US904129A - Superheater for steam-boilers. - Google Patents

Description

A. W. HORSEY & H. H. VAUGHAN.

SUPBRHBATER F011 STEAM BoILERs. APPLIOATION H LBD` IEB. 7, 1 908.

904, 129. Patented Nov. 17, 1908.

s SHEETS-SHEET 1.

A. W. HORSEY & H. H. VAUGHAN.

SUPBRHEATER Pon STEAM BOILERS.

APPLICATION FILED FEB. '7. 1906.

904, 1 29. Patented Nov. 17, 1908.

s SHEETS-SHEET 2.

A. W. HORSEY & H. H. VAUGHAN.

SUPERHEATBR FOR STEAMk BOILERS.

K APPLICATION FILED FEB. 7, 1906.

904, 129. Patented Nov'. 17, 1908.

3 SHEETS-SHEET 3.

@2l/572222? 6 da v 7i, wwf/71 fg@ y STATES PATENT OEFIOE.

ARTHUR WILMOT HORSEY AND HENRY HOGUE VAUGHAN, OF MONTREAL, QUEBEC, CANADA, ASSIGNORS TO AMERICAN LOCOMOTIVE COMPANY, A CORPORATION 0F NEW YORK.

SUPERHEATER FOR STEAM-BOILERS.

Specification of Letters Patent.

Patented Nov. 17, 1908.

Application filed February 7, 1906. Serial No. 300,022.

To all whom it may concern:

Be it known that we, ARTHUR IV. HoRsEY, a subject of King Edward VII, and HENRY H. VAUGHAN, a citizen of the United States, both residents of Montreal, Canada, have invented a certain new, useful, and Improved Superheater for Stea1n-Boilers,otl which the following is a full, clear, and'exact description, such as vwill enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to superheaters for steam boilers and has particular reference to improvements upon superheaters for locomotlve boilers, thatv is, -such as have a plurality of re-tubes.

It is customary to use a portion of the heat from gases of combustion as they pass from the boiler to the stack for superheatinof the steam from the boiler. The saturated steam from the dr -pipe is conducted to the point of use, usua ly the engine steam chest or chests, through a passage-way of large supericial area, which is exposed to the hot gases from and in the ues of the boiler. This passage-Way constitutes the superheater, the steam therein absorbing heat from the gases and taking on a higher temperature.

Heretofore in locomotive practice, it has been customary to arrange a header in the smoke box, said header being a singlemember, divided by suitable walls or partitions into two or more compartments. In superheaters of this class, the saturated steam from the boiler is delivered into one compartment of the header and flows thence through tubes arranged in the front end of the boiler and thence back into another compartment of the header. While a certain degree of superheat is obtainable with this construction, such a superheater is not as economical or efficient as might be for 'the reason that the superheated steam upon returning to the header loses considerable of its heat through Contact with the walls which confine the saturated steam. The saturated steam being of lower temperature than the superheated steam keeps the common walls or partitions much lower in temperature than said superheated steam and therefore constantly extracts heat from said superheated steam, thereby lowering its temperaturc. Such headers, as now used, are generally made in sections. bolted together. Again, the superheatiug tubes are arranged behind the header or headers and are so connected to said header as to make it diiiicult to remove them unless one or more sections of said header are also removed. So constructed it is diiicult to ascertain which of the several su erheatin tubes is at fault when a leak is iscovere and furthermore, when detected the fault is dilzlicult to remedy. It is also necessary to remove the tubes of these superheaters in order to clean or renew the same from time to time. Another disadvantage lies in the fact that the present superheaters are not properly supported in the front end and iiues of the boiler and for this reason are a source of both anno ance and danger. This fault is particular y noticeable at the return bends of the superheating lues, which, being free to vibrate, rattle against the containing iire tubes. Furthermore, the return bends ,which are now used for connecting the rear ends of the superheating tubes occup -so eat an area in the fire .tubes and are o such orm as to favor the accumulation of solid matter thereon, and cause the frequent clogging or stopping of the fire flues or tubes. I

The primary object of our invention is to improve th'e construction and the arrangement of superheaters in and upon fire-tube boilers and to increase the eiiiciency thereof.

