US1132069A - Steam-superheater. - Google Patents

Description

i "M MW W. F. J. CASEY. STEAM SUPBRHEATER.

APPLICATION FILED' MAR. 21, 1913.

19132,@69. Patented Mar. 16,1915,

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M @WM x S/Mmwf 'UNTTEE STATES PATENT OEETCE,

WILLEM E. J'. CASEY, OF KINGSTON, ONTRO, CANADA, ASSGNOR T0 LOCOIVIOTTVE SUPERHEATEBL COMPANY, 0F NEW YORK, N. Y., A CORPORATION OF DELAWARE.

STEAM-SU'PEBHEATEE.

Specification of Letters Patent. Pmtjgmtgd Inlay 169 159150 application ined. mmh san-1era. serial no. 755,942.

To all whom. it may concern: Y

Be it known that ll, WILLIAM F. al. CASEY, of the city of Kingston, in the Province of Ontario and Dominion of Ganada, have invented certain new and useful llmprovements in Steam-Superheaters, of whichl the following is a full, clear, and exact description.

This invention relates to improvements in locomotive superheaters, and the main object of the invention is to provide a superheater of simplified and improved construction, having its tubes arranged in groups or 'units in such a way that any unit may be removed independently ot all other units and without disturbing the header, to which all units are connected.

A- further object isv to provide a superheater so arranged that the cost of manufacture and maintenance will be greatly reduced as compared with corresponding costs of superheaters at present in use.

A still' further object is to provide a superheater so arranged that the inertia of the tubes when the locomotive is stopped will not have any appreciable tendency to loosen the ioints between the tubes and header', and also will not have any bending edect on the tubes.

Another object is to provide a superheater which may be constructed of a minimum number of parts having a minimum of joints to leak, the tubes of which are straight and connected without any upsetting ot their ends.

Still vanother object is to provide a superheater which may be connected directly to the cylinders by very short pipes.

' Another object is to.` provide a superheater having the wet and superheated steam headers termed in a single casting and yet entirely isolated from one another.

The superheaters at present in general use present a number of disadvantages from the standpoints of manufacture, maintenance and repair. The tubes are more or less bent at their connection with the headers so that the inertia of the tubes operates through considerable leverage upon the joints, and thus tends to produce -leaks Being bent, the tubes themselves are constantly subject to stresses and in addition, the strain produced by the bending greatly weakens the tubes so that leaks'frequently develop. rThe tubes are generally upset at their ends for connection to the header, and this obviously increases the cost of manufacture still further. .Repairs are rendered dihcult as it is `frequently necessary to remove a large number of tubes of bent type in order to get out a damaged tube.

The present invention aims to overcome thesedisadvantages by providing wet and superheated steam headers in a single heavy casting. The superheater tubes are absolutely straight and connected to one another and to the headers by return bends, into which the tubes are screwed. The return bends connecting the tube units with the headers are clamped to the headers, the clamping bolts being arranged so slightly out of the center line of the tube that the inerita of the tubes operates practically as a straight thrust against the clamps, so that there is practically no tendency to loosen the ]oints. Each tube unit is arranged in a sing'le ire tube of the boiler, and the connections with the headers are arranged so that they` do not overlap one another, thus permitting the removal ot any one unit without disturbing the surrounding units.

ln the drawings which illustrate this invention: Figure l is a half front elevation of the superheater showing some ot the tube units removed, and a portion of the wet steam header' in section. Eig. 2 is a sectional view on the line 2-2, Eig. l, showing the superheater tubes in position. Eigl 3 is an enlarged sectional View on the line 3-3, Fig. l, and illustrates the connection between a tube unit and header. Referring more particularly to the drawings, 5 designates a boiler shell having front and back tube plates 6 and 7 respectively between which are supported a plurality ot ire tubes 8, and 9 designates the smoke box at the front end of the boiler, in which the superheater headers are mounted.

The wet steam header l0 and superlieater steam header 11 are tormedin a single casting having at the top a central neck 12, to which the steam supply pipe is connected, and at the bottom a pair of discharge. necks 13 located one at each side of the header so as to be connected directly to the engine cylinders by a minimum length oi pipe. The dry and superheated steam headers are suitably tapered to distribute and collect uniformly from all their vertical branches la and-15 respectively. These branches are vertically disposed between the upper wet stream header and the lower superheated steam header, and are separated from one another by vertical spaces 16 which register with the vertical rows of the lire tubes 8. Each of these vertically disposed branches 14'and 15 tapers from the header with which it communicates toward the opposite header, from which it is separated by a double slot inclosing an air space 17. It will thus be seen that the two headers are entirely isolated from one another even at the blind ends of their branches, so that there will be no loss of heat through the walls from the superheated steam header into the wet steam header. The area at the ends of these branches is so small that the air space 17 may in many cases be dispensed with, without appreciably reducing the efliciency of the superheater.

