US1830505A - Tubular oil heater - Google Patents

Description

Nov. 3, 1931. A. CHRISTY TUBULAR OIL HEATER Filed Feb. 16.

1929 2 Sheets-Sha i j v 2 3 gwuemtoz All 6/2275? NOV. 3, 1931. c s 1,830,505

TUBULAR OIL HEATER Filed Feb. 16, 1929 2 Sheets-Shae! 2 gwvemto o flza/mszy W 1% WW.

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE ANKER L. CHRISTY, OF CHICAGO, ILLINOIS, ASSIGNOR TO GYRO PROCESS DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN comm, or

TUBULAR OIL HEATER Application filed February 16, 1929. Serial No. 340,556.

This invention relates to improvements in oil heaters and has to do particularly with heaters of the type employing tubes or pipes through which the oil under treatment is passed and subjected to the influence of elevated temperatures produced by passing heated gases through a furnace setting in which the tubes or pipes are stationarily p0- sitioned. The oil in passing through the pipes may be heated sufliciently to vaporize or partially vaporize the same or may be still further heated to effect molecular decomposition thereof.

In heaters of this type improved results have been secured by placing within the tubes longitudinally extending cores, which being of smaller diameter than the internal diameter of the tubes or pipes, serve to provide substantially annular passages between the adjoining walls of the cores and tubes through which the oil or oil vapor under heat treatment is passed. In this manner very efficient heat transfer between the walls of the tubes and the oil undergoing treatment is permitted, since the heat is imparted to the oil by contact with the latter with the heated surfaces of the tubes with which the oil comes into contact. If the cores were omitted there would be a tendency to overheat the oil which comes into contact with the tube surfaces and to detrimentally crack or overheat the same and yet not to secure sufficient heating of the inner body of oil passing through the tubes, particularly when the oil is in the dispersed phase, since a vaporous or gaseous body is a relatively poor conductor of heat. To avoid this condition, it has been proposed that such tubes shall be of small diameter but in practice this has been found to be objectionable for various mechanical reasons, since the plan involves the employment of a great number of tubes and difficulty is encountered in connecting serially the ends of the various tubes and also to effect the support of the tubes in the furnace setting so as to overcome the tendency thereof to sag or drop under the high internal temperatures of the furnace.

The present invention therefore provides a tubular heating element in which is removably positioned a plurality of longitudinally extending cores so located that a relatively thin annular passage is provided between the adjoining Walls of the cores and heating element through which the oil under treatment is passed, the tubular heating elementpurposes between the oil vapor and the heated surface of the tubular element, allowing a tubular element of satisfactory strength and durability to be utilized.

It is another object of the invention to arrange the cores within such tubular elements in axially offset or eccentric relationship to the true longitudinal aXisof said element. This is done in order that there will be a greater space forrthe flow of the oil vapors along that side of the tube which receives the greatest heat input. Of course, if the tube receives heat to an equal degree on all sides then the core is located in the true axis of the tube, but this is a rare condition in 'vide for efiicient contact for heat transfer furnace design, for the reason that the tubes ordinarily occupy what is known as a tube chamber through which the furnace gases sweep or flow in a single direction. Therefore, in order to obtain the maximum benefit and heat transfer it has been found that by placing the cores to one side of the true axes of the tubes improved heat transfer is secured between the furnace gases and the oil vapors under treatment in said tubes.

A further object resides in the provision of means for looking or positively retaining theQSbg;

cores in fixed positions within the tubes, 'preventing loss of position of the cores by rotation or from other causes.

With these and other objects in View which will appear as the description proceeds, the invention consists in the novel features of construction;combinations of elements and arrangements of described an claims.

parts hereinafter to be fully pointed out in the appended oil' converter or heater formed in accordance with the present invention, Figure 2 is an enlarged vertical sectional view taken through one of the tubes .of, the

heater and disclosing the same provided with the internal core formed in' accordance with the present invention,

'Figure3 is a vertical transverse sectional view taken on the line 3-3 of Figure 2, i

T Figure 4 is'adetail perspective view of one of the cores. 1

Figure 5 is anenlarged vertical sectional view taken through the inlet header,- Figure 6, is a side elevation of one of the leg-members for the core, i a

Figure '7 is-an enlarged vertical sectional view'taken through a tube having a core of a slightly modified form, a a

Figure 8 is an end elevation thereof, and Figure 9is an end elevation of one ofthe cores. r

H Referring moreparticularly to the drawings, the numeral 1 designates an oil heater 'or converter: formed in accordance-with the present invention. As usual, this heater comprises a setting 2 provided with aninternally; arranged bridge wall 3 which divides the' settin internally into burner and tube cham rs 4 and 5 respectively. Supported v by the walls of the setting 2 and the bridge wall 3, and'arra'nged within the tube cham-' ber 5, are rows or passes of longitudinally arranged tubes 6 through which the oil under treatment is circulated. The entrance row of I the tubes 6 also passes through the burner chamber 4 in order that the entrance portion of the first pass of tubes may besubjected directly to the intense radiant heat developed within the chamber. This first pass or row of tubes is indicated by the numeral 6*, and

its entranceportions are connected with a header 7 into which an'oil line 8 is led from other suitable apparatus. In the particular heaterunder consideration the oil flows into the header 7 in a vaporous state and-isthen distributed uniformly to each of the tubes I constituting the first pass 6. The entrance ends of the tubes in the pass 6 are provided with orifice'plugs 9. These plugs are formed with carefully diametered axial passages, so disposed that an equal volume i of oil will flow into each of the tubes constituting the pass 6. a

