US1068301A - Steam-generator. - Google Patents

Description

G. 1L BETTINGTON. STEAM GENERATOR.

APPLICATION FILED NOV.15, 1909.

.1. ,UBHfiO'k m Patented July 22, 1913.

4 SHEETS-181113131 1.

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STEAM GENERATOR. APPLICATION TILED NOV. 15, 1909. 1 a r Patented July 22, 1913.

4 SHEETSSHEET 2.

U. A. BETTINGTON.

STEAM GENERATOR.

APPLICATION FILED NOV.15, 1909.

1,068,301 m Patented m 22, 1913.

4 SHBETS-SHEET 3.

CLAUDE ALBEMARLE IBET'IINGTON, 0F PICCADILLY, LONDON, ENGLAND.

STEAM-GENERATOR.

Specification of Letters Patent.

Patented uly 22, 1913.

Application filedNovember 15, 1909. Serial N 0. 528,151.

To all whom it may concern."

.Be it known that I, CLAUDE ALBEMARLE B'nrrINcroN, a subject of the King of Great Britain, residing at the Junior United Service Glub,11 and 12 Charles street, St. J mites, and of 14 Half Moon street, Piccadilly, in the county of London, England, have invented certain new and useful Improvements Relating to Steam-Generators, of which the following is a specification.

This invention relates to steam generators and particularly to those of the kind set forth in the specification of my prior British Patent No. 19501 of 1906,'in which the tubes are so arranged as to inclose, and assist in forming a combustion chamber. In steam generators of this type it has been proposed to provide a central steam and water drum surrounded by a receiver or header which receives the upper ends of the water tubes, the wall dividing the drum from the header being perforatedwith' a number of small holes for the intercommu'nication of the steam and water.

The chief object of the present invention is to construct the steam and water drum and the top and bottom receivers or headers, so that they possess greater strength, simplicity and accessibility than heretofore and so that the generator can be manufactured, erected, entered, inspected", cleaned and re-tubed when necessary with greater facility. According to this invention I provide either the said drum or the header surrounding the same with a manhole or the like and construct the wall between the said receiver or header and the drum in such a manner that ready access can be had to the two chambers so that the necessary attention can be given to the whole of the inclosed parts without necessitating the dismantling of the boiler. The dividing wall serves the purpose of stays and enables the end plates of the drum and header to be of less thickness than would otherwise be necessary in order to provide sufficient strength in the absence'of staying. It further allows ofsuitable thicknesses of plate to be used; one at least of which is subjected to a high temperature, but being of ideal form and unweakened, can be made sufficiently strong to resist the pressure while at the same time thin enough to be always efficiently cooled by its contained watert-he other, especially where weakened by the necessary tube holes is outside the high temperature zone-can be made of almost any desired thickness to compensate for metal cut away. The seams where necessary are protected and efficiently cooled. The said receiver or header and the drum are preferably composed of end plates and side plates, the slde plate of the drum being formed with large apertures and serving as the inner wall of the header. The lower end plates of the drum and header are connected with the plate dividing the said drum from theheader, 111 such a manner'as to form a recess which constitutes a dead space so that the oint is not appreciably swept bythe hot gases and thus endangered. The header may e provided with an annular trough which may be termed a launder into which the feed water is introduced for the purpose of causing the water to flow in the direction of the down-take or downcomer tubes, and the up take tubes are provided with prolongations or the like and the down-take tubes are unprovided with said prolongations whereby the contents are discharged into the header approximatelyat the surface of the con tained water, thus as well as reducing the agitation of said water and any tendency to priming which might otherwise occur, causes the water to circulate in a definite path. The outer receiver may be provided with suitable doors through which the tubes may be withdrawn and replaced.

