US1992336A - Boiler tube cleaning apparatus - Google Patents

Description

Feb. 26, 1935. g, s. TURNER 1,992,336

BOILER TUBE CLEANING APPARATUS Filed Feb. 15, 1950 4 Sheets-Sheet 1 IN V EN TOR Feb. 26, 1935. c. s. TURNER BOILER TUBE CLEANING APPARATUS 4- Sheets-Sheet 2 Filed Feb. 15. 1950 INVENTOR.

BY a1 9 ATTORNEYS.

FIG. )2

Feb. 26, 1935. c. s. TURNER BOILER TUBE CLEANING APPARATUS Filed Feb. 15, 1930 4 Sheets-Sheet 3 I IN VEN TOR.

EB V 7Q].- TTORNES.

Feb. 26, 1935. c. s. TURNER BOILER CLEANING APPARATUS 4 Sheets-Sheet 4 Filed Feb. 15, 1930 FIG-.7

FIG- 8 INV'ENTOR.

*EQ #8,. -61 93F ATTOR YS.

Patented Feb. 26, 1935 'omrso srarss 1,992,336 BOILER, TUBE CLEANING APPARATUS Charles S. Turner, Detroit, Mich, assignor, by mesne assignments, to Diamond Power Speoialty Corporation, Detroit, Mich, a corporation of Michigan Application February 15, 1930, Serial No. 428,721 11 Claims. (01. 122+392) This invention relates to boiler tube cleaning apparatus, and has for its object'an improved organization of parts whereby the efiicient removal of soot accumulation onindividual boiler tubes'may be effected without interferences with the continued operation of the boiler to which the tubes are appurtenant. The mechanism herein disclosed permits the effectuation of this desired result without involving the impairment of the blower tube at intervals generally corresponding to the spacing of the boiler tubes which would otherwise occur if an entirely separate pipe were used for the latter purpose. One form in common use of which I am aware travels the space occupied by the tubes in a direction perpendicular to the axial extent of these latter, and consequently is subjected at intervals along its length to impairing variances of thermal conditions due to the alternated proximity or otherwise of specific points therealong to the boiler tubes themselves, which are capable of exerting a marked cooling influence by absorbing heat therefrom in considerable quantities, the boiler tubes being themselves cooled by the steam and water within them, while the blower tubesordinarily remain empty during the greater portion of the time in which the boiler is in operation.

It is an already ascertained fact in boiler work, that where tubes are used, and where there is a resultant marked variance between the thermal conditions prevailing within the tubes and in the space surrounding and separating them, for a space immediately surrounding the outer walls of each tube generally not in excess of an inch and a half therefrom, a great deal of the heat prevailing in the spaces between said tubes is absorbed or drawn into the metal of the latter because of the high heat conductivity thereof, but that as to any space much in excess of this temperatures increase rapidly, so that there will be spots or areas in the spaces between said tubes wherein an undesirably greater degree of heat prevails and cannot be conductively reduced as regards impairment of any metal parts positioned therein in whole or in part. In other words, if the spacing between the tubes be not in excess of three inches, this shortest distance between them will represent an area or zone, possibly somewhat overlapping if the spacing of the tubes be less than three inches, wherein there is a high degree of drawing away of heat by the walls of the tubes themselves aided by whatever fins or the like may be present: but interspersed with these spaces there will, even under these conditions, be spaces, to which reference will hereinafter 'be made diagrammatically, from which the heat is not efiiciently drawn away. Aside from the undesirability of being thus limited to a maximum space of three inches between all adjacent boiler tubes, and the relatively small size of anyblower'pipe which can accordingly be passed between them in a" direction axially transverse thereof, there will thus appear inthe metal wall of the blower tube at intervals alternated with the boiler-tube-aided portions of the pipe, spots or spaces where, due to the high heat conditions prevailing, rapid impairment or warping of the metal wall will take place.

Attempts havebeen made to obviate this difficulty by the selection of some special metallurgical element or'mixture for use in the construction of the blower tube pipe, which would render it of relatively high'resistant character to heat, but these efforts havebeen of a dubious degree of success, and I have approached the'solution of this problem from an entirely different angle, to wit: The fixed integration of the steam blower pipes with selected ones of the tubesand in generally longitudinal alignment therewith, so that the walls of the steam blower pipe portion participate inthe heat conduction or withdrawal influence already remarked upon as characteristic of the-walls of the boiler tubes them selves.

