CONSTRUCTION OF FURNACES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Thomas Robinson at the
Office of the Commissioners of Patents on the 7th February 1883.
THOMAS ROBINSON of Preston in the County of Lancaster
THE CONSTRUCTION OF FURNACES
"
"IMPROVEMENTS IN
This invention is designed principally to be applied to the construction of the
furnaces of steam boilers, but the same principle of construction is also equally
applicable to other kinds of furnaces.
The object of the invention is to economize fuel by obtaining a more perfect
consumption of the smoke and other products of combustion before their entering
into the flue or chimney so that the nuisance from smoke may be as far as possible
obviated.
The principal feature of novelty in my invention is that the flame smoke and
other products of combustion arising from the burning fuel are drawn to the front
of the furnace and passed again through the fire before reaching the flue.
In carrying out my invention in place of the ordinary bridge immediately
behind the fire bars I construct a solid mid-feather or partition wall of fire brick
filling up the whole area of the flue leaving only therein about four to six or more
openings in a line across the flue a few inches above the level of the fire bars or at
about the central line of the flue. In each of these openings I fix a pipe or tube of
metal fire-clay or other suitable material having both ends open.
The rear end fits in the opening in the mid-feather, and the front end
terminates at or about the rear end of the dead-plate, which latter is placed at
about the height of the bottom of the row of tubes.
The air entering the ash-pit at the front and passing upwards through the fire-
bars assists in the combustion of the fuel, and the products of combustion pass
upwards between the tubes to the upper part of the furnace, but as there is no

page_text: opening above the bridge as usual they are compelled to return to the front
and entering the tubes at their front end are carried through the midfeather into
the flue.
The tubes being immediately over the burning fuel and in the midst of the flames
will become heated to a bright red heat and all smoke or other combustible
products will become converted into gas and flame in passing through these red
hot tubes.
In "firing up" the fuel is thrown onto the top of the tubes and falls between
them onto the fire-bars. A baffle-plate is fixed in the front of the furnace above
the door inside to give a downward direction to any air that may enter at the
furnace door during the operation of " firing-up.”

page_text: •
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Robinson in the Great Seal Patent Office on the
4th August 1883.
THOMAS ROBINSON of Preston in the County of Lancaster IMPROVEMENTS IN
THE CONSTRUCTION OF FURNACES
This invention is designed principally to be applied to the construction of the
furnaces of steam boilers but the same principle of construction is also equally
applicable to other kinds of furnaces.
The object of the invention is to economize fuel by obtaining a more perfect
consumption of the smoke and other products of combustion before their entering
into the flue or chimney so that the nuisance from smoke may be as far as possible
obviated.
The principal feature of novelty in my invention is that the flame smoke and
other products of combustion arising from the burning fuel are drawn to the front
of the furnace and passed again through the fire before reaching the flue.
:
Such being the nature and object of my said invention I will now proceed to
describe in detail the manner in which the same is to be or may be performed or
carried into practical effect and in order that the same may be clearly understood
I have annexed hereunto a sheet of drawings illustrative thereof and have marked
the same with figures and letters of reference corresponding with those in the
following explanation thereof.
Fig. 1. in the annexed drawing is a vertical longitudinal section. of a furnace
constructed according to my invention and Fig. 2 is a horizontal section of the
same. Fig 3. is a longitudinal section and Fig. 4 a transverse section of a
modification.
In carrying out my invention (see Figs 1 and 2) in place of the ordinary bridge
immediately behind the fire bars a, a I construct a solid midfeather or partition
wall of fire brick b, b filling up the whole area of the flue leaving only therein about
four to six or more openings in a line across the flue a few inches above the level
of the fire bars or at about the central line of the flue. In each of these openings
I fix a pipe or tube c, c of metal fire-clay or other suitable material having both
ends open. The rear end fits in the opening in the midfeather b, b and the front
end terminates at or about the rear end of the dead plate d, d which latter is
placed at about the height of the bottom of the row of tubes c, c so as to support
the front ends of the same.
The air entering the ashpit e, e at the front and passing upwards through the
fire bars a, a as shown by the arrows assists in the combustion of the fuel, and the
products of combustion pass upwards between the tubes c, c to the upper part of
the furnace, but as there is no opening above the bridge as usual they are compelled
to return to the front and entering the tubes c, c at their front end are carried
through the mid-feather into the flue f, f.
The tubes c, c being immediately over the burning fuel and in the midst of the
flame will become heated to a bright red heat and all smoke or other combustible
products will become converted into gas and flame in passing through these red
hot tubes.
In "firing-up" the fuel is thrown onto the top of the tubes c, c and falls between
them onto the fire bars a, a. A baffle plate g, g Fig. 1. is fixed in the front of the
furnace above the door inside to give a downward direction to any air that may
enter at the furnace door during the operation of "firing up."
In the modification shown at Figs 3. and 4 the tubes c, c are placed higher up
in the furnace their front ends being supported on a plate d³, d'; the dead plate d, à

page_text: being placed in the usual position about level with the fire bars a, a and the
furnace door being in the ordinary position.
In furnaces other than steam boiler furnaces and where the space is not so
limited, instead of the tubes c, c of metal or fire clay I propose to build hollow
chambers of fire brick arched from end to end, the front end abutting against the
front wall of the furnace, and the rear end thereof against the bridge. The rear
ends will be open, and there will be an opening into the interior in the upper side
at the front end.
Having now described the nature and object of my said invention together with
the manner in which the same is to be or may be performed or carried into
practical effect I wish it to be understood that I claim as my invention closing up
the space above the bridge of the furnace and fitting therein tubes or hollow
chambers above the fire bars and open at each end, so that the flame, smoke, and
other products of combustion passing upwards between the said tubes or chambers
shall be drawn towards the front of the furnace and pass back through the said
tubes or chambers before reaching the flue, substantially in the manner and for the
purposes herein-before set forth and described, and illustrated by the accompanying
drawings
In witness whereof I the said Thomas Robinson have hereunto set my hand
and seal this second day of August in the year of our Lord one thousand eight
hundred and eighty three.