US2597423A

US2597423A - Steam generator

Info

Publication number: US2597423A
Application number: US65761A
Authority: US
Inventors: Woynar Basil
Original assignee: Combustion Engineering Superheater Inc
Current assignee: Combustion Engineering Inc
Priority date: 1948-12-17
Filing date: 1948-12-17
Publication date: 1952-05-20
Anticipated expiration: 1969-05-20
Also published as: DE950497C; FR987258A; GB664791A

Description

B. woYNAR 2,597,423

STEAM GENERATOR 5 Sheets-Sheet 2 l I( l l /l l 4 BHs/ Way/VHF INVENTOR.

May 20, 1952 Filed Dec. 17, 1948 May 20, 1952 B. woYNAR 2,597,423

STEAM GENERATOR Dec. 17, 5 Shee'l-:S-sheet 3 MMM BSL W0 Y/VHR INVENTOR.

May 20, 1952 B. woYNAR 2,597,423

STEAM GENERATOR Filed Deo. 17, 1948 5 Sheets-Sheet 4 I l l l l l a l l I BHs/.L warf/AR l l INVENToR.

mj viii c `WM May 20, 1952 B. woYNAR 2,597,423

STEAM GENERATOR Filed Dec. 17, 194s s sheets-sheet s BHS! L W0 Y/V? INVENTOR.

Patented May 20, i952 STEAM GENERATOR Basil Woynar, Chicago, Ill., assigner to Combustion Engineering-Superheater,

tion of Delaware Inc., a corpora- Application December 17, 1948, serial No. 65,161

The present invention relates to an improved steam generator of the forced circulation type which is of high capacity and compact construction.

The limited space allocated by builders of electric or diesel-electric locomotives for the mounting of steam generators to heat cars of a train and for other purposes makes it difficult to obtain access to the heat absorbing elements of such generators for inspection or repair and accordingly it is desirable to provide in the generator construction for the ready removal of such elements to permit their inspection and/or repair.

In accordance with the present invention com-p pactness of construction is obtained in part by utilizing forced circulation of water through the heat absorbing elements of the generator together with a novel arrangement of these elements which not only minimizes the space that they occupy but also facilitates the removal of a Worn element from the generator when required Without substantially disturbing other parts such as auxiliaries of the steam generator or of the diesel motor installation itself.

Although the tubular elements through which l water is circulated under pressure by the circulating pump afford some protection against the high temperatures at which combustion of fuel takes place, it is desirable to further protect the casing enclosing the generating elements against heat and flames to which it may be exposed in through spaces and interstices between the tubular elements.

2 Claims. (Cl. 122-250) How the above and other advantagesv are ath tained will be best understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

Figure 1 is a sectional elevational view of a steam generator constructed in accordance with the present invention.

Figure 2 is a sectional view of the steam gen- `erator 'as viewed in elevation on the accordingly designated section line in Figure 1.

Figure 3 is a partial sectional View on an enlarged scale taken on line 3-3 in Figure 4.

Figures 4 and 5 are plan views corresponding to Figure 1; Figure 4 being in section, some parts being omitted in each View for clarity of illustration.

Figure 6 is a side elevational view and Figure 7 a corresponding plan view of one of the radiantly heated steam generating coils; and Figure 8 is an elevational view and Figure 9 is a corresponding plan view of an exemplication of the convection heated coils of the steam generator.

