US1768169A - Superheating system for fire-tube boilers - Google Patents

Description

June 24, 1930.

P. THOMSEN SUPERHEATING SYSTEM FORFIRE TUBE BOILERS Filed Jari. 22, 1927 2 Sheets-Sheetl l duerma .une 24; 1930. P. THOMSEN 1,768,169

SUPERHEATING SYSTEM FOR FIRE TUBE BOILRS Filed Jan. 2T?, 1927 2 SheetS-Sheet 2 20 I 10 ZL 18 20 w," @MPb Patented June 24, 1930 'UNIT- rar :PETER THOMSEN, 'DECEASED, LATE OF CASSEL, GrERMiLNY,` BY REINOLD KRUM MACHER, ADMINISTRATOR, `OF CASSEL, GER-M'ANY, ASSGNOR TO SGHMDTSCI-IE 'HEISSDAMPF-GESELLSCHAFT MIT BESCHRNKTEE HAFTUNG, OF i CASSEL-NL- HELMSHOHE,GERMANY, ACORPORATION-OF GERMANY l VstimaRIYIEA'rINGsY'sTnivi non MRE-TUBE Bomans Application'ledJanuary 22, 1927,` Serial No. 162,873, and in Germany January 23, 1926.

This invention relatesV to a superheating systemffor fire-tubeboilers .andy-has for its object to provide 1 an efficient apparatus whereby the steam may be heated to higher temperatures than have; previously been practicable in commercial boilers'.V

The known type of superheater, wherein the steam is passed through U-loops disposed in the fire tubes of the boiler, is not effective to heat the steam above about 330 C., sinc.I the combustion gases, in traversing the fire tubes, transmit too much heat to the boiler water because of the large surface of the fire-tubes in contact with the water. If, on the other hand, a superheater of the so-called furnace flue type is used, in which all the superheater elements are located togetherin only one large lfire tube or chamber or in a few large fire tubes, a higher temperature may be attained. In this case, however, the boilers evaporating surface in contact with the water becomes too small and thefire gases are not utilized favourably enough.

The present invent-ion is designed to provide means whereby the steam may be superheated to 375 to 400 C. while doing away with these disadvantages. To this end, the vsuperheater -comprlsestwo stages, the first stage consisting of a lire-tube superheater7 the pipes of which are disposed in Va pluralvity of fire tubes of the boiler, the second stage consisting of a furnace flue superheater the pipes of which are located in vone or more comparatively large pipesor tubular chambers, the two stages being connected Vin f' series. In lthe first stage the steam is superheated to a certain degree and in the second stage the steam isi-raised to the desired high temperature. The second stage 1s preferably disposed in such a manner with'respect to the elementsand the header ofthe first stage superheater, that the pipes of the. respective stages may be mounted and taken outl without interfering with each other.

While the provisionof the second-stage superheater necessarily somewhat reduces the heat`-absorbing or evaporating surface of the boiler, yet the second stage of the superheater having a greater and more efhcient 50 rheating surface as compared with the lire Vposed between tubefirst stage superlieater, the whole arrangement is very efficient where it is desired to superheat steam to a high' temperature. I The invention is illustrated in the accompanying drawing as applied to a cylindrical marine boiler, but it may be used with other types of boilers. i

Fig. `1 is a view of the front end of a niarine boiler with parts'broken away, showing a preferred embodiment of the invention; Fig. 2 is a sectional viewtalren on 2,-42 of Fig.v l, and

Fig. 3 is a sectional view takeny on the line 3 3 of Fig. 1L f Y Themarine boiler shown in the drawing haslire tubes 6 and cylindrical chambers 7 extending the length of the boiler to permit the combustion gases to'pass from the vrear Oftheboiler to the smoke box 8 and through the air-preheater tubes 8f to the stack 9.

