Improvements in or relating to Boiler and other Furnaces.
Year: 1891

page_text: Date of Application, 2nd Nov., 1891-Accepted, 5th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in or relating to Boiler and other Furnaces.
I, FRIEDRICH STEFFENS of Speersort 4 Hamburg in the Empire of Germany
Merchant 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 relates to furnaces for heating steam boilers or for other purposes
and it consists in a construction for providing an air feed for consuming or
completely burning up the combustible matters in the smoke as hereinafter
described. This consists of a wall surrounding the combustion space on all sides
except at one place where it is left open for the supply of fuel through the furnace
inlet closed in the usual way by the furnace door. This wall is so placed as to
leave a free space all round between it and the side walls of the usual combustion
chamber. The space within this special or inner wall is closed above by a cover
plate or if the wall is high enough, by the arched roof of the furnace, and its floor
is formed by a grate of fire bars.
The inner wall is pierced by a suitable number of openings to allow the gases
to pass into the space outside this inner wall and thence to the furnace flues or
tubes or to their other destination. These openings are preferably vertical slits.
In the body of the inner wall are a number of rising air channels opening below in
an air supplying main channel common to all, this main channel receiving air from
the ash space below the grate and allowing said air to rise within the body of
the wall in the said air channels so that it is heated to a high temperature and
issues into the fuel chamber above the solid fuel therein so as to mix with the
flaming gases and tend to completely burn up all combustible matter therein.
The grate does not differ in any special way from any ordinary construction but
it should be somewhat smaller in the openings so as to allow less air to pass up
through the grate.
The accompanying drawings illustrate two forms of this improved furnace fuel
chamber wall-Fig. 1 being a vertical section and Fig. 2 a horizontal section of a
furnace with such inner wall of oblong shape. Figs. 3 and 4 vertical sections at
right angles and Fig. 5 a horizontal section of a furnace with an inner wall of
cylindrical form and of modified construction as hereinafter described. Figs. 6
and 7 elevation and plan respectively of the base of the second form of inner wall.
The fuel receiving space is encircled by the upright wall A of suitable shape
in plan so as to extend all round the space where the fuel is to burn, with the
exception of the part c necessarily left free for charging the furnace. f is the
furnace door. The base C carries the grate R and the wall A is covered in at
the top for instance by plate B. The wall A is made with a number of upright
air channels a open below so that air may pass into them through the holes o from
the main air feed channel D in the basc C. The channels a open at a' severally
into the fuel space inside the wall A. Between the sections of the wall A which
have the channels a are the slits or spaces ii by which the products of combustion
pass out of the fuel space. The direction of air and gases is indicated by arrows
in the figs. of the drawing.
It is convenient to make the wall A of a convenient number of upright pieces of
fire brick made with the air channels a a¹, erected at suitable distances apart and
closed by the cover plate B.
The form shown in Figs. 3 to 7 is suitable for cooking stoves or ranges. The
wall A is carried up to the main cover plate H of the stove where it overlaps and
is secured at A'. The plate B is made up of a number of removeable concentric

page_text: rings and disk in the same manner as the usual covering over the fire in such
ranges or kitcheners."
In the furnace shown in Figs. 1 and 2 the plate B may be removed and the
vault may serve as roof to the space by carrying up the wall A to touch the
vault x.
The air inlet main channel D may be provided with any suitable-damper or
contrivance for controlling the inlet of air.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is ;-
In boiler furnaces and other forms of fuel combustion furnaces and the like the
combination with the combustion or furnace chamber of an inner wall encircling
and dividing an inner fuel receiving and burning space from an outer flame or fire
gas space, this wall consisting of a number of divisions separated by a flame
passage slit or space and having air channels a communicating with the channel D
in the base C and opening at a into the fuel receiving space aforesaid, this latter
space being bounded below by the grate and above by the cover plate B or by the
vault in place of said cover plate.
Dated thin and dow of Now 1001
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicant.