US1116428A

US1116428A - Steam-generator.

Info

Publication number: US1116428A
Application number: US68804312A
Authority: US
Inventors: James Howden
Original assignee: Individual
Current assignee: Individual
Priority date: 1912-04-02
Filing date: 1912-04-02
Publication date: 1914-11-10
Anticipated expiration: 1931-11-10

Description

J. HOWDEN.

STEAM GENERATOR.

APPLICATION FILED 1011.2, 1912.

Patented Nov. 10, 1914.

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lllllllllll Illllllrllllll x a HEEEEE w E Lu. WKNW NMR INVENTOR JAMES HOWDEN BY BimQ ATTORNEY WITNE-SES J. HOWDEN.

STEAM GENERATOR.

APPLICATION FILED Ann, 1912.

1,11 6,428, Patented Nov. 10, 1914.

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INVENTOR JAMES HOWDEN ATTORNEY JAMES HOWDEN, 01E GLASGOW, SCOTLAND.

STEAM-GENERATOR.

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Specification of Letters Patent.

Patented Nov. 10, 1914.

Application filed April 2, 1912. Serial No. 688,043.

To all whom it may concern:

Be it known that 1, JAMES HOWDEN, a subject of the King of the United Kingdom of Great Britain and Ireland, and residing at Glasgow, Scotland, have invented a certain new and useful Improvement in Steam- Generators, of which the following is a specification.

This invention relates to steam generators of the type in which horizontal top and bottom drums of semi-circular cross section are connected by vertical tubes relatively small in diameter, the bottom drums being located immediately over the fire grates, and the upper drums being extended rearwardly to form a roof forthe combustion chamber;

' the grates being contained in a structure,

I which carries the evaporative parts of the boiler and its adjuncts but has no other functional connection therewith.

One object of the invention is to render a boiler of this type more readily portable, the construction adopted being such. that the boiler may, when required, be entirely completed, proved and tested under, steam and thereafter taken to pieces so that the parts may be conveniently carried by men, mules, or other available means of transport over the most difiicultjcountry and readily put together again. 1 V

. On account of its lightness, strength, du-

rability'and compactness, as also on account of its high efficiency a boiler constructed as hereinafter described is also most suitable for small high-speed steamships, such as torpedo boats, destroyers etc. The top and. bottom drums may be made so small in cross. sectionthat they cannot admit of the usual manhole doors through which the tubes can be examined cleaned internally, renewed, or otherwise manipulated, though each drum has a handhole at one end for observation and partial cleaning. The drums may, however, be easily cleaned, While being accessible at all parts, in that each element is made in three separate parts, instead of one, as hitherto, the top and bottom drums being made each complete in itself, forming two parts, While the tube plates and Water tubes form a third part.

Each drum is or may be finished in one piece by suitable machinery from one plate having diderent thicknesses, or to which small parts may be attached by rivets or otherwise. The semi-circular part of the drum over the fire is preferably thinner than the part to Which the tube plates are attached. The thickest parts of the plates are the inturned flanges to which the tube plates are attached with their tubes; in certain cases also parts of the drum ends are similarly thickened. These flanges are planed all around at the sides and ends, as are also the tube plates, so as to make true faces affording a perfectly tight joint; the tube plates being secured to the top and bottom drums preferably by screw pins. The end of the lower drum above the fire and the front end of the upper drum to which the uptake plates are attached are slightly curved outward, so as to bear sufiiciently Whatever pressure may be used. The front end of each lOWGl drum may be fiat With a hand hole flanged inward to give suificient strength, and the back end of the upper drum may be similarly formed with a hand hole.

When a boiler composed of a number of pairs of drums is completed, the lower drums are united by equalizing Water pipes at the front ends of the same, While the upper drums are united by an equalizing steam pipe, as many pairs of drums being used in a ,single boiler as is necessary for the amount of steam required for one unit. A very small boiler may consist of only one top and bottom drum with the connecting tubes and tube plates, the drums and grate beingmade sufficient in length to give the amount of steam required. In all ordinary cases, however, when considerable power is required, one grate may be made sufficiently wide to serve two or even more pairs of drums.

- The complete cleaning of the drums and tubes or renewal of tubes may be easily accomplished by the detachment of each element from the others and removal of one or more as may be required, so that the tubes and tube plates may be separated from the.

drums. Such operations can be accomplished in a short time, and the tube plates and drums again put together and restored in their respective positions in the boiler framing. In boiler units with a considerable number of drums one or more may be removed and the rest of the boiler still used, blind flanges being provided on the short branch pipes or branches connecting them to the steam equalizing pipe. The equalizing water pipes on the front end of the lower drums are treated in similar manner when any of the drums are removed. In cases where extreme lightness is not of special importance, the front end of the lower drum and the back end of the upper drum, both having hand holes, may be riveted as separate pieces into the drums, these ends not being exposed in any way to the fire gases.

From one end of the steam collecting pipe the saturated steam is led down by a pipe to a horizontal cross branch or box a part of which is flattened to form a tube plate into which superheating tubes are fixed. These tubes after entering the combustion chamber are bent upward and after passing across the combustion chamber horizontally near to the upper drums pass through into a similar cross branch or box on the other side of the boiler at a higher level than the first cross branch or box, doors being provided to afford a means of access. From the second branch or box the superheated steam is led up to the main steam pipe, so as to be used as superheated steam. Stop valves are provided so that the degree of superheat can be regulated according to the extent of opening of these valves. If desired, means may be provided for flooding the superheater tubes.

