Improvements in Steam Boilers and Boiler Furnaces.
Year: 1893

page_text: Date of Application, 16th Feb., 1893
Complete Specification Left, 10th Nov., 1893-Accepted, 16th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers and Boiler Furnaces.
We, CHARLES ALBERT KNIGHT and GEORGE WILLIAM THODE both of
21 Bothwell Street in the City of Glasgow, Engineers, do hereby declare the
nature of this invention to be as follows:-
This invention which relates to sectional steam generators of the water-tube type
has for its object by suitable arrangement and connection of the heating surfaces
in conjunction with division of the combustion chamber into compartments to ensure
more complete combustion of the fuel used in the furnace and consequently absence
of smoke as also the better utilization of the heat generated.
In carrying out the invention as applied for example to the well known
Babcock & Wilcox type of water tube boiler in which a series of inclined water
tubes situated over a furnace or within a combustion chamber are connected at
each end to headers connected in turn to a steam and water drum or reservoir
we detach from the series of inclined tubes one or more rows and place them at
a lower level over the furnace or we add a separate section composed of one
or more rows so situated and over or upon this detached row or section we
build or form a roof or lay bricks or tiles extending the whole length or nearly
the length of the furnace. At the rear front end or in the centre or at both
ends simultaneously of the furnace we build or form a brick arch or arches so
that the gases generated by the combustion of the fuel in part rise and impinge
upon the tubes under the tile or brick work roof formed over the lower row or
rows of tubes and thence pass through between the end of said roof or roofs and
the arch or arches by which their direction is reversed. By this arrangement the
combustion chamber is divided into two compartments, the one directly over the
furnace in which the heat radiated from the fuel direct is utilized in converting
into steam the water circulating through the lower row or rows or section of the
boiler and the other situated over the tiles or brickwork built upon or over the
lower rows of tubes and in which the volatile gases become thoroughly mixed with
the air admitted either through the fuel or through separate passages and in
being consumed part with their heat to the water circulating through the tubes in
the upper section of the boiler.
In general the tubes composing the detached row or section are carried through
the lower combustion chamber and through the bridge and are so arranged as to
break up and assist in intermingling the gases arising immediately from the fuel in
the furnace. In front the tubes are connected to short headers nippled or con-
nected by straight or bent tubes to the main headers and at the rear they either
extend and are connected to lower extensions of the rear headers or to separate
short headers nippled to the main rear headers or they are connected to a cross
drum at the rear of the bridge which may serve as an auxiliary mud drum or
collector in which impurities in the water are collected and blown off at intervals.
In this latter case the said cross drum is connected to the main steam and water
drum or to the rear headers or to the rear mud drum frequently provided under
the rear headers so as to ensure proper circulation of the water through the tubes
in the lower combustion chamber.
In cases in which mechanical stokers or fuel feeders constitute the furnace or
part of it the flow of the fire gases may take place as in handfiring either from the
front to the rear or preferably from the rear towards the front of the furnace in
which the flame bridge arch is situated in proximity to the front headers and the
gases as their direction is reversed in passing through said arch and over the tile
or brickwork on the lower tubes are deflected by brickwork so as to cause the

page_text: combustion to be completed after which they traverse the main series of the tubes
as usual.
Such arrangements are specially applicable with the use of the Tenbrink type
of furnace or others of a like type in which the fire grate is highly inclined and
the fire gases flow in a forward direction owing to the inclination of the furnace.
In such cases the tubes over which the brick or tile covering is built to form the
duplex combustion chamber, are connected at either end to short headers manifolds
or cross boxes in front connected direct to the front headers and at rear connected
by rows of tubes to the rear header or other part of the boiler.
The flame bridge arch is constructed of brickwork supported by blocks of
suitable form so placed as to serve the further purpose of supporting the ends of
the tiles or brickwork over the lower series of tubes to prevent them sliding down-
wards. These supporting blocks whilst along with the lower row or rows of tubes
serving to break up into separate streams the fire gases are situated at such
intervals apart as to give ample passage for the fire gases, but to provide free access
for fitting the blocks in place and building or repairing the arch several of the
straight or bent water tubes at the front end may be omitted.
Dated this 15th day of February 1893.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Steam Boilers and Boiler Furnaces.
We, CHARLES ALBERT KNIGHT and GEORGE WILLIAM THODE both of
21 Bothwell Street in the City of Glasgow, Engineers, 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, which relates to sectional steam generators of the water-tube
type has for its object by special arrangement of the heating surfaces and division
of the combustion chamber into compartments to ensure more complete combustion
of the fuel used in the furnace and therefore the better utilization of the heat
generated as well as absence of smoke.
In the accompanying drawings which illustrate our invention
Figure 1 is a longitudinal section of a water tube boiler of the Babcock & Wilcox
type shewing one modification of the improved furnace and of the arrangement
of detached section of tubes.
Figures 2 and 3 are cross sections of the same taken respectively on the
lines 2-2 and 3-3.
Figure 4 is a sectional elevation corresponding to Figure 1 but shewing a
mechanical stoker applied in lieu of the stationary fire grate.
Figure 5 is a similar view but shewing a modified construction of the divided
furnace or combustion chamber a stationary fire grate being used as in Figure 1;
Figure 6 a similar view but shewing a mechanical stoker applied to the furnace;
Figure 7 a view corresponding to Figure 1 shewing a further modification of the
divided furnace or combustion chamber and detached tube section.
In the several boilers represented in the drawings the main series of inclined
water tubes A are situated over the furnace B or within a combustion chamber C
and are connected at each end to headers D D connected in turn to a steam and
water drum or reservoir E but from the series of inclined tubes one or more rows A¹
is or are detached and placed at a lower level over the furnace or there is added
a separate section composed of one or more rows so situated; and over or upon
this detached row or section A¹ there is built or formed a roof F, or bricks or tiles
are laid, extending the whole length or nearly the length of the furnace B. At
the rear or front end or in the centre or at both ends simultaneously of the
furnace a brick arch or arches F1 is or are built or formed so that the gases

