Improvements in Combustion Furnaces.
Year: 1893

page_text: Date of Application, 30th Aug., 1893
Complete Specification Left. 5th Oct.. 1893-Accepted, 18th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Combustion Furnaces.
I, JAMES SHENTON, of Perry Barr, Birmingham, in the County of Warwick,
Manufacturer, do hereby declare the nature of my said invention to be as
follows:-
My invention has for its object improvements in combustion furnaces which are
much more economical than those now in use and more effective for the purpose.
I will explain my invention as applied to the front of an ordinary steam boiler.
I form the furnace in shape somewhat similar to those now in use having its
grate bars and entrance door for firing and to the dust hole. Inside the furnace I
carry a tube which I call a superheater. This superheater is connected to the
upper part of the steam portion of the boiler and conveys steam therefrom to the
superheater. Connected also to the superheater is one or more vertical pipes which
pass through the top of the chamber and having the upper portion bent so as to
turn into the bonnet portion of one two or more down pipes which conveys the
superheated steam or hot air down to and underneath the fire grate of the furnace.
The effect is to carry down a certain amount of highly heated air under the furnace
in a most convenient and economical manner so as to effectively accomplish the
object and to effect a great saving in the cost of fuel.
Dated this 29th day of August 1202
GEORGE BAKKER,
77, Colmore Row, Birmingham, Agent.
COMPLETE SPECIFICATION.
Improvements in Combustion Furnaces.
I, JAMES SHENTON, of Perry Barr, Birmingham, in the County of Warwick,
Manufacturer, do hereby declare the nature of my said invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :—
My invention has for its object improvements in combustion furnaces which are
much more economical than those now in use and more effective for the purpose
whether it be for use in the heating of steam boilers or of other kinds of furnaces,
but I will explain my invention as applied to the front of ordinary steam boilers.
I form the furnace in shape similar to those now in use having its grate bars and
entrance door both for firing and to the dust hole. Inside the brickwork of the
furnace along one or both sides, I carry a tube or tubes which I call a superheater.
This super-heater is connected to the upper part of the steam portion of the boiler
and conveys steam therefrom to the superheater. Connected also to the super-
heater is one or more vertical pipes which pass through the top of the chamber
and having the upper portion bent so as to turn into the bonnet portion or funnel
entrance of one two or more down pipes which conveys the superheated steam or
hot air down to and underneath the fire grate of the furnace this action at the same
time carrying a quantity of fresh air under the grate. The effect is to carry
down a certain amount of highly heated air under the furnace in a most convenient
and economical manner so as to effectively accomplish the object and to effect a
great saving in the cost of fuel.
In order that my invention may be clearly understood and more easily carried
into practice I have appended hereunto a double sized sheet of drawings upon

page_text: nave mustrated my improved mode of combustion applied to the heating
of an ordinary steam boiler and from which its application to other furnaces for
various purposes will be readily understood.
Figure 1., is a longitudinal section through a furnace showing part of the
boiler.
Figure II., is a cross section through Figure 1 on the line 1-2.
Figure 3., is a front elevation of the furnace and the front end of a boiler.
Figure 4., shows a modification in the arrangement of the superheater.
Figure 5., is a sectional plan of Figure 4.
Figure 6., shows a further modification in the superheater.
Figure 7., is a plan of same.
In carrying my invention into effect I form the furnace A in shape similar to
those now in use having its grate bars B and entrance doors D for firing and D¹ to
the dust hole E. I prefer to connect the furnace to the boiler tube by a narrow
neck W the brickwork protecting the front. plate thereof. Within the brickwork
at one or both sides of the furnace I carry the tube or tubes F which are so placed
as to receive the full effect of the heat of the furnace being at the same time
protected from damage by the fire-brick or fire-clay lining a'. This arrangement
obviates the burning and slitting of the tubes which occurs in other systems. These
tubes F are connected to the upper part of the steam portion of the boiler K so
that steam is supplied to the superheaters F by the pipes f2. Running up through
the top of the chamber A are the pipes f' which convey the superheated steam into
the funnel mouths h' of one two or more down pipes H which are also built
within the brick sides a² of the chamber in such a position that they receive as
much heat as possible without damage and are bent to convey the draught into the
dust hole under the fire bars of the furnace. It will be noticed that the pipes H
deliver the heated air and superheated steam under the furnace crosswise to the
direction of the natural draft produced by the chimney and I prefer that they
should point rather to the entrance of the furnace than to the back to ensure the
heated air rising through the fire bars at the very front so as to utilize the whole
fire grate area. It is a mistake to inject the air in the direction of the natural
draught. The injection of the superheated air into the funnel as shown causes
an incurrent of fresh air at this point which intermixes with the superheated steam
or hot air and thus forms a current which is most favorable to combustion when
introduced as before indicated, so much so, that in furnaces in which my improve-
ments are embodied, the finest slack may be used without the emission of
unconsumed gases from the chimney and with much less accumulation of, ashes or
dust. The amount of the current or draught is regulated by the valves f³ or ƒ*
which are placed as shown, or one valve will do and the amount of pipe required in
the superheater is regulated by the size of the furnace or of the draught required,
but generally I find a pipe or pipes running the length of the furnace, is or are
sufficient. Figures 4 and 5 show a modification in which the heating surface is
enlarged by the use of two or more longitudinal or vertical pipes or by the use of a
zig-zag pipe S, as Figure 6. In the case of pipes R Figure 4 the longitudinal
pipes may be made smaller in diameter than the vertical inlet and delivery pipes,
which in such cases would be formed at each end of the longitudinal pipes. In
case I apply the air direct to boiler furnaces not having a separate furnace, I
turn the pipes upwards or backwards so that the heated air is delivered under
the dead plate instead of in the direction of the natural draught which is a
mistake.
I am aware that steam has been conveyed direct to the underside of furnace
grates but this has the objection of causing an accumulation of water by con-
densation of the steam while the steam so conveyed is nothing like so effective, and
I do not claim as new in itself either superheating steam, or the use of such super-
heated steam for heating air supplied to a fire. It is the particular construction of
the parts and their arrangement in conjunction with a furnace separate from the
boiler which constitutes my invention.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. The improvements in combustion furnaces substantially as and for the
purpose herein set forth and shown upon the accompanying drawings.
2nd. In combustion furnaces fed by hot air as herein set forth conducting the air
under the grate by side pipes.
3rd. In combustion furnaces fed by hot air placing the superheating pipe or
pipes behind fire bricks or fireclay.
4th. In combustion furnaces inside a boiler flue turning the discharge pipe or
pipes upwards or backwards or crosswise to deliver the air other than in the
direction of the natural draught.
Dated this 3rd day of October 1893.
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent for Applicant.