US1734079A - Heater - Google Patents

Description

Nov. 5, 1929.

wf'M. cRoss HEATERV Fued Feb. 16, 1925 2 sheets-sheet 1 Nov. 5, 1929.

w. M. cRoss HEATER Filed Feb. 16,"1925 z sheets-sheet 2 INVENToR.

@g/M, ATTORNEY.

2li/less.'

Patented Nov. 5, 1,929v

WALTER M. cnoss, or xANsAs CITY, MISSOURI HEATER Application led February This inventionrelates to improvements in heaters, and refers more particularly to a furnace construction in which is positioned a plurality of connected tubes so arranged that the fluid medium circulated through the tubes will 'be more eiiciently heated thanf4 in the usual type of furnaces where banks of tubes are positioned centrally'in the' combustion chamer or a separate heating chamber provided therefor. 'i

Among the `salient objects of the invention are, to provide a construction in which Va plu# rality of heating tubes connected'tojorm a continuous coil or manifoldedxas maybe detier continuously around the four sides of the interior reflecting ysurfaces of the combustiorr chamber in juxtaposition or close proximately to the side interior walls or reflecting surfaces' of the chamber; to provide a construction in which the tubes may be arranged in one 0r more rows or tiers in close relation to the in.- terior side walls and upper reiecting surface or roof in a manner that the reflecting surfaces are reduced materially whereby the tubes containing' the iluid medium are themselves reflecting surfaces receiving the radiant heat of the furnace directly, thus affording 'the more efficient heat exchange and eliminating the objection of excessively heating the refleeting surfaces ;l to provide a heater construction by means of which higherV temperatures may be utilized in the combustion zone, as the heat is more readily transferred and removed from the combustion vstage bythe fluid medium contained in the tubes.

A further object is to reduce the side wall temperatures to a point where the brick work will not deteriorate due to excessive temperatures and to afford a more complete combus tion by maintaining higher temperatures and increasing the percentage of carbon dioxide in the combustion gases without the formation of carbon monoxide, thus effecting a saving of fuel and producing optimum combustion conditions which consist of combustion gases having a minimum amount of air, a maximum amount of carbon dioxide and without material formation of carbon monoxide.

Y Referring to the drawings, the construction sired and arranged in either a single row or' facilitate and simplify the tluiditravel.

16, 1925. Serial N0. 9,439.

shown has but a single bank of tubes in the combustion space, although it is understood that a plurality of tiers may be set in proximity to each ofthe side walls in place of the single tier. .f

Fig. 1 is a side sectional view of the heater. Fig'. 2 is a View taken along the line2-2 in Fig. 1

jFige 3 is a View takenalong the line 3 3 in Fig. 1.`

VFig- 4g is a perspective diagrammatic View drawn to show the travel of the fluid medium through the connected tubes. ".lhetubes are shown yas a continuous pipe instead of showing the4 headers actually used in` order to Fig. 5 is a view taken along the line 5 5 in Fig. 1.

Fig. 6 is a view taken along the' line-- in Figl. i f

Referring to the drawings, at 1 is shown a heavily insulated heater whose ywalls are built of fire resisting material such as fire: ,i

brick, carborundum brick or similar refractory materials. Heat is supplied thereto by means of burners diagrammatically shown at 2. Centrally of the combustion chamber 3 is a checker-work brick wall 4 which serves to more uniformly distribute the heating gases. In therear of the combustion chamber is a bridge wall 5 open at the top to permit the passage of the gases from the combustion chamber to the flue chamber 6 where theypass downwardly over the superheating -tubes 7 and the preheating tubes 8 and out through the flue shown at 9 the .tubes in the "tube chamber acquiring substantially only convection heat as distinguished from the radiant heat acquired by the tubes disposed against the reflecting surfaces of the fire chamber and the roof of the tube chamber.

Briefly describing thev travel of the fluid medium which may consist of liquid, vapors,

or gases or mixtures of the same, they are introduced through the inlet line 10 and are 95 circulated through the preheating tubes 8 in a manner shown in Fig. 4. From the preheating tubes the fluid passes through the transfer line 11 to the tubes 12 arranged along the interior side walls of the combustion nected to zig-zag '25 'as 7. It Willlbe noted chamber around all four sides, the

to the next tube above at the completion of each circuit about the chamber.

fluid rising This circuitous travel is continued until the fluid reaches the tubes on a le'vel With, or substantially on a level with, the rear bridge wall 5. At thisv point the travel is through the tubes designated as 13 which are positioned von the two interior side and front wallsL and are so connected by `means of return. bends to cause the fluid to slfuttlecock back and forth about, the three sides of the combustion chamber until it reaches the transfer line 14 upper 'surface the passed to the upper re- On this ward in a continuous flow, the tubes being connected by return bends to course the fluid longitudinallyof the heater, working from one side of the heater across to the opposite side where a transfer tube 16 passes the 'heated medium to the superheater tubes designatedl that the tubes around the sidewalls are positioned only Within the while the roof tubes, or

combustion chamber,

thoselaid against the upper"reflecting'sur .face, extend not only the length of the combustion' chamber but also across thel top of From... the s uperheater discharged the flue chamber.

