US1257519A - Steam-generator. - Google Patents

Description

J. F. OTIS.

STEAM GENERATOR.

.APPLICATION EILED FEB. 23. 1911.

. Patented. Feb. 26, 1918.

Jenn r. o'rrs, oroswnso, New Yoan.

STE-GENETOR.

nettare.

Specicaton of Letters Patent.

Application led February 231, 1917. Serial No. 150,492.

To all whom z't may concern.'

Be it known that l, JOHN F. Drie, a citizen of the United States, and resident of Oswego, New' York, haveinvented certain new and useful Improvements in Steam- Generators, of which the following is a specication.

This invention relates to certain improvements in steam generators; and the objects and nature of the invention will be readily understood by those skilled in the art in the light of the following explanation of the accompanying drawings illustrating what l now believe to be the preferred embodiment or mechanical expression of my invention from among other forms and constructions within the spirit and scope thereof.

, My invention is characterized, in whole or in part, by aseparator plate spanning the steam space within the shell of the generator and located the greatest possible distance from the water line consistent with the provision of the desired steam space between said plate and the top flue sheet, with the multiplicity of fire tubes extending through and approximately closely rlitting perforations in said plate, which erforations are reamed out beveled or ared to form approximately sharp edges around the tubes to separate water from the thin films of steam that follow the hot surfaces of the tubes in passing through the perforations, said plate bein otherwise imperforate lto prevent upwar passage of steam except past said edges and along said tube surfaces, said generator being further characterized by a steam and water tight 'joint between the edge portion of the plate and the shell of the generator to prevent upward passage of steam or water past the edge of the plate, said joint, in the embodiment illustrated, being formed by an angle` iron ring secured to and extendingaround the inner surface of the sliell to prevent passage of steam or water between the inner surface of the shell and the adjacentsurface of the ring, with the plate resting on the ring and tightly held thereto to form a tight joint therewith, the portion of the'ring below the plate forming a deflector to deflect Water thrown up along the surface of the shell, inwardly against the hot tube surfaces.

An object of the invention is to improve the construction of steam generators of com paratively small size wherein water is very rapidly evapora under high heat to mtain a maximum volume of superheated rarement 're-r. ac, mi.

steam, and to reduce the-discharge of saturated steam from the generator, to the minimum.

A further object of the invention isto provide certain improvements in separator plates in steam generators and the mounting therefor.

A further object of the invention is to provide steam generators of the fire tube type with' improvements relating -to the separator diaphragms employed in such generators in the production of dry steam.

The invention consists in certain novel features in construction and in combinations and arrangements as more fully and particularly set forthv and pointed out hereinafter.

ln the accompanying drawings Figure l, is a vertical section of a steam generator embodying my invention.

Fig. 2 is a detail vertical section on an enlarged scale. i

ln the embodiment illustrated, l show an upright shell l to the upper end of which is suitablysecured a top horizontal sheet 2. A bottom tube sheet 3 is arranged within the lower end of the shell, and is formed with an annular depending wall 4 coperating with the lower portion of the shell to form water leg 5 into which the feed water for the generator'is discharged in any suitable manner. 'lhe lowerl end of wall fl is bent outwardly to form an annular horizontal Harige 6 rigidly secured to the lower end of the boiler shell and forming the bottom wall of the water leg.

A eat number or multiplicity of comparatively small diameter approximately closely arranged straight fire tubes 7 open through and at their ends are secured in the tube sheets. These straight vertical tubes extend from the lower tube sheet upwardly through the water and steam space within the shell to the upper tube sheet, and open into a suitable combustion chamber 8 formed by a hood mounted on the upper end of the generator. At their lower ends, the tubes open into a combustion chamber inclosed by the unbroken annular water leg 5. The generator is shown mounted on a fire brick 'burner chamber 9 and its metal jacket. The

combustion chamber forms an upward continuation of this burner chamber.