Particular or special objects of the invention are: to provide a superheater which shall constitute a substantially direct passage between the dry-pipe and the steam feed or discharge pipe which supplies the engine to provide. a superheater which shall be of such formas to avoid the interchange of heat between the saturated and superheated steam through metallic contact, as is the case in the superheaters now in use ;-'to provide a superheater which shall otter the least possible obstruction to the passage of the steam; z'. c., one in which the steam passages shall be arranged to avoid the creation of contlicting or impinging streams -or currents ofsteanU-to provide a superheater which shall be especially adapted for installation in the front ends of locomotive boilers ;-to provide a superheater in which the parts or members shall be rigidly connected and held against vibration ;-to provide a superheater which may be easily dismembered, and from which one or more of superheating tubes may be removed without disturbing the others and practically without interrupting the operation of the.superheater;-to provide a superheater in which the greater number of parts shall be of uniform shape and size and consequently easy to repair or replace ,--to provide a superheater wherein the superheating tubes shall be connected with the headers in such manner that the connections shall be upon the front of the headers and easily accessible ,--to provide a snperheater that shall have a plurality of superheating tubes arranged in the re tubes of the boiler, but the construction of which shall, notwithstanding, besuch as to permit the fire tubes to be readily cleaned g-to provide a superheater of the type having a large number of superheating loops or tubes arranged in the boiler iiues and to equip said loops with bends or turns of a form adapted to prevent the accumulation of solid matter thereon, whereby the tireftubes shall be kept clear.

A further and particular object of the in- Vention is to provide means for protecting thesuperheater from the intense heat of the hot gases when steam is cut ofi' from the superheater; and further to provide means of this kind which shall automatically operate in response to the throttle to cut off or permit and indicate the low of gases through the boiler tubes which contain parts of the superheater, according as steam is cut off from Aor admitted to the superheater.

Still further objects of our invention will appear hereinafter.

Our invention consists generally in a steam superheater which comprises two distinct headers, for connection respectively with the boiler dry-pipe and the steam feed or supply pipe, in combination with a plurality of superheating tubes having respective ends connected with said headers, said tubes being arranged in the path of the hot gases between the boiler and the stack and, generally, within the tire-tubes of the boiler.

Our invention also consists in a superheater broadly characterized as above in which the headers are of comb-like structure, to present a plurality of parallel sub-headers, to whichsub-headers the ends of the superheating tubes may be conveniently connected.

Our invention also consists in the combination of a boiler and its front end with a superheater comprising a plurality of superheating tubes and headers whereto the tubes are connected, the whole being characterized by the arrangement of one ot' the headers at the top of the smoke box for ready connection with the boiler dry-pipe, and by the arrangement of the other header at a lower point.

Our invention also consists in various details of construction and combination of parts ;-all as hereinafter described and particularly pointed out in the claims.

Uur invention will be more readily under- @calas stood by reference to the accompanying drawings which form a part of the specification, and in which Figure l is a longitudinal vertical section of the front end of a locomotive boiler, illustrating a superheater embodying our invention; Fig. 2 is a section on the line 52X-X ot Fig. l; Fig. 3 is an enlarged section through one of the enlarged flucs or lire-tubes showing the superheating tubes therein, viewed in the direction of the tire-box; Figs. 4l; and 5 are detail views of one ot the ret-urn bends u'sed on each superheater tube, Fig. 4: being a horizontal section and F ig. 5 is a side elevation thereof; Fig. 6 is an enlarged detail illustrating the manner in which the forward ends of the superheating tubes are attached to the headers; Fig. 'T is a front elevation of the headers, slightly modied in design.

lVe have here shown our in-vention in the form in which we prefer to construct 4or embody it, and in whiclgiorm it is etiicient, durable` and most satisfactory to engineers.

rl`he superheater hereinshown is one of the several containing the gist of our invention all oi which may be constructed within the scope of the invention, this particular superhcater ditliering from the others in special features, details and characteristics which it it for use in and upon locomotive boilers.

As shown in the drawings, A represents a locomotive boiler, having a large number ot' fire tubes C extending between its flue sheets L. The upper part of the boiler contains a number of larger fire-tubes C to contain the steam pipes or tubes, ot' the super-heater. These occupy considerable space in the enlarged tire-tubes, and to make the free cross sectional area of the tire-tubes the same throughout, the rear ends ot' the tubes C are reduced in diameter at their rear ends near the tire-box flue sheet, as shown at points 1G. i

l represents the steam dome oi the boiler and E is the dry-steam pipe containing the throttle valve D and lea-ding from the dome to an expansion joint or coupling provided in the front tine sheet L ot the boiler. The boiler has the usual front end o1' smoke-box F having the stack H and an exhaust nozzle (i, above which latter are the pipes K.