In the accompanying drawings Figure 1 is a part front elevation, art vertical section; Fig. 2 is a longitudinal vertical section at right angles to Fig. 1 and Fig. 3 is a part horizontal section of a boiler embodying the invention, said boiler, including two furnaces each fitted with two elements. Figs. 4 and 5 are vertical sections at right angles to each other of a portion of a lower drum. Fig. 6 is a developed plan view showing one form of plate suitable for the construction of a drum in one piece, the thickened portions being indicated by hatched lines. Fig. 7 is a horizontal section showing the staggered arrangement of the ends of the feed water heater tubes. Figs. 8 to 12 show modified arrangements of the feed water heater tubes and boxes. Fig. 13 shows a modified construction of the superheater boxes.

Referring to the drawings, the boiler comprises upper drums A and lower drums B, said upper drums being connected by means of short branches O to an equalizing steam pipe D. Water tubes E are connected to top and bottom tube plates F and G, as shown particularly in Figs. 1 and 2, said tube plates being secured to the upper and lower drums A and B preferably by screw pins,

the jointing faces on both drums and tube plates being made suitable for this purpose.

As shown articularly in Figs. 4 and 5,- the inturned anges on the drums are thickened for'attachment to the tube plates, the drums being made in one piece from a single plate of substantially the shape shown in Fig. 6, the'thickened portions of the plate .b'eing indicated by hatched lines. I

The space between the inner elements is wider than the space between the inner and outer elements, on account of the brickwork separating the two furnaces. It is preferred to provide a partition H, Fig. 3, between the elements in each furnace, so as to prevent passage of the gases from one furnace to the other when one furnace is not being utilized.

Each upper drum may be formed with a thickened extension located over the combustion chamber I, as indicated in Figs. 8, 10 and 11, being faced up level with the sides and front end of the drum to which the upper tube plate is jointed, the upper tube plate being substantially the same length as the tube plate on the lower drum, and the said extensions being stiffened to bear the working pressure by means of the usual bridges and stays as shown.

The saturated steam is led from one end of the collecting pipe to a header-J which is flattened at one side to receive the supsrheating tubes K which pass through a door L at one side of the combustion chamber and, after being bent upwardly, as shown, pass beneath the bottom plates of the upper drums A,-thence through a door M on the opposite side of. the combustion chamber to a header N. Alternatively, the headers J and N may be of the construction shown in Fig. 13.

A stop valve 0 is fitted by preference on the header N and connected to the main steam supply pipe, and a valve P is connected to the collecting pipe and to the main steam supply pipe. This valve P is of sufficient size to supply all or nearly all the steam evaporated by the boiler, and is used in conjunction with the valveO for'the purpose of giving a supply of steam more or less superheated.

As shown in Fig. 1, the lower drums B are supported at their front ends where they are protected'from the action of the hot gases, and within the said lower drums at the front ends thereof are diaphragm plates Q which cause the front tubes E to act as downcomers and also insure collection of sediment. Connecting the bottom drums B at the front ends is a common feed water pipe R which may also be used as a common blow-off.

At the rear of each combustion chamber are or may be arranged lower, or lower and upper, water boxes disposed horizontally and of triangular or other suitable form in cross section. A lower water box is shown in Figs. 8 and 9, and upper Water boxes are shown in Figs. 10, 11 and 12. The boxes S may be made each in one piece but with separate doors T for access to the interior or may comprise sections suitably connected together. Fitted to said boxesare tubes U preferably of less diameter than the upright water tubes E of tha'generator.

The said tubes U are staggered, as shown in Fig. 7, and are so placed that the touch, or

nearly touch, each other vertically and thus form a water wall at the rear of each combustion chamber. The upper water boxes are situated near the lower side of the said upper drums where they extend rearwardly over the combustion chamber. The lower boxes are preferably placed above the level of the fire grate and are protected more or less from the heat by means of brickwork or other non-combustible material. Feed water is led to the lower box or boxes by means of a pipe V provided with a nonreturn check valve, and flows through the tubes U, by way of the upper box or boxes, if these are provided, into the upper drums, the feed'water being heated in its passage by the action of the hot gases on the tubes U.

Having now described my invention what ll claim and desire to secure by Letters Patent of the United States is 1 In a water tube steam generator, in combination a top and a bottom drum, each drum being of semi-cylindrical formation and having its ends integral with the body, the edges of the body and of the ends being inturned and of thicker section than the rest of the drum, said edges forming the boundaries of an aperture, and a fiat tube plate fitted to said inturned edges and closmg said aperture, and water tubes connecting the tube plates of the top and bottom drums.

2. In a water tubesteam boiler, in combination, a top and a bottom drum, each drum comprising a semi-cylindrical body having its ends integral with the body; said ends and body belng inturned and thickened at the edges; said edges affording the boundaries of an aperture; flat tube plates removably fitted to the inturned edges and closing said apertures; the tube plates for the-top and bottom drums being of equal length; and Water tubes connecting the tube plates.

In testimony whereof I have signed my name to this specification in the presenceof two subscribing witnesses.

JAMES HOWDEN,

Witnesses 'WALLAQE FAIRWEATHER,

JOHN MCCLEARY.