Year: 1899

page_text: We, JOSEPH HALLETT, of 108, Fenchurch Street, in the City of London, Con-
sulting Engineer, and GEORGE HALLIDAY, of 23, Alfred Place, Bedford Square, in
the County of London, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to an improved construction of water tube steam
generator.
According thereto the steam generator is constructed with interchangeable
sections each comprising two vertical or approximately vertical water chambers
arranged parallel or approximately parallel with each other, a nest of water tubes
connecting the inner walls of the said chambers, and flue tubes extending centrally
through the water tubes, or some of them, so as to form therewith annular water
spaces and connecting the outer walls of the water chambers, these flue tubes being
secured to the said outer walls that fluid tight joint
a
SO
can
be easily produced between the two but SO nevertheless as - to
admit of the ready withdrawal of such tubes for inspection or cleaning
thereof, or for inspection, cleaning or stopping of the water tubes through
which they ordinarily pass. The sections are arranged parallel with each other,
with the water tubes and flue tubes inclined downward and backward above a fire
grate or grates, the upper ends of the water chambers being suitably connected
with one or more steam and water drums (hereinafter called steam drums) located
above them, and the sections and steam drum or drums being enclosed in a casing
the parts of which opposite to the ends of the sections are arranged to form front
and rear smoke boxes that are provided with doors by which ready access can be
gained to the flue tubes.
The top of the front smoke box and the top of the space above the nests of tubes
communicate with an uptake or chimney above, it may be through separate
openings controlled by dampers, and the rear smoke box communicates with the
front one through the flue tubes and is placed in communication at the lower
end with the combustion chamber above the grate or grates through a passage
behind the fire bridge, the arrangement being such that flame and hot gases can
pass partly amongst and between the water tubes direct to the uptake and the
remainder can pass to the rear smoke box, and then through the flue tubes to the
front smoke box whence they pass to the uptake, or as at starting or other desired
times, the flame and hot gases can wholly pass to the uptake through the space
surrounding the water tubes.
In one construction of steam generator according to this invention, the sections,
of which there may conveniently be three, are arranged to extend from front to
back of the generator and are supported upon suitable bearers above one or
more fire grates so that flame and hot gases can pass upward between the water
chambers of the sections and amongst the water tubes one or more lower rows of
which are preferably without flue tubes. The lower rows of water tubes are

page_text: suitably arranged to form between them a combustion chamber above the fire grate
or grates.
To enable the flue tubes to be securely fixed in a readily detachable manner to
the outer walls of the water chambers 'one end of each tube is provided with a collar
and nut to abut against opposite sides of the adjacent outer wall, the collar being
on the inside and of such a diameter as to admit of its passing through the corre-
sponding water tube. The other end of each flue tube is provided with a collar
and nut to abut against opposite sides of a plug that surrounds the tube and is
screwed into a hole in the outer wall of the water chamber of sufficient size to
admit of the insertion and securing of the corresponding water tube, or a tube
stopper.
Supported centrally above the sections by suitable bearings is a steam drum
that is preferably slightly inclined backward and downward and is connected
near its ends to the upper ends of the front and rear water chambers by pipes
opposite the upper ends of which there is arranged within the steam drum a
suitable baffle or steam separating device such as a concave plate having its concave
side uppermost. The sections are enclosed in a suitable casing the back and front
portions of which are arranged to form smoke boxes that communicate with the
ends of the flue tubes and are provided with hinged doors by which ready access
can be gained to the said tubes, the rear chamber being in communication with
the space above the grate through passages behind the fire bridge, and the upper
end of the front smoke box and the space above the nests of tubes being arranged
below and in communication with an uptake arranged above and carried by the
casing and through which the steam drum extends. The tubes connecting the
front water chambers to the steam drum are located in or below the uptake. The
rear connecting tubes, which may be enclosed in the uptake or casing or not, act as
downtake tubes.