Referring rst to Figure l, the steam generator has a U-shaped gas passage, one leg of which forms a furnace chamber l0 downwardly fired by fuel burner means Il. The furnaceV l0 communicates through its inner side wall at the lower end thereof with the adjacent convection passage l2 from the upper end of Which spent gases pass to a stack i3. The walls of the furnace chamber I0 are lined with radiantly heated steam generating surface comprising steam generating

coils

2i, 22 and 23 of rectangular configuration (Fig. 4) whose successive tube convolutions are superimposed in vertically spaced relation to form a generally spiral path for fluid flow. These three convection coils are connected to receive a supply of water from a horizontal generally U`- shaped supply tubular header 25 that extends along the three outer sides (Fig. 5) of the convection passage l2 at the top of therectangular shaped generator at the left hand end thereof. One end of the ntubular header 25 is closed olf or blind while the other end is connected by piping to the pump provided for the recirculation of water as will appear later. The three coils 2|, 22 and 23 are superimposed in the furnace chamber Hl and the various convolutions of each coil have fins' 24 that lill the spaces between the tube convolutions and provide substantially solid walls bounding the combustion chamber. The parts of the coil convolutions on the inner side of the combustion chamber I0 form a Wall dividing yit from the convection passage l2.

The uppermostcoil 2| receives water from the outer end of the leg 2B of the U-shaped header 25 through the coil lead 21 (Figs. 2, 4 and 5). The opposite end of this coil discharges steam and water through the outlet lead 28, at a position partway along the dividing wall between the furnace and convection passages l0, i2, into a steam and Water collecting header 30 which ex-y tends transversely across the top of the generator in a plane above and tothe right of the Water supply header 25 and in a horizontal position above and adjacent the dividing Wall between the furnace chamber l0 and the convection passage I2. The middle radiant coil 22 (Figs. 6 and 7 also) receives its supply of water from near the outer end of the other leg 3| of the U-shap'ed the wall between the convection passage and furnace chamber.

The lowermost radiant coil 23 is of special construction as is disclosed in the copending application of Joseph F. Grinn, filed November 12, 1948, under Serial No. 59,630, now abandoned. Alternate convolutions of this coil (Fig. 1) are extended so that they lie along the

side walls

34, 35 and the outer end wall 36 of the convection passage I2 near the bottom thereof, the tube portions along the side walls extending through a gas outlet 31 which places the lower end of furnace I in communication with the convection passage I2. The coil 23 is disposed so that its lowermost convolution 38 lies against the bottom or floor of the furnace and convection chambers to afford cooling protection to these regions. By extending parts of'the lower radiant coil 23 into the convection passage I2 protection is afforded to the lower Walls of the latter which in the operation of a generator having a U-shaped-gas passage are forcibly impinged upon by the stream of gases emerging from the furnace .I0 through the communicating outlet 31 tothen turn upwardly and flow through the convection passage I2 to the stack I3. By providing that alternate convolutions of the coil23 extend into the convection passage, the spaces 40between the

remaining convolutions

4I, 42 and 43 in the inner wall of furnace I0 leave slot-like spaces inv the inner side Vwall of the furnace chamber to form the outlet 31 through which the gases may flow into the convection passage. Inasmuch as those .portions of the convolutions of coil 23 that lie against the side and outer walls of the convection chamber are spaced apart Ybecause of the alternatelocation 0f these parts in the coil ns 39 parallel to the Walls are providedto .ll thesegaps and space the convolutions. yBecause .of such extension of the lowermost radiant coil 23 into the convection'passage I 2-it.is supplied from the water header 25 through a lead -44 (Figs. 4.and 5) located at the back outside .corner of the convection :passage and extending downwardly along the outer end wall in this corner. The steam and Water discharge lead 45 from the opposite end of .this coil extends upwardlyalong the opposite wall of the convection passage I2 in the other outer or front corner, the extreme end portion of the discharge lead46 of this coil being bent to extend inwardly at an angle and then across the top of the convection passage to'the steam collectingheader 30 which, as mentionedis located centrally along the top of the wall that divides the convection passage I2 and the furnace I0.