@The saddle, the cylinders and steam chest are represented below the smokebox, and MMM represent the steam feed or supply pipes which connect with the live steam pasA sages in the saddle, and therethrough to the steam chests.

An apron or bathe-plate 2?v having a lop section 24 extends from the upper part of the flue sheet and downward to the top of the exhaust nozzle G, terminating in a supplementary apron 23 in front ot said nozzle. The usualv cinder or spark screen is reprepetticout arrange to divide-or close H the up er part of the compartment O back of the eflector or apron in order to shut off the fiow of gases through the upper tubes of the boller, and in this upper part O we arrange our superheater. v

Briey described our superheater comprises the saturated steam header 1, the body of which is located above the enlarged fire `tubes, C', of the boiler, the su erheated steam header 3, the body of which 1s located below the fire tubes, C', and a large number of small steam pipes 10. Each pipe 10 is in the form of a loop that extends back into one of the enlarged {ire-tubes of the boiler. In`

each case the forward ends of the steam pipe or loop 10 are connected with the headers 1 and 3 respectively. The steam which enters header 1 is distributed in the pipes 10, and after'being subjected to the heat within the fire-tubes returns to and is collected in the lower header 3, whence it is conveyed to the engine steam chests.

The header 1 is provided with a rearwardly extending pipe-section or neck 1 located centrally as shown in Fig. 2, and connected with the dry pipe E of the boiler. The ends of the header 3 are provided with forwardly extending bosses and flanges, and have openings which communicate with the j steam` feed pipes M-M of the two engines,

els

. the upper flanges of said pipes being bolted to the header 3 as shown in Figs. 1 and 2. Both headers are provided with wide bracket lugs extending approximately to the sides Aof the smoke-box and resting upon brackets 5 and 6 on said sides. The headers may be rigidly bolted to these brackets, but ordinarily their weight is sufliciently great to render such fastenings unnecessary, provided the several lugsv and brackets are formed to Yinterlock and thus prevent horizontal lateral movement of the headers. In addition to these fastenings for the header, it will be noted that they are made perfectly rigid by connection with the boiler flue sheet and the feed pipes M.

Furthermore, as will appear from inspection of the drawings, we prefer toplace the supporting lugs above7 the respective centers of gravity of the headers so that the headers will swing from the brackets 5 and 6, and maintain their positions when first loosely placed in the front end of the boiler.l

Y A first and most important object,towit, the complete separation of the saturated and superheated steam containers,-is attained in the structurethus far described, the headers being separate bodiesand free 'from contact throughout. The saturated or low temperature steam which enters the upper header can in no wise aHect or lower the temperature of the superheated steam in the other header. The headers are distinct structures, and the only heat communicationl between them is through the superheating tubes.

It is desirable that the su erheating tubes shall be of standard or uni orm dimensions.

We secure this advantage and at the same time adhere to the idea of forming the headers as separate bodies by providing the horizontal body of each header with a plurality ofperpendicular header branches 9. and 4 respectively. The header bodies are made to correspond with the desi n of the boiler and the layout of its fire tu es and the header branches occupy alternate positions between the vertical rows of boiler fire-tubes. In

these positions it is an easy matter to conv neet the ends of the superheating tubes to the header branches. The formation of the downwardly extending header branches on the u per header body, and the upwardly exten ing header branches or fingers on the lower header body gives the headers the appearance of two intermeshed combs, and the relatively wide spaces between the alternating header branches permit the superheating tubes to be freely inserted 'or withdrawn from the thus exposed boiler fire-tubes, after the headers have been secured in their places.

