US3292599A

US3292599A - Multichambered fired heater and tube wall construction

Info

Publication number: US3292599A
Application number: US418225A
Authority: US
Inventors: Merle A Zimmerman
Original assignee: WASTE HEAT ENGINEERING CORP
Current assignee: WASTE HEAT ENGINEERING CORP
Priority date: 1964-12-14
Filing date: 1964-12-14
Publication date: 1966-12-20
Anticipated expiration: 1983-12-20

Description

Dec. 20, 1966 M. A. ZIMMERMAN 3,292,599

MULTICHAMBERED FIRED HEATER AND TUBE WALL GONSTRUCTON Filed Dc. 14. 1964,

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United States Patent O 3,292,599 MULTICHAIVIBERED FIRED HEATER AND TUBE WALL CONSTRUCTION g g Merle A. Zimmerman, Shreveport, La., assignor vto Waste Heat Engineering Corp., a corporation of Texas Filed Dec. 14, 1964, Ser. No. 418,225 4 Claims. (Cl. 122-510) The present invention relates to a multichambered tired heater and to a tube wall construction therefor.

Various forms of lluid heaters have been heretofore proposed, such by way of example that as shown in United States Patent No. 2,396,200. The present invention may be considered an improvement of the tube arrangement and tube wall construction for heaters such as that illustrated in Letters Patent 2,396,200 as will be more fully described hereinafter.

In the heating of lluids such as hydrocarbon oils and the like, it is desirable to accomplish the heating of the fluids in a manner to avoid undesirable effects thereon. To accomplish this, it is desirable that the heating of the fluids be substantially uniform and not occur in local areas on the tubes through which the fluid is conducted which localized heating causes hot spots which may cause deleterious effects on thel fluid being heated.

Also, it is desirable to accomplish heating of the fluids while simultaneously avoiding flame impingement upon the tubes through which the iluid is flowing to reduce the possibility of forming hot spots, and to conduct the combustion or heating gases adjacent the tubes and through the heater in a manner to eflciently and properly accomplish the heating of the fluids.

An object of the present invention is to provide a multichambered tired heater in which several streams of iluid may be heated under controlled temperature conditions simultaneously and to heat the tubes from both sides in a manner to produce a very uniform heat transfer rate of greater intensity than that commonly allowable when the tubes are heated from one side only or from both sides. Such construction provides superior heating characteristics and at the same time permits a substantial savings in costs through the reduction in the number of tubes and the saving in heater construction costs.

Another object is to form a multichambered fired heater with rows of tubes which inhibit the passage of heating gases through the rows of tubes and thereby reduces the possibility of flame impingement directly on the tubes. i

Another object of the present invention is to provide a construction and arrangement of tubes in a heater to form a wall and thereby divide the heater into multichambers with burners therein to heat each side of the tubes uniformly.

Still another object of the invention is a tube wall construction to divide a heater into -a number of chambers, each chamber having a plurality of burners therein for heating the tubes, and the tubes being connected together to inhibit combustion gases passing between thetubes and thereby avoid llame impingement upon the tubes.

Another object of the present invention is to connect a plurality of tubes together to form a dividing wall in a fired heater in a manner to heat the tubes to produce a uniform heat transfer rate.

Other objects and advantages of the present invention will become more readily apparent from consideration of the following description and drawings wherein:

FIG. 1 is a schematic representation of a heater embodying the present invention; and

FIG. 2 is an enlarged sectional view showing one form of the tube wall of the present invention.

Attention is rst directed to FIG. 1 of the drawings wherein a structure is referred to generally by the numeral ICC 2. The structure 2 forms a suitable enclosure to accomplish the purposes of the present invention, such structure being formed of suitable refractory material such as fire brick or the like. The construction of the structure 2 is not critical to the present invention and any suitable well-known and standard practice of forming the structure 2 may be employed.