Baffle plates are or may be placed between the water tubes at different levels
so as to ensure a better distribution of the hot gases amongst such tubes and to
offer sufficient resistance to the hot gases to ensure that some of them will pass
through the rear smoke box to the flue tubes and thence through the front smoke
box to the uptake. Suitable dampers are or may be provided for controlling the
passage of flame and hot gases through the smoke boxes and flue tubes, so that
flame and hot gases can, when desired, pass direct to the uptake instead of passing
first through the flue tubes.
The lower adjacent parts of the rear water chambers are connected together
by pipes secured in flanged holes in the side walls of the chambers, the outer
sides of the outer rear chambers being connected by similar flanged parts: to
discharge pipes, the arrangement being such that mud collecting in the bottoms
of the rear lower water chambers can be readily discharged into a mud drum or
other receptacle.
The water tubes, or some of them, are or may be provided with spirally twisted
strips of metal for the purpose of imparting a circular motion to the water flowing
through them and thus bringing it into effective contact with the heated walls of
the water tubes and of the flue tubes extending through the water tubes.
The outer plate of each water chamber may conveniently be a flat plate bearing
against a flanged part of the inner plate which is of dished shape, the two, Hanges
being secured together, it may be by bolts and nuts, so that they can be readily
separated when desired.
The rear water chambers are or may be directly supported by a beam of I or.
other section and a metal shoe or protector that are carried by pillars of refractory
material arranged between the fire bridge and the rear smoke box which comi-
municates with the space above the grate or grates through the openings between
the pillars and the passage between such pillars and the fire bridge. The front
water chambers are or may be supported by a beam carried by the front plate of
the furnace and ash pit.
Steam generators according to this invention may be variously modified. Thus

page_text: the steam drum instead of being arranged from front to back of the generator
may be arranged lengthwise thereof and parallel to the sets of, water chambers and
either between such chambers or over one of them.
We, JOSEPH HALLETT, of 108, Fenchurch Street, in the City of London, Con-
sulting Engineer, and GEORGE HALLIDAY, of 23, Alfred Place, Bedford Square, in
the County of London, 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 has reference to improvements in water tube steam generator
as I shall now describe with reference to the accompanying illustrative drawings
wherein Fig. 1 shows partly in longitudinal vertical section and partly in side
elevation, a water tube steam generator constructed according thereto. Fig. 2
shows the steam generator partly in front elevation and partly in vertical section on
the lines A A, B B and CC of Fig. 1. Fig. 3 is a detail view to a larger scale.
The improved steam generator is constructed with interchangeable steam
generating sections each comprising two vertical or approximately vertical water
chainbers 1 and 2 (hereinafter called headers) arranged parallel or approximately
parallel to each other, a nest of water tubes 3 connecting the inner walls 1, 2
of the said headers, and flue tubes 4 extending centrally through the water tubes 3,
or some of them, so as to form therewith annular water spaces 5 and connecting
the, outer walls 1b2b of the headers, these flue tubes being so secured to the said
outer walls, as hereinafter described, that a fluid tight joint can be easily produced
between the two but so nevertheless as to admit of the ready withdrawal of such
tubes for inspection or cleaning thereof, or for inspection, cleaning or stopping
the water tubes 3 through which they ordinarily pass. The sections are arranged
parallel with each other with the water tubes 3 and flue tubes 4 inclined downward
and backward above a fire grate or grates 6, the upper ends of the headers being
suitably connected with a steam and water drum 7 (hereinafter called a steam
drum) or there may be more than one such drum, located above them, and the
sections, and steam drum or drums or part thereof, being enclosed in a casing 8
the parts of which opposite to the ends of the sections are arranged to form front
and rear smoke boxes 9 and 10 respectively that are provided with hinged doors
11 by which ready access can be gained to the flue tubes 4.