The steam passes from the top 'of the u. spa wi te the shell, throat pipe ico y 10, in this instance opening into the steam phragm -13 spans the steam space within the generator shell, and this plate is located as close to the top tube sheet as possible and yet 'so as to leave the required steam space between said tube sheet and plate. In other words',-I have found it desirable to locate this plate as far as possible from the water level in the generator, to keep the plate the greatest possible distance above the water in the boiler consistent with other requirements as to the location of the plate. The plate is perforated for the passage of the fire tubes, and each perforation contracts, flares or bevels from its lower end to its upper end from the bottom surface of the sheet to the top surface thereof, to form an upper annular edge 14 surrounding the surface of the lire tube in the perforation. The number of perforations equal the number of fire tubes, and the smallest diameter of each perforation is such with respect to the exterior diameter of the tube therein, that the steam can pass through the plate only in thin films along the hot surfaces of the fire tubes. The edges 14, tend to separate water from the steam and the bevel of the perforations not only produce the sharp separating edges 14 that closely-fit the tubes, but also aid in guiding the tubes into the perforations during assembling of the tubes in the shell.-

The purpose of the plate is to reduce to the minimum possibility of water passing from the generator with the steam, to separate the largest possible percentage of water from the steam before the steam enters the space above the plate, and to prevent passage of water'to the space above the plate, the plate is hence imperforate (except for the perforations filled by th"e`l tubes), and

a liquid tight joint is formed between the plate and the inner surface of the shell.

In the particular example illustrated, the plate'is supported by an angle iron ring or annulus 15 riveted or otherwise secured to the shell and preferably calked at 15a to provide a liquid and steam tight joint between the inner surface of the shell and the adjacent surface of the ring. The lower depending portion 16 of the rin is preferably flared or beveled to form a de ector that will direct or force water driven up along the inner surface of the shell, inwardly therefrom against the hot tube surfaces.

The flat under face of the separator plate rests on the top face of this ring, and means are provided whereby au approximately steam and water tight joint is formed between the abutting surfaces of the plate and ring. For instance, in the' embodiment shown, tapered threaded pins or studs 18 are arranged over andibearing down on the top surface of the edge portion of the plate to drive the plate down on and hold the same tightly to the ring. These studs are radially arranged with respect to the plate and Shell and extend from the exterior of the shell inwardly through holes tapped therein. The arrangement is such that the studs 18 need not be driven or screwed inwardly to wedge the plate down on the ring, until after the parts of the generator have been assembled and secured, and particularly until after the fire tubes have been all assembled and secured with respect to the tube sheets and said plate. It would be exceedingly diiicult if not impossible, to secure the plate in fixed position in the shell (before the tubes are applied) with its perforations in absolutely accurate alinement with the corresponding perforations in the two tube sheets so that the tubes could be assembled and secured in the generator without bending or possibly damaging the same, this is particularly diiicult because of the many hundred (sometimes almost fourteen hundred) comparatively long and small dialneter tubes (sometimes thirty inch tubes of one half inch diameter are employed) employed in these generators.

In view of the difficulty encountered in assembling this vast number of small diameter usually thin-walled-copper tubes in the Shell, the Separator plate is preferably of an exterior diameter less than the interior diameter of that portion of the shell just above the angle iron ring 15. For instance, where said interior diameter of the shell is somewhere near forty inches I usually employ a separator plate of a diameter of about thirty nine inches. This separator plate rests loosely on the angle iron ring after the heads or flue sheets have been fixed to the shell and before the tubes have been assembled therein.

In assemblin the end heads or iue sheets and the shell it 1s exceedingly difficult, if not impossible, to get the perforations in the two Sheets in accurate alinement with the corresponding perforations in the separator plate and to so rivet said two sheets to the shell as to attain accurate parallelism of the two sheets and the separator plate. I overcome this diiiiculty by providing the loosely arranged reduced diameter separator plate, as the plate can be slightly tilted, and shifted rotatively and horizontally by the tubes or by a suitable implement, while the tubes are bein inserted through the flue sheets and hea s preparatory to upsetting, Hanging or otherwise securing the tube ends to the flue usuaria' sheets. The separator plate can be, thus moved or shifted to permit the tubes to slip therethrough without damage to the tubes.-

After the tubes have all been properly located in the iu'e sheets and separator plate, the separator plate is forced down onto the angle iron to form a tight joint therewith, by screwing the threaded studs 18 inwardly through the threaded holes in the shell until said tapered studs tightly and rigidly bear down to the desired degree on the top surface of the plate. The outer ends or heads of the studs can then be -cut od and the outer ends thereof riveted down as shown.

ll do not herein make claim to the boiler shell formation and to the superheater, as such features are claimed in my patent applications filed April 11, 1914, Se. No. 831,137, and January 13, 1917, S. No. 142,215, respectively.