. tubes the heated fluid medium is upper reflecting through the-line 18 tankor any desired Y In' the corners o 'are headers,

plugs 20 by be cleaned.

surface. of these return shown 1n Fig. 6.

to a vaporzer,

subsequent stage. Also, valves may be positioned in the Ainlet and outlet lines for the collecting urpose of control. the combustion 1 ch amber such as those shown at 19. The tubesare connected into these headers and yopposite the ends of the tubes are cleaning means of which the tubes may Return bends 21 are used for connecting up the tubes positioned adjacent the The construction bends is diagrammatically These return bends are also fitted with cleaning plugs similar to those utilized in the\corner headers.

,Above the bridge wall at the rear of lthe combustion chamber, the corner headers will.

have only return bend connect only into one distinguished from same header and connections as the tubes lface of the headers as the lower portions of the the header in the front corner of the combustion chamber where'the tubes connect intol two surfaces as shownin Fig. headers are so 5. It is understood that divided that a travel of the fluid medium is effected from the transfer inlet line 11 to the discharge line discharged 14 through which the medium is into the roof tubes 15.

the corner continuous The novelty in arranging tubes in this manner, adjacent and in close proximity to the interior side walls and roof,

is to eliminate materially the amount vof direct radiant heat Which isprojecte'd onto the side walls and interior roof surfaces producing deterioration due to the excessive temperatures present. In a heater where the tubes are positioned centrally in the combustion space, a considerable part of the heat absorbed by the tubes is reflected heat from 4the wallsof the chamber and Where high temperatures are an advantage objectionable deterioration is an ever present factor. j

'Where the'tubes are positioned 4in close proximity to the side walls, and where they cover at least0% or more of the side wall and upper reflecting surfaces,.they receive the direct radiant heat of the chamber and due to the fluid medium coursing ltherethrough carry away this heat more than tubes positioned centrally in acombus .tion space. A heater of this character affords -sence of carbon monoxlde present .in the combustion gases than has heretofore been posrapidly than have heretofore been usual,v permitting y sible under temperatures existent in a heater or furnace. For example. in an oil fired furtemperanace the general practice is to have F. and as tures ranging from 14:00o to 18009' high as 20003 F. where there is present carbon dioxide to the extent of approximately 7 under relatively satisfactory combustion conditions.- In a'heater such as that describedin the Apresent invention, temperatures. as high as 2800"A to 30000 F. may be mai in the combustion chamber without deterioration of the brickwork and wherejcombustion conditions are controlled to the extent that there is substantially no `carbon monoxide formed and as much as 12% to 14% of carbon dioxide present inthe combustion gases. Such conditions would realize great fuel saving While eliminating the structural deterioration accompanying` the present day practice.

It will be noted that the fluid mediumA coursing through the preheater travels in an opposed direction to the combustion gases, while in the super-heater tubes it is coursed inthe same direction as the gases. This is to Aincrease the efliciency and produce a better heat exchange.

tained l objections of I This` construction w1ll Afurnish a heating surface per square foot within the combustion chamber which will absorb amount of heat than is capa-ble of being absorbed where v-the heating surface is putin 'the nested tube arrangement.

It is conceivable, also, that the tubes may be omitted from the rear reflecting surface or front face of the bridge wall in order to a larger obvia-te expansion difficulties and in case the tubes in the side walls are sunk partially in the masonry, the omission of' these rear tubes would prevent disintegration of the brickwork occasioned-'by expansion and contraction.

Although for illustrative purposes the invention has been shown and described in connection with apparatus of more or less specific details of construction,'arrangement and location of parts, and as embodying in its mode of operation a certain series and ,sequence of somewhat definite steps and operating conditions, it will be understood that many of the objects and advantages of the invention may be obtained to a greater or less extent through the .employment of apparatus of modified character, or, in fact 'through variations or, in some case omissions, of certain of the component steps, without departing from the spirit and scope of the invention.

The present invention may be utilized in connection with the heating of liquids or vapors of any kind. It is particularly useful in the heating of hydrocarbon oils either in connection with their distillation in what in the industry is termed pipe still distillation, or in the connection with cracking installations or in the heating of water inl steam boiler installation, the heater taking the'place in the latter case of the boiler tubes and headers.