The ends of the header branches and the adjacent surfaces of the header bodies are` provided with interlocking points or lugs, serving to hold the headers in place while the tubes are being applied. The metallic contact between the lugs, and hence between the two headers, is of such slight extent that it is negligible as a factor in heat conduction; otherwise any such connection would be objectionable, for reasons before pointed out. Each header body, with its communieating header branches is preferably a single metal casting. The headers may be -readily manufactured in the forms shown and by so doing we avoid the packed joints that have proved so objectionable in other superheaters. In casting the headers, it is an easy matter to form the fronts and backs of the headerbranches on converging lines, as shown in Fig. l, and this is done in order that the cross sectional area thereof shall correspond to the areas of the pipe connections which at when the defiector plate 23 is removed. -We therefore provide the fronts of the header branches with a number of holes to recelve the ends of the pipes l0. Because ,ing in the clogging of the fire-tubes.

ofthe great number of these pipes vand be# cause it would be undesirablefto make so many holes in the header branches, we reduce the necessary number of openings by employing union connections 9 on the header branches. These connections, as shown in Fig. 2, are single, double 'or quadruple, according to position. A detail View of a quadruple union or connection is given in Fig. 6, from which it will be seen that the union 9 is is screwed mto the hole in the header branch. The connection bosses are at right angles to the neck, and the elbow formation is preserved in the forward end of the casting, presenting itself in an inwardly projecting portion 9 wherein the several curves are merged.

The ends of the superheatin loops 10 are provided with flanges 10 an are brought forward to the connections 9, lwhereto they are joined by union couplings 14. The pipes 10, the flanges 10, the unions 14 and the necks of the members 9 are of uniform size throughout and hence are interchangeable. The union connections 9 may also be of uniform size, but to avoid leaving a number of openings to be plugged, and tomaintaineA a uniform flow of steam through the pipes connectedwith the single, doub e and quadruple unions, we prefer to make them of di erent sizes and to proportion their internal dimensions to the number of super-l 'heating pipes connected to each. These different sizes are represented in the header openings at the right hand of Fig. 2.

We have hitherto spoken of the superheating pipes as though each were formed of a single-bent pipe or tube, but it will be understood that such form would be expensive and otherwise objectionable, and that each loop is made up of two pipe sections 10 having their rear ends joined by an elbow 17. The pipes are carried back in the fire-tubes C', and the elbows are located near the shouldered or reduced ends of said tubes. We prefer to place two loops in each lire-tube, and, as shown, their elbow castings lie one upon the other. These elbows or return bends 17 are of a novel form Sulliciently importent to require detailed cle-.V

scription. Considered strictly as elbows or return bends, they perform the ordinary function of connecting the pipes; but they are distinguished from other elbows by the pointing of their ends and other projections.

We have found that the return bends usuali employed in superheaters which present ffat or approximately flat surfaces to the gases moving through the fire-tubes cause or favor the accumulation of solids upon and against the elbows, not infrequently resurto avoid this difficulty, we provide each elbow with a sharp end or point 18 presented rovided with a neck or boss that toward the fire-box which is kept clean by the attrition of the gases'and moving solids.

The elbows 17 are provided with interf locking or engaging lugs 19 which serve to hold them apart, and the elbows are also provided with lugs 2O that serve to center the group of pipes in the fire-tubes. It should be noted that the lugs 19 and 20 of the ref turn bends 17 are pointed like the bend or elbow itself and for theame purpose.

The particular advantages of the construction' described are that contact between the superheating and fire-tubes is prevented, and the superheating tubes are held against objectionable vibration. The superheating tubes are rigidlyy held and are properly spaced at their forward endsand also at their rear ends, the re-tubes are easily accessible between the headers of the superheater, both the lire-tubes and the superheating pipes may be effectively and easily cleaned without dismembering or removing any parts of the superheater. The superheating tubes, by reason of their construction and positions, maybe quickl removed when need be, as for purposes o repair or renewal.

If it becomes necessary to remove one or more tubes when no others are at hand to replace them, the pipes are simply taken out and the union couplings plug ed, after which the superheater is ready for` rther use.