The top of the front smoke box 9 and the top of the space 12 above the nests of
tubes communicate with an uptake or chimney 13 above through separate
openings 14 and 15 controlled respectively by dampers 14 and 16; in some
cases only the opening 15 may be controlled by a damper. The dampers 14ª and 16
are shown as plates fixed to operating rock shafts 14 and 16 respectively. The
rear smoke box 10 communicates with the front one 9 through the flue tubes 4 and
is placed in communication at the lower end with the combustion chamber 18,
As
above the grate or grates 6, through a passage 19 behind the fire bridge 20.
will be seen, the arrangement is such that flame and hot gases can divide in the
combustion chamber 18, part passing amongst and between the water tubes 3 and

page_text: through the opening 15 direct to the uptake 13, and the remainder passing through
the passage 19 to the rear smoke box 10 and then through the flue tubes 4 to the
front smoke box 9 whence they pass to the uptake 13, or, as, at starting, or other
desired times, the flame and hot gases can, by, fully opening the damper 16 and
closing the damper 14*, be caused to wholly pass to the uptake through the space
surrounding the water tubes 3.
By dividing the hot gases into two streams flowing simultaneously from the
combustion chamber, the flue tubes can be heated practically to the same tempera-
ture as the water tubes; whereby the heating surfaces afforded by such flue tubes
can be efficiently utilized.
In the construction of steam generator shown by way of example in the drawings,
there are three sections arranged to extend from front to back of the generator
and supported upon suitable.bearers 21 above three fire grates G so that flame and
hot gases can pass upward between the headers of each sections and amongst the
water tubes 3. The bearers 21 may be, as shown, girders of I section, the rear
one, carrying the rear headers, being arranged within a metal shoe or protector 21*
carried by pillars 21b of. refractory material that are arranged between the fire
bridge 20 and the rear smoke box 10 and between which are openings forming
part of the passage 19 through which the rear smoke box communicates with the
space above the fire grates. One or more of the lower rows of water tubes is or are
preferably without flue tubes. In the example shown, the water tubes in the lower
row of such tubes are without flue tubes. The two lower rows, of water tubes 3
are suitably arranged to form between them a supplementary combustion
cuamber 22 above the corresponding fire grate 6. The portions of the inner and
outer header walls 1, 1 and 2, 2b opposite the ends of this supplementary com-
bustion chamber are strengthened by stays 1 and 2ª.
To enable the flue tubes 4 to be securely fixed in a readily detachable manner
to the outer walls 1b, 2h of the headers 1 and 2 respectively, one end, say. the
rear end, of each flue tube is provided with a collar 24 and nut 25.to abut
against opposite sides of the adjacent outer wall 2, the collar being on the inside
and of such a diameter as to admit of its passing through the corresponding water
tube 3. The other end of each flue tube is provided with a collar 24 and nut 25*
to abut against opposite sides of a plug 26 that surrounds the tube end and is
screwed into a hole 27 formed in the outer wall 1b of the front header 1 and made
of sufficient size to admit of the insertion and securing of the corresponding
water tube 3, or of a tube stopper. By the construction described, the outer wall
of each header is effectually stayed; whilst at the same time each flue tube can be
easily removed when desired.
I
The steam drum 7 is supported centrally above the sections by suitable bear-
ings 28. It is preferably slightly inclined backward and downward and is
connected near its front and rear ends to the upper ends of the front and rear
headers 1 and 2 by pipes 30 and 31 respectively. Opposite the upper ends of these
pipes there is arranged within the steam drum a suitable baffle or steam separating
device such as a concave plate 32 having its concave side uppermost.
The pipes 30 connecting the front headers 1 to the steam drum 7 are located in
or below the uptake 13. The rear connecting tubes 31, which may be enclosed
in the uptake or casing S, or, as shown, arranged outside thereof, act as downtake
tubes.
