US620807A - smith - Google Patents

Description

No. 620,807. Pafentd Mar. 7, |899- W. M. SMITH.

STEAM GENERATOR. (Application led Dec. 21, 1897. (No Model.) 4 Sheets-Sheet I.

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No. 620,807. V Patented Mar. 7, |899. w. M. SMITH.

STEAM GENERATOR.

(Application med me. 21, i897.) l(N0 Model.) 4 Sheets-Sheet 2.

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N0. 6205807- T Patented Mar.`7, |899.

W. M. SMITH.

STEAM GENERATOR.

(Application led Dec. 21, 1897.) (No Model.) 4 Sheets- Sheet 3.

No. 620,807. Patented Mar. 7, |899. W. M. SMITH.

l STEAM GENERATOR.

(Application filed Dec. 21, 1897.)

4 Sheets-Sheet 4.

(No Model.)

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VALTER MACKERSIE SMITH, OF NEWCASTLE-UPON-TYNE, ENGLAND.

STEAM-GEN ERATO R.

SPECIFICATION forming part of Letters 'Patent N0. 620,807', dated March 7, 1899. d Application filed December 21,1897. Serial No. 662,877. (N model l To @ZZ whom it may concern,.-

Beit known that I, WALTER MACKERSIE SMITH, a subject of the Queen of Great Britain and Ireland, residing at J esmond, Newcastleu upon-Tyne, in the county of N orthurnberland, England, have invented Improvements in Steam-Generators, of which the following is a specification.

This invention has reference to improve# ments in steam-generators of the locomotive type. Accordingthereto the fire-box of such a steam-generator is provided with watert-ubes arranged to connect the water-space at one point with that at another, so as to obtain increased heating-surface and better water circulation. The water-tubes are preferably curved and may connect points on the same side, opposite sides, sides and rear end, or sides and rear end with the roof of the tire-box. They may be connected to the rebox shell by coupling devices or unions, so

as to be removable from the interior of the tire-box through the tire-door opening, orthey may be inserted through holes in the inner and outer shells of the fire-box and be fixed in the inner shell by expanding, the holes in the outer shell being provided with movable closures for gaining ready access to the tube ends.

In the accompanying illustrative drawings, Figure lis a longitudinal section on the line m of Fig. 2; and Fig. 2 is a transverse s ection on the line y y of Fig. 1, showing the nre-box portion of a steam-generator of the locomotive type with one arrangement of water-tubes having their ends connected to the inner walls of the irebox by coupling devices according to this invention. Figs. 3 and 4 show a hre-box with modified arrangements of water-tubes according to this invention, Fig. 3 being a central longitudinal section on the line as of Fig. 4, and Fig. 4 being a sectional plan on the line z z of Fig. 3. Fig. 5 is a central longitudinal section; and Fig. 6, an end view showing, to alarger scale than Figs. l to 4, inclusive, a tube end with coupling device for connecting the same to the shell ot the fire-box. Figs. '7 and 8, Figs. 9 and 10, Figs. 11 and 12,- and Figs. 13 and 14 are similar views to Figs. 5 and 6, showing modiiied arrangements of coupling devices.4

Referring to Figs. 1 and 2 of the drawings,

l is the outer shell of the fire-box, 2 the in- .ner shell of the fire-box, and 3 curved waterflame and hot gas to pass around and between I do not confine myself to any particular shape of the tubes, nor do Iv limit myself to any particular point in the sides or crown of the ire-b0x at which to insert the tubes.

They may be continued down near to the bottom of the fire-box, as shown by dotted lines at 3* in Fig. 2. In this case the plate forming the inner shell 2 may be bulged inward, as shown at 2n, so as to form projections in which the lower ends of the tubes 3* can be secured, or a suitable junction-pipe, such as 2b, may be fixed at its ends to the adjacent side of the fire-box, and to it the lower ends of the tubes 3* can be lixed. The number of tubes shown inr Fig. l is seventeen, nine being connected to one side of the fire-box and eight to the other side. The number and also the size of the tubes can, however, be varied so as to provide the amount of extra heatingsurface required'.

