US1275080A - Steam-superheater. - Google Patents

Description

1. s. NICHOLS.

STEAM SUPERHEATER.

APP L|cAT|oN FILED MAY 8. 1915.

" Patented Aug.v 6, 1918.

3 SHEETS-SHEET l.

J. S.'NICHOLS.

STEAM SUPERHEATER.

APPLICATION'FILED MAY 8. 1915.

- Patented Aug. 6, 1918..

3 SHEETS-SHEET 2.

1,275,080. APPLICATION MAY s 1915. Patented Aug. 6 1918.

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UED sTATEs PATENT oEEifeE.

JAMES S. NICHOLS, 0F ATLANTA, GEORGIA.

s'TEAMsUPEnHEATER.

T o all whom t may concern Beit known that I, JAMES S. NICHOLS, a

citizen of the United States, residing at Atlanta, in the lcounty of Fulton and State of Georgia, have invented new and useful Improvements in Steam-Superheaters, of -which the following is a specification.

The present invention relates to im rovements in superheaters for steam boi ers in generaLand it is particularly applicable to steam locomotives.

The primary objects of the invention are to provide, an improved superheater which will not only realize the benefits and advantages derived from the superheaters as heretofore or at present used, but which will :obviate the disadvantages found to exist,

and which will operate with greater elticiency, a circulation of steam being maintained in the tubes of the superheater continuously, thus providing for a constant supply of superheated steam which is ready for immediate use, avoiding the development of excess of pressure of superheated steam or the waste of steam or water,` or overheating or burning out of the superheater; to rovide an improved valve construction an arrangement whereby control of the engine will be certain and positive andthe supply of superheated steam'to the engine for motive power and the supply of saturated steam thereto for starting, stoppin or lubricating from burning or other injury.

To these and other ends the invention con-l sists in certain improvements and combinations and arrangements of parts allas will be more fully described, the features of novelty being pointed out particularly in the claims at 'the end of the specification.l

In the accompanying drawing: l

'Figure 1 represents a central longitudinal section taken vertically through the forward portion of a steam boiler equipped with a superheater constructed in accordance with the pi'esent invention.

Fig. 2 is a top plan view of the controlling valve and its casing, the top of the casing being removed.

Fig. 3 represents a longitudinal section of one of the tubes of the boiler and oneof the superheater elements :fitted therein.

Specification of Letters Patent. Patented Aug, 6, 1918, Application filed May 8, 1915. Serial No. 26,873. l

Fig. 4 represents a section on the line 4 4. of Fig. 3. 1

Figs. 5 and 6 representtransversesections (n the lines 5-5 and 6-6, respectively, of

Fig. 7 represents a central vertical section through the controlling valve and its casing.

Figs. 8, 9 and l0 represent transverse sectail is especially adapted to fulil the condi-4 tions incident tothe installation of superlheaters on steam locomotives, although it is to' be understood that the invention is not confined to this particular. use nor to .the particular construction shown, as other uses and equivalent constructions are contemj.

plated.

In the present instance, Fig. 1 represents, for instance, a tubular steam boiler ofthe locomotive type, 1 designating the shell having a steam dome 2, a'ire box 3, a smokev box 4, forward and rear tube sheets 5 and 6, respectively, and tubes 7 extending through the water space of the boilerbetween the fire box and smoke box and connecting the forward and rear tube sheets, it being understood that in this type\,of boiler the heated gases or products'of cdmbiistion fioiv Alongitudinally through these tubes in passing from the rebox to the smoke box.

A suitable number of boiler tubes con- I tain superheater elements, Figs. 3'to 6, in-

clusive, showing one of these superheater.

doubles upon itself, extending forwardly to.

