US2527410A - Heater for fluids - Google Patents

Description

Oct. 24, 1950 K. w. FLEISCHER HEATER FOR FLUIDS 3 Sheets-Sheet l Filed Sept. 7, 1944 axle WITNESS [.pfrrro/P/ver Oct. 24, 1950 K, w FLElsCHER 2,527,410

HEATER FOR FLUIDS Filed Sept. 7, 1944 3 Sheets-Sheet 2 ,ZZ-(ig. E.

@xfree/v? Oct. 24, 1950 K. w. LEnscHER HEATER FOR FLuIDs sheets-Sheet 3 Filed Sept. 7, 1944 mfr/V565 @Mama Patented Oct. 24, 1950 HEATER FOR FLUIDE nur: W. Fleischer, Philadelphia, 11s.,.mignoi to 1 Solas Corporation of America, Philadelphia, Pa., a corporation oi' Pennsylvania Application September 7, 1944, Serial No. 552,643

This invention relates to a heater for uids, and it is an object of the invention to provide an improvement for effecting positive control of the heating of fluids in one or more tube banks through which iiuid is circulated.

The above and other objects and advantages o! the invention will become apparent from the following description takenin commotion with the accompanying drawings forming a part of this specication, and of which: y i

Fig. l is a vertical cross sectional view more or less diagrammatically illustrating an embodiment of the invention;

Figs. 2 and 3 are fragmentary views, taken at lines 2-2 and 3-3 of Fig. l, respectively, to illustrate the invention more clearly; and

Fig. 4 is a vertical sectional View similar to Fig. 1 illustrating another embodiment of the invention.

Referring to Fig. l, the invention is shown applied to a heater lil having a floor Ii and side walls i2 and Id including vertical portions i5 and i6, sloping Wall portions ii and I3, and straight wall portions I3 and 2t which extend upwardly from the sloping wall portions. The

floor III and side walls I2 and It are formed of suitable refractory material disposed Within a framework or outer shell (not shown) which is supported on a foundation in any well known manner.

The oor II and side walls l2 and ill form a heating chamber 2i which is divided into two cells 22 and 23 by a refractory wall 2li which is centrally disposed between the side walls I2 and it and extends upwardly from the oor il a distance substantially equal to the height of the side wall portions l5 and i6.

A bank of fluid conduits is located in each of the cells 22 and 23 adjacent the side wall portions i5 and i6, respectively. The tube banks 25 and 26 comprise single rows of horizontally disposed conduits 2'l and 28, respectively, which are located one above the other and connected at their ends to providetwo elongated paths of flow for the fluids to be heated. f

Above the tube banks and 26 and in the space 23 between the sloping wall portions i1 and i8 are located two banks oi iiuid conduits 30 and BI, respectively. The tube banks 30 and 3l comprise horizontally disposed vconduits 32 and 33 which are connected at their ends to form two elongated paths of iiow for the uids to be heated.

In accordance with this invention, the side wall portions I5 and I6 are provided with spaced bafiies or shields 34 which extend or project in- 4 Claims. (Cl. 122-356) wardly from the inner surfaces of the side wall portions I5 and I6 toward the tube banks 25 and 26 to subdivide the cells 22 and 23 into a plurality oi heating zones 35 and 36, respectively; and heat producers or burners 31 are provided at the side wall portions I5and I6 for independently ring such heating zones.

The spaced baiiles or shields 34 are shown as horizontally disposed ridges extending alongside of and co-extensive with the lengths of the conduits 21 and 28. The apcesV 39 of the sloping sides ofthe ridges 34 are located closely adjacent to and midway between adjacent conduits 21 and 2 8 kin each of the tube banks 25 and 26. With this arrangement each heating zone 35 and 36 is intimately associated with a denite part or batch of tubes of the tube banks 25 and 26.

The burners 3l are distributed at the side wall portions I5 and I6 in any suitable manner, and, as shown most clearly in Fig. 2, may be arranged -in staggered relation so that a horizontally disposed row of burners is associated with each heating zone 35 and 36. Each burner is formed with a passage within which is disposed a burner tube or sleeve di As shown in Figs. 1 and 3, the outer ends of sleeves IH are connected by pipes 42 to horizontally disposed manifolds :i3 which in turn are connected to a larger vertically disposed manifold lili to which fuel is delivered through a conduit t5 from a suitable source of supply. A main control valve i6 is connected in conduit d5, and valves 4'( are provided to control the pressure and rate at which the fuel is supplied to the horizontal manifolds t3. The supply of the fuel for each burner 37 may be individually controlled by valves M8 connected in the pipes t2.

Although not to be limited thereto, the burners 3l may be of the kind described and illustrated in Hess Patent No. 2,215,079, granted September 17, i940 and assigned to the same assignee as this application. The burners 3l are fully described in the aforementioned Hess patent which may be considered .as being incorporated in this application, and, if desired, reference may be had thereto for a detailed description of the burner structure.