The tubes 18 are arranged in groups of four, eaclr group being termed a unit and occupying a single fire tube 8. Either the two upper or the two lower tubes of each unit are longer than the remaining two, and project slightly beyond the front surface of the header where they are screwed into return bends 19. The4 opposite arm of each of these return bends is ground to t an opening 2O of the vertical header pas` sage. These return bends are suitably inclined from the horizontal and are tightly clamped in pairs against the headers by clamps 21, mounted on studs 22 secured to the headers, suitable nuts 23 being provided for tightening the clamps. As will be seen from Fig. 1 of the drawings, the passages 14 and 15 of the dry and-superheated steam headers are alternately arranged, so that the return bends 19 of each unit which pro` ject in opposite directions will connect on one side with' a wet steam passage and o'n the opposite side with a superheated steam passage. The front ends of the remaining two tubes of each unit are connected together by horizontally disposed return bends 24C, which lie well back in the spaces 16 between the steam passages. The rear ends of the tubes of each unit are connected in pairs by vertically disposed return bends 25, which are preferably arranged one a short distance in front ofthe other to permit a free circulation of heat around each. These return bends 25 are each provided with lugs 26 engaging e inner surface of the fire tubes and holding the rear ends of the superheater tubes gainst rattling. The

.tubes are absolutely straight, as 'clearly shown by Fig. 2 of the drawing, and are preferably connected to the return bends 242 and 25 by screw threads.

The wet steam enters the superheater through the neck 12 and flows through the tapering header 10 to all the passages 14E in uniform volume. The taper of the passages distributes the steam uniformly to each tube unit. In each unit the steam flows rearwardly through the pipe designated a, around the bent 25x, forwardly through the tube around the bent 24:y rearwardly through the tube c, around the bent 252 and forwardly through the tube d discharging into the superheated steam passage 15 through which the steam flows into the header 11, and escapes to the engine cylinders through the nearest neck 13. It will thus be seen that the steam travels the length of the lire tubes four times, and thereby becomes thoroughly dried and superheated so as to have the desired increased eiiciency.

From the foregoing description, it will be readily seen that the entire superheater consists of a minimum number of parts arranged with the greatest simplicity, the tubes being perfectly straight and free from upsets. The connection between the tube units and headers is so short and so little out of the line of the tube axis that the inertia of the tubes when the locomotive is stopped acts practically as a longitudinal thrust on the studs 22, so that the joints are not loosened in any way. Any unit may be removed independently of all others by merely loosening the two clamps holding it to the headers. The tapering of the headers and passages provides an absolutely uniform distribution of steam to all tube units, and a similar uniform collection.

Having thus described my invention, what I claim is 1. In combination with a locomotive boiler provided with a plurality of flue tubes arranged in spaced vertical rows, saturated and superheated header branches alternately' and vertically disposed in front of the tube sheet in the spaces between said rows of flue tubes, openings in the front of said branches, and superheated elements in the smoke tubes said elements having ends formed as re verse bends and adapted to be detachably engaged with openings in adjacent' header branches.

2. In combination with a locomotive boiler provided with a plurality of Hue tubes arranged in spaced vertical rows, saturated and superheated header branches alternately and vertically disposed in front of the tube sheet in the spaces between said rows of flue tubes, openings -in the front of said branches, and superheater elements comprising straight tubes united by reverse bends in the smoke tubes said` elements being adapted to be detachably engaged with openings in adjacent header branches.

3. In combination with a locomotive boiler provided with a lurality of flue tubes arranged in spacedp vertical rows, saturated and superheated header branches alternately ibo and vertically disposed in front of the tube Licence sheet in the spaces between said rows of flue tubes, openings in the front of said branches, superheater elements in the smoke tubes said elements having-'ends formed as reverse bends and adapted to be detachably engaged with openings in adjacent header branches and clamps for holding said reverse bends in position.

4:. In combination with a locomotive boiler provided with a plurality of flue tubes arranged in spaced vertical rows, an integral cast steam chamber comprising saturated and. superheated headers respectively Y above and below said rows and parallel to the tube sheet and having straight hollow branches between the headers and lying in the spaces between said rows of flue tubes, said branches opening alternately into the respective headers, said branches also having openings in their front walls, superheater elements in the smoke tubes said elements comprising straight tubes connected in series and having ends formed as reverse bends so as to detachably engage openings in adjacent branches, and clamps for holding said reverse bends in position.

5. In combination with a locomotive boiler provided with a plurality of flue tubes arranged in spaced vertical rows, saturated and superheated header branches alternately yand vertically disposed in front of the tube sheet in the spaces between said rows of flue tubes, superheated elements in the Hue tubes said tubes comprising a pair of" straight tubes projecting between the branches to substantially the rontwalls thereof, a-l reverse bend on each straight end the open end of said bend being spherically ground to t a correspondingly ground opening in the adjacent branch,and a clamp for holdl spaced vertical rows the spaces being substantially vnarrower than the tubes, and asuperheater comprising saturated and superheated header branches alternately and vertically disposed in front of the tube sheet in the spaces between said rows of flue tubes, and` superheater elements in the flue tubes said elements being adapted tovpass in and out between the header branches and ending in front of said branches in reverse bends which respectively detachably engage openings in the front wallsof adjacent branches.

7. ln combination with a locomotive boiler provided with a plurality of Hue tubes arranged in spaced vertical rows, saturated and superheated header branchesalternately and vertically disposed in front ofthe tube sheet in the spaces between said rows of flue tubes, superheater elements in the line tubes each element comprising a air of straight tubes projecting between t e branches to substantially the front walls thereof, a reverse bend permanently fixed to each straight end and .having its open end spherically .ground to fit a correspondingly ground openingin the adjacent branch, and a clamp for simultaneously holding two reverse bends of dierent units in position against a header' branch.

ln witness whereof l have hereunto set my hand in the presence of two witnesses.

WlLLlill/i F. J. CASEY,

Witnesses: Y

- FREDERICK TnnNnw, Breen A.. Kamm.,

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