theforward .end of the superheater element lill yce

where it is formed with a return bend 1l. The tube or pipe is then extended rearwardly for substantially the length of the superheater element and is formed at the rear with a return bend l2, the tube or pipe then extending forwardly to a point in proximity to the return bend i@ near the middle of the superheater element, at which point it is Jformed with a return bend 13 `which is adjacent or opposite to the return bend l0. From the return bend 13 the pipe or tube extends rearwardly, where it is formed with return bend ift which lies directly above the return bend l2, and from the return bend lei the tube or pipe extends forwardly vto the outlet terminal 9. ln order to protect the return bends of the superheater element Jtrom the direct action of the llame or the highly heated gases, as well as the wearing effect et cinders, and to enable the superheater element to be extended to a Vpoint closer to the tire boa. than it has heretofore been deemed 'possible or expedient, a water jacket is provided tor the return bends l2 and lhis water iaclret as shown comprises tube l5 which preferably has a diameter about oneshal'l: the diameter of the boiler tube l and extends transversely `through the boiler tube, `the ends of the transverse or Water jacket tube l5 being fitted tightly in the walls of the boiler tube Z and providing a chamber or passageway tor the water in tbe boiler. The forward side of the transverse tube l5 is formed with indentations 15 in which rest the return bends l2 and la of the superheater element, the tube l5 performing the function of protecting the return bends of the superheater from the'direct action of the llames or highly-heated gases and from the cinders passing through the boiler flue, and the indentations in this transverse tube serve to support or hold the superheater in proper position, within. the tlue. Means is also provided 'for protecting the intermediate return bends l0 and 'i3 from the direct inluence of the flame or highly-heated gases and cinders. As shown, a block 17 is provided which has recesses 13 and 19 iormed in its frontq and rear sides into which the return bends l0 and 13 are tted. these return bends being thereby iuclosed and protected from the influences referred to above.

The superheater element ot the construction just described not only avoids the destructive induences referred to above, but it enables the superheater to be placed closer to the ire box and to be made in greater length than heretofore, and moreover, the number of return bends which it possesses insures 'greater efficiency in the breaking` up of the wet core in the saturated steam, ywith the result that the superheating action is more uniform and complete.

The inlet ends 8 of the superheater eleatacan ments communicate with thesaturated steamchamber or box 20, and the'outlet ends 9 of the superheater elements communicate with a superheated steam chamber or box 21. The present invention provides a novel valve construction and arrangement whereby the` superheated steam and the saturated steam are controlled, providing always for-a con- I tinuous circulation of steam through the superheater elements. In the embodiment of the invention shown, a valve casing22 is provided which is advantageously located in the closest proximity to the engine or cylinders of a locomotive in order to reduce to a minimum the length of the piping and consequently the volume of steam between the valve and the engine or cylinders and which is beyond the control of thevalve. In the' present instance, the valve is located in the smoke box 4 and at the forward side of the forward Hue sheet 5. The valve casing is suitably divided or partitioned to form the saturated steam chamber 20, the superheated steam chamber 2l, and the motlve steam chamber 23, this latter chamber having its outlet connected by the branch pipe 24 to the driving cylinders or engine. The valve casing is also formed with a valve housing 25, and in the present instancea single rotatable valve is fitted into the valve housing to control both the saturated steam and the superheated steam. A valve 26 of this type is shown in the form of a rotary plug which is slightly conical or tapered, it having an enlarged diameter at the bottom, and it is 10) formed with ports 27, 28 and 29 for the control of superheated steam and with ports 30 and 3l for the control of saturated ste-ani, these sets of ports being located in different planes longitudinally of the valve. The 105 valve housing 25 is formed with aportf'3-3 leading' from the superheated steam chamber 2l; the port 34 communicates with a pipe 35'which pipe leads tothe dome 2, and l the housing 25 is also formed with a port 36 110 which leads into the motive steam chamber 23. The ports 33, 34 and 36 are arranged to cooperate with the ports 27, 28and 29, respectively, ofthe valve. The valve housing is also formed in a diii'erent plane with 115 ports 37 and 38 to coperate with the ports 3G and 3l, respectively, the port 37 comn'nmicating with the saturated-steam chamber 2O and the port 38 with the motive steam chamber 23. The saturated steam chamber 120 2,0 is in communication with the steam dome 2 through a pipe 39 which leads from the upper portion of the steam dome to the saturated steam chamber 20. The present invention enables thejusual throttle valve in 15425l the steam dome to be dispensed with, a single valve serving as a throttle to control both saturated andV superheated steam.v To enable the valve 26 to be adjusted as desired to supply saturated or superheated steam to the asumo engine or driving cylinders,'it is provided with a stem 40 which preferably extends to the exterior of the boiler or smoke box and is provided with an arm or crank 41 which in turn may be connected by a rod 42 to a suitable lever or handle located in the cab of the locomotive at any point convenient fo` the engineer the exterior location of the ollerative connections for the valve avoiding delays and other objections found to exist with the arrangements of the operative connections of the ordinary type of valve, which connections have heretofore been located within the steam space of theboiler, and 4hence such connectioiswere inaccessible for inspection or repair and also required stuiiing boxes which are troublesome.