In order that the said invention may be clearly understood and readily carried into effect, I will describe the same moretully with reference to the accompanying drawings, in which Figure 1 is a sectional elevation of a generator showing one constructional form of my improvements Fig. 1 and Fig. 1 are, respectively, enlarged views showing the doors in the upper and lower end plates to permit the insert-ion, expanding, cleaning or renewing of the tubes. Fig. 2 is a sectional elevation showing a modified constructional form; Fig. 3-is a horizontal sectional view on the line 3-3, Fig. 1. Fig. 4 is'a plan of Fig. 2. Figs. 5 and 6 are sectional elevations of modified constructions of headers. Figs. 7 and 8 represent respectively a side elevation and a plan of adetail, and Figs. 9 to 1 2' are views of other details. In these figures A is the steam and water drum, B is the concentric receiver or header divided from the said drum by the wall A which is provided with large apertures A The drum is provided with dished end pieces A, A riveted or otherwise suitably attached to the said wall A. The receiver or header B is composed of an outer wall B. and annular end ieces B, B.

x A is a manho e glVing access 1n the example shown in Figs. 1 and 6 to the interior of'the drum A, from which access to the receiver or header B is obtained through the aforesaid apertures A The wall A'- is continued by means of the portions A to the lower dished ends A and B thus forming powerful tension stays, capable of supporting the whole pressure on the end A and that of B not taken by the rod stays and outer wall 13', the chamber A in etfect being nothing more than a cylindrical drum with ends suitably dished I and only of sufiicient thicknessto resist the internal pressure assoclated w1th the relatively small diameter drum A while the necessary full diameter of steamand water drum or header is secured as above described. It is obvious that if some such method were not ado ted it would be necessary to make the dis ed ends A and A of such thickness in order to sustain the pressure resulting on the overall diameter especially as the ends are weakened by the holes out for thetubes D, as to render such constructions impracticable in conjunction wit-h the high temperature to which it is necessarily subjected; on the other hand the tube plate B is relieved of all tensile strain due to the center rtion, across its tube holes, and could if further strength was necessary be made ofthicker plate, as it does not cover the high temperature zone.

The outerplate B it will be observed is subjected to the greatest bursting pressure,

but not being subjected to any temperature ofconse uence and further being strengthened by t 1e turned up sides of the end plates B and B it does not introduce any diffieulty.

Rod stays E (Figs. 1 and 6) screwed or 1 otherwise fixed into the end plates B and B and which may be hollow, take the pressure on the flat surfaces B and B", thus obviating the necesslt of curving these surfaces to withstand t e tension due to the pressure, and thereby reducing its thickness and simplifying the problem of tube holes and doors.

short lengths of lighter tubin or rolled plates, with more or less open ongitudinal seams, provide channels through the body of water in the receiver B, through whic the rapidl risin' columns of water containing bu bles o steam are carried to the working'water level where they more readily ,se arate as desired without appreciably d1stur in the said body of water in B which is itself thus continuously augmented rows D of tubes, which it will be observed are the farthest from the source of heat and are as aforesaid not provided with projecting channels F. Therefore by a well known process of circulation these outer rows of tubes D receiving the least heat tend to become downcomers, bein further encouraged to do so as hereina ter explained, by

this arrangement the.liberation of steam is facilitated and a definite path for the circulation of the water is provided.

A circular launder G is arranged just inside the outer wall plate B and being of comparatively li ht construction and a loose fit, it may on the outer upturned edge of the plate B. The inner side of the said launder may be lower than its outer side, and is preferably provided with slots or apertures around its top edge. This launder receives the colder feed water atone or more points by means of a pipe or pipes H and distributes it throughrthe slots referred to or on overflowing over the edge of the launder to the outer row of tubes, where it mingles with the heated water and passes down to the bottom header J with the water-in circulation, whereby the general circulation through the boiler is encouraged and certain impurities deposited in the lower header or. mud-drum before evaporation takes place. As one object of the launder is to dissipate any sudden change of temperature of the feed water it is preferable to leave it loose and free to expand or contract or only lightly attached to plate 13', which latter is t en protected from any great variation of temperature of the feed water by the layer of hot water or steam between itself and the high side of the launder. As this launder is not essential to the operation of the boiler, it may be omitted, especially in cases where hot feed water is to be used.

