IMPROVEMENTS IN APPARATUS FOR HEATING OVENS
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Walter George Fearnley at the
Office of the Commissioners of Patents, with his Petition, on the
23rd April 1874.
I, WALTER GEORGE FEARNLEY, of Wells Street, Camberwell, in the
County of Surrey, Gas Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN APPARATUS FOR HEATING OVENS," to be
as follows:-
The main object of this Invention is to remedy the objection now
complained of by the public authoritics with respect to bakers' ovens,
namely, the giving off of dense volumes of smoke when heating the
same.
It has hitherto been the practice to burn solid fuel when heating
bakers' ovens, but none of the means adopted in steam boiler and other
furnaces for preventing the evolution of smoke have been found
applicable to the fire-places of such ovens.
In lieu of solid fuel I now propose to use gaseous fuel, such as car-
buretted hydrogen gas combined with a suitable proportion of atmo-
spheric air, and for this purpose I fit the oven with an arrangement of

page_text: pipes which will so distribute jets of flame as effectually to heat the
oven without producing smoke, and will present little or no obstruction
to the filling of the oven with the batch intended to be baked.
The bakers' oven as at present constructed is provided with a central
door for giving access to the interior, and on one side of this door is the
fire-place, and on the other the flue for leading off the gases of com-
bustion.
According to one mode of effecting the object of this Invention I
propose to fit the fire-place and ash-pit with a gas combustion apparatus.
Thus in the ash-pit I provide an air chamber into which I lead a gas
supply pipe, suitably fitted to inject gas into one or more pipes that dip
into the upper part of the air chamber. These tubes will be of sufficient
capacity to supply to the burner or burners of the apparatus both gas
and air for consumption after the manner of the Bunsen burner, and
they will connect with horizontal parallel tubes set in the fire-place.
Into these parallel tubes fit telescopically pipes which carry any suitable
form of burner at their outer ends. To this burner may be connected a
rod terminating in a handle, which will serve to thrust the burner
forward into the oven and retract it when desired. By this arrangement
I am enabled when the gas is ignited to inject a mass of blue flame into
the oven, and to withdraw the apparatus entirely from the oven when
the requisite heat has been attained. Instead however of using a
telescopic arrangement, I may fix the gas burner in the fire-place and
rely upon the circulation established in the oven for carrying the flame
and gases of combustion forward into the oven.
When the oven is provided with a ventilator at back I may use
pierced pipes arranged on opposite sides of the oven, and at about six
inches more or less from the floor thereof for my burners, supplying them
with mingled gas and air from one or more air chambers at the front of
the oven. If however the ventilation is near the front of the oven, which
is the usual place, the pierced pipes should be arranged on one side of
the oven only, and that the furthest from the ventilator.