The burners 3l may be operated with a suitable fuel, such as a mixture of a gas and air, for example, which is supplied to each of the burners and subdivided into a plurality of gas streams by distributors or tips 49 xed to the inner ends of the sleeves 4I which terminate at cup-shaped spaces 50. Substantially complete combustion of the fuel is eiiected in the cupshaped spaces En, so that iiame impingement of the conduits 21 and 28 is avoided. The refractory wall surfaces of the cup-shaped spaces 50 are heated to incandescence and constitute high temperature zones or regions from which heat is radiated to the conduits 21 and 28. The heated products of combustion formed in the cupshaped spaces 50 heat to incandescence the inner surfaces of the wall portions I and I6 surrounding the cup-shaped spaces and also the sloping sides 40 of the baffles 34.

In the heater I0 shown and just described, one stream of fluid to be heated may enter the top part of tube bank 30 and pass from the bottom part thereof to the tube bank 25 for downward ilow to the latter. Similarly, another stream of fluid to be heated may enter the top part of tube bank 3I and pass from the bottom part thereof to the tube bank 26 for downward flow through the latter. Heat is radiated directly to one side of the tube banks 25 and 26 from the cup-shaped spaces 50, inner wall surfaces surrounding the cup-shaped spaces, and the sloping walls 40 of the baffles. Both sides of the central refractory wall 24 are heated to a highly radiant condition by heat radiated from the combustion gases, the cup-shaped spaces 50, inner Wall surfaces surrounding the cup-shaped spaces, and sloping walls 40; and reflected radiant heat is transmitted from the central wall 24 to the opposite sides of the tube banks 25 and 26.

The hot combustion gases formed in the cupshaped spaces 50 and discharged from the cells 22 and 23 pass over the conduits 32 and 33 and inner surfaces of the sloping wall portions I 1 and I8 to effect heating of the tube banks 30 and 3l before being discharged from the heater I0.

While a part of the heating of the tube banks 25 and 26 is effected by the hot combustion gases formed in the cup-shaped spaces 58 of the heating zones 22 and 23, these tube banks at one side are heated predominantly by heat radiated directly from the incandescent side wall portions I5 and I6, and at the other side by heat re-radiated from the unfired central wall 24, as described above. Hence, by regulating the rate of supply of fuel to the burners 31 and the heat output of the burners, it is possible to obtain positive control of the heating of the tube banks 25 and 26 throughout the entire path of fluid flow provided by the conduits 21 and 28.

In the embodiment shown in Fig. 1, for example, ve conduits 21 and 28 are associated with each heating zone 35 and 35, respectively. The apices 39 of the baffles 34 terminate midway between adjacent conduits 21 and 28 in each of the tube banks, so that the baflles 34 effectively shield the burners 31 between adjacent heating zones. By way of illustration and without limitation, the distance from the inner surfaces of the side Wall portions I5 and IB, that is, the outer extremities of the cup-shaped spaces 58, to the conduit centers may be about 14 inches when conduits 21 and 28 approximately four inches in diameter are employed; and the apices 39 may be midway between adjacent conduits in the tube banks 25 and 26 and approximately three inches .from the vertical planes of the conduit centers.

If desired, the extreme ends of the baiiles 34 may project even closer to the centers of the tube banks than shown in Fig, 1. In any event, the baffles 34 are associated with a definite number of conduits in each tube bank and the heating of each group of conduits 21 and 28 directly opposite one of the heating zones can be positively controlled by regulating the burners 31 provided to fire each such heating zone. Thus, as the fluid to be heated flows downwardly through the tube banks 25 and 28, for example, the desired heating of the fluids may be effected in the ilve uppermost conduits 21 and 28 by regulating the burners 31 in the top rows at the side wall portions I5 and I5. Similarly, as the fluid to be heated passes through successively lower heating zones 35 and 36, the heating of the conduits 21 and 28 associated with each successive heating zone can be positively and accurately controlled by proper adjustment of the burners 31 provided for firing each heating zone.

The heaterv III is extremely flexible in operation. This can best be illustrated by assuming that in a particular instance it is desired to cut out the lowermost or bottom rows of burners 31 in each of the side wall portions I5 and I6, and that it is necessary to effect the same heating of the upper parts of the tube banks 25 and 26 that is accomplished when the bottom or lowermost heating zones 35 and 36 are being operated. In such case it is a simple matter to increase the heating effect produced in the upper or ltop heating zones 35 and 36 by increasing the heat output of the burners 31 associated with such heating zones, thereby compensating for the reduction in heating resulting from the cutting out of the lowermost rows of burners 31.

It may also be desirable to provide a heater embodying the invention in which the central refractory wall 24 is omitted. Such a modification is shown in Fig. 4 in which parts similar to those illustrated in Fig. 1 are designated by the same reference numerals. In the heater Illa of Fig. 4, heat is radiated directly to one side of the tube banks 25 and 26 from the side Wall portions I5 and I8 adjacent to which the tube banks are located. Thus, heat is radiated to one side of the tube bank 25 from the side wall portion I 5 which includes heat radiated from the cup-shaped spaces 50, the inner surfaces of the side wall portion I5 surrounding the cup-shaped spaces, and the sloping sides 48 of the baflies 34. Similarly, heat is radiated directly to one side of the tube bank 26 from the inner surfaces of the side wall portion I6.