In referring to the adaptability of our'.

heate'r by means of al plate which will bev provided for such emergencies, after which the superheater will continue to supply steam to the op osite engine. A

A principal o jection to the use of superheaters, particularly upon locomotives, has been based upon their lack of durability. It has been` found that the small-superheating pipes burn out quickly an`d are much shorter lived than the other parts of the boiler. We find that this is due to the fact that the superheating pipes are subject t`o the high temperature throughout the time that the boiler is under fire. Now it is plain that when the throttle is open, the superheater, being filled with steam, is protected thereby, but when the steam is cut' olf, the pipes, being no longer cooled by the' steam, arey burned by the hot furnace gases. Asa a consequence, the pipes quickly give out and cannot be relied upon for any extended period. We obviate this diilicult -by providing means for shutting ofi' the ow of hot gases upon the superheater. when it is deprived of steam, said tive dry pipe.

means com rise a damper 22 arranged below the forwar end of the superheater; that is, between the flue-sheet ,and the superheater at a point below the lowest tier of superheating tubes. When this damper is closed, the upper compartment O of the smokebox is closed off from the remainder of the smokebox, and, obviously, the flow of hot ases through the upper tubes of the boiler 1s interrupted. In this manner the temperature within the enlarged fire tubes is much diminished, and the superheating pipes` are saved from a temperature that would be destructive. The lower header of the superheater, with its horizontal flange 25,.forms a partial'floor for the compartment O, and the damper 22 is arranged to close against the rear side of said header 3, thus completely shutting olf the exitof gases at that point. The damper 22 may be adapted for operation from the engine cab; that is, it may be operated from the throttle valve lever or by an independent lever; but we prefer to employ an automatic damper operating mechanism which shall respond directly to the action of the throttle valve without imposing any extra load upon the throttle lever. This mechanism comprises a small steam cylinder 30 and its piston, which latter has its rod connected with" an arm 3l that'is fixed on the end of the damper shaft 27. outside the smokebox.

The steam end of the cylinder 30, is supplied with steam through a pipe 30 leading from one of the steam chests or connected in any other suitable manner with the locomo- When the throttle valve is open, the steam admitted to the cylinder 30 will kforce out the piston and hold the damper 22 open, while when the pressure is relieved the piston will retire and permit the damper to be closed by a suitable spring, or by a weight 32 arranged on an arm extending from the shaft 27. This mechanism will operate properly as long as the shaft 27 and damper 22 remain intact; and the superheating pipeswill be automatically exposed to and protected from the furnace heat according as the throttle is opened or closed. It is obvious, however, that being in the direct line of the hotgases emerging from the boiler flues, the damper will ultimately burn out; and if this should occur durinfr the run of a locomotive, the engineer shoult bewarned. Tothis end we arrange a target on the other, (the engineers) slde of the locomotive, the target comprising an arm 84,-preferably'carrying a disk 35 and connected to the shaft'27. This has the normal function of informing the engineer of the position of the damper, the target being raised when the damper is opened and lowered when the damper is closed. (See dotted lines Fig. 1.) If the shaft 27 is burned away, it is obvious that the target will be disconnected from the' damper operating mechanism, and, falling, will assume an abnormal position and thereby attract the attention of the engineer.

le have herein described the specific structure which we consider to be best adapted for locomotives, but it will be understood that our invention is not confined or limited to this structure, which may be modified by any skilled person without departing from the spirit of our invention.

Having thus described our invention, we claim as new, and desire to secure by Letters Patent: v i

l. A superheater comprising a saturated steam header body located above a set of superheating fire tubes and having a plurality of header branches extending downwardly between the vertical rows of said fire tubes, a superheated steam header located below the set of superheating fire tubes and having a plurality of header branches extending upwardly and alternated in position with the saturated header branches, and a plurality of loops of superheating pipe connected at their ends to the saturated and superheated header branches respectively.

2. A superheater comprising a saturated and a superheated steam header body, each having a plurality lof header branches, the saturated and superheated steam header` branches being relatively alternated in position, and a plurality of loops of superheat-l ing pipes connecting a header branch to the two adjacent header branches. 3. In a steam boiler superheater, the combination of a plurality of vertical rows of loops of superheating pipe, a saturated and a superheated steam header body, each having a,.plurality of header branches which are alternated in position on the two header bodies and extend vertically between the rows of superheating pipe' loops, and connections between the superheating pipe loops on either side of the header branches, alternately with a saturated and a superheated header branch. 4. A superheater for locomotive boilers comprising two parallel header bodies provided with a plurality of relatively perpendicular parallel header branches spaced to correspond with the flues of a boiler, and a plurality of superheating pipes extending from the forward side of said header branches and backwardly between respective header branches,l substantiallyas described.

5. A superheater comprising a plurality of alternated saturated and superheated steam header branches, in combination with a plurality of superheating pipes arranged behind said header branches and having fianged ends andunions whereby they are connected to the fronts of said header branches, substantially as described.

