US2194500A - Art of heating hydrocarbons - Google Patents

Description

March 26, 1940.A

E. c. HERTHEI. gr AL ART 0F HEATING HYDROCARBONS Filed Feb. 4, 1935 3 Sheets-Sheet 1 X Ruf:

INVENTORS EUGENE C. HEFT/VEL f4/VBY THOIIJB. /f/MBALL Gm) S11/m44) cf- ATTORNEYS March 26, 1940.

E. C. HERTHEL El' AL ART 0F HEATING HYDROCARBONS l Filed Feb. 4, 1955 3 Sheets-Sheet 2 INVENTORS EUGENE CAHg/PT//EL N0 7"//0/1146 BJf/MBAL'L ATTORNEYS March 25, 19.40- E. c. HERTHEL Er A1. 1 2,194,500

RT 0F HEATING HYDROCARBONS Filed Feb. 4. 1935 5 Sheets-Sheet 3 INVENTORS EUGENE C, HE/ Tlv/El. QA/0 T40/m45 5. 7MB/ML BY QW, m, mm M ATTORN EYS Patented Mar. 26, 1940 ART 0F HEATING HYDROCARBONS Eugene C. Herthel, Flossmoor, Ill., and Thomas B, Kimball, Hammond, Ind., assignors to Sinclair Refining Company, New York, N. Y., a corporation of Maine Application February 4, 1935, Serial No. 4,826

3 Claims.

This invention relates to improvements in oil heating furnaces. The invention provides an oil heating furnace combining several important advantages with respect to economy of construction, economy of operation, efficiency of operation, and ease and latitude of control. 'Ihis last mentioned featureof the improved oil heating furnace of this invention, ease and latitude of control, gives it special utility in the field of thermal cracking. It is, however, of general application in oil heating operations and has a similar special utility wherever ease and latitude of control are important.

The improved oil heating furnace of this invention comprises a chamber, rectangular in horizontal cross-section and substantially longer than wide, vertical heating tubes arranged in rows parallel to and spaced from the longer' walls and the longer horizontal axis of the chamber, these rows of heating tubes being spaced substantially further from the longer horizontal axis of the chamber than from the nearer of the walls of the chamber, a plurality of fuel burners opening into the chamber through a 'series of ports along the longer axis of the roof of the chamber and between the innermost of the rows of heating tubes and means for independently regulating each of these several burners, a stack iiue beneath the 'chamber and a port or a. series of ports conmeeting' the stack flue with the lower part of the chamber along the longer axis of the floor of the chamber and between the innermost of the rows of heating tubes. A heat radiating baille is, with advantage, arranged along the longer horizontal axis and in the lower part of' the chamber and between the innermost of the rows of heating tubes.

An oil heating furnace embodying the invention is illustrated in the accompanying drawings. In

` the accompanying drawings, an elevation in section of a furnace embodying the invention is shown in 1, a horizontal section of this furnace is. shown in Fig. 2 and a vertical section normal to that shown in Fig. l is shown in Fig. 3.

The chamber of the oil heating furnace illusytrated comprises two longer walls, l and 2, two shorter walls, 3 and 4, a roof 5 and a floor Two rows, 'l and t and 9 and il), of vertical heat ing tubes I l are arranged along each of the long er walls l and respectively. In the furnace illustrated, each of these rows of heating tubes is extended to a central point on the. shorter wall 3. Eight fuel burners l2 open into the chamber through a corresponding series of ports i3 along the longer axis of the roof 5. The letters a tol h are appended to the reference characters l2 and I3 separately to designate the several burners and the corresponding ports, respectively.

'Ihe burners l2 may be of any conventional type for burning gaseous, liquid or solid fue-1. .Each

of these burners is provided with independent means for regulation, such as the valves Illa, Mb, Ido, iid, etc., in the furnace illustrated A heat radiating baffle i5 is arranged on the oor of the chamber between the pairs of rows of heating tubes. A stack flue l5, co,mmunicating` with the interior of the chamber through a series of ports il, is arranged beneath the iioor 6. In thefurnace illustrated, the stack iiue it, spaced below the furnace chamber, is connected to the ports l'l by means of the throat i8. f f

The heating tubes l l may be connected to establish one, two or more paths of oil flow through the furnace. They may, for example, be connected to provide'two symmetrical paths of oil flow along each of the longer walls of the furnace chamber, but these paths of flow may take a variety of forms. For example, the heating tubes may be connected as shown in the upper half of the section constituting Fig. 2, two parallel streams of oil entering the furnace at one end and being discharged at the other,

or theymay be connected as shown in the lower half of the section. constituting Fig. 2, two parallel streams of oil entering the furnace at one.