The steam generating surface in the convection passage I2` consists of several coil units 53, I, 52, 53 and 54, (Fig. 4) each made up of parallel `tube lengths serially interconnected for fluid flow by returnbends and having the componenttubes-disposed in spaced relation in several parallel rows orlayers solthat the tubes of each element are distributedamong severalparallel planes (three in this instance) vas will' be seen in Fig. 9,`which is a plan view of the coil 59 that is illustrated in elevation also in Fig. 8. Horizontal gas-deflecting baiiies 59 extend transversely part-wayvacross the convection .passage in alternation from-its inner -and'outer boundary walls so as to'cause the gases to flow tortuously through the passage Aand intimately contact theheatabsorbing 4surface afforded by the convection coils. Some of the tubes of ythe various c0ils'50 to 54 are disposed to lie against fhave the suix fs applied thereto.

and form a lining for the

outer walls

34, 35 and 36 of the convection passage and the spaces between adjacent tubes extending along the wall are closed by fins 55 on the tubes. For purposes of convenience the water inlet leads for these various coils are designated by adding the suffix "w to the coil numerals in Fig. 4 and the steam and water discharge ends of lthese coils The entire assembly of radiant and convection coils is received within a casing 64 which is made up of

metal walls

65 and 66 separated by insulation v61 with the metallic wall sheets welded together and to a bottom sheet 68 to form a gas-tight rectangular boxlike casing open at its top for receiving the generating coils.

Although the contiguous convolutions of radiant coils 2 I-23 have fins 24 which are in contact to form a substantially solid metallic wall around combustion chamber III and the parts of the convection coils 50-54 that lie against the outer walls 34, `35,36 of passage I2 have similar ns 55 which with thetubes constitute a continuous wall surface, the high rate of fuel combustion might cause gases to still leak between the fins andseep between the coils and walls of casing 64 or otherwise'be diverted from their normal path of flow between furnace I0 and stack I3.

A metallic plate-of heat resistant steel alloy bent to U-shape forms a shroud 60 surrounding the convection passage I2 and a similar shroud 6I surrounds the furnace chamber I0. Both are Welded at the distal ends of their U-legs to a metal baiile sheet 62 that extends downwardly between the furnace chamber 'I0 and convection passage I2 as far as the gas outlet 31.

As shown in Fig. 3 the upper end edge of shroud 60 is welded at 10 along its entire'U- shaped perimeter to the under side of thelower flange 1I of the channel-shaped rectangular dome structureIZ that extends around the entire upper end of the generator casing and is fastened to the latter by the bolts 13 that extend through the rectangular clamping channel 1.4 whose inner leg 15 clamps the flange 1I of the dome structure against the top of the casing. The shroud 6I for the furnace chamber coils 2l to 22 is likewise welded at 16 on its upper end edge all around its U-shaped perimeter to the un'der side of the flange 1I of the dome structure. The supply and collecting headers 2.5 .and 30 are carried by the dome structure whichthus supports both the radiant and convection .coils depending into the furnace I0 and convection passage I2 with the shrouds '60 and 6I extending to the oors of the furnace and convection passage. As statedI above, the distal ends of the two U-shaped shrouds 60 and 6I are welded to the baffle that extends between the furnace chamber and convection passage from the top of the generator to the gas outlet '31 of the furnace so that the furnace coils and those in the-convection passage are both boxed in by Vthe .U-shaped shrouds 60 and v6I and thelbafllelocated between the latter. y

The arrangement of the coils in thefurnace chamber andconvection passage andtheirconnection for water supply to the U-shaped' header 25 extending along the top of the generatoron the outer marginal edges of the convection passage and for steam and water discharge .to -the steam collecting header 30 that extends transversely across thegenerator substantially midway between the furnace I0 and convection passage I2, vpermits'theentire coil assembly depend- 82 passes from the distributing header 25 in parallel through three circuits comprising the coils 2| to 23 lining the furnace walls, all of which coils discharge into the collecting header 30. The supply header 25 also feeds the convection circuits comprising the ve coils 50 to 54, inclusive, whose tubes are disposed in the passage I2.