1t is evident that various changes and departures might be resorted to without departing from the spirit and scope of iny invention and hence l[ do not wish to limit myself to the exact disclosures hereof.

What ll claim is 1. A steam generator of the multiplicity of fire tube type, having a separator plate located in the steam space remote from the waterV level, said plate formed with perforations closely receiving the fire tubes, said perforations being flared to produce edges surrounding the tubes to separate water from the steam passing through the plate along the tubes. 2. A steam generator of the type substantially as described, having a lseparator plate formed with perforations receiving 'the lire tubes, said perforations being flared downwardly to form separator edges around the tubes, the plate being formed to prevent passage of steam and water except past said edges and along the surfaces of the tubes.

3. A steam generator of the type substantially as described, having a separator plate formed with fiarin perforations receiving the fire tubes and forming separator edges close to and around said tubes. .A

4t. A steam generator of the type substantially as described, havingxa separator plate perforated for the passage of the fire tubes, and a ring tightly secured to the generator shell and against the inner surface thereof against passage of steam or water between the ring and the shell, and means securing said plate down onr said ring. Y

5. A steam generator of the type substantially as described, having a separator plate perforated for the passage of the-fire tubes, and an angle iron ring supporting said plate and to which the same is held, said ring being tightly secured around the inner surface of the generator shell.

6. A steam generator of the type substantially as described, having a separator plate l .ma

perforated for the passage of the fire tubes, a ring supporting said plate, said ring being secured around the inner surface of the generator shell, and means clamping the plate down on the ring, said means extending to the exterior of the shell.

7. A steam generator of the type substantially as'described, having a separator plate perforated for the passage of the fire tubes,

and a ring on which said plate restsand by which it is supported, said ring tightly fitting around the inner surface of the generator shell, the under portion of said ring forming a deflector to throw water inwardly below the plate and against the re tubes.

8. A steam generator of the type substantially as described, having a separator plate perforated for the passage of the fire tubes, means fixed to and within the generator shell and on which said plate rests, and devices operative from the exterior of the shell for tightly wedgingsaid plate down onto and against said means.

9. A steam generator of the type substantially as described, having a separator plate perforated for the passage of the fire tubes, a ring on which said plate rests and by which it is supported, said ring being secured around the inner surface of the generator shell, and tapered studs extending through said shell to the exterior thereof All and projectingover said plate and tightly A wedging the same down onto said ring.

10. A steam generator having a shell with end flue sheets, a separator plate between said sheets, a xed support within the shell on which said plate loosely rests during assembly, lire tubes passing through the sheets and plate, and means operative from the exterior of the shell for fixing the position of said plate down on said suppoigt after assembly, sald plate being tiltable and movable laterallyy and rotatively while the tubes are being assembled in the sheets and plate and prior to the adjustment of said means 'to operative position.

shell and on which the plate. is secured to form a tight joint completely around the edge portion thereof and between the same and the inner surface of the shell.

' 12. A steam generator comprising a shell, upper and lower tube sheets, vertical fire ltubes extending between said sheets, a separator plate spanning the upper end of the steam space within said shell and formed with perforations forming water-separating edges closely receiving sald tubes and formrit ing film-like passages between the edge Walls plate, and means to tightly clamp the plate of the perforations and hot surfaces of said to the support to provide a tight joint bei tubes for the upward passage of films of tween the plate and inner surface of the steam, said plate being otherwise imperfoshell, the diameter of said plate bein less 5 rate to force said upward How of films of than the internal diameter of the portion of steam alon the tube surfaces and through the shell adjacent to the edge of the plate. the plate or extractionl `of moisture from Signed, the steam, a support Within the shell for said JOHN F. OTIS.

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