6. A superheater comprising a plurality of parallel alternated saturated and superheatbodies and between vertical rows of tlues, so

as to aordaccess to the fines, and aplurality of superheating tubes extending in said tlues and having their ends connected to said header branches.

8. In a superheater for re tube boilers, a plurality of alternately disposed steam header branches, which are spaced apart to afford access to the lue's of the boiler, and a plurality of superheating pipes extending in said lues and having their ends connected to said header branches.

9. A superheater comprising a plurality of parallel saturated and superheated steam header branches in combination with a plurality of superheating loops comprising pipes, extending between said header branches and joined to the front walls of said header branches.

10. A steam boiler, in combination with a plurality of parallel saturated and superheated steam header branches spaced between and to correspond with the flues of a boiler, and a plurahty of superheating pipes each connected with two of said header branches, substantially as described.

11. A locomotive boiler containing a plurality of vertical rows of ues, in combination with superheating loops or pipes extending in said iues, and a plurality of saturated and superheated steam header branches connected with said superheating loops, there being one of said saturated steam header branches for each two vertical rows of lues,l

rality ofyertical rows vof Hues, in Combina tion with superheating loops or pipes arranged in said lues, and a plurality of saturated and .superheated steam header branches connected with said superheating loops, there being one saturated and one superheated steam header branch for each branches, located on opposite sides. of said rst speciied header branch, to which the opposite ends of said pipes are connected, substantially as described..

15. In a superheater for fire tube boilers, a plurality of alternated saturated and superheated steam ducts or headers, respectively, joined at their upper and lower ends and a plurality of superheating loops or pipes ex* tending in tire tubes of a boiler and having their ends connected with said headers; whereby steam entering the saturated steam passage is divided into minute streams of substantially equal length between the point of admission and the point of discharge, substantially as described.

16. In a superheater for fire tube boilers, a plurality of superheating loops extending in vertical rows of lire tubes, in combination with saturated and superheated steam header branches or passages, located in planes between the axes of the rows of fire tubes, and

supplying steam to and receiving steam from` the loops or pipes on their opposite sides, substantially as described.

17. In a steam boiler superheater, the combination of header branches located between vertical rows of tire tubes, and superheating loops or pipes extending in the re tubes and connected to the header branches, substantially as described.

18. In a steam boiler superheater, the combination of alternated saturated and superheated steam header branches, and superheating pipes or loops in rows of boiler tubes, the superheating pipes in the rows of boiler tubes on opposite sides of a header branch being connected thereto, substantially as herein described.

19. A superheater comprising a saturated steam header body, .in combination with a superheated steam header body, a plurality of header branches depending from the saturated steam header body, a plurality of header branches extending upward from the superheated steam header body, between the header branches of the saturated steam header body, and suitable superheating pipes or loops extending in lire tubes of a boiler and connected, at their opposite ends, to said saturated and superheated header branches, respectively, substantially as described.

20. A fire tube .boiler yhaving the usual smoke box, in combination with two separate groupsof steam header branches disposed in said smoke box, arallel with the front iue sheet, one thereo being connected with the dry pipe of the boiler and the other with the steam engine or engines, and a plurality of looped superheatin tubes havingtheir ends connected with said groups of steam header branches, and extendmg between the header branches of said roups and in the fire tubes of said boiler, sugstantially as described.

21., A superheater comprising saturated and superheated steam header branches, located forward of the front flue sheet of a locomotive boiler, in combination with a plurality of superheatin loops'or pipes connected to the forwar sides of said header branches and passing rearwardly between them, substantiall as described.

22. A boiler an its front end, in combination with a saturated steam header body supported in the upper part of said front end and connected with the boiler dry pipe, a superheated steam header body supported in the lower part of said front end, a plurality of superheating pipes extending in loops o'r pairs in fiues of the boiler and connecting said header bodies, and a steam feed pipe connected to the lower header body, substantially as described.

Inv testimony whereof, we have hereunto set our hands, this 10th day of January, 1906, in the presence of two subscribing witnesses.

ARTHUR WILMOT HORSEY. HENRY HOGUE VAUGHAN.

Witnesses:

FRED. J. SEARS, ARTHUR H. EVANS.

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