US2129900A - Heating of fluids - Google Patents

Description

Sept. 13, 1938. M. w. BARNES HEATING OF FLUIDS Filed Jan, 20, 1934 INVENTOR MAR N W; BARNES g 5 TORNEY Patented Sept. 13,1938 I UNITED STATES PATENT OFFICE 2,129,900 HEATING or FLUIDS Marion W. Barnes, Chicago, Ill., assignor to Universal Oil Products Company, Chicago, 111., a corporation of Delaware Application January 20, 1934, Serial No. 707,535 3 Claims. (01:122-356) This invention particularly refers to improveof the furnace is separated from combustion merits in the heating of fluids which is particuzones 5 and 6 by relatively short suspended walls larly well adapted to subjecting hydrocarbon oils 1 and 1 whereby the main furnace structure is to the high temperatures required for their pyrodivided into three separate heating zones 4, 5

5 lytic conversion, although it is not limited to such and 6. 5 use and may be employed to advantage in the A plurality of suitable firing tunnels such as heatingof liquid, vapors and gases generally as indicated at 8 are provided at each end of the well a mixtur f th same, furnace and a. combustible fuel-air-mixture of I have previously disclosed an improved type any suitable form is supplied by means of burnl0 of furnace for the heating of fluids having two ers 9 through firing compartment ill of tunnels 10 independently fired combustion zones each con- 8 to each of the combustion zones 5 and 6. Any taining fluid conduits supplied predominantly desired portion of the air required for combuswith radiant heat, the heating conditions in each 'tion as well as any desired quantity of excess air being independently controlled, and having a, may be supplied to each of the combustion zones centrally located fluid heating zone separated through ducts II and II' of firing tunnels 8 15 from each combustion zone by a bridge wall and which, in the case illustrated, are located respeccontaining a fluid conduit around which the comtively' above and beneath firing compartments l0. bustion gases from both combustion zones pass Excess air may also be admitted; when desired, in a downward direction thereby supplying fluid through firing tunnels l0.

heat thereto. The present invention embodies It will be noted that in the furnace structure 20 improvements to this general type of furnace here illustrated there are no obstructions in the structure, comprising locating the fluid heating direct path of flow of the combustion gases from bank adjacent the roof of the furnace 'above firing tunnels 3 t0 t f u heating Z0118 Walls and at substantially right angles to the source of I and 'l' preferably extending only a relatively heat. I have found that this arrangement augshort distance below roof 2 sufllcient top o 25 ments the natural draft conditions in the furthe sweep of hot combustion gases along the roof nace, since the movement of the gases through of the furnace to fluid heating zone 4 but not sufthe furnace due to the stack draft is in harmony ficient to obstruct or retard the free flow of gases with the natural tendency of the heated gases to through the combustion zones into the fluid heatrise. This largely eliminates eddy currents and ng z e- It w ll also b t d t firing 30' the back-wash of gases along the fluid conduit nels 8 are elevated, in the preferred embodiment and results in a more definite separation of radihere illustrated, sufficiently to prevent the sweep ant and convection heat than in any other furof hot combustion gases along the fl 0f t nace of the so-called open radiant type. This furnace. In this manner predominantly'radiant eliminates any dangerous and excessive superimt is mpart d o t fluid Conduits along e 35 posing of convection and radiant heat in the fluid roof and floor of the combustion zones with a conduits located within the combustion zones and minimum of superimposed convection heat. The permits better control of the heating conditions general direction of fiow'of the hot combustion in each of the three heating zones. The improved gases from firing tunnels l0 through combustion 40 form of furnace of the present invention elimizones 5 and 8 tofiuid heating zone 4 is indicated 40 nates expensive bridge wall construction, underby the arrows in the figure. The hot combusground flues and considerably decreases the tion a s m b th Combustion Zones commihheight of the main furnace structure. gle within and beneath fluid heating zone 4 and The features of the present invention and their pass upward therethrough to a suitable flue I2 advantages will be more apparent with reference leading to a stack, not shown. to the accompanying diagrammatic drawing and A fluid conduit l3 comprising, in the case illusthe following description thereof, the single figure trated, a sin l h ri o l row f horizon al y sof the drawing being a cross-sectional elevation posed tubes I4 is located adj the floor of of one specific form of furnace embodied by the combustion zone 5 and a similar fluid conduit 15,