The stays EE Figs. 1 and 6 may be made hollow in order to allow of the introduction of cleaning rods or chains to 0psired,.or a steam jet may be passed through them, all of which methods can be employed to externally clean the tubes if necessary; when not in use the said hollow stays may be temporarily closed with loose plugs or while flowing radiall to the outer row orthe introduction of colder feed water. By

e merely allowed to rest crate brushes scrapers or the like if decaps. Also in making the stays hollow I introduce the well known expedient of immediately detecting faulty stays, thereby conducing to further safety.

In order to provide means for inserting, expanding, cleaning or renewing tubes, I provide opposite the tube ends 111 the end plate B", (l ig. 1) a door 0 of the well known type having a projecting stud and preferably circular in plan and provided with a recess around the edge to take a jointing ring of any suitable material. The

, lies firstly in the fact that all the door holes can conveniently be made circular instead of square or elliptical and secondly the fact that the seating of the door is inside, where the addition of pressure tends to tighten the joint. Further it is possible to clean and inspect without the use of special tools or a mirror, the faces on the underside of the plate B Obviously this form of door, which is circular and larger than the aperture it covers is impossible to blow elf, but becomes tighter under pressure, and it is therefore quite safe to remove the nut and the cap or dog C with the boiler working under full pressure. This fact has an important advantage especially for marine work as by making dog C in this form of a cap, preferably with machined faces and restin on a machined seating on the end plate T it is possible in mostcascs, in the unusual event of the oint between the door (1 and lower face of the plate B leaking or blowing out, to stop the leak by removing the cap or dog 0 and dropping a disk of suitable jointing material with a hole in the center, over the projecting stud of the said door. ()n replacing the cap or dog 0 and the nut C an external joint is formed to check the leak on the defective internal joint. The screwed stays'E may have their upper ends plain or are formed with square ends in order to allow the use of a Wrench or spanner for screwing them home to the merely. expanded in. The method of joining the end plate Aiof the drum A and the end plate B of the header 1) with the portion A of the side plate A interposed provides a protected expansion joint between A and B The end plate A being ex: posed to a very fierce temperature is liable to rapid change, and is therefore preferably kept thin in order to facilitate conduction. The end plate B not being subject to this high temperature can consequently be made as thick as may be desirable to compensate for the material cut away for the tubes. The recess formed by the said joint forms a dead space so that the joint is not appreciably swept by the hot gases and thus endangered. The lower part A of the plate A may be made thicker than the upper part of said plate in order to reduce the weight and at the same time compensate for the portions cut away to form the apertures, A

The bottom header J is composed of an inner and outer circumferential plate, J and J respectively which together with the top and bottom plates J and J form a closed hollow ring header, the flat ends J and'J being further stiffened in the ex ample shown in Figs. 1 and 6 by the rod stays J which may be conveniently made and fitted the same as the stays E before referred to, some or all of which may be made hollow if necessary for the purposes already described. The top plate J is drilled to receive the ends of the tubes D, D as shown, while the lower plate is in the example sh-ownin Fig. 1 provided with holes through which the end of-the mandrel of a tube expander may be inserted'and operated. As

it is unnecessary to make the majority of these latter holes larger than is merely required for the said mandrel, it is preferred to make circular holes of considerably smallerdiameter than the outside of the tubes, whereby a gain in strength and efficiency is obtained. A method of closing these mandrel holes is used similar to but somewhat simpler than that employed in the top header l3 hereinbefore described. The doors J 6 have stems which project out-- wardly through the said holes and owing to the small diameter of the holes the nut can be conveniently made to perform the purpose of the cap or dog in the above mentioned device, while it is still possible to remedy a leak while ,under pressure by removing the nut and placing on the stem of the door J a suitable washer. In order to place the tube expander, and subsequently the doors J in position it is necessary to provide occasional hand holes These are preferably made elliptical in form and suiticiently large to allow of the introduction of an expander and a mans arm. These hand holes are closed by elliptical doors and caps or dogs, which doors owing to their elliptical shape can be inserted from the outside. The header J is provided with a suitable blow off pipe M. While the header J is shown in the examples illustrated made up sides sufficiently deep to take the place of the plates J', J

