Improvements in Water Tube Steam Generators.
Year: 1893

page_text: Date of Aplication, 5th Dec., 1893
Complete Specification Left, 5th Oct., 1894-Accepted, 10th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Water Tube Steam Generators.
1, WILLIAM CROSS, a Director of the Firm of R. & W. Hawthorn, Leslie and Co.,
Limited, Engineers and Shipbuilders, of Forth Banks Works, Newcastle-upon-Tyne,
in the County of Northumberland, and Hebburn Shipyard, in the County of
Durham, do hereby declare the nature of this invention to be as follows:-
My invention relates to steam generators of the water tube type. In these as
usually heretofore constructed one or more upper steam or steam and water
receivers and two or more lower water vessels have been connected together by
water tubes, either straight or more or less sinuously arranged and so as to form
the side and division walls of the furnace or furnaces, and in some cases to serve as
return flues.
The object of my present invention is to provide a new, simple, cheap, and strong
form and construction of water tube boiler, and of great efficiency as a steam
generator.
According to my invention in its simplest form I employ a single upper chamber,
receiver, or drum of suitable form for steam and water, and from the lower part
thereof at either side of the vertical centre line and for practically its full length I
suspend a series of groups of pendulous tubes of small diameter and of suitably
bent, sinuous, or more or less U-shaped configuration. Both ends of each tube are
open and fixed into the lower part of the drum, and each group of tubes is arranged
transversely to the direction of length of the drum and may consist of any desired
number of separate tubes fixed at suitable distances apart.
The row of inner legs of each group on either side is so arranged as to form the
side walls of the furnace which is arranged between them and below the drum, and
the outer legs are bent outwardly to such form and in such manner as to leave an
open space of a more or less U-shape between the inner and outer legs.
Thus each bent tube acts as both an upward and downward circulating tube and
forms with the drum a complete circuit.
Inside the drum suitable baffle plates are or may be arranged for aiding the
water circulation and for the better separation of steam and water.
may employ two or more upper drums connected together or not, in which case
the series of groups of pendulous tubes are arranged at the outer sides of the centre
lines of each outer drum so as to form the walls of the furnace contained between
them and beneath said drums.
The upper drum or drums with the pendulous tubes is or are suspended or fixed
in any suitable manner, and the furnace is as stated arranged between the two side
groups of tubes at a suitable distance above their lower parts and is closed at its
back end either by a solid wall or by a suitable water leg.
By this construction the inner leg of every tube is nearer to the furnace than its
outer leg, which latter therefore is exposed to less heat, and hence good circulation
is effected throughout the whole structure.
At or about the lowest part of each tube a suitable blow-out cock or cleaning
plug may be provided, or a valved pipe may lead from each tube into a common
mud drum or receiver..
The furnace gases pass through the side rows (ie., between the inner legs) of the
tubes and then pass partly along the open or U space between the inner and outer
legs and partly in and amongst the outer legs. In this U space suitable battle plates
or shields are or may be arranged for improving the water circulation and directing

page_text: the hot gases as required. A common uptake is provided at the back end to which
the gases are directed and pass.
To increase the heating surface if required I use in combination with the above
described drum and side groups of pendulous circulating tubes a line or group of
"Field" circulating tubes arranged in the lower part of the drum or drums between
said spendulous side tubes and above the furnace.
The pendulous tubes may be of any suitable lengths and the open U space or
spaces between the legs is or are preferably made of sufficient area to admit of
access for cleaning, repairing, and so forth. The whole is enclosed in a suitable
casing and furnished with the usual boiler and furnace and other 'fittings.
Dated this 5th day of December 1893.
J. C. CHAPMAN, C.P.A.,
Agent.
COMPLETE SPECIFICATION.
* Improvements in Water Tube Steam Generators.
.1, WILLIAM CROSS, arDirector of the Firm of R. & W.. Hawthorn, Leslie & Co.,
Limited, Engineers and Shipbuilders, of St. Peters and Forth Banks Works,
Newcastle-upon-Tyne, in the County of Northumberland, and Hebburn Shipyard,
.in.the.County.of. Durham, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascertained
inrand by the following statement :-
My invention relates to steam generators of the water tube-type. In these as
usually theretofore constructed one or more upper steam or steam .and-water
receivers and two or more lower water vessels have been connected, together by
water tubes; either straight or more or less sinuously arranged, and so as to form
the side and division walls of the furnace or furnaces, and in some cases to serve as
oreturn flues.
The object of my present invention is to provide a new, simple, cheap, and
strong form and construction of water tube boiler, of great efficiency as a. steam
Egenerator.
f
lutdescribing my invention will refer to the accompanying drawings.
In Sheet Fig. 1 is a sectional elevation, and Fig. 2 a half cross-section and
halfcback endelevation of one form of my improved boiler. In this arrangement
1 employ a single upper chamber, receiver, or drum. such as A of suitable form,
forssteam and water, and from the lower part thereof at either side of the .vertical
centre line and for practically its full length as in Fig. 1. suspend a series of
groups&G G G of pendulous tubes TTT of small diameter and of suitably. bent,
sinuous, or more or less U-shaped.configuration such as illustrated. The tubes may
uber continuous without joints, or in sections with joints at or about their lower parts
or where required, as shown for example at c, Fig. 2. Both ends of each .tube. are
uopen and ifixed into the drums below water level, and each group G is arranged
nitransversely to the direction of length of the.drum and may consist of any desired
number of separate tubes: fixed at suitable distances apart. Five. separate tubes are
shown in Fig. 2 for example.
The row of inner legs of each tube group G on either side is arranged to form
the side walls of the furnace F which is placed between them at suitable level and
below the drum A, and iu communication with a common uptake W. The .outer
legs bare bent outwardly to such form and in. such manner as to leave antopen
space S of a more or less U-shape between the inner and outer legs t, t, and in the
spaces S suitable baffle plates or shields such as P in Fig. 2 are or may be arranged
for directing thengases as required to effect the best..water circulation. Thus
reach :bent tube T acts as both an upward and downward circulator and forms
with the drum.A a complete water circuit in the direction indicated by the full
arrows.