Steam pipe 10 conducts the steainfroin the boiler to a wet-steam chamber 11V at 'the' center of the smoke box. Leads 12feXtend laterally from chamber. 11 to U-loops 13, po-

sitioned in the fire tubes 6, and'leads 14 conduct theV steam from the U-loops back toV av `second steam chamber 15 the steam attaining a certain degree'ofsuperheat during its u passage ythrough loops 13 which constitute the first stage Vof the superheater. f From chamber 15 the steam is conducted by pipes 16 to the headers 17. ofthe second *Y stage. A number of parallel 'steam coils 18 extend from headers 17, into the chambers 7V and back to otherheaders 19,' whencethe Vsteam is conducted by pipes 2O `to theengiiies.l Connecting chambers 2l are` inter- 17 and 19.

Due to the comparatively large diameter of chambers 7, the gases-whicli-come in contact with coils 18 are hotter than those passing through the fire tubes 6; hence the steam in passing through the second stage is raised to ay much higherl .temperature thanjis reached in the first stage of the superheater.v i

superheaterfof the illustrated embodiment is arranged so.v that (at least in the lower The, lire tubesuperheater (the primary y the une steam coils 18 and-fV headers Y portion of the boiler) ineach horizontal row of fire tubes there are disposed four elements each located in three fire'tubes. In the upper portion of the boiler the arrangement is modified so that some of the elements are disposed in two ktire tubes only.

' The second-stage superheater (the secondary superheater) comprises .a number ofcoiled elements arranged in the ilues or chainbers .7 inparallel planes.` ln each plane preferably tivo (as shown? inthe drawings) or more coils are disposed the ends of which are Yconnected tothe ,connectingY chambers 21 removably secured to the headers 17 Vand 19.

rlhe chambers? preferably are arranged in tlieupper portion el the lire tube area o'l the boiler-and on that sideorn the boiler Where Vthe header of the lire tube (first stage) superheater is not situated. rllhus in the exampleV illustrated the tubes or 'chambers 7 are located each on one side of saidfire tube area of the boiler Whereasthe hea-ders VAil and 15 aredisposed in ytrent of the middleV portion of the boiler. Y'lfhus the elements of the dif?V ferent superheaterswill notinterfere with each other. 'i .Y i

v/*hat is claimedis v l. A superheater for a tire tube boiler, compi'ising besides the lire tubes a tube or chamber of large cross-section extending length- Wise of the boiler and adapted to conduct combustion gases, saidsuperheater comprising a first stage disposed iii the lire tubes ofl the boiler, andaseccnd stage disposed in said tube .or chamber and connected inseries With VVVsaid first stageY to receivesteam therefrom.

12. A superheater for a fire tubeboiler, com- Y prising a plurality et elements disposed in the lire tubes ci. the boiler-headers `lier. said elements, a cylindrical chamber' extending through 'the boiler yand adapted to conductcombustion gases, a plurality o elements dispesed in saidchamber and .connected iii series with said l'lirstlmentioned elements to receive steam therefrom, headers''or said second mentioned elements, said iirstmen tioned elements bein;ovv ada ited to be mounted and to be taken j s 7;. n y out Without interfering With said second mentioned elements.

Vclaim 2, in which the second mentioned ele- 3. A- superlieating system asv deined iii elements to receive steam therefrom,and a header for said second mentioned elements,`

said chamber being arranged on a sideof the boiler opposite to said first mentionedlr r i header. Y Y

5. A superheater for a re tube boiler, com.-

prising a chamber receiving Wet steam fromY the boiler,..a plurality Ainf heat exchange ele- .ments arranged `to conduct steam from said chamber throiigh'thetire tubes, yan enlarged chamber extending through the boiler and adapted to conduct combustionvgases, heat exchange elementsdisposed in said chamber and connectedin .series with said lfirst inentioned elements to receive v'steam therefrom, said first mentioned heat exchange elements and said second mentioned heat exchange elementsbeing adapte-d to be mountedY and .re. p

moved independently of each other. v

REINOLD KRUMMACHER,

' Administrator of Peter Thomsen, Deceased.

mentsconsist of Va series of coils disposed in 'A combustion gases, a plurality 'of element-s dis- Y posed in said chamber in parallel planes and 'connected Vin series With said first mentioned l Y y extend-ing vthrou the boiler and adapted to conduct

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