The structure 2, by reason of its closed end, bottom, top, and side walls, as will be described in greater detail, forms a space referred to generally by the numeral 3. It will be noted that a plurality of spaced rows of tubes illustrated at 4 are provided in the space 3 to divide the space 3 into separate chambers 5, 6, 7, 8 and 9. Of course, the tubes in each row are joined at their ends to form a continuous lluid conducting path in that row.

Burners 11 are mounted in each of the chambers 5, 6, 7, 8, and 9 as illustrated for heating the spaced rows 4 of tubes on each side thereof.

It can be appreciated that the rows of tubes 4 are formed by tubes 15 which are connected together, as will be described in greater detail hereinafter, to form continuous divider Walls between the chambers 5, 6, 7, 8, and 9, and the tubes 15 also serve to conduct lluid therethrough which fluid is heated by the burners 11 in the various chambers. Flues 5a, 6a, 7a, 8a and 9a are formed in the structure 2 which communicate with the chambers 5, 6, 7, 8 and 9, respectively, at their upper ends and also communicate with the common discharge 18 which is connected to the stack 19 for discharge of the combustion gases from the structure 2.

If desired, iluid conducting tubes may also be provided as illustrated at 20 adjacent the fines 5a, 6a, 7a, 8a and 9a so that as the combustion gases from the burners 3 are conducted to the ues 5a, 6a, 7a, 8a and 9a, heating of the tubes 20 and the uid flowing therethrough may be effected.

A convection tube section 19a is arranged below the stack 19 as illustrated in the drawings, FIG. 1 for heating of fluid therein by the stack gases. It can be appreciated that the convection tube section 19a, tubes 20 as well as the tubes 15 are mounted in the structure 2 so that fluid is conducted therethrough in a well-known manner for heating thereof. If desired, the convection section 19a, the tubes 20 and the tubes 15 may be connected in series, so that the fluid is first pre-heated in convection section 19a and tubes 20 and then conducted to tubes 15 for final heat. In some instances, convection section 19a may serve as a preheater for a iluid stream which is then conducted to tubes 20 for final heat. The spaced rows of tubes 4 may be also connected to receive and heat separate iluid streams. For example tube row 4a may be connected to receive one uid stream, tube rows 4b and 4c may be connected in series to receive a second uid stream, and tube row 4d may be connected to still a third fluid stream for heating thereof. In this event, the burners 11 in chambers 8 and 9 will lbe provided with suitable controls by means well known in the art to maintain the desired temperature in chambers 8 and 9 so as to heat the fluid in tube row 4a to the desired temperature. Similarly, the burners in chambers 5 and 6 heat tube wall 4d and the burners in chambers 6, 7 and 8 heat tube walls 4b and 4c.

Of course, any suitable number of chambers and tube rows may be provided, depending upon the size of the heater.

The structure 2 includes end and side walls and a bottom and top of any suitable construction well known. The combustion or heating draft -gases are generated by the burners 11 and then flow through the chambers to accomplish their heating function and are then discharged out the upper end of each chamber and into common discharge 18 to be discharged from the structure through their upper end 28 in any suitable manner such as by bolting or the like to the structure 2 at 29. They are then permitted to hang downwardly and a receptacle 30 formed by the

guide walls

32 and 33 receives an extension 30a.

formed on the lower end of the rows 4 so that the spaced rows 11 upon heating may extend downwardly towards the receptacle 30.

A form of the tube wall is shown in FIG. 2 of the drawings and is shown as including tubes 15 which are provided with ns 35 formed on each side thereof and connected vided with suitable refractory material 36 on their surfaces v between the tubes 15 as shown in FIG. 2 of the drawings to inhibit overheating of the tubes 15 at the point where the ns 35 are connected with the tubes.

