Improvements in or relating to Water-tube Boilers.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Water-tube Boilers.
I, THOMAS HENRY WELLS, of Hillingdon, Uxbridge, Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to water-tube boilers for land or marine work, more
especially to that class or type known as large-tube water-tube boilers, and has
for its chief object to obtain greater efficiency and economy in working combined
with ease of management and repairs and saving in weight and space.
A boiler constructed in accordance with my invention comprises water chambers
of suitable form (for small boilers they may be three in number and for larger
boilers four, according to circumstances) connected by a number of sets of straight
generating tubes any of which can be quickly and easily taken out and replaced
by a new tube or tubes without disturbing the remainder. The generating tubes
are disposed some vertically and others at an angle, which should preferably
be not less than 30° to the horizontal, and the tubes are so arranged as to form a
combustion chamber wherein the furnace gases are mixed with heated air,
supplied as hereinafter described, before passing through the upper inclined tubes,
and thence into the uptake. More perfect combustion of the gases is thus
obtained with resultant economy and efficiency in the working of the boiler.
The four chamber boiler comprises a top and bottom and two side water
chambers the latter being each connected with the top and bottom chambers by
the inclined rows of tubes aforesaid. The top and bottom water chambers may
also be connected by vertical tubes suitably spaced within the combustion
chamber provided by the inclined rows of tubes, but these vertical tubes may if
circumstances require be dispensed with. Two furnaces would be employed thus
giving the advantages of alternate firing, the grates being arranged beneath the
lower rows of inclined tubes.
The three chamber boiler comprises a top and bottom and a side water chamber.
the top and bottom water chambers being connected with one another by vertical
tubes and by inclined tubes with the side chamber (or all the tubes may be
inclined) the space enclosed by the tubes and water chambers constituting the
combustion chamber.
In both cases the upper chamber may act as the steam receiver with or without
an additional steam dome or receiver.
Any or all of the water chambers may be connected by circulating pipes if
circumstances render it desirable.
The side water chamber or chambers may be fitted with a cover or covers
which on removal will permit the upper and lower sets of inclined tubes to be
drawn out or replaced; or if preferred, the side chamber or chambers may be
made without a cover or covers and of form suitable for the particular case, the
tubes being then drawn out into and replaced through the top and bottom
chambers respectively.
The casing of the boilers may consist either wholly or in part, as the require-

page_text: ments of the work determine, of an inner and an outer skin (the latter suitably
lagged) between which air is circulated and heated before passing into the
combustion chamber to mix with the gases. Suitable provision is made for
regulating the air supply.
Dated this 18th day of December 1899.
Improvements in or relating to Water-tube Boilers.
I, THOMAS HENRY WELLS, of Hillingdon, Uxbridge, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
This invention relates to a new or improved construction and arrangement of
water-tube boilers for land or marine work, whereby great efficiency and economy
in working are attained, combined with ease of management and repairs and
saving in weight and space.
A tubulous boiler constructed in accordance with my invention has either three
or four horizontal water chambers (according to the size of the boiler or as
circumstances may render desirable) said chambers being connected by rows of
generating tubes so as to provide a combustion chamber or chambers beneath
which the furnace or furnaces are arranged. The furnace gases enter the said
combustion chamber through the interspaces of the tubes which connect the
bottom chamber with the side chamber or chambers and are therein mixed with
air, supplied in any suitable manner, before passing out through the interspaces
of the upper tubes to the uptake. The said generating tubes (which are expanded
at their ends into the water chambers in the usual way) may be either straight
or curved, or both straight and curved tubes may be used in the same boiler, and
the water chambers and generating tubes are so constructed and arranged, as will
hereinafter appear, that any desired tube may be removed and a fresh one sub-
stituted without disturbing the remainder.
My four chamber boiler comprises a top, a bottom and two side water chambers.
the latter being each connected with the top and bottom chambers by rows of
inclined generating tubes, which should preferably make an angle of not less
than 30 degrees with the horizontal. The space enclosed by the water chambers
and generating tubes constitutes a combustion chamber of which the ends are
closed by the boiler casing. The top and bottom water chambers may also be
directly connected by vertical generating tubes arranged within the combustion
chamber aforesaid, but these vertical tubes may if circumstances require be
dispensed with. Two furnaces would preferably be employed arranged on either
side of the bottom water chamber beneath the lower rows of inclined tubes, thus
giving the advantages of alternate firing.
My three chamber boiler comprises a top, a bottom and one side water chamber,
the top and bottom chambers being connected with one another by vertical
generating tubes, and by inclined tubes (preferably making an angle of not less
than 30 degrees with the horizontal) with the side chamber. Or the tubes
connecting the top with the bottom chamber may also be inclined. The furnace
is arranged beneath the lower rows of inclined tubes and the space enclosed by