The operation of the boiler equipped with a superheater and controlling valve embodying the present invention may be briefly described as follows Under normal conditions with the'engine not in running operation or with the locomotive at a standstill, the valve 26 Will occupy the position shown in\Fig. 10, the superheated steam port 36 and the saturated steam port 38 leading to the motive steaml chamber 23 being then closed and the ports 27 and 28 of the valve will establish communication between the ports 33 and 34 of the valve housing. Saturated steam will then flow from the steam dome through the` pipe 39 into the saturated steam chamber 20 and will then flow through the super-l heater elements in the boiler tubes, this steam Ibeing superheated on its Way through the superheater elements and the superheated steam from the superheater elements will enter the superheated steam chamber 2l, and as this steam is not being used at this time it will return to the steam dome through the ports'33, 27, 28 and 34.- and the pipe 35. This circulation of steam through the superheater elements will be set up and maintained thermally, the saturated steam descending to the superheater elements being heavier than the superheated steam Which rises from the superheater elements.

This circulation of steam through the superheater elements will increase the eiliciency of the boiler owing to the utilization of the heating surface of the superheater elements to raise the temperatureof the steam in the boiler, and it will avoid the development of excessive pressure in .the superh ater which heretofore required release and oss of steam power or water and overheating and burning of the superheater elements. In starting the engine, it is necessary, in order to obtain proper or the best results, to feed the saturated steam to the cylinder. This is accomplished by shifting the valve 26 into the position shown in" j Fig. 9, this movement of the valve bringing the ports 30 and 31 therein into colfnmuni-- urated steam then flowing to the cylindersv through the pipe'2el. While the valve is in A.

this position, y the circulation of steam through the superheater elements continues, owing to communication being maintained between the ports 27 and 28 ofthe valve with the ports 33 and 34 of the valve housing, the superheated steam, however, flowing from the superheater elementslback to the steam dome. After the engine or locomotive has been started, it is desirable to cut ofi' the flow of saturated steam to the engine or cylinders and to supply the superheatedsteam thereto. This is accomplished by shifting the valve 26 into the position shown in Fig. 8, the ports 30 and 31 of the Valve being out of communication with the ports 37 and 38 of the valve housing, thus cutting ofi' the supply of saturated steam from the engine or cylinders, and the ports 27 and 29 of the valve being 1n communica'- tion With the ports 33 and 36 of the valve housing, superheated steam then flowingv from the superheated steam chamber 21 through the ports 27 and 29 into the motive steam chamber 23, thence through the pipe 24 to the engine or cylinders. valve in this position, the return of superheated steam to the steam dome is cut-'r as the port 28 of the valve is ,then out v'of -registry with the port 34. The throttling of eitherthe 'saturated or the superheated steam may be accomplished 'by luncovering more or less the ports in the valve. In stopping the engine or locomotive, it is eX- pedient to use saturated steam, and this is accomplished by rotating the valve back to the position shown in Fig. 9, the supply of superheated steam to the engineor cylinders l .being thereby cut oif and saturated steam -being supplied to the engine or cylinders.

Furthermore, the valve may be adjusted or l set to feed saturated steam to the cylinders, from time to time, in order that the saturated steam may serve the purpose of lubricating the cylinders and pistons and other Working parts. Owing to the proximity of the throttle or controlling valve t0 the cylinders, the` train, when the invention is applied to a locomotive, may be stopped promptly by the air brakes, as the amount of steam beyond the throttle or controlling valve is reduced to a minimum as compared ,l with theipreviously used superheater systems Where a considerable amount of steam` must be Worked out of the piping beyond thecontrollingvalve before the drivingof the locomotive ceases.

Accordingfto the present invention, the steam supply pipe 39 leads from. the topv of the' deme, and consequently ittakes up theflv means connecting and incasing said opposed intermediate return bends.

8. A superheater unit for steam boilers comprising a pipe having opposed return bends formed intermediately the ends of the unit, and means for connecting and protecting said bends from the iniiuence of flame or heat and cinders.

9. A superheater unit for steam boilers comprising a pipe having opposed return bends formed intermediately the ends of the unit, and a member recessed to receive and protect said opposed return bends.

10. The combination of a boiler tube, a superheater unit therein, and a Water jacket in the tube for protecting one end of said unit.

1l. The combination of a boiler tube, a superheater unit therein having return Copies of this patent may bends at its rear end, and a water jacket for protecting said return bends. y

.12. The combination of a boiler tube, a super-heater unit therein having return bends at its rear end, and a tube extending transversely of said boiler tube adjacent to said return bends of the superheater unit.

13. The combination of a boiler tube, a superheater unit therein having return bends at its rear end and a tube extending transversely of the boiler tube and having indentations in its forward side to receive and protect said return bends at the rear end of the superheater unit.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JAMES S. NICHOLS. Witnesses R. B Foss;r i P. J. HARLLEE.

be obtained for five cents each, by addressing the "Commissioner of Patents,

,Washingtom D. C.

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