Improvements in Furnaces.
Year: 1894

page_text: Date of Application, 15th Mar., 1894
Complete Specification Left, 14th Dec., 1894--Accepted, 9th Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Furnaces.
We THOMAS SYDNEY LEA of The Larches Kidderminster Worcestershire,
Barrister at Law and JouN BARLOW of Crescent Villa Kidderminster Mechanical
Engineer do hereby declare the nature of this invention to be as follows:-
At the front of the furnace and below it we fix a perforated dead plate with holes
of sufficient size and number to admit a suitable amount of air to the furnace. These
holes are countersunk from below to prevent choking up by ashes. Beneath this
perforated dead plate is placed an air chamber into which the air passes on its way
to the dead plate and the furnace above the dead plate. Such air is warmed to
some extent by passage through such air chamber and may also be warmed before
arrival at the air chamber if desired in one of the many well known ways. To
remove the slack or ashes that may fall through the dead plate we may con struct
the air chamber with a floor like a damper which can be drawn out from time
to time.
Dated this 15th day of March 1894.
We THOMAS SIDNEY LEA of The Larches Kidderminster Worcestershire
Barrister at Law and JOHN BARLOW of Crescent Villa Kidderminster Mechanical
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 :-
Our invention relates to improvements in the construction of boiler and other
furnaces of the well known ordinary description in which air is admitted through
the furnace door. We obtain thereby a more perfect combustion of the fuel and a
diminution of the quantity of smoke produced.
We fix on the floor of the furnace-between the front end of the firebars and the
door plate a perforated dead plate with holes of sufficient size and number to admit
a suitable quantity of air to the furnace. These holes are countersunk from below
to prevent their being choked up by ashes. We employ preferably a plate three
quarters of an inch thick, with holes one half inch in diameter above and seven
eighths of an inch in diameter below spaced one inch and a half apart but the
thickness of the plate and the number size and spacing of the holes may be varied
at pleasure according to the kind of fuel used and the quantity of air desired to be
admitted in this way.
Below this dead plate and enclosing the space beneath it we place an air chamber
consisting of back and side plates and a front plate flush with the front of the boiler.
We make these plates preferably eight inches deep but their depth can be
modified as may be convenient. The air enters the air chamber through its bottom
and through an aperture made for that purpose in the front plate. It is guided and

page_text: directed by the back and side plates of the air chamber and passes through the holes
in the dead plate into the furnace where it unites with the air entering through the
furnace door. During its passage through the air chamber the air is warmed to
some extent and it may also if desired be warmed before arrival at the air chamber
in one of the many well known ways. It may also be found convenient to close in
the bottom of the air chamber or to fit it with a floor like a damper which can be
drawn out from time to time in order to permit the slack and ashes which may
accumulate in the air chamber to fall through into the space below. In order that
our invention may be properly understood and readily carried into practical effect
we have hereunto attached the accompanying sheets of drawings marked with figures
and letters of reference.
Fig. 1 is a vertical longitudinal section of the front part of the furnace.
Fig. 2 is a plan of the furnace floor.
Fig. 3 is an elevation of the front of the boiler.
Figs. 4 and 5 are an enlarged plan and section of the dead plate.
Fig. 6 is an elevation of the front plate of the air chamber.
In these figures A is the door plate, B the furnace door. C the dead plate
perforated with the holes D D; E E, are the firebars, F is the back, G, G, the sides
of the air chamber. H is the front of the same containing the aperture I ; K is a
tbin sheet placed in front of the air chamber for ornamental purposes to give the
front of the boiler a more sightly appearance and pierced with numerous holes so as
not to impede the access of air to the aperture I. L is the floor of the air chamber.
M M form part of the ornamentation of the boiler front.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what we
claim is,
1. The arrangement in furnaces constructed as hereinbefore described of a dead
plate perforated with countersunk holes substantially as and for the purpose
set forth.
2. In furnaces of a like description the combination and arrangement of dead plate
and air chamber (with or without a bottom as the case may be) described and
illustrated in the drawings annexed substantially as and for the purpose set forth.
Dated this 14th day of December 1894.
JOHN STANWELL BIRKETT,
Agent for the Applicants.