The water-tubes 3 are shown in Fig. 3 as inclined to the horizontal, the angle being such as to cause free circulation of the water in the tubes and the water-space 5 between the inner and outer shells l and 2. The tubes at the upper part of Fig. 4 are shown as connected to diierent parts of the same side plate of the inner fire-box shell 2. The tube 3 at the lower part of Fig. 4 is shown as fixed at one end to one side of the inner fire-box shell and at the other end to the rear end plate 2a of the said inner fire-box shell. Fig. 3 shows in dotted lines the rearward ends of a number of tubes so continued to the end plate 2. The tubes may also be arranged to cross from. one side of the tire-box to the other side, as

indicated in dotted lines at 3f* in Fig. 2. They.'

may also be arranged to connect the rear end wall 2 to the roof of the fire-box, as indicated by dotted lines at 3b in Fig. 1. The points where the ends of the tubes are connected to the plate or plates forming the inner shell of the re-box may be arranged nearer to or farther from the longitudinal center line or transverse center line 'y' y' of the fire-box, as indicated, for example, by the pipes 3. (Shown in dotted lines in Fig. 4.)

The shape of the tubes as seen in plan may be variously modified, as indicated in Fig. 4, which shows several dierent shapes the tubes may assume; but they are preferably so arranged as to interfere as little as possible with free access to the boilertubes. The tubes may be so bent that they can be placed in position by being passed through suitable holes in the inner and outer shells, the ends of the tubes being suitably fixed in the holes in the inner Sheik-as, for example, by expanding them by a tube-expander. inserted from the outside ot the fire-box through the holes in the outer shell l. Fig. 4 shows the tube ends thus fixed by expanding them in the shell 2 of the fire-box. In this case the holes in the outer shell l, through which the tubes are inserted, are made larger than those in the inner shell and are fitted with removable closures, such as screw-plugs 4 or covers or doors 4, which admit of ready access being gained to the tubes for the purpose of examining, cleaning, and removing them and for further tightening up their ends in the inner shell 2 when desired.

Instead of fixing the ends of the water-tubes by expanding them in holes in the walls and crown of the {ire-box, as hereinbefore described, I prefer to connect them to the lirebox by couplings or unions, which enable the tubes to be readily detached and removed when necessary through the fire-door opening 8. In this case the removable closures 4 4 are dispensed with.

Figs. 5 and 6 show one form of coupling suitable for this purpose. It comprises a hollow screw plug or nipple 9, (hereinafter called a plug,) which is screwed tightly into a thickened part of the fire-box shell 2 and pro; jects into the lire-box, and a nut l0, which is screwed onto the inwardly-projecting end of the plug and also onto the thickened adjacent end 3 of the water-tube 3. The screwed part of the plug projecting into the fire-box is made larger in diameter than thel screwed part of the tube 3, and the pitch of the screwthread thereon is also made greater than that on the tube. The two screw-threads on the nut are made the one to lit the plug and the other to it the tube. To iix the tube end in place,the nut is run back onto the tube,which is placed in position, after which the nut l0 is run forward onto the plug and screwed up tight.' As the screw-thread on the latter is coarser than that on the tube end, the conical end of the tube is drawn tightly into or against a conical seat 9n on the plug, thus forming a steam-tight joint. By screwing back the nut the tube end can be readily detached.

Figs. 7 and 8 show a modification in which the tube end :is provided with a collar 3e, by which its coned end is forced into close con' tact with the coned end of the plug 9 by the flange l0 of the coupling-nut I0. The collar is preferably formed on a sleeve 3f, screwed tightly onto the tube end.

In the arrangement shown in Figs. 9 and l0 the tube end has fixed toit in a duid-tight manner an externally-screw-threaded sleeve Il, having a coned end Il, which is fixed in place by passing it through the hole in the fire-box plate 2 when the plug 9 is removed, then screwing the said plug through the hole until it bears in a water-tight manner against the coned end ll"L of the sleeve, and finally screwing the nut 10 on the sleeve until it bears in a steam-tight manner against the plug.