Baffle plates 32. are or may be placed as shown between the water tubes 3
at different levels so as to ensure a better distribution of the flame and hot gases
amongst such tubes and to offer sufficient resistance to the hot gases to ensure
that some of them will pass through the rear smoke box 10 to the flue tubes 4
and thence through the front smoke box 9 to the uptake 13 when the damper 16 is
partly opened. The said damper 10 serves to control the quantity of hot gases
that passes to the uptake direct through the opening 15 and the quantity that
passes indirectly through the opening 14 to the uptake. By fully opening the
damper 16 and closing the damper 14, the whole of the hot gases from the fire on

page_text: the fire grates will be caused to flow over and amongst the water tubes 3 and
through the opening 15 to the uptake:13, and by closing the damper 16 and opening
the damper 14, the whole of then hot gases will be caused to flow
through the rear passage 19, rear suiokeitbox. 10, flue tubes 4, front smoke
box 9 and opening 14 to the uptake, whilsta by partly opening both dampers, the
hot gases will be caused to divide, part, passing amongst the water tubes and
through the opening 15 to the uptake and part flowing as described through the
flue tubes to the uptake, the quantity of gases passing by each route being capable
of easy adjustment by suitably regulating the position of the two dampers.
The lower adjacent parts of the rear headers 2 are connected together by pipes
34 secured in flanged hoies 35 in the side walls of the headers, and the outer sides
of the outer rear headers are connected by similar flanged parts 35 to discharge
pipes 36, the arrangement being such that mud collecting in the bottoms of the
rear lower headers can be readily discharged into a mud drum 37 or other
receptacle.
The water tubes 3 or some of them, are or may be provided with spirally twisted
strips of metal for the purpose of imparting a circular motion to the water flowing
through them and thus bringing it into effective contact with the heated walls
of the water tubes and of the flue tubes extending through the water tubes.
To enable access to be gained in a simple and ready manner to the interior
of the headers 1 and 2 for inspecting and cleaning the same and for gaining free
access to the water tubes 3 for the purpose of cleaning, stopping or withdrawing
and replacing such tubes, the outer wall 1b, 2b of each header is made removable
and adapted to be secured to the flanged part 1° or 2° of the inner wall 1* or 2^,
which is made of dished shape, by studs 38 and nuts 38, or by bolts and nuts as
may be desired.
Steam generators according to this invention may be variously modified. Thus
the steam drum instead of being arranged from front to back of the generator may
be arranged transversely thereto and parallel to the sets of headers and either
between such headers or over one of them.
Fig. 4 is a longitudinal section and Fig. 5 a front elevation, showing the upper
part of a boiler thus constructed, the transversely arranged steam drum being
over the rear header.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. In a water tube steam generator having one or more steam generating
elements comprising or each comprising two headers connected by concentrically
arranged water and flue tubes and arranged within a casing above a firegrate
so as to form front and rear smoke boxes with which the flue tubes communicate,
connecting the lower end of one of the smoke boxes with the combustion chamber
above the fire grate, and the top of the other smoke box with the chimney, and
controlling the exit of hot gases to the chimney by one or more dampers, the
arrangement being such that by suitably adjusting the position of the said
damper or dampers, the hot gases coming from the fire can be caused to flow over
and amongst the water tubes direct to the chimney, or to pass through the flue
tubes on their way to the chimney, or can be divided into two separate streams one
of which will flow over and amongst the water tubes direct to the chimney whilst
the other will flow from the combustion chamber into one of the smoke boxes and
thence through the flue tubes and the other smoke box to the chimney, substantially
as described.
2. A water tube steam generator of the kind having a steam generating element
comprising two headers connected by concentrically arranged water and flue
tubes as set forth, wherein the inner plate of each header to which the water tubes
are secured is dished and flanged and the outer plate to which the flue tubes are
detachably connected is secured in a readily removable manner to the flanged part

page_text: of the inner plate so that such outer plate can be readily removed for enabling
access to be gained to the interior of the header and water tubes without damaging
any part of the steam generator, substantially astdescribed and shown.
'
3. A water tube steam generator of the kind herein referred to wherein the outer
wall of either header is formed with large openings arranged opposite the water
tubes and fitted with screw plugs through which the corresponding ends of the
fluettubes extend, the said tube ends each having a collar bearing against the inner
side of the plug and a nut screwed. on its outer end, substantially as-herein
described for the purposes set forth..
4. A water tube steam generator constructed arranged and operating substan-
tially as hereinbefore described with reference to Figs. 1, 2 and 3 of the drawings
annexed, or modified according to Figs. 4 and. 5.