end and being discharged at intermediate points after flowing to the other end and back, or they may be connected vas shown in the right hand part of the lower half of the section constituting Fig. 2, two parallel streams of oil entering the furnace at one end and being discharged at the same end after owing to the other end and,

back. Instead of providing two rows of heating tubes along each of thelonger walls, as in the furnace illustrated, one row or ,three or four vor more rows may be arranged along each of the longer walls of the furnace. Also, the tube spacing may be varied along the rows and, where two or more rows are arranged along leach, long wall of the furnace chamber, the tube spacing,

of the furnace above a port or ports along this axis communicating with the stack iiue, in accordance with the invention, the hot products of combustion generated by ope-ration of the several burners move downwardly through the furnace chamber in generally vertical paths making it possible to establish independent control of the conditions prevailing in a series of 'zones ing it possible to vary an established control with` out requiring, with respect to efficiency o-r capacity, rearrangement or reconstruction of the furnace. An individual furnace embodying this invention is thus characterized by extreme flexibility.

The vertical arrangement of the heating tubes in the oil heating furnace of the invention alfords the usual advantages of Vertical tubes in oil heating furnaces. Further, however, the vertical arrangement of the heating tubes in eifect divides the path or paths of oil flow through the furnace into a series of zones corresponding to the several zones of control in the furnace chamber. The establishment and maintenance of smooth oil temperature gradients along the path or paths of oil flow through the furnace is thus facilitated. The heating tubes are also thus relieved of the burden of local irregularities in rates of heat transfer through the tube walls. Uniformity in distribution of heat transfer as between the upper part and the lower part of the furnace chamber is promoted by provision of the heat radiating baiiie.

The following example of applications of the oil heating furnace of the invention will illustrate its utility. In reforming gasoline or gasolinecontaining stocks to produce gasoline of improved fanti-knock value, the stock may be mildly heated over the rst part of its travel through the furnace to avoid local overheating of the heating tubes particularly through the region of Vaporization of the stock, intensely heated over the vmiddle part of its travel to effect the reforming and mildly heated over the last part of its travel to control and limit the extent of the reaction. In cracking gas oil to produce gasoline, the stock may be intensely heated over the first part of its travel through the furnace to bring it to the cracking temperature as rapidly as possible and mildly heated over the last part of its travel, after reaching the cracking temperature, to accomplish maximum efficiency with maximum yield. In Viscosity breaking, the stock may be intensely heated, for maximum capacity, up to that point in its travel at which limiting metal temperatures are reached in the tubes and the heating may be controlled for the rest of its travel with respect to such limiting metal temperatures. All of these operationscan be carried out in a single furnace embodying this invention.

The ease and latitude of control, and the subdivision of this control, provided in the oil heating yfurnace of this invention materially assist in the development of maximum capacities in that it makes possible the maintenance of maximum rates, per unit of area of tube wall, of heat transfer, subject only to limitations involved in the processing to which the oil is being subjected, throughout the battery of heating tubes in the furnace without exceeding safe metal temperatures at any point in the battery and without requiring limitation of heat transfer rate in one part of the battery to avoid exceeding safe metal temperatures in another part of the battery. The ease and latitude of control provided in the oil heating furnace of this invention similarly assist in the development of maximum eiciencies.

We claim:l

1. An oil heating furnace comprising a chamber rectangular in horizontal crossfsection and substantially longer than wide, vertical heating tubes arranged in rows parallel to and spaced from the longer walls andthe longer horizontal axis ofsaid chambensaid rows being spaced substantially further from said axis than from the nearer of said walls, a plurality of fuel burners opening into said chamber through a series of lports along the longer axis of the roof of said chamber and between the innermost of said rows of heating tubes, means for independently regulating said several burners, a plurality of connections between adjacent ends of pairs of said heating tubes and cooperating with said heating tubes to form a heating coil extending along the longer horizontal axis of said chamber a distancesubstantially greater than the distance between adlonger walls and the longer horizontal axis of saidA chamber, said rows being spaced substantially further from said axis than from the nearer of said walls, a plurality of fuel burners opening into said chamber through a seriesof ports along the longer axis of the roof of said chamber and between the innermost of said rows of heating tubes, means for independently regulating said several burners, a plurality of connections between adiacent ends of pairs of said heating tubes and lcooperating With said heating tubes to form a heating coil extending along the longer horizontal axis of said chamber a distance substantially greater than the distance between adjacent burners, a stack flue beneath said chamber, means connecting said stack iiue and said chamber along the longer axis of the floor of said chamber and between the innermost of said rows of heating tubes, and a heat radiating baffle arranged. along the longer horizontal axis and in the lower part of said chamber and between the innermost of said rows of heating tubes.

3. An oil heating furnace comprising a chamber rectangular in horizontal cross-section and substantially longer than wide, vertical heating tubes arranged in rows parallel to and spaced Y,

from the longer walls and the longer horizontal axis of said chamber, said rows being spaced substantially further from said axis than from the nearer of said walls, a plurality of fuel burners opening into said chamber between the innermost of said rows of heating tubes through a `series of ports spaced along the longer axis of said chamber, means for independently regulating said several burners, a plurality of connections be-`

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