Improvements relating to Furnaces for the More Perfect Consumption of Smoke.
Year: 1893

page_text: Date of Application, 13th June, 1893
Complete Specification Left, 13th Mar., 1894-Accepted, 28th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements relating to Furnaces for the More Perfect
Consumption of Smoke.
I, JOSEPH ROBSON of Mary Street, Sheffield in the County of York, Engineers'
Tool Manufacturer, do hereby declare the nature of my invention to be as
follows:-
This invention relates to improvements in the mechanism and arrangement of
apparatus applicable to furnaces and more particularly to boiler furnaces with the
object of reducing the production of smoke to a minimum.
In carrying out my invention as applied to a steam boiler for example I proceed
as follows.
I make a partly circular frame of cast iron to support the brickwork of the
bridge, with ledge to support the ends of fire bars, and also provided with a
centrally pivotted air valve or door situated below the bars. The air valve is
carried upon the plain ends of screw threaded bolts passed through lugs upon the
semicircular frame on each side of the opening, and weighted to aid in closing it.
On the top of the semicircular frame I fix an angle plate by bolts and cotters, to
carry the brickwork, and to the back of this plate I fix a perforated plate opposite
to but at a little distance from the air opening, to meet the incoming stream of air
and distribute it.
Connected with the valve or air door is a rod reaching to the firing door or
thereabouts, and provided with a right and left hand screw coupling by which its
length can be adjusted.
It is connected with one end of a horizontal pivotted bar, the other end of which
has a short joint piece connected with an upright tumbler working on a short shaft
or axis upon which is also fixed a weighted lever.
The tumbler is made of a crutch shape at its top end, and is at right angles with
the closed first door and immediately underneath its bottom edge.
The action of opening or closing door actuates the tumbler, and through it the
intermediate levers and rod and the air valve or door.
Thus when the fire door is opened to put fuel upon the fire, the air valve is closed
by the action of the tumbler against which the door strikes and when the door is
closed it strikes against the opposite side of the crutch head of tumbler and
reversing it also opens the air valve.
In connection with the above, I use a door to the furnace provided with a hit
and miss ventilator, or having apertures constructed in it for the admission of air,
inside the door and a little distance from it, I fix a baffle plate preferably
perforated and open at the sides and bottom against which the air impinges and is
distributed.
The air valve may be arranged to close after a short period from the closing of
the fire door by means of a cylinder and plunger the action of which is well known.
Dated the 12th day of June 1893.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.

page_text: Improvements relating to Furnaces for the More Perfect
Consumption of Smoke.
I, JOSEPH ROBSON of Mary Street, Sheffield, in the County of York Engineers"
Tool Manufacturer 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 improvements in the mechanism and arrangement of
apparatus applicable to furnaces, and more particularly to the furnaces of steam-
boilers, the object being to reduce the production of smoke in such furnaces to a
minimum.
The annexed sheet of drawings illustrates my invention as applied to the furnace
of a steam boiler for driving a works engine and other machinery, or the like.
Fig. 1, sectional view of a boiler furnace fitted with my improved apparatus.
Fig. 2, air valve as seen from the front.
Fig. 3, air disperser at back of air valve.
Fig. 4, furnace door with air grate.
Fig. 5, various details of the mechanism.
I construct a metal plate 1, shaped to fit the lower part of the flue 2, and its
upper part arranged to carry the brickwork of the bridge, it is also provided with
an opening 3, having lugs on each side and a pivotted door or air-valve 4, weighted
or made heavier on its lower side, and connected with mechanism at the front of
boiler by means of a long rod 5.
The said plate is also provided with a ledge to support the ends of the firebars 6.
I prefer to support the air-valve 4, upon the pointed ends of screwed bolts 7,
which pass through the lugs beforementioned.
The bridge-plate is marked 8, and the bridge 9, but I do not bind myself to the
arrangement of these parts.
At the back of the air-valve 4, I fix a metal box 10, having numerous openings
or air ports 11, this acts as a distributor to the incoming current of air, by dividing
it into streams and so distributing it into the space at the back of the bridge, and
causing it to mix with, and effect the combustion of the unburnt gases and what
would otherwise be smoke.
The rod 5, which passes to the front of the firing door 12, or thereabouts is
provided with a right and left hand screw coupling 13, by which the length of the
rod and the position of the air-valve can be regulated.
It is connected with one end of a horizontal pivotted bar 14, the opposite end of
which has a short joint piece 15, connected with a tumbler 16, working on a short
shaft 17, upon which is also fixed a weighted lever 18.
The tumbler is made crutch-shape at its top end, and is at right angles with the
closed fire-door, and immediately underneath its bottom edge.
The action of opening the firing door, actuates the crutch tumbler 16, and the
intermediate connections, and thus opens and closes the air valve 4.
Thus when the fire-door 12, is opened to put on fuel, the air-valve 4, is closed by
the action of the tumbler against which the bottom edge of the door strikes, and
when after firing the door is closed it strikes the opposite side of the tumbler,
reversing it and opening the air-valve.
I prefer to use in connection with the before described apparatus, a firing door
provided with a hit and miss ventilator 19, and a baffle plate 20, open at the sides
and perforated at the front, against which the air rushing through the ventilator
impinges and is distributed.
I
may if desirable arrange to close the air-valve after the firing door is closed,
by means of a cylinder and plunger the action of which is well known.

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 :-
1. In connection with furnaces, the improved mechanism for opening a valve to
admit air to the back of the bridge, and dispersing same to aid the combustion of
unburnt gases and prevent smoke; as hereinbefore described and substantially as
shown.
2. In connection with furnaces, for the purpose specified, the tumbler (16) and
weighted lever (18) connected with a rod (5) attached to an air valve (4), in
combination with a diffusing box (10) constructed and arranged, and operating as
hereinbefore described, and substantially as shown.
Dated the 12th day of March 1894.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.