page_text: Inside the drum A suitable baffle plates such as B are or may be arranged for
ailing the water circulation and for the better separation of steam and water.
C is an exterior casing of the usual or suitable kind and p represents the main
'steam pipe.
I may employ two or more upper drums A. A, connected together or not, as shown
at a in Fig. 3, Sheet 2, in which case the series of groups G of continuous pendulous
tubes T may be arranged at the outer sides of the centre lines of each drum so as
to form the walls of the furnace F which is situated at suitable level between them
and beneath said drums.
The upper drum or drums with their pendulous tubes is or are suspended or fixed
in any suitable manner, and the back end of the furnace F is closed either by the
solid wall as in Fig. 1, or by a water leg if desired, smoke passages of suitable
area being formed at either side leading to the uptake W.
To increase the heating surface if required
above described drum or drums and side groups of pendulous circulating tubes T
may use in combination with the
a line or group of "Field " circulating or other drop tubes arranged in the lower
part of the drum or drums between the said pendulous side tubes and above the
furnace. This arrangement is indicated in Figs. 3 and 4, D D representing
"Field" tubes.
In
The principle above described may obviously be carried out in many ways, and
to suit varying conditions of area, height, power, source of heat, and so forth.
Sheet 3 I have illustrated two modified forms. Fig. 5 is a plan with some tubes
broken off, and Fig. 6 a cross-section of one arrangement. The pendulous groups G
are herein disposed on the adjacent sides of two drums A and in such manner as to
nearly approach one another at the upper parts, but inclined outwardly so as to
leave room for the furnace F between them. The drums are connected together as
shown by the tubes aa, and provided with doors M M at ends. Fig. 7 is a plan
half in section and Fig. 8 a central cross section of a circular arrangement of my
improved boiler which is very compact and well adapted for small work and for oil
or gas burning. The drum A is here made of annular form, and various groups G of
pendulous tubes T are arranged in radial directions so that the inner legs t nearly
approach one another at the centre, whereat the oil or gas jets () are arranged
below them. M M are hand holes or doors on the outer side of the drum for access
to the tube ends, C the exterior casing, C¹ a plate for dispersing the gases, and
W the uptake.
By the above described constructions the inner leg t of every tube T is nearer to
the furnace or source of heat than its outer leg, which latter therefore being
exposed to less heat good water circulation is effected throughout the whole
structure, its direction being indicated in the figures by full arrows. The flow of
furnace gases is indicated by dotted arrows. These pass through the side rows
(i.e. between the inner legs t) of the tubes T and then partly along the open
spaces S between the inner and outer legs, and partly in and amongst the outer
legs t', being suitably directed by the baffle plates C and P, and thence to the
uptake W.
The pendulous tubes T may be of any required lengths, and for cleaning same a
blow-off cock or cleaning plug may be arranged at or about the lowest part of each
tube, but I find it best to joint each tube with a union and nut about its lowest part
as shown for example at c in Fig. 6, by unscrewing which the tube can be opened
for access when required.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. In a water tube steam generator the use of one or more steam and water
drums from which depend a series of groups of continuous circulating tubes fixed
transversely to the direction of length of the drum or drums, each group com-
prising a number of suitably curved or sinuous tubes open at both ends and fixed

page_text: :
thereat into the said drum or drums and arranged in such manner that the inuer
legs form side walls enclosing the furnace or other source of heat and are therefore
exposed to a higher temperature than the other or outer legs, substantially as and
for the purposes above described and illustrated.
-
2. In a water tube steam generator such as is above referred to making the
pendulous continuous circulating tubes with a joint and union about the lowest
part, as and for the purpose above specified.
3. In a water tube steam generator such as is above referred to the combination
with a drum or drums having side groups of pendulous continuous circulating tubes
enclosing the furnace or source of heat of a line or group of "Field" or drop tubes
arranged in the lower part of the drum or drums above the furnace, substantially
as shown for the purpose specified.
4. The several arrangements of my improved water tube steam generator substan-
tially as above described and illustrated respectively in Figs. 1 and 2, 3 and 4,
5 and 6, 7 and 8 of the drawings.
Dated this 5th day of October 1894.
For the Applicant,
J. C. CHAPMAN,
70, Chancery Lane, London, W.C., Chartered Patent Agent.