In Fig. 1 one of the tubes in the outer row of tubes D has a portion removed, the

exposed ends being connected by the pipes K through the flanged elbow joints K and K with a water jacketed fuel pipe L in such a manner thatwater will automatically' circulate from the lower header J through the lower pi e K into the jacket and out again toget er with any steam which may have formed, through the upper of the pipes K to the top header B, and t us protects the fuel pipe against burning. This particular tube would be an up comer and so be provided with project-in channel the same as the inner 'rows. .5 blow-ofi pipe M is provided at the lower part of the water jacket. L is an inner concentric fuel pipe of a cross sectional area preferably equal to one half the area of annular space formed between the pipes L and L. The capacity of theinner pipe L will thus be one-third of the total capacity when both pipes are in operation. and that of the pipe L will-be two-thirds of the total capacity. N is a filling of refractory mate'- rial which may be plastered in position while moist between the tubes D of the innermost row which together with said refractory material form the wall of the combustion chamber. The weight of these columns or lining of fire bricks or refractory material is carried on the brackets P, which are fitted behind the inner tubes, the leg P resting on the plate J By placing these with the passage of the same gases through leg brackets in close contact with the tubes and in such a manner that the said tubes tend to prevent the hottest gases from i1n-. pinging directly on them, they remain relatively unharmed in an otherwise destructivelyhot, atmosphere, while this arrangement further does not materially interfere the boiler. The upper ends of the said leg brackets are formed in the shape of a horse shoe (Figs. 7 and S) and closely envelop the water tubes. Instead of using the support-- ing bracket I, I may form a support for a bracket Q (Fig. 2) upon which the lining of fire brick is supported.

As shown in Figs. 11 and 12, the tubes,

are constricted at one point and the bracket Q, is so formed that it fits over this constriction and falls into the position shown where it is retained in place.

A superheater may be arranged around -the outer row of tubes. In the arrangement shown in Fig. 1, the header 0 is vertical and the tubes 0' are horizontal, while in the example shown in Fig. 2 the headers O and O" are horizontal and the tubes 0 arranged substantially vertical. In the former arrangement the header is divided into two chambers which are connected one with the 'other by means of a p1 e 0 thus insuring an'equal circulation o' the steam through the tubes. Around the top portions of the tubes and the header is arranged a casing G" which forms a smoke box terminating in a flue or stack G.

- In order to obviate the necessity of using staysin the headers as in Fig. 1 and to provide greateraccessibility to the same, the

header may be constructed as shown in Figs. 2 and 5 in which the header B is of the same height as the steam drum A, the. slots in this case being considerably longer than in the example shown in Figs. 1 and 6. Further by reason of the increased height, the launder and the extensions of the tubes may be omitted, though obviously, if desired, these may be employed. A number of-hollow stays E are provided though these are more for the purpose of providingacce'ss to the outer portions of the tubes for cleaning urposes, and may obviously be omitted. Through these hollow stays, chain cleaners or the like may be introduced. The upper end plate B may be dished as in the example shown in Fig. 2, or approximately flat as in Fig. 5. The said end plate is provided with holes over which suitable doors pasing tubes therethrough when desired.

The lower header may be similarly constructed with dished ends J J and stays are therefore unnecessary. 7

The jacketed pipe L may as shown in Fig. 2 be supplied with the feed water by the pipe M, the water passing out at the top of said jacket. through the pipe M to theinlet pipe H of the header B.