Various embodiments of this are herewith offered in the drawings, whereinf-- Figure 1 is a" perspective of an installation, wherein, for the sake of simplicity, but one set of the tubes whose cleansing is desired, is shown as extending between the headers or drums.

Figure 2 is a side elevational view of such an installation, showing a blower pipe and several tubes whose cleansing is desired, being in a more extended degree side elevationally representative of the showing in Figure 1.

Figure 3 isa partly sectional plan view taken along the line Y-Y of Figure 2, showing a plurality of such parallel-arranged blower tubes and boiler tubes.

Figures 4, 5 and 6 are cross sectional representations on a large scale of various'types of blower tubes and jets which may be employed in con junction with boiler tubes which are also shown.

Figure '7 is a largely sectional representation analogous to Fig. 2 of a somewhat modified system of boiler and blower tube assembly in which but a single blower pipe is secured to any one boiler tube.

Figure 8 is ,a' sectional representation showing a slightly modified manner of feeding the steam to the blower tubes,,wherein the supply header or conduit is located within the confines of the boiler drum, with branches radiating each way to suitably positioned blower tubes secured to all or selected ones of the boiler tubes, the blower tubes and jets therein being also of somewhat modified .form.

Figure 9 is a plan view taken along the line Z-Z of Figure 8, bringing out the extent of the blower tubes on either side of the boiler wall and of the supply conduit, and the arrangement of the blower tubes.

Figure 10 is a partly sectional and partly diagrammatic view illustrating the positioning of blower tubes in the manner herein .disclosed within the zone or space of probable most efiective heat absorption attributable to the walls of a boiler tube.

Figure 11 is an elevational view of ,a possible modified form of structural and thermal integration of the boiler ".tube and. of .the steam .bjlower pipe, wherein the latter, instead .of being arranged lengthwise of the blower pipe, is posietioned spirally thereabout.

. Figure 1215 .a sectional .view of another modified form of structurally integrated boiler tube and steam jet pipe, wherein the latter is :of completely circular cross section and only peripherally touches the boiler tube, though also partly encircled by a built-out extension from the wall thereof.

'12 represents the wall .or-shell enclosing a boiler element of any desired constructional details, and 13 a lower drum from which the several series of boiler tubes, as for example, 14 to 20, inclusive, or as many more ,or less as may be desired, lead to the upper drum or header 21. Positioned convenien-tly to the bank ,of boiler tubes, though externally oflthe lower chamber 13, and controlled bya suitable valve, as 22, is ,a steam supply pipe .23, from which lead various branch supplypipes as -40 connectedto blower tube passages 24 to 29 inclusive, secured and respectively appurtenant to the ,tubesrof the plain boiler tube series 14 to 20. In Figure 3 boiler :tubes thus equipped with integrated steamblower pipes are shown positioned only upon every alternate one of the series of boiler tubes, 14 to :20, inclusive, as upon the boiler tubes 15, 17 and 19, which alternated arrang ment is, undersomecircumstanees, adequate, the preferable form of steam jet nozzle there employed being :the doubly apertured type illustrated crossesectionally in Figure 10, wherein the jet apertures 43 and 44 direct their cleaning blasts ,on either .side of the straight row of plain boiler tubes with which their respective integrated boiler tubes 15, 1'7 and 19 are aligned. The lower passage tubes extend in general parallel relation to the several supporting and thermally integrated boiler tube elements, to the degree of beg E pp nded and so far as possible metallurgically integrated with the wall of the particular boiler tube on which it is severally carried, preferably, as shown in Figures 1, "2 and 8, on the side farthest from the source of heat, which is of course positioned generally below the tube banks. Whichever of the particular structural embodiments thereof, which are suggested in the several cross-sectional figures, are used, the more or less grafted-on steam, blower pipe portion of each, as 41, for example, in Figure 5, or 43 and 44 in Figure 4, is of such size that its outer peripheral point does not lie farther away from the boiler tube W311 than the approximate inch and one-half mentioned in an earlier paragraph hereof as the maximum distance away from such wall from which it can effectively draw away heat units. And of course the more nearly perfect the metallurgical union of the boiler tube wall and of the steam pipe wall, the greater is the degree of heat conduction which may reasonably .be expected to take place. The desired restriction of the radial extent of the steam blower pipe relatively to the boiler tube is brought .out in partly sectional and partly diagrammatic Figure 10, wherein the dotted circle V represents the outer border or edge of the one and one-half inch zone heretofore referred to, and the space between that and the dotted circle U represents -a zone so far removed from the boiler tube wall that the latter is incapable of participation to any effective degree in absorbing heat therefrom.