In the event it becomes necessary to remove any of the rsteam generating surface, breaking of l.

the various piping connections including that at 85 between collector header 30 and drum 8i) and removal of bolts 13 and clamp 14 permits the entire steam generating surface surrounded by shrouds 60, 6| to be lifted out of the casing with

headers

25, 30 and removed through a hatch 85 in the roof of the engine. The detachment of stack I3 and the burner assembly Il may not always prove desirable or necessary when removing the coils both in the furnace I0 and coni vection passage l2. If only a single coil requires replacing it may be detached after cutting its leads from connection with the supply and co1- lecting headers.

In both radiant and convection sections the shrouds 60, 6| provide additional protection for the inner lining of the generator casing. ASince they fit the tubesI snugly, these shrouds afford protection that would be lacking if the bare inner casing plates 6B which are located somewhat farl ther away from tubes were exposed to the sweeping action of gases leaking through the slots in the fins, which can be compared with the action of a torch, particularly in the radiant section of the generator. In the convection section, in ady dition to the above protection the shrouds guarantee the desired gas iiow and make it impossible for gases to 'bypass portions of the heating surface by following the path of the least resistance between the tubes and the casing, particularly at the back of the convection section.

What is claimed is:

1. In a steam generator having a vertical furnace fired from its top end by fuel burners and communicating through its inner Wall at its lower end with a contiguous convection passage; an upright casing enclosing said furnace and convection passage; a tubular water supply header bent into a U-shaped loop and disposed so as to extend along the marginal edges of one end of said casing at its top, said header being closed at one end and having a water supply connection communicating with the opposite end of said header; a collecting header mounted to extend transversely of said casing adjacent the distal ends of the legs of said U-shaped header; radiantly heated tubular steam generating elements connected at opposite ends thereof to said supply and collecting headers, respectively, and depending therefrom in superimposed spirally Wound convolutions to lie against the walls of said furnace with the portions at one side of each convolution disposed in contacting relation substantially beneath said collecting header to form a Wall dividing the interior of said casing to form said furnace and adjacent convection passage; and other tube coils depending vertically from said supply and collecting headers into said convection passage, whereby all of said steam generating surface depends from said headers and may be removed from the casing with the latter.

2. In a steam generator having a vertical furnace fired from its top end by fuel burners and communicating through an outlet in its inner wall at its lower end with a contiguous convection passage; an upright casing enclosing said furnace and convection chamber; a tubular water supply header bent into a U-shaped loop and disposed so as to extend along the marginal edges of one end of said casing at its top; a collecting header mounted to extend transversely of said casing adjacent the distal ends of the legs of said U-shaped supply header; radiantly heated tubular steam generating elements connected at opposite ends thereof to said supply and collecting headers respectively and depending therefrom in superimposed spirally Wound convolutions to lie against the Walls of said furnace with the portions at one side of each convolution disposed in contacting relation substantially beneath said collecting header to form a Wall dividing said furnace from said adjacent convection passage; other tube coils depending vertically from said supply and collecting headers into said convection passage; a frame extending around the perimeter of said casing at the top thereof and supporting said headers; a baffle ex tending across said casing adjacent said Wall from the outlet of said furnace to said frame and attached thereto along its upper edge; and a pair of vertically disposed substantially U-shaped shrouds extending closely around the outer sides of the groups of radiant and convection elements, respectively, from top to bottom of said casing and attached along the perimeters of their upper ends to said frame and along the distal ends of their U-leg portions to the baille lying between the furnace and convection passage.

' BASIL WOYNAR.

REFERENCES CITED The following references are of record in the y le of this patent:

UNITED STATES PATENTS Number Name Date 1,812,966 Lofer July 7, 1931 1,814,605 Mayr July 14, 1931 1,960,005 Gleichmann May 22, 1934 1,976,029 Laird Oct.'9, 1934 2,170,349 Bailey Aug. 22, 1939 FOREIGN PATENTS Number Country Date 23,213 Great Britain Oct. 21, 1907 662,966 Germany July 26, 1938