A New or Improved Construction of Steam Generators of the Water-tube Type.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
A New or Improved Construction of Steam Generators of the
Water-tube Type.
I, JAMES THOMAS STEWART, of 3, Southbrook Terrace, Horton Road, Bradford,
in the County of York, Engineer, do hereby declare the nature of this invention to
be as follows:
This invention relates to a new or improved construction of steam generators of
the water-tube type and has for its object the combination in one and the same
boiler of important features of water-tube and cylindrical flued boilers.
In my new or improved construction of steam generators I fit the top steam-and-
water-drum with a series of water-tubes and down-comers both of which serve a
lower water-drum as is usual in boilers of the water-tube type. The said down-
comers carry or support the said top steam-and-water-drum by means of suitable
collars or fastenings. The lower water-drum according to this my invention is of a
special construction and takes the form of a tube or casing within which are
cylindrical furnace flues which latter will thus be entirely surrounded by the water
in the said casing or lower water-drum. The said furnace flues may be of any
ordinary type used in cylindrical flued boilers and are fixed so as to be eccentric
to the said casing or lower water-drum thereby increasing the water space between
the crowns of the said furnace flues and the top of the said casing or lower water-
drum. The said furnace flues have preferably a conical or bottle-neck" back
end so as to increase the surface for and facilitate the fixing of a special series of
water-tubes which serve the said casing or lower water-drum from the back or end
of the said top steam-and-water-drum. The said back-end series of water-tubes
afford a considerable increase in heating surface and are bent so as to direct and
mix the gases and thus fulfil the purpose of combustion chamber or fire-box of
cylindrical flued boilers.
In order to ensure circulation in the said casing or lower water-drum the said
down-comers discharge directly over a baffle plate of approximately A section.
Λ
The covering or shell of steam generators constructed in accordance with this my
invention may be of any suitable shape or design.
The water-tubes used in the construction of steam generators built in accordance
with this my invention may ne arranged in any suitable order or manner.
It will be understood that the shape or form of the said casing or lower water-
drum may be variously modified and in one instance I make the said casing or
lower water-drum of two separate and independent cylindrical or other suitably
shaped casings or drums each of such casings or drums having a furnace flue or flues
therein.
It is obvious that a boiler constructed in accordance with this my invention will
be an efficient steam generator the heating and evaporating surface of the said

page_text: furnace flues and the said back-end series of water-túbes being over and above that
of boilers of the water-tube type now in general use.
Dated this 92nd dur of Norah 1807
A New or Improved Construction of Steam Generators of the
Water-tube Type.
I, JAMES THOMAS STEWART, of 3, Southbrook Terrace, Horton Road, Bradford,
in the County of York, Engineer, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement: —
This invention relates to a new or improved construction of steam generator, and
has for its object the combination, in one and the same generator, of drums, and
water tubes in such a manner, as to be improvements of flue boilers, and also
embraces important features of marine and water tube boilers, to obtain efficient
circulation of water, and the diffusion of the heat generated in the furnaces, to the
best advantage, and economy of fuel.
The accompanying Sheets 1 and 2 of drawings illustrates a steam generator, or
combination of generators, in accordance with this invention. And the same letters
indicates like parts in all the figures therein.
Figures 1, 2, 3, 4, 5 and 6, are shown in longitudinal transverse, and sectional
elevations:
Figures 7 and 8, are shown in diagramatic sections, and include various combina-
tions or forms of steam generators, constructed in accordance with this my
invention.
This improved generator, shown in Figs. 1 and 2, Sheet 1, consists of a top or
upper cylindrical steam and water drum A, fixed horizontally, and with end plates.
This steam and water drum A, is connected to the lower furnace water drum B,
by a series of water tubes K, K³, K³, K³, and down-comers C; which supports the
upper steam drum A. The down-comers C, have funnel shaped ends at bottom E,
to distribute the water circulation around the furnace tubes or flues G, G.
The lower furnace or water drums 13, is of special construction and is built in the
form of a tube or elongated casing, within which are placed the cylindrical furnaces
or furnace flues G, G, and which latter are surrounded with water. The furnace
flues G, Gare made of any of the present forms or types used in the construction of
cylindrical boilers, but I introduce by preference conical or bottle-neck ends for
Hlues at H, so as to increase the space to facilitate the fixing of the water tubes K,
to the furnace lower water drum casing B. The furnaces or flues G, G, I fix
eccentric in the casing B, and thereby increase the water space between the crowns
of furnace flues G, G, and the top of casing B, and this makes increased space for
the fixing of water tubes K1, K2, K³. Notwithstanding the object of facilitating the
fixing of water tubes K¹ K2 K3 may be accomplished in other ways. For instance
by making the portions of casing B, bellied or dome-shaped immediately above the
crowns of the furnace flues G, G. The lower furnace water drum B, casing can
also be made in other modified forms as hereinafter described.