present invention. also comprising, in the case illustrated, a single 50 Referring to the drawing, the main furnace horizontal row of horizontally disposed tubes l4, structure comprises end walls I and l, a roof 2, is located adjacent the floor of combustion zone 6. a floor 3 and side walls which do not appear in Another fluid conduit l6 comprising, in the case the particular view shown. A centrally located illustrated, a single horizontal row of horizontally fluid heating zone E extending-through the roof disposed tubes I4 is located adjacent the roof of 55 combustion zone 5 and a similar fluid conduit I! also comprising, in the case illustrated, a single horizontal row of horizontally disposed tubes I4 is located adjacent the rbof of combustion zone 6. Another fluid conduit l8 comprising a plurality of horizontally parallel rows of horizontally disposed tubes is located within fluid heating zone 4, Although not illustrated in the drawing, the tubes I4 of each of the banks l3, l5, l6, l1 and I8 extend across the entire width of the various heating zones and terminate in suitable headers or return bends, preferably located outside the heated zone. It will be understood that two or more rows of tubes may, when desired, be employed in any or all of the fluid conduits l3, I5,- I 6 and I1 although preferably when more than a single row is utilized the tubes are so spaced that the projected surface of each is exposed to direct radiation from the flames and hot combustion gases in combustion zones 5 and6. It is also within the scope of the invention, when desired, to eliminate the portions of fluid conduits I3 and l5 located beneath fluid heating zone 4 and indicated in the drawing at I3 and I5, respectively. Elimination of .these tubes will serve. to substantially increase the heat imparted to tube bank l8 and particularly the lower 2 or 3 rows of this bank.

As indicated by the arrows on the drawing, the oil or other fluid toibe heated enters the upper row of tubes in tube bank l8, flowing in series through adjacent tubes in the same row and through the adjacent rows of tubes in a general direction counter-current to the direction of flow of combustion gases through this zone of the furnace, emerging from the lower row of tubes in bank I 8 and entering the end tube of roof bank l1 adjacent tube bank l8, flowing in series through adjacent tubes in bank IT in a general direction counter-current to the direction of flring, emerging from the end tube of bank I! adjacent the end wall of the furnace and entering the last tube at the same end of floor bank l5, flowing in series through adjacent tubes in this bank in a general direction concurrent to the direction of firing, flowing then in series through adjacent tubes in rection countercurrent to the direction of firing, emerging from the end tube of bank l3 adjacent the other end wall of the furnace and entering the last tube at the same end of roof bank l6, flowing in series through adjacent tubes in this bank in a general direction concurrent to the direction of firing and being discharged from the end tube of bank I 6 adjacent bank I8 and from the furnace.

This general type of flow wherein the same stream of fluid passes through the fluid conduits -in one combustion zone of the furnace and then through the fluid conduits in the other combusthrough the end walls floor bank H in a general disuch as those containing a substantial proportion of materials within the boiling range of motor fuel, wherein itis desirable to first heat the distillate to the desired conversion temperature and then to maintain the stream of heated distillate at or near the maximum temperature previously attained for a predetermined time.

I claim as my invention:

1. In combination with a furnace having end walls, a roof and a floor, means forming a convection heating zone extending upwardly from a the central portion oi the furnace roof, heating tubes in said zone, .additional heating tubes in the end portions of the furnace proper on the opposite sides of said zone, means for firin the furnace above the floor in opposite directions substantially horizontally toward the central portion of the furnace, means for removing combustion gases from the convection heating zone, and means for passing fluid serially through the tubes in said zone and in the furnace proper on the opposite sides of said zone.

2. In combination with a furnace having end walls, a roof and a floor, means for firing the furnace through the end walls and above the floor in opposite, substantially horizontal directions toward the central portion of the furnace, means forming an outlet duct for combustion gases through the central portion of the furnace roof, heating tubes in said duct, additional heating tubes in the furnace proper on both sides of said duct, and disposed substantially at right angles to the direction of flring, and means for a passing fluid serially through the first-mentioned furnace floor, said roof tubes 'and additional tubes being disposed substantially at right angles to the direction of firing, and means for passing fluid serially through the first-mentioned tubes, the roof tubes and said additional tubes.

MARION w. BAnNns.

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