Heat is also radiated to the opposite sides of the tube banks 25 and 26 from the inner surfaces of the side wall portions I6 and I5, respectively. Thus, the side of the tube bank 25 facing the side wall portion I6 is heated by heat radiated from such side wall portion, and the side of the tube bank 26 facing the side wall portion I5 is heated by heat radiated from the latter. The same positive control of the heating of the tube banks is effected in Fig. 4 as in the embodiment first described, and, since themodication of Fig. 4 is generally the same as the embodiment of Fig. 1 with the central refractory wall 24 omitted, furither description will not needlessly be repeated ere.

In view of the foregoing, it will now be understood that an improved heater for fluids has been provided for obtaining positive heat control over an entire tube bank. While the heater of the invention may be employed for heating all kinds of fluids, it is especially useful for heating hydrocarbons to the high temperatures required for thermal or catalytic conversion. While specific paths of ilow for fluids to be heated have been described above, it is to be understood that the tube banks, as well as the conduits in the individual tube banks, may be connected in any desirable manner toprovide one or more paths of flow for fluid to be heated. Irrespective of the manner fluid flows through the tube banks, the flexibility of the heater of the invention and the positive heat control of all parts of each tube bank enables a wide variety of heating curves 'to be obtained depending upon the character of the uid undergoing heating.

The positive heat control described can be obtained when the iluid conduits are disposed vertically instead of horizontally, as shown and described herein. When the fluid conduits of a tube bank are vertical, the baflles or shields are disposed vertically at the inner surfaces of the heater walls. The refractory bales may be of any desired shape and formed of ceramic material or alloys capable of withstanding high temperatures.

Although several embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that modifications may be made without departing fromthe spirit and scope of the invention, as pointed out in the following claims.

What is claimed is: A

l. A heater for fluids comprising structure forming a radiant heating chamber comprising side walls including spaced vertical side wall portions and' wall portions sloping upwardly and inwardly from the side wall portions to form a space having an opening at the upper part thereof, banks of fluid conduits disposed in the chamber adjacent the vertical side wall portions, spaced bales extending parallel to the tube banks and for the full length thereof at the inner surfaces of the vertical side wall portions and projecting toward the tube banks, said 'baffles being arranged n such a way that the chamber is divided into a plurality of parallel heating zones, means for independently ring the heating zones comprising a row of radiant burners distributed at the wall between each pair of bales, means to adjust simultaneously the burners of each row, and a bank of fluid conduits disposed in the space between the sloping wall portions.

2. A heater for fluids comprising structure ineluding spaced apart side walls forming a radiant heating chamber, a wall disposed between the side walls for dividing the chamber into a plurality of cells, a bank of horizontally extending uid conduits disposed in each cell adjacent to one of the side walls, spaced bailles at the' inner surfaces of the side walls projecting toward the tube bank and parallel thereto for the major portion of the length thereof, said baffles being arranged in such a way that vthe cells are divided into a plurality of parallel heating zones, means for independently ring the Zones comprising a row of radiant burners distributed at the sidewalls in each zone, and means by which all the burners in each row can be adjusted at one time.

3. A heater for -fluids comprising structure including a wall forming a radiant heating chamber, a bank of tubes adjacent to the wall and through which uid is adapted to flow, means including a plurality of rows of radiant burners distributed at the wall for ring the chamber, high temperature refractory means extending parallel to the tubes and between the bank o tubes for the full length thereof and the wall to separate the rows of burners into groups from each of which radiant heat is transmitted substantially entirely to a particular batch of tubes in the tube bank, and means by which all of the burners in each group can be adjusted at one time to selectively control the heating of fluid flowing through each batch of tubes.

4. A heater for fluids comprising structure including a wall forming a radiant heating chamber, a bank of horizontally disposed fluid conduits in the chamber adjacent to the wall, spaced bales extending parallel to the tubes of the bank at the inner surface of the wall and projecting toward the tube bank for the full length thereof, said baflies bein-g arranged in such a way that the chamber is divided into a plurality of heating zones each of which is directly opposite a portion of the tube bank, means for independently ring each zone comprising a plurality of rows of burners distributed along the wall with a row between each pair of bailles for heating the wall and the baies to a highly radiant condition, and means by which all of the burners in each row can be adjusted at one time.

KURT WM. FLEISCHER.

REFERENCES CITED The following references are of record in the file ofA this patent:

UNITED STATES PATENTS Number Name Date 1,523,657 Mather Jan. 20, 1925 Y 1,875,549 Barker Sept. 6, 1932 2,081,927 Hassler et al Jun-e 11937 2,306,818 Lyster Dec. 29, 1942

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