In order to improve the water circulation in the furnace water drum B, the

page_text: down-comers C, discharge from an enlarged funnel shaped orifice E upon and
directly over a baffle plate or midfeather E of approximately inverted V.shaper in
section, and running for the whole length of the casing B, and thereby distributing
the circulation of water, all over, and round the furnace flues G, G.
The water tubes K, connect the back end of steam drum A, with the lower furnace
water drum B, and thereby increasing the heating surface of generator and they
are curved, so as to diffuse the heated gasses, and direct them through an opening M,
in back end plate above the furnace water drum B,. and between the water
tubes K', K.
The centre water tubes K, K, I prefer to make them straight, and of such a
length, that they can be withdrawn into steam drum A, to facilitate renewals or
repairs.
•
The water tubes K2, K2, are curved so as to come in the same plane, and between
water tubes K', so that the gases are only allowed, to pass through at the top and
bottom ends where the tubes enter the upper steam and water drum A, and the
lower furnace water drum B, by these means the heated gases, are diffused, mixed,
and efficiently distributed on their way from the furnaces to the chimney.
The direction of the heated gases and flame of combustion, are clearly shown by
the aid of full arrows.
The outside casing or covering L, can be constructed of brick-work, or sheet
metal, covered or lined with a non-conducting material.
Referring to the drawings on Sheet 1. Figure 1, is a cross-sectional elevation
on the line X, Y, and Figure 2, a longitudinal section on the line Y, Z, of Figure 1,
as above described and in which the circulation of the water is indicated by dotted
arrows.
Referring to the drawings on Sheet 2, Figure 3, is a transverse section and
Figure 4, is a longitudinal section of a steam generator with a single furnace
flue G, surrounded by a cylindrical casing or water drum B, and is connected to
steam drum A, by the water tubes K, K, and with the down-comers C, C, which
deliver into water drum B, on either side and below the centre line of furnace
flue G, and close to the inner sides, of delivery orifices of down-comers C, C, I fix
baffle plates F, F, to direct the water circulation upwards, and round the furnace
flue G. This type of steam generator is suitable for small and medium sizes of
steam generators.
Figure 5, is a transverse and Fig. 6, is a longitudinal section of steam generator
with two furnace water drums B, B, each having a single furnace flue G, and both
the furnace water casings B, B are connected into one main steam drum A, by the
water tubes K, K', and the downcomers C, C, are fixed on either side in a similar
manner as described in Figures, 3, and 4, but in this case I prefer to fix the baffle
plates F, F, on the upper sides of delivery orifices of the down-comers C, C, to direct
the water circulation downwards and round the farmace flues G, G. The water
tubes K, K, also connect the steam drum A, to the two furnace water drums B, B,
on either side as shown.
Figure 7. This shows a transverse section of steam generator, consisting of a
combination of two lower water drums B, 13, each provided with two furnace
flues G, G, and connected to three upper steam drums A, A, A, with downcomers C, C,
and water tubes .K³, K', similar as in generator shown on Figures 1, and 2, in
Sheet 1.
Figure 8. Is a longitudinal diagramatic section of a combination of any of the
preceding steam generators placed in position back to back.
In all the above combinations, the combustion chamber 0, can be utilized for
heating the feed water, and for superheating the steam, and for other purposes.
It is evident that in carrying out this invention, modifications can be made other
than those herein described without departing from the nature and substance of this
invention, and improvements in steam generators, and I do not confine myself to
the exact proportions of steam drums, water drums, water tubes, downcomers, or
baffle plates as described and set forth.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A steam generator constructed as shown in Figures 1, and 2, on Sheet 1, and
as shown in Figures 3, 4, 5, 6, 7, and 8, on Sheet 2. The combination of either
of them arranged and operating substantially as described.
2. In a steam generator the combination of a steam-drum or drums, such as A,
and connected with, water tubes K, K1, K2, K³, and down-comers C, to the lower
furnace water-drums or drum B, and the special construction of the furnace water
drum B, in the different arrangements as shown and described.
3. In a steam generator the introduction of circulating, or baffle plates F, under
or in close proximity to the delivery orifices of the down-comers C, to secure an
efficient circulation of water round the furnace flues G, substantially as shown
and described.
Dated this 20th Ab of Decembar 1807