It can be appreciated that the construction as well as the arrangement of the tube Wall 4 in the heater 2 substantially prevents communication or passage of heating gases from one chamber to the next in the structure such as described with regard to FIG. 1 of the drawings. Thus, the combustion or heating gases from the burners 11 are communicated upwardly in the chamber rather vthan around the tubes and .the flow of heating gases elected by the construction of the tube wall 4, as Well as its arrangement in the structure 2 in relation to the ilue of each respective chamber and the stack 19 tends to more evenly and properly distribute the draft gases adjacent the tubes 15 and thereby uniformly heat the tubes at a greater intensity than heretofore possible. Also, the continuous tube Wall 4 substantially, if not completely, eliminates passage of the heating gases between the tubes 15 in the tube wall from one chamber to the next and thereby pre-` vents the llame from the burner 11 from coming into diface for a process heater which is impervious to :the ow vof heating gases from one chamber to the next.

Under some circumstances, it may be desirable to provide an expansion joint which is formed in the dividerV wall 14 formed by the tubes 15 and their interconnecting ns 35, and this may be accomplished by forming a slot 40 in one or more of the tins 35 and securing a pin 41 in an adjacent overlapping fin. An enlarged end 42 mayA be formed on the pin 41 after it has been positioned in the slot 40 and the refractory material then formed to accommodate free longitudinal movement of the pin 41 relative to 4the slot 40, it being noted that the diameter of the pin 41 is less than the length of the slot 40 to accomodate relative movement therebetween. Upon expansion or extension of the wall 4 by reasonof heating, the overlapping fins 35 may move relative to each other and thereby accommodate extension of the tube wall 4 without rupturing or deforming the wall 4. The tube wall 4 is constructed so that the axes` of the tubes 15 are substantially in alignment, or substantially in a common plane.

Broadly, the present invention relates to a multichambered fired heater and to a tube wall construction therefor.

What is claimed is:

1. A tube wall partition for a multichambered tired heater comprising:

(a) a plurality of hollow tubes having their axes lying substantially in a common plane;

(b) unitary metallic tins extending outwardly from said tubes;

(c) means interconnecting adjacent tubes together by said tins to form a substantially vertical wall;

(d) refractory material secured on each side ofl said fins between said tubes to inhibit overheating of said tubes where joined with said lins;

(e) means for supporting the uppermost tube from inside of the heater;

(f) said fins between said tubes supporting and suspending said tubes below the uppermost tube.

2. The structure as set forth in claim 1 including an expansion joint formed by said ns to accommodate longitudinal expansion of the tube wall.

3. The structure as set forth in claim 2 wherein said expansion joint is formed by providing slot means in one of said ns, and pin means connected with an adjacent overlapping fin, said Ipin means tting in said slot means and having a diameter less than the length of said slot to accommodate longitudinal movement of said tube wall.

4. The structure as set forth in claim 1 including means with the lowermost tube and the heater to serve as a guide for the downward expansion of said tubes.

References Cited by the Examiner UNITED STATES PATENTS 1,836,603 12/1931 Ladd 122-235 2,108,397 2/ 1938 Watts --..Q 122-356 X 2,293,735 8/ 1942 Hardgrove 122-6 2,456,786 12/ 1948 Kniel et al. 122-356 3,160,144 12/ 1964 Daman 122-235 KENNETH W. SPRAGUE, Primary Examiner.

Claims

1. A TUBE WALL PARITITION FOR A MULTICHAMBERED FIRED HEATER COMPRISING: (A) A PLURALITY OF HOLLOW TUBES HAVING THEIR AXES LYING SUBSTANTIALLY IN A COMMON PLANE; (B) UNITARY METALLIC FINS EXTENDING OUTWARDLY FROM SAID TUBES; (C) MEANS INTERCONNECTING ADJACENT TUBES TOGETHER BY SAID FINS TO FORM A SUBSTANTIALLY VERTICAL WALL; (D) REFRACTORY MATERIAL SECURED ON EACH SIDE OF SAID FINS BETWEEN SAID TUBES TO INHIBIT OVERHEATING OF SAID TUBES WHERE JOINED WITH SAID FINS;