page_text: generated by the combustion of the fuel in part rise and impinge upon the tubes A¹
under the tile or brick work roof F formed over the lower row or rows of tubes
and thence pass through between the end of said roof or roofs and the arch or
arches F1 by which their direction is reversed. By this arrangement the com-
bustion chamber is divided into two compartments, the one directly over the
furnace or fire grate B in which the heat radiated from the fuel direct is utilized
in converting into steam the water circulating through the lower row or rows or
section of the boiler and the other situated over the tiles or brickwork F built
upon or over the lower rows of tubes A¹ and in which the volatile gases become
thoroughly mixed with the air admitted either through the fuel or as indicated in
Figure 5 through separate passages g and in being consumed part with their heat
to the water circulating through the tubes A in the upper section of the boiler.
In general the tubes composing the detached row or section A¹ are carried through
the lower combustion chamber and through the bridge G and are so arranged as
to break up and assist in intermingling the gases arising immediately from the
fuel in the furnace. In front the tubes A¹ are connected to short headers D'
nippled or connected by straight or bent tubes d to the main headers D or they
may be connected direct to the front header as shewn at Figure 7 and at the
rear they either extend and are connected to lower extensions of the rear headers D
as indicated at Figures 1 and 5 or to separate short headers or drums H nippled to
the main rear headers as indicated at Figures 4 and 6 or they may be connected
to a cross drum at the rear of the bridge G which may serve as an auxiliary
mud drum or collector in which impurities in the water are collected and blown
off at intervals. The auxiliary mud drum or sludge intercepter l' may also as
shewn at Figures 1, 4, 5, 6 and 7 be fitted to the tubes A¹ in the examples in
which said tubes are carried rearwards and connected to the rear headers of the
boiler the arrangement as regards the intercepter being similar to that described
in the Specification of Letters Patent No. 1134 of 1892. The cross drum I or I¹
may be connected to the main steam and water drum E or to the rear headers or
as indicated at Figures 4 and 6 to the rear mud drum H frequently provided under
the rear headers D so as to ensure proper circulation of the water through the
tubes A in the lower combustion chamber. In cases in which mechanical stokers
or fuel feeders constitute the furnace or part of it the flow of the fire gases may
take place as in hand-firing either from the front to the rear or preferably as
indicated at Figure 6 from the rear towards the front of the furnace in which the
flame bridge arch F is situated in proximity to the front headers D and the
gases as their direction is reversed in passing through said arch and over the tile
or brickwork F on the lower tubes A' are deflected by the brickwork so as to cause
the combustion to be completed after which they traverse the main series of the
tubes A as usual. Such an arrangement is specially applicable in the form known
as the "Tenbrink" type of furnace or others of a like type in which the fire grate
is highly inclined and the fire gases flow in a forward direction owing to the
inclination of the furnace. The flame bridge arch is constructed of brickwork
supported by blocks of suitable form so placed as to serve the further purpose of
supporting the ends of the tiles or brickwork over the lower series of tubes to
prevent them sliding downwards. These supporting blocks whilst along with the
lower row or rows of tubes serving to break up the fire gases into separate streams
are situated at such intervals apart as to give ample passage for the fire gases ;
but to provide free access for fitting the blocks in place and building repairing or
cleaning the arch one or more of the straight or bent water tubes at the front end
may be omitted.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is―
1. The improved sectional steam generator hereinbefore described under several

page_text: 2. A sectional steam generator composed of a main series of inclined water tubes
headers and drum and a section of water tubes detached from the main series but
'connected to the headers in combination with a furnace divided into compartments
by a roof and arch separating the main series from the detached section of tubes
substantially as described.
Dated this 9th day of November 1893
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.