page_text: the generating tubes and water chambers constitutes the combustion chamber
the ends of which are closed by the boiler casing.
In both cases the upper water chamber may act as the steam receiver, with or
without an additional steam dome or receiver.
The top and bottom water chambers are connected together by circulating or
downcomer pipes and may be also connected by like pipes with the side chambers
if found desirable.
The side water chamber or chambers may be fitted with a cover or covers which
on removal will permit any of the upper and lower sets of inclined tubes to be
drawn out and replaced, or, if preferred, the side chamber or chambers may be
made without a cover or covers, and of form suitable for the particular case, the
tubes being then drawn out and replaced either direct or through the top and
bottom chambers respectively, according to the position of the tube to be
renewed.
Air may be supplied to the combustion chambers direct by fans or any other
recognised and suitable means, or the casing of the boiler may consist either
wholly or in part, as the requirements of the work may determine, of an inner
and an outer skin (the latter suitably lagged) between which air is circulated and
heated before passing into the combustion chamber to mix with the gases.
Suitable provision would of course be made for regulating the air supply.
In the accompanying drawings, which are of a diagrammatic nature:-
Figure 1 is a part sectional end elevation of a four chamber tubulous boiler
constructed in accordance with my invention.
Figure 2 is a similar view of a slightly modified construction, curved, in lieu
of straight generating tubes being shewn.
Figure 3 is a cross section of a three chamber boiler constructed according to
my invention.
Similar letters refer to like parts in all the figures.
Referring to Figures 1 and 2, A A¹ are the top and bottom water chambers
and B B are two side water chambers. The top water chamber A is connected
with the two side water chambers by rows of generating tubes D, and the bottom
water chamber A¹ is connected with said side chambers by rows of generating
tubes E. These generating tubes may be either straight, as in Figure 1, or
curved, as in Figure 2, or both straight and curved tubes may be used in the
same boiler if preferred. The top and bottom water chambers may also be
directly connected by rows of vertical generating tubes F, but these latter may
be dispensed with should circumstances render it desirable. The space enclosed
by the inclined tubes D E and the water chambers forms a combustion chamber
or chambers G the ends of which are closed by the casing C. The furnaces H
are arranged beneath the lower rows of inclined tubes E, two being preferably
employed thus giving the advantages of alternate firing, and the hot gases there-
from, passing through the interspaces of said tubes E into the combustion cham-
ber or chambers G are therein mixed with air as before explained before passing
through the interspaces of the upper inclined tubes D to the uptake. I I' are
downcomers external to the casing at both ends of the boiler for assisting the
circulation, the downcomers I¹ which connect the side chambers with the top
and bottom chambers are not however absolutely essential and may be dispensed
with if considered desirable.
In the three chamber type, illustrated in Figure 3 and specially suitable for
small boilers, the top and bottom chambers A A¹ are connected by the rows of
generating tubes F¹, which may be either inclined as shewn or vertical, whilst
the side chamber B connects with said top and bottom chambers by the generating
tubes D E. As in the arrangement previously described the generating tubes
may be either straight or curved or a mixture of both. The furnace H is situated
beneath the lower row of inclined tubes E through the interspaces of which the
hot gases pass into the combustion chamber G provided by the generating tubes
and water chambers, and are therein mixed with air before passing through the

page_text: interspaces of the tubes D and F1 to the uptake as in the arrangement first
described. In this arrangement also downcomers external to the casing would
be provided, connecting the top and bottom chambers with one another, and also
with the side chamber B if considered desirable, but these latter, i.e. the down-
comers connecting the side chamber with the top and bottom chambers, may be
dispensed with if preferred. In both arrangements the axis or axes of the side
water chamber or chambers must, as illustrated, be intermediate of the levels of
the axes of the top and bottom water chambers so as to avoid horizontal generat-
ing tubes which would impede the circulation. Preferably, as before stated,
the tubes D E should make an angle of not less than 30 degrees with the
horizontal.
Any tube may be removed and a fresh one substituted without disturbing the
remainder by withdrawing it direct or through the top or bottom chamber A A¹
according to its position, or the side chamber or chambers B B¹ may be provided
with any suitable or well known arrangement of cover or covers, as will be readily
understood, through which the generating tubes D and E may be withdrawn
and replaced.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a water-tube boiler and in combination, a casing, an upper, a lower and
two side water chambers, inclined generating tubes connecting each side chamber
with the upper and lower chambers respectively, and a furnace or furnaces
disposed beneath the generating tubes which connect the lower chamber with
the side chambers, the said upper and lower chambers being connected or not by
vertical generating tubes passing through the combustion chamber, the whole
constructed, arranged and adapted to operate substantially as described and as
illustrated in Figures 1 and 2 of the annexed drawings.
2. In a water-tube boiler and in combination, a casing, an upper, a lower and
a side water chamber, inclined or vertical generating tubes connecting the upper
and lower chambers, inclined generating tubes connecting the side chamber
with the upper and lower chambers, and a furnace beneath the generating tubes
which connect the side and bottom chambers, when constructed. arranged and
adapted to operate substantially as described and as illustrated in Figure 3 of
the annexed drawings.
Datad +1 101 J Contamakan 1000