The oil or oil vapor after flowing through the pass 6' enters a second header 10 ar-- rangedatthe rear end of the setting 2, and

from'thi's latter header the oil vapor passes into the next lower row or bank of tubes 6",

and after traversing this bank of tubes theoil vapor enters a third header 11 arranged in the bridge wall 3, and then flows through the lower rows of tubes 6- and passes from these tubesto fractionating or other apparaing through said tubes, to temperaturesin excess of lOO0- F. I prefer to employ tubes wherein cracking reactions are permitted to tus not shown. "In lieu of headers 10. and 11 individual return bends maybe provided bebut may possess a diameter of app-roximately three inches and of materials which will stand furnace temperatures of from 1500 to 2000 F., particularly when the tubes are wherein the oil vapors are heated, while passof such relatively large diameter for the rea used in the construction of an oil converter son that they withstand furnace conditions to far better advantage than tubes of much smaller diameter[ However, inorder toprovide for efiicient heat transfer, due to the use stituting one or more of the passes 6, 6 and 6 are provided internally with longitudi-' nally aligned cores '12. In the present in-' stance these cores have been shown as posi-.

tioned in the top rows 6 and 6", the row 6 .Qf these relatively large tubes, the tubes con- 1 serving as a soaking zone through which the oil vapor flows *at reduced velocity and take place to perhaps a greater extent than in the previous passes. These cores produce substantially annular passages in the tubes inwhich they are situated for oil vapor travel. The vapor is most effectively heated by coming into contact with the heated surfaces of the inner tube wall. A gas-to-metal therefore the annular passage, which is desfer. If the cores were omitted the oil vapor contact produces goodheat interchange, and

passing through the center of the tube would not be apt to attain the same temperature. as that portion of the oil vapo'r contacting with the tube walls, and this condition has. re

sulted in the employment of unnecessarily high furnace temperatures. 7 This results, first in an unequal circulation offheat, sec- 0nd, in the overheating of that portion of the oilvapor which contacts directly with the; tube walls, causingvexcessive decomposition of that oil vapor and the production of excessive gas and, third, the underheatin of the body of oil which does not come into direct contact with'the heated surfaces of the tubes'.-

It is. knovvn that poor efficiency obtains in the matter of heat transfer between gaseous bodies as compared with heat-transfer between a gaseous body and a solid body.

Therefore, by the inclusion ofv the cores 12 within certain or all of the tubes 6, I 'amenabled toemploy tubes of standard mechanical design and'strength andyetobtain a a resoroe to' say, with the longitudinal axes of'said tubes offset with respect to corr espondingv axesof the tubes. This is' done'in order that passages 13 will possess their greatest area ,on that side of the tube which receives the greatest heat input. In practice,.the tubes arearranged in the tube chamber and it will be observed that the furnacegases travel downwardly through this chamber from'the I top or ceiling of the setting toward the bot- 4 tom thereof, where said gases find outlet from the setting through astac'k opening 14. Therefore,'in the chamber 5 the cores are p0- sitioned so that the vapor passages 13 have their portion ofgre'atest area. disposed toward. the tops of .said tubes and, conversely,v the portion of less area atthe bottoms of said tubes. The cores in the first passof tubes. 6, which are disposed in registrationwith the burner chamber 4 are located in substantial- .ly the reverse order to that described above, for the reason that the'greatest heat input is from the bottom of that portion of the'tube 6 which passes through. the chamber 4:. Each of the cores .12 consists of a suitable length oftubing which may be, for example, 12 'inches'in length and if the internal di'-. ameter of the tubular heating element should be 25-64 inches the outside-diameter of} the core section maybe 2.25 inches. This ratio in diameters provides for a vapor passage "13 of desired area. The core sections may be formed from the same materials as the tubular heating elements. To support the cores within the tubular heating elements, each of said core sections is provided, contiguous to its opposite ends, with annular grooves 15,

which receive split metallic rings 16. These rings conform substantially to the outside diameter of the core sections, said rings, however, are provided-with outwardly struck legs 17. which engage with the inner walls of the tubular heating elements 'to properly support the core sections" in their applied positions.

When the cores arearranged eccentrically within the tube sections it is desirableto pro vide means for positively retaining the'cores. in such eccentric positions to control efi'e'c tively the shape of the vapor passages 13.