Carrying this illustrative comparison one degree further, I have indicated at 55 in Figure 3 a more or less diamond-shaped space bounded by four boiler tubes, which, even if the space between the latter be not in excess of a total of three inches, will still be left without efficient heat-removal, and will consequently have prevailing within it such a relatively high temperature that heat-impairment of a steam blower tube positioned within it wouldalmost inevitably take place, since such blower tubes, being empty during the greater part of the time during which the boiler is in operation, have not the cooling influence of contained steam or water, as have the boiler tubes. So long as efficient heat conduction is provided for between them, and the blower tubes are kept close to the boiler tubes,

in the manner described, the boiler tubes can assist in keeping the blower tubes at a safely low temperature by absorbing heat from them.

An alternative arrangement to that suggested in Figure ,3 is'shown in Figure 4:, wherein the blower jet openings 50 and 51 are so positioned to discharge on either side of their corresponding row of boiler tubes. If, however, it is desired to position the steam supply tubes in other than the direct alignment with their corresponding tubes shown in Figure 3, as for example, midway between adjacent rows thereof, either of the single jet forms of steam or other fluid spray shown at' ll, il with peripheral jet openings 48, 49 in Figures 5 and 6, may be employed. It will be noted that in all of the cross-sectional variances illustrated, for example, in Figures 4, 5, and 6 the blower tubes are not of truly circular cross section, but rather bound a more or less crescent-sectioned area, and are metallurgically integrated with the boiler tube wall, as by welding thereto the lateral edges of an, in itself, troughed or cross-sectionally semicircularmember, which may, as shown, have no wall on the boiler tubeside. The purpose of this is, of course, the restriction of the outer curved peripheral portion thereof when applied to the boiler tube to a position as close thereto as possible, so that heat conduction between them may be as rapid and efficient as is possible, which would not be the case to any such degree if a fullycircularsteam blower pipe were used. It will be obvious that, subject to the sup plying of a cleansing steam flow and its control by means of a valve as 22, cleansing jets ofv steam or other fluid, may be projected against the surfaces of-the several boiler tubes, without interference with the continued operation of the latter as component elements of the boiler structure as a whole. I I

My preferred positioning of the branch steam. supply pipes 40 in the embodiment in which they are arranged outsidethe'lower drum, so that theylie as close a'spossible to the boiler tubes, for. most effective heat'dissipation, isshown in plan in Figure 7, while as also therein shown the blower tubes are arranged in direct line with the several boiler tubes to which each is appurtenant, so that the blower tubes are protected against direct impingement by radiant heat and the most highly heated gases. 7

In the modified form of construction shown in Figures 8 and 9, I position the steam supply header 31 within the boiler drum or wall 32, and lead therefrom, indifferent directions, branch steam jet supply pipes 33 and 34 which,'with their supporting boiler tubes pass through, the wallof the drum 32 to direct connection with the'channels steam pipes adjacent to them in the series as arranged, but as well, their own supporting pipes 37 and 38.

In the modified construction shown in Figure 10, I have illustrated the structural and thermal integration of a boiler tube 46 and of a steam pipe 47 appendingly associated therewith in a spiral rather than a longitudinal direction, although my experience leads me to the opinion that this is a less satisfactory construction in an operative sense than the straight longitudinal construction shown in most of the other figures of drawing, as well as being more expensive to manufacture. I illustrate this in order to further elucidate the scope which I desire assigned to my disclosure of the idea of integrating a boiler tube and a steam supply pipe in some manner which will fixedly locate the steam supply pipe within the zone of thermal conductivity by the walls of the boiler tube in the manner and to the degree heretofore indicated.

Fig. 12 represents a modified construction in which the union betweenthe boiler and soot blower tubing, each individually complete and cylindrical, is preponderantly structural rather than metallurgical. In this figure the steam blower pipe 52, provided with jet apertures 53 at suitable intervals along its length, really only peripherally touches the boiler tube, as 24, but is surrounded by a heatconductive elongated clamp or similar attaching element 54 extending outwardly from the boiler tube wall, to which it may be welded, on either side of the lower tube. Through the member 54 effective heat-conduction takes place between the tubes 14"-52, though probably not with the de gree of efliciency expectable from the more thoroughly and intimately integrated structural associations of the steam pipe and the boiler tube wall in the embodiments previously described. I therefore desire my disclosure in the preceding paragraphs and the use of such language ascriptive thereof in the claims, to be considered as embodying the equivalency of the words structurally and metallurgically, accordingly. In any and all of these forms the same principle is followed as regards the restriction of the diametrical extent of the steam blower pipe away from the wall of its supporting boiler tube within the indicated limit of thermal conductivity by the latter of the higher temperature units to a degree which will prevent oxidation and resultant impairment of the walls of the blower and steam conductor pipes. While, as heretofore stated, approximately an inch and a half is the now understood standard maximum for this, I do not this zone of heat conduction materially aids and I increases the degree of absorption of theheat units by the boiler tube wall, in effect offering a line of easiesttravel therefor. v

