Improvements in Furnaces and Fittings for the same for Steam Boilers and for like purposes
Year: 1897

page_text: Date of Application, 29th June, 1897
Complete Specification Left, 24th Mar., 1898-Accepted, 11th June,
1898
PROVISIONAL SPECIFICATION.
Improvements in Furnaces and Fittings for the same for Steam
Boilers and for like purposes.
•
I, EDMUND HOWL, of The Quarries, near Dudley, in the County of Stafford,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in the construction and arrangement of
steam boilers and other furnaces, wherein an induced or forced draught is
employed; the object of my invention being to obtain a more equal and uniform
distribution of the forced draught and to provide a furnace where the fire bars and
bearers have a minimum amount of dividing metal or rib projection so as to provide
a minimum.amount of obstruction or resistance to the currents of air which have
to pass through the bar openings. I also so arrange and construct my fire bridges
as to facilitate the clearing of all obstruction and to render easy a thorough clean-
ing, of the ash pits and other spaces beneath or in connection with the furnaces.
In carrying my invention into effect when applying my improvements to a
Cornish type of steam boiler I arrange one or more trunks or conduits beneath the
fire grate through which the forced or induced draught is conveyed for feeding
through the fire bars. I make my air trunk or conduit pipe into which a steam
jet nozzle or other well known method of induced air supply pipe enters with an
open end for discharging such current into the space beneath the fire bars, this
open end I provide with an equalising or relief opening or openings which give
additional space for a free discharge of the forced draught so that the whole volume
of the current is not discharged immediately beneath and directly under the grate,
but a portion is caused to escape into the closed chamber space or ash pit so that
an equalising effect is produced upon the current which passes from the closed ash
pit into and through the fire bar spaces of the furnace.
This relief exit of the induced current or this regulating or equalising opening
I provide in various forms to suit the type of boiler or other furnace to which my
improved system of induced draught is to be applied. Thus I may make a conduit
in the form of a loop having two outer supply openings with the inner ends tied
or bridged together, the junction piece or loop end being provided with suitable
relief passages in addition to the discharge openings for feeding the forced draught
to the furnace bars. I vary the shape of my conduit pipes or trunks as may be
required to suit the ordinary furnace fittings of the particular boiler to which such
is to be applied.
I make my fire bridges sometimes with an opening or openings with or without
movable doors or covers which can be opened and closed from the outer front of
the boiler to give increased facilities for cleaning out the space behind the fire
bridge by raking or other tools.
To give the maximum area of opening between the furnace bars I arrange my
bearers in such a manner that they may not form any interruption to the con-
tinuity of the openings between the bars such as exist with the usual form of
bearer or support now generally employed for carrying furnace bars. I
accomplish this purpose in one convenient manner by making the bearers with a

page_text: double or jaw like support for the bars at one end with a single or shelf like support
at the opposite end, the bars being provided with dividing or distance piece ribs at
positions preferably away from the actual bearers. Instead of 'making the
furnace bars with special bearers I may use ordinary bars and bearers when it is
desired to apply my improved forced draught equalising conduit trunks without 5
altering the furnace bars and supports.
I employ any form of steam jet nozzle and any type of blower that may be found
convenient in connection with my improvements.
It is to be understood that one feature of my invention consists in the return
draught device which is carried out by forming the discharge opening from the 1
air trunk of smaller area than the trunk and providing an additional opening
directed against the direction of air movement in the trunk. This additional
opening returns air to the fire bars near the furnace front and so tends to equalise
the supply of air through the whole surfaces of the fire bars.
1770 1.3
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MARKS & CLERK,
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18, Southampton Buildings London, W.C., and
13, Temple Street, Birmingham; - Agents.
Improvements in Furnaces and Fittings for the same for Steam
Boilers and for like purposes.
-
--1--
I, EDMUND HOWL, of The Quarries, near Dudley, in the County of Stafford,
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::
t :
"
My invention relates to improvements in the construction and arrangement of
steam boiler and other furnaces, wherein an induced or forced draught is employed,
my object being to obtain a more equal and uniform distribution of the forced
draught and to provide a furnace having fire bars and bearers with a minimum
amount of dividing metal or rib projection to obstruct or resist the currents of air
which have to pass through the bar openings, I also so arrange and construct my
fire bridges as to facilitate the clearing of all obstruction and to render a thorough
cleaning of the ash pits and other spaces beneath or in connection with the
furnaces.
In the accompanying sheet of explanatory drawings to be hereinafter referred
to.-.
..
Figure 1 is a longitudinal section, Figure 2 a cross section, and Figure 3 à front
elevation of a Cornish boiler with my invention applied thereto..>
.
The same reference letters in the different views indicate the same parts:
In the application of my invention to a Cornish type of steam boiler such as
illustrated I arrange one or more trunks or conduits as A beneath the fire grate
through which the forced or induced draught is conveyed for feeding through the
fire bars B.. I make each trunk or conduit pipe A into which a steam jet nozzle
or other well known method of induced air supply pipe enters with an open end A¹
for discharging such current into the space beneath the fire bars, and also with
equalising or relief openings or an opening as A² for providing an outlet for the
discharge of the forced draught so that the whole volume of the current, is not
discharged immediately beneath the grate adjacent to the outlet A, but a portion
is caused to escape into the closed chamber.space or ash pit C, and thus an equalis-
Filoil

page_text: ing effect is produced upon the current which passes from the closed ash pit into
and through the fire bar spaces of the furnace.
I arrange the additional exit or equalising opening or openings for the forced or
induced current. in various forms to suit the type of boiler or other furnace to
which my improved system is to be applied. Thus I may make a conduit in the
form of a loop having two outer openings discharging in opposite directions, such
as hereinbefore described, and provided also with suitable additional relief passages
or openings, when necessary, to obtain an efficient equalisation of the air supply.
to the furnace I vary the shape of the conduit pipes or trunks A as may be required
to suit the ordinary furnace fittings of the particular boiler to which they are to
be applied.
I sometimes make the fire bridge D with an opening or openings with or without
movable doors or covers which can be opened and closed from the outer front of
the boiler to give increased facilities for cleaning out the space behind the fire
bridge by raking or other tools.
To give the maximum area of opening between the furnace bars I arrange my.
bearers E in such a manner that they shall not form any interruption to the
continuity of the openings between the bars such as exist with the usual form of
bearer or support now generally employed for carrying furnace bars. I accomplish
this purpose in one convenient manner by making the bearers with a double or
jaw like support on the one side with a single or shelf like support
on the opposite side as illustrated, the bars being provided with dividing
or distance piece ribs as bat positions preferably away from the actual
bearers. Instead of making the furnace bars with special bearers I may use
ordinary bars and bearers when it is desired to apply my improved forced draught
equalising conduit trunks without altering the furnace bars and supports.
I employ any form of steam jet nozzle as l' or any type of blower that
found convenient in connection with my improvements.
may be
It is to be understood that one feature of my invention consists in the return
draught device which is carried out by forming the discharge opening A¹ from
the air trunk A of smaller area than the trunk and providing an additional
opening A directed against the direction of air movement in the trunk. This
additional opening returns air to the fire bars near the furnace front and so tends
to equalise the supply of air through the whole surfaces of the fire bars.
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. The combination with steam boiler and other furnaces working under a forced
or induced draught, of air supply trunks or conduits arranged beneath the fire
grate and having equalising discharge apertures, substantially as described.
-
2. The construction and arrangement of parts constituting the improvements in
steam boiler and other furnaces and fittings, substantially as and for the purposes
described, and as illustrated.
1000