Improvements in Furnaces.
Year: 1893

page_text: Date of Application, 21st Feb., 1893-Accepted: 4th Nov., 1893
COMPLETE SPECIFICATION.
Improvements in Furnaces.
I GEORGE BARKER of 77 Colmore Row Birmingham in the County of Warwick
Consulting Engineer do hereby declare the nature of my said invention as communi-
catel to me from abroad by Samuel Paxson Hutchinson of 2116 Park Avenue
City and County of Philadelphia State of Pennsylvania Conveyancer 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, and has for its object cheap construction, and
economical combustion of fuel, and more particularly the avoidance of the discharge
of smoke and partially. consumed gases from the fuel.
To this end my invention consists in an improved construction of furnace and
grate and device for heating the air preliminary to contact with the solid and
gaseous portions of the fuel as hereinafter set forth more fully and particularly
and shown in the accompanying drawing in which
Figure 1 shows a plan of a furnace embodying this invention:
Figure 2 a central vertical section thereof.
Figure 3 a horizontal section in the plane indicated by the dotted line rx in.
Figure 2.
Figure 4 a vertical central section of the furnace as applied to a vertical steam
boiler.
Figure 5 a vertical central section as applied to an air heating furnace.
1 represents the ash pit, 2 the furnace chamber 3 the grate bearing, 4 the shell
enclosing the furnace chamber 2 and ash pit 1. The shell 4 should be air tight
and is preferably made of plate iron or steel and fitted and secured to the base or
hearth 5.
In the ash pit 1 are draft openings 6, which serve also to empty ashes, and
are provided with doors 7, by which the air draft can be moderated or entirely
closed.
The grate bearing 3 is in the form of an internally projecting flange, having a
series of perforations 8 in it upon which fits a ring 9 having similar perforations 10
which register with the perforations 8 when the ring 9 is in one adjustment and in
another closes them and by intermediate adjustments varies the extent of uncovering
of the openings 8, the ring 9 is adjusted by a lever 30 fitted air tight through the
shell 4. Within the ring 9 on the bearing 3 rests a grate 11 formed preferably of
tubular bars 12, having minute apertures 13 from which water in a finely divided.
state or steam may be introduced into the ash pit.
In the shell 4 is a door opening 14, for the introduction of fuel fitted with an air
tight door 15.
Above the door opening is an arch or tile 16 of perforated refractory material
such as steatite or fire brick, and above this tile 16 is a second perforated arch 17
of refractory material preferably having perforations not opposite those in the tile
or arch 16.
Resting upon the grate 11 are a series of parallel strips or staves 18 of refractory
material having grooves or lengthwise spaces 19 in the back reaching from the
openings 10 up nearly or quite to the upper ends, through which grooves air passes
from the apertures 10 and becoming heated enters the furnace chamber above the
fuel. Instead of groove 19 in the back of the staves 18 they may be made with a
long channel or tube 19 formed in them.
Upon the central portion of the grate 11 is placed a perforated dome 20 which
protects the centre of the grate from excessive heat and consequent warping and

page_text: also serves to distribute the air, and partially heat it as it passes from the ash pit
into the fuel.
The fire is kindled by light fuel placed on the grate, and coal or coke for the
permanent fire added the feeding door is then closed and as the staves 18 become
heated the air from the ash pit passes through the apertures 8 and 10 through the
grooves 19 and mingles with the gases above the fuel and burns at a high tem-
perature; the arch or tile 16 becomes highly heated and deflecting heat back upon
the fuel greatly increases the heat at the centre of the furnace and facilitates the
liberation of gas from the fuel.
The temperature rises in the furnace chamber above the fuel to an intense beat
which can be moderated by partially closing the apertures 8 by the lever 30
and ring 9 and can be arrested by entirely closing the apertures 8 and the ash pit
doors 7.
The products of combustion pass upwards through the perforations in the tiles
or arches 16 and 17 and are utilized as shown in Figure 4 by passing through the
flue of a boiler 22 and as shown in Figure 5 then around the air heating flues of
a hot air apparatus.
The effect of the double perforated tiles 16 and 17 is to retain the heat of the
gases and air in the furnace until complete combustion has been effected and prevent
the apparatus for utilizing the heat from reducing the furnace temperature.
The proportions of furnace that experience has indicated best for working this
furnace is with the chamber from the grate 11 to the tile 16 equal to one diameter
of the furnace and that preferably not less than 18 inches and the diameter of the
dome 20 about one half the diameter of the inside of the furnace chamber within
the staves 18.
When the combustion is actively in progress it is accelerated by allowing steam
or water to enter the ash pit 1 and moisten the air supply therein.
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:
1. In a furnace the shell 4, ash pit 1 grate 11 dome 20, staves 18, perforated
grate bearing 3 and adjustable ring 9 in combination with the perforated tiles 16
and 17, arranged to operate substantially as set forth.
2. In a furnace the ash pit 1, provided with air tight fitting doors and the
perforated grate bearing 3, and tubular perforated grate Il in combination with the
grooved staves 18 arranged to operate substantially as set forth.
3. In a furnace, the air tight shell 4, staves 18 and means of admitting and
regulating air thereto from the ash pit 1, in combination with the tiles 16 and 17
arranged to operate substantially as set forth.
4. In a furnace the air tight shell 4, perforated arch 16, staves 18, and means of
admitting air thereto from the ash pit 1, in combination with grate 11 and perforated
dome 20, arranged to operate substantially as set forth.
Dated this 20th day of February 1893.
GEORGE BARKER.