I claim as my invention:

l. A heater of the character described comprising a fire chamber and a tube chamber separated by an intermediate walk/ja plurality of connected heating tubes disposed upon the interior side and upper reflecting surfaces of the fire chamber and roof of the tube chamber, separate banks of preheating and superheating coils in the tube chamber acquiring substantially only convection heat,`

serial connections between the separate units whereby a fluid medium may be circulated therethrough.

Q. A heater of the character described, comprising a fire chamber and a tube chamber separated by an intermediate wall, a plurality of connected heating tubes disposed upon the interior side and upper reflecting surfaces of the fire chamber and roof of the tube chamber, separate preheating and superheating coils in the tube chamber, connections between the separate units whereby a fluid medium is circulated in an opposed direction to the heating gases in the preheater and in the direction of the gases in the superheating tubes.

3. In the process of cracking oil in a tubular oil heater, the improvement which consists in heating the oil in three Stages, in the first ofVv which the oil containing tubes are subjected to a countercurrent heating effect by heating gases previously cooled in the two succeeding oil heating stages, and in the second of which the oil is heated by radiant heat absorbed lfrom the combustion chamber of the furnace and the highly heated combustion gases, and in the third stage the oil contain- ,Y

heated first through the tubes of the tube bank x v in the heat. chamber last traversed by the heat'- ing gases, with (a direction of oil flow therethrough generally counter to the direction of flow of the heating gases over the tubes, and

then passing the oil through the radiant heat absorbing elements, and finally passing the oil through the tubes of the bankinthe heating chamber first encountered by the heating gases, with a direction of oil flow through the last mentioned tubes generally parallel to the diection of flow of the heatinggases @ver the tu es.

5. In an oil heater of the type comprising a `combustion chamber, a heating chamber which is separated from the combustion chamber, a bridge wall over which the heating gases pass from the combustion chamber into the heating chamber which has a heating gas v loutlet at its lower end, and also comprising upper and lower groups of horizontally disposed tubes arranged in superimposed .rows in said heating chamber, and conduit elements absorbing radiant heat from the combustion chamber and from the heating gases before the latter come into contact with said tubes, the improvement which consists in connections to said tubes and elements for first` passing the oil successively through tubes of the lower group located at successively higher levels, and for then passing the oil through the radiant heat absorbing elements, and for finally passing the oil successively through tubes ofthe upper group located at successively lower levels.

6. In the process of heat treating a fluid medium in a tubular heater, the improvement which consists in heating the fluid medium in three stages, in the first of which fluid containing tubes are subjected to the countercurrent heating effect of heating gases previously cooled in the vtwo succeeding fluid Iheating stages, and in the second of which the/fluid medium is heated by radiant heat absorbed from the combustion chamber ofthe furnace and the highly heated combustion gases, and in the third stage the fluid containing tubes are subjected to a parallelcurrent heating loo effect by heating gases previously cooled in the second fluid heating stage.

7. In the process of heat Atreating a liquid in a tubular heater, the improvement which consists in heating the liquid in three stages, vin the first of which the liquid containing v tubes are subjected to the` countercurrent heating effect of heating. gases previously cooled in the two succeeding liquid heating stages, and inthe second ofwhich the liquid is heated by radiant heat absorbed from the combustion chamber of the furnace and the highly heated'combustion gases, and in the third stage the liquid containing tubes are subjected to a parallel current heating-effect by heating gases previously cooled in the second liquid heating stage. 8. A heater of the character described, comprising a fire chamber and atube chamber separated byl an intermediate wall, a plurality of connected heating tubes disposed upon the interior side and upper reflecting surfaces of the lire chamber and roof of the tube chamber, separate banks of preheating and superheating coils in the tube chamber acquiring substantially,y only convection heat, serial connectionsbetween the separate units) whereby a fluid medium may be circulated therethrough, the tubes on the sur- K -faces of said re chamber being uncovered so as to receive radiant heat.

9. -A heaterof the character described, comprising a fire chamber and a tube chamber separated by an. intermediate walL a .35 plurality of` connected heating tubes disposed upon the interior side' and upper re# ecting surfaces of the fire chamber and roof of the tube chamber, separate preheating andA superheating coils in the tube chamber, con- 40' nections between the separate units whereby i a uid medium is circulated in an oppose direction to the heatin gases in the preheater A and'invthe direction o thegases in the super-I heating tubes, the tubes in said fire chamber being uncovered so that the same may receiveradiant heat.

WALTER M; cRoss.

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