In the modification illustrated in Fig. 6, the lower portionof the drum A forming the dividing wall between the said drum and the header B is made in a separate plate A, and the end plate A is in one piece covering the drum A and the header B, the said plate A* being supported by means of stringers B suitably attached to the said plate A. This plate is provided with holes A to give accss to the header B as in the previous construct-ions.

The fire bricks surrounding the inner row of tubes are preferably constructed as shown in plan at Fig. 9, this construction being such that when in position as shown in Fig.

10, they are locked in position. As the last brick cannot be placed in position its place has to be taken by mortar or the like which is inserted. T he said bricks are so arranged that suflicient of the usual liquid slag formed during the working of the boiler is retained and chilled during working to automatically seal up any cracks or crevices between the tubes and the stud bricks.

What I claim and desire tosecure by Letters Patent of the United States is 1. In a water tube steam generator, the combination with the combustion chamber, independent top and bottom plates of the steam and water drum, independent top and bottom plates of the header surrounding the drum, water tubes in the torm of a ring surrounding the combustion chamber and communicating with said header, of a wall forming the outer sides of the drum and the inner sides of the header, the said walls being termed with apertures so that ready access can be had to the drum and header, and an annulartrough in said header.

2. In a water tube steam generator, the combination with the combustion chamber, independent top and bottom plates ot the steam and water drum, independent top and .bottom plates of the header surrounding the drum, water tubes in the form of a ring surrounding the combustion chamber and communicating with said header, of a wall '"ztorming the outer sides of the drum and the inner sides of the header, the said walls being formed with apertures so that ready access can be had to the drum and header, and an annular trough in said header, and prolongations on the innermost 01"" the atore: said tubes,

3. In a water tube steam generator, the combination with the combustion chamber,-

independent top and bottom plates of the steam and water drum, independent top and bottom plates of the header surrounding the drum, water tubes in the form of a ring surrounding the combustion chamber and communicating with said header, of a wall forming the outer sides of the drum and the inner sides of the header, the said walls being formed with apertures so that ready access can be had to the drum and header, fire bricks covering the inner row of said tubes, and means for supporting said fire bricks.

4. In a water tube steam generator, the combination with the combustion chamber, independent top and bottom plates of the steam and water drum, independent top and bottom plates of the header surrounding the drum, water tubes in the form of a ring surrounding the combustion chamber and communicating with said header, of a wall forming the outer sides of the drum and the inner sides of the header, the said walls being termed with apertures so that ready access can be had to the drum and header, fire brick covering the inner row of said tubes, and brackets for supporting said fire brick,

5. In a water tube steam generator, the combination with the steam and water drum, the header surrounding the same and the water tubes in the form of a ring sur rounding the furnace and communicating with said header, of a dividing wall between the said drum and header, said wall being provided with means whereby ready access can be had to the two chambers, fire brick covering the inner row of said tubes, brackets for supporting said tire brick, and top parts of said brackets that partly encircle the tubes.

6. In a water tube steam generator, the combination with the steam and water drum, the header surrounding the same and the water tubes in the form of a ring surrounding the furnace and communicating with said header, of a dividing wall between the saiddrum and header, said wall being provided with means whereby ready access can be had to the two chambers, a. number of fire bricks covering the inner row of tubes, said bricks being so formed as to be locked when in position.

7. In a water tube steam generator, the combination with the steam and water drum, the header surroundingthe same and the water tubes in the form of a ring surrounding the furnace and communicating with said header, of a dividing wall be tween the said drum and header, said wall being provided with means whereby ready a cess can be had to the two chambers, a number of fire bricks covering the inner row of tubes. and refractory material plastered in position to take the place of the last of the series of fire bricks. 4

In testimony whereof I atlix my signature in presence of two witnesses.

CLAUDE ALBEMARLE BETTINGTON. Witnesses I. SnLBY WARDLE,

'Inos. I HARGREAVES.

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