This end is primarily obtainedby locking the core sections against rotation; A convenient method for accomplishing this consists in providing the end core sections with radiall movable prongs or pins 18 which are slidably mounted. in'radial openings l9formed in the cores. Each of these pins includes a beveled inner end as at 20, and engageable with the beveled end'of each pinis a set screw 21 hav- .ing 'a'conical end. .Thissetscrew is acces siblefrom the endof the tube, and it will be seen that byrotati'ng the samein afclock wise direction, the pin 18' may be forced outwardly and. radially to bite into the inner wall of the tube- This engagement is so positive as q to prevent rotation of the cores or lossof position thereof. The set screw construction described, however,is only provided in con- 'nection with the core sections located at theends of the tubes, and the remalning sections aligned c ore section, there being an opening 23 formed in the wall of said aligning core.

section to receivethe protruding end of .the

ffinger 22. This connection is carriedout inthe remalnlng core sections situated 1n the tubes.

Inthe modified form of construction dis- 'closedin Figures 7,8 and f the drawings, the core members 24 have Welded. thereto at it'sends short pin-sections 25 which serve as legs for the corejwhen the latter is positioned withinthe tubular/heatingeleinents. As the sity of pointing the radially movable for holding the cores in place.

In view of. the foregoing it will be seen that the present invention provides an im-' proved oil heater of the tubular type or socalled pipe still variety wherein eficient heat passing through the tubes and the internal heat developed within .the setting of the heater. This issecured mainly by the'provision of the removable cores which'provides si'multaneously for the employment of large diameter tubes and yet provides for efi'ective heat'transfer. The'core sections'may be re- 7 moved from the tubes to admit of their clean-v .pins or legs 25 are positioned longitudinally, of the core 24: it will be seen that they offer a broad bearing surface to the inside of the tubes and thus eliminate the useof and neces-i pins 18' transfer. takes place between the oilvapor ing from time to time and, furthermore, are 4 constructed for the purpose of-obtaining cient form and location.

, Vihat is claimed is: v

1. llnan .oil heater, a

be passed, a plurality of longitudinally alignedcore sections arranged in. said heat ing eleinent,-meansfor supporting said core sections in spaced relation from the inner .wall of the tubular heating element to define a substantially annular vapor passage, and y means for retaining'the core sections in fixed positions in connection-with the tubular heating element.

ment, a plurality of core sections arranged 2. In an oil heater, a tubularheating elei the inner walls of the latter toprovide a sub stantially" annular vapor passageway, spacing elements carried by each of said core sections' and arranged to engage with the inner' walls of the tubular heating element, and

- means co operative with said core sections for Y restraining the latter againstaxial rotation" within the heating-element.

3. In an o'l heater, a'tubular heating ele-- ment, a plurality of separable core: sections arranged longitudinally within said heating element, the outer walls of said core sections bein spaced from the inner walls of the heatmg 'eleme'nt, said core sections having the ends thereof provided with circular. grooves, and supporting rings positioned within said grooves and provided with radiating 'legportions, the latter being adapted to engage with the inner walls of the tubular heating element to effect the support of the .core sections therein.

4:- In an oil heater, 2:: tubularhcating ele ment, a core section positioned within said heatmg element, said core section consistingof a cylindrical metallic body of substantially uniform diameter throughout the length thereof, means'carried by said core section for supporting the'latter-within saidv ment, an eccentrically mounted pin projecting from one end of each of said core sections and arranged. to be received within openings formed in the complemental ends of registering sections, said pins serving to prevent relative axial rotation between said sections.

, 8. In an oil heater, a heating tube,la core" positioned in said tubeand. extending longitudinally thereof, the outer walls of the core being spaced fromthe' inner walls of-said t'ubeto provide a longitudinally extending annular passageway for high ve ocitytravel mg said core in spaced operative relationship with respect to the inner walls of the tube and providing for free unobstructednonturbulent. flow of the oil vapor through said of oil vapor, supporting means for'maintaim passageway, and means for positively re-- tainingsaid Icore within said tube and secure against axial and longitudinal displacement with respect thereto.

In testimony whereof I aflix my signature.-

ANKER Ii. CHRISTYI.

heating element in axial oflset' relationship 1 to the longitudinal axis of said heating ele-' ment, and'fric tional means forp'ositively locking sai 'tation within the heating element.

core section against axial roi 4 the heatin element and with the longitudinal axis 0? each core section ofiset with respect'to the correspondin axis of the heatingelement, and means or positively locking/ said core sections'in fixed positions within said heating'element.

6. A core section forjtubular' oil'heaters coin rising a cylindrical metallic body of substantially uniform diameter throughout .the length thereof, said section being pro;

vided with circular grooves at its opposite ends, resilient rings arranged to'be posi-j tioned 'within said grooves, said rings being provided with integral radially extending legs for effecting the support of said core s'ection, and a radially movable pin carried by one end of saidcore section. "7. In an oil heater, a tubular heating element, a plurality of longitudinally aligned core sections arranged within said heating element and disposed to one side of the heat- 3 'ing element,means for supporting said core sections so that their walls are spaced from the inner walls of the tubular heating ele-

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