Figs. ll and l2 show a modification somewhat like that illustrated in Figs. 9 and 10, except that the plug 9 screws onto the sleeve Il, which is made shorter andis unprovided with a nut.

Figs. I3 and 14 show another modification, in which the tube end is outwardly :flared or coned and the interior of the plug 9 is i11- wardly coned, and a ferrule or ring I2, coned externally and internally to it the plug and tube end, respectively, is forced into close contact with each of them, so as to make a IOO steam-tight joint with both and hold the tube end in place by a forcing-nut l0, screwed into the plug 9. The outer end of the plug may be formed, as shown in dotted lines, to serve as an abutment for the tube end.

With each arrangement the tube end is released by simply screwing back the nut IO in Figs. 5 to 8, inclusive, and Figs. 13 and I4, the nut l0 and plug 9 in Figs. 9 and IO, and the plug 9 in Figs. Il and l2.

I am aware that the tube-plate in the {irebox of a locomotive-boiler has heretofore been connected to the rear end wall 2 of the firebox by rearwardly and upwardly inclined water-tubes, upon which the brick arch has sometimes been placed; also,that the said tube plate has been provided with a rearwardly and upwardly inclined water-chamber connected by tubes to the rear end plate 2*L of the IIO noprovision has been made to admit of such tubes being easily and readily removed and replaced without the necessity of taking the boiler to pieces. This drawback is overcome by employing the couplings or union hereinbefore described.

What I claim is-' I. Ina steam-generator of the locomotive type, the combination with the inner shell of the fire-box, of a series of bent tubes within the iire-box on either side secured at their ends in said shell and extending obliquely from the forward end of the box toward the rearward end, whereby access to the lines is unobstructed and eiiicient circulation of the water between the shells forming the walls of the lire-box is effected.

2. In a steam-generator of the locomotive type, the combination with the fire-box of such generator, of water-tubes located within said iire-box. and each of which has its ends connected to the portion of the inner shell of the fire-box in rear of the tube-plate, so as to be in free communication with the waterspace formed by and between the inner and outer shells of said fire-box, all of said tubes being so arranged as to admit of free and unobstructed access to the boiler-tubes from the tire-door, substantially as described.

3. In a steam-generator of the locomotive type, the combination with the tire-box of such a generatonof water-tubes located within 'said {ire-box and havingtheir ends connected to the portion of the inner shell of the firebox in rear of the tube-plate, so as to be in free communication with the water space formed by and between the inner and outer shells of said fire-box, and coupling devices whereby the ends of said tubes can be readily connected to and disconnected from the 7 said inner shell from the inside of said firebox, substantially as described.

4. In a steam-generator of the locomotive type, the combination with the fire-box of such generator, of Water-tubes locatedl within said tire-box, and coupling devices provided in the inner wall of the re-box adapted to thrust the ends of the tubes endwise and to connect them in a detachable manner to said inner Wall, substantially as described.

5. In a steam-generator of the locomotive type the combination with the iire-box of such generator,of water-tubes located within said fire-box, hollow plugs or nipples screwed into the inner shell of the fire-box from the inside and adapted to form seatings at their inner ends, the ends of the said tubes being adapted to form a joint with said seatings, and coup-- ling nuts within the fire-box adapted to tighten the ends of the tubes against the said seatings, substantially as described.

6. In a steam-generatorv of the locomotive type the conibinationwith the re-boX of such generator, of water-tubes located within said tire-box, hollow plugs fixed in the wall of, and projecting inwardly into, the iire-boX, the projecting ends of each plug being externally screw-threaded and formed with a conical seating, and coupling-nuts each threaded in ternally at one portion to screw upon :the corresponding plug and provided at another portion of smaller diameter with internal screwthreads of a different pitch to the others and adapted to screw upon the screw-threaded end portion of the adjacent water-tubes, the ends of said water-tubes being coned correspondingly to the seatings on the plugs, substantially as described.

In testimony whereof I have signed my name to this specication in the presence of two subscribing witnesses.

WALTER MACKERSIE SMITH.

Witnesses:

RALPH J. RoBsoN, JOHN WEATHERBURN,

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