Year: 1886

page_text: Date of Application, 16th Sept., 1886.
Complete Left, 16th June, 1887.
Complete Accepted, 16th Sept., 1887.
1, LUKE CHEETHAM SHAW, of Hall Street, Harpurhey, Manchester in the County
of Lancaster, Commercial Traveller, do hereby declare the nature of this invention to
be as follows:-
My invention relates to improvements in furnaces for steam boilers and has for its
objects to prevent smoke, and economize fuel by employing self-acting means, which
cause a supply of atmospheric air to be introduced into the furnace, each time fuel is
introduced, and which can be regulated accordingly to all conditions, in order to
ensure a perfect combustion of the gases generated.
To this end I form between the ordinary fire-bars and fire-bridge underneath the
combustion chamber an air chamber or flue.
The combustion chamber near the fire-bars I form with a bull-nose, and the fire
bridge hollow, and with one or more openings, so as to establish a communication.
between the air and combustion chambers for the purpose of admitting into the
latter a supply of atmospheric air.
The said air chamber I provide with a midfeather, and in front, near the fire bars,
with a valve or damper, which latter carries on its spindle, a wheel provided externally
and internally, with ratchet teeth, in which pawls suitably fixed, are working.
As the fuel in the furnace gets burnt, the said valve or damper will gradually and
self-actingly close on the principle of a sand glass & a rod being suitably connected
to the valve or damper and the furnace door, each time the latter is opened for the
purpose of introducing into the furnace a fresh charge of fuel, the said valve or
damper also opens, and after the furnace door is again closed, the sand glass
commences its function and regulates the supply of atmospheric air according to
the charge of fuel and its gradual consumption and requirements in each particular
case.
LUKE C. SHAW.
By F. Bosshardt & Co.,
Agents to the Applicant,
Manchester.

page_text: Improvements in Furnaces for Steam Boilers.
I LUKE CHEETHAM SHAW of Hall Street, Harpurhey, Manchester, in the County of
Lancaster, Commercial Traveller, do hereby declare the nature of my invention and
in what manner the same is to be performed to, be particularly described and
ascertained in and by the following statement:-
My invention relates to improvements in furnaces for steam boilers and has for its
objects to prevent smoke and economise fuel by employing self acting means which
cause a supply of atmospheric air to be introduced into the furnace each time fuel is
introduced and which can be regulated accordingly to all conditions in order to ensure
a perfect combustion of the gases generated.
To this end I form between the ordinary fire-bars and fire-bridge underneath the
combustion chamber, an air chamber or flue.
The top of the combustion chamber facing the firebars I form with a bull nose and
the firebridge hollow or with one or more openings therethrough so as to establish a
communication between the air chamber and combustion chamber for the purpose of
admitting into the latter a supply of atmospheric air.
The said air chamber I sometimes provide with a mid feather and fit the same in
front near the fire bars with a valve or damper which latter carries on its spindle a
wheel provided with ratchet teeth in which a pawl suitably fixed is working.
As the fuel in the furnace gets burnt, the said valve or damper will gradually and
self actingly close on the principle of a sand glass and a rod being suitably connected
between the valve or damper and the furnace door, each time the latter is opened (for
the purpose of introducing into the furnace a fresh charge of fuel) the said valve or
damper also opens and after the furnace door is again closed the sand glass commences
its function and so regulates the supply of atmospheric air according to the charge of
fuel and its gradual consumption and requirements in each particular case.
On the accompanying drawing Fig. 1. is a front view and Fig. 2. a side sectional
view of a steam boiler furnace embracing my improvements.
In performing my invention I form between the ordinary fire bars a and the fire
bridge b. (which is placed further back in the flue for the purpose) underneath the
combustion chamber, an air chamber c.
This air chamber is by preference constructed of fire clay slabs c¹ the front one of
which facing the fire bars is formed with a bull nose and which slabs in some cases
rest upon a mid-feather passing down the centre of the air chamber. The front
of this air chamber c is enclosed by a casting d. a front side and plan view of which
are severally illustrated on a larger scale by Figs. 4. 5. and 6.
I form a communication or passage e between the air chamber and the combustion
chamber for the admission of air to pass from one to the other and in order that the
combustion chamber may be cleaned out at the same time as the flues, I arrange that
the back plate d' shall be capable of removal.
In the casting d forming the front of the air chamber I provide a swivelling valve
'

page_text: or damper g. seen separately in Figs. 7 and 8 mounted on a horizontal spindle h
carrying at one extremity a ratchet wheel i. and having affixed at the other a
"sand glass" arrangement j. whereby the damper can be closed self-actingly when
the sand preponderates in the uppermost bulb in a manner well understood.
And in order to open this valve each time the furnace door is opened for the purpose
of introducing a fresh charge of fuel, I further connect the spindle of the same
swivelling damper with such furnace door by means of a rod k the front extremity of
which is embraced by the prongs of a fork 1. projecting below the furnace door and
near the hinge (as illustrated more clearly in Fig. 1. and in detail on an enlarged
scale Figs. 9. 10 and 11).
The other extremity of the same rod is jointed to an oscillating link m mounted
loosely upon the damper spindle and carrying a pawl n. which takes into the teeth of
the ratchet wheel as it oscillates in one direction but leaves the damper free in moving
in the opposite direction.
In Figs. 12 and 13. are illustrated a front and side view respectively of the ratchet
wheel and pawl arrangement whilst the "sand glass "bulbs are illustrated by front
and side views in Figs. 14 and 15.
The action of my improved smoke preventing and fuel economising apparatus may
be described as follows :-
The fresh fuel having been supplied to the furnace and the furnace door closed
again the swivelling damper has been turned upon its axis in the direction of the
arrows to the extent of a third of a revolution say from the vertical (or closed) position
to the open position seen in Fig. 2. This permits a large quantity of air to enter the
air chamber c. and passing therethrough to meet the products of combustion as they
are passing over the bridge b and leaving the combustion chamber and thus to
materially assist in consuming them.
The weighted bulb of the "sand glass." has also been carried round in the same
direction and to the same angle as the damper and is thus in the position for its
contents to gravitate into the empty bulb.
The freshly fed fuel having now gradually become incandescent and the sand
beginning to preponderate in the lower bulb-it gradually exercises its influence upon
the spindle h. and causes the same to turn (still in the same direction as the arrows)
until the damper arrives in the vertical or closed position and so cuts off the air supply.
entirely.
It will thus be observed that the swivelling damper has performed half a revolution
upon its axis and is now ready for the operation to be repeated at the next opening
of the furnace door.
In this manner I ensure an entire freedom from smoke in a steam boiler furnace
and am enabled to considerably economise the fuel employed.
Having thus particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The combination and arrangement of apparatus for consuming smoke and
economising fuel in steam boilers and other furnaces substantially as hereinbefore
described and illustrated on the accompanying drawings.
2nd. The employment of an air chamber fitted with a self acting swiveling damper
mounted and operated substantially as and for the purposes herein before described
and illustrated on the accompanying drawings.
1007
JOHN G. WILSON,
Agent for the Applicant.