber, said further air passages being substantially parallel to each other and to said burners.

31. A burner for furnaces comprising a burner setting; a plurality of burner holders independently mounted and separately removable from the setting, said holders having matching recessed portions to provide air passages therebetween; 'burner nozzles mounted upon each holder; a fuel manifold; and valve controlled means connecting the manifold and each holder for supplying fuel through the holders to the burner nozzles whereby any holder may be removed independently of the remaining holders and burner nozzles.

32'. A burner for furnaces comprising a burnersetting; a plurality of burner units each consisting of a burner holder and a plurality of burner nozzles connected thereto; a common supply manifold; means for supplying fuel independently to said units from said common supply manifold and means for detachably mounting the burner units in separately removable relation within the setting, said units having matched recessed portions to form air passages therebetween.

33. In a furnace construction, a combinafor o-zles positioned to project gas and entrained 40 a tile assembled supported by and removable tion dil and as burning unit comprising va plurality of orizpontally extending burner tiles mounted in a Wall of the furnace, gas l nozzles positioned t-o project gas into the burner tiles and a `tube positioned immediately adjacent said burner tiles in the Wall of said furnace, said tube, being adapted to admit an oil burner and the supply pipes leading thereto. 34. In a furnace construction, a combination oil and gas burning unit comprising a plurality of horizontally extending burner tiles mounted in a Wall of the furnace, gas nozzles positioned to project gas into the g5 burner tiles and a tube positioned immediately adjacent said burner tiles in the wall of said furnace, said tube being adapted to admit an oil burner and the supply pipes leading thereto, wall means defining an enclosed space back of said burner tiles, said Wall means having openings therein for admitting air to said space and to said burner tiles, and an opening in said tube communicating with said enclosedspace for supplying air from said space into said tube.

35. In a furnace construction, a combination. oil and gas burning unit comprising a j combustion chamber Wall having a plurality of passages extending therethrough, gas nozair through therespective passages into the combustion chamber, said wall having other passages therethrough positioned between said passages for the admission of air only and having an opening immediately adjacent said passages for admitting an oil burner and the supply pipes leading thereto. 1

36. In a furnace construction, a setting, tile holders removably mounted in the setting and with each holder, each .tile assembly defining a plurality of substantially parallel passages for admitting gas and entrained air and defini'ng other adjacent passages for admitting 451 air alone, and gas nozzles positioned to project fuelgas and entrained air into said rst passages.

Signed at Los Angeles, California, this 3d day of Aug., 1927. 5G" HEBERT V. LEAHY.