. And while I- have, in my disclosure, generally used the word steam'as illustrative of the tubecle'aning element employed, I desire this to be considered as including any fiuid appropriate for the purpose, even'air, if desired.

What I claim is: 5 1.. In combination with. a plurality of spacedly arranged boiler tubes located in position of rela-' tively probable soot precipitation upon theirexternal surfaces, a blowerpipe integrally secured to the wallof one of said tubes and connected with an external fluid supply source, the passage Y formed by the blower pipe being separated from the passage formed by theboiler tube to' which the blower pipe is secured by a common wall, such blower pipe being provided with spaced jet openings through which the fluid may forcibly emerge against the surfaces of its several neighboring boiler tubes to effect the dislocation therefrom of deposited matter, the direction of such fluid emission being generally coincident with the direction of gas flow past the tubes.

2. In combination with a boiler and a plurality of boiler tubes therein having portions substantially spaced from the boiler walls, a soot blower installation including a blower passage member united with one of the boiler tubes, all portions of which blower passage member arranged within the hotter portions of the boiler lie within a radial distance of one and one half inches from the surface of the boiler tube.

3. In combination with a boiler and a plurality of boiler tubes therein having portions substantially spaced from the boiler walls, a soot blower installation including a blower passage member united with one of the boiler tubes, all those portions of which blower passage member which are in greatest need of protection against burning out being arranged to lie in an unbroken path. of heat conduction extending to the boiler tube and not longer than one and one half inches.

4. In combination with a boiler and a plurality of boiler tubes therein having portions substantially spaced from the boiler walls, said boiler tubes being spaced from each other in such a manner that the space between the outer surface of one tube and the outer surface of an adjacent tube does not exceed three inches, a soot blower installation including a blower passage member intimately metallioally united with one of the boiler tubes and extending radially from the outer surface of said tube toward an adjacent tube, all points of which'blower passage member which lie in its parts most liable to burning out being arranged in paths of direct and unbroken metallic heat conduction extending to the boiler tube and not longer than two inches.

5. In combination with a relatively isolated boiler tube of a steamboiler, a soot blower including a channel member extending along and welded to the leeward side of the boiler tube, all those portions of which channel member subjected to highest temperatures lie within a distance of one and one-half inches from the tube.

6. In combination with a relatively isolated boiler tube of a steam boiler and a second tube spaced therefrom a distance not exceeding three inches, a soot blower including a channel member welded to the first mentioned tube and extending toward the second mentioned tube, all portions of which channel member which are in greatest need of protection against burning out being arranged to lie within two inches of the tube. V V

7. In combination with a spaced boiler tube of .a steam boiler, a soot blower including a channeled member extending along the leeward side of the boiler tube and so integrated therewith as to provide an efficient and unbroken heat bridge between them, all portions of said channeled member which lie within the hotter portions of the boiler being lessthan one and onehalf inches from the boiler tube.

' 8. In combination, a boiler tube, and means providing a' blower element in juxtaposition to said boiler tube, said means being wholly within a .radial distance of one and one-half inches from the surface of said boiler tube.

9. In combination, a boiler tube, and means providing a blower elementin juxtaposition to said boiler tube and integrally secured thereto, said means being wholly within the relatively cool zone immediately surroundingsaid boiler tube.

10. In combination, a boiler tube, and means integrally secured to the side of the boiler tube most remote from the source of heat providing a blower element extending longitudinally of the boiler tube, said means being wholly within the relatively cool zone immediately surrounding said boiler tube. V

11. In combination with a relatively isolated boiler tube of a steam boiler, a soot blower including an arcuate shaped channel member extending along and having its longitudinal edges welded to the leeward side of the boiler tube, all those portions of which channel member subjected to highest temperatures lie within the relatively cool zone immediately surrounding the 20 boiler tube.

- CHARLES S. TURNER.

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