Improvements in Apparatus for Heating Bakers' and similar Ovens by Means of Dowson and other Analogous Gases.
Year: 1891

page_text: Date of Application, 6th June, 1891-Accepted, 1st Aug., 1891
COMPLETE SPECIFICATION.
Improvements in Apparatus for Heating Bakers' and similar Ovens
by Means of Dowson and other Analogous Gases.
I, JOHAN LUDVIG WALDEMAR OLSEN, of Stove Strandstræde, 10, Copenhagen,
in the Kingdom of Denmark, 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 :-
My invention relates to improvements in apparatus for heating bakers' and
similar ovens by means of certain gascous mixtures, and its object is to enable the
cheap mixtures of gas and air such as Dowson-gas to be employed economically
and satisfactorily for that purpose.
In order that my invention, and the best means by which it is to be carried into
practical effect, may be thoroughly understood, I will now describe them in detail,
referring in so doing to the accompanying figures which are to be taken as part of
this Specification and read therewith."
Fig. 1 is a rear elevation of the front plate.
Fig. 2 is a vertical section taken on the line a-x of Fig. 1.
Fig. 3 is a vertical section taken on the line y-y of the same figure.
Fig. 4 is a plan of the heating-gas jet.
Fig. 5 is a longitudinal section of a bakers' oven to which my invention has been
applied.
a is a plate or frame which is built into the front of the oven so as to cover
its mouth. is the gas supply pipe, its function being to introduce the heating gas
into the oven.
It is passed through the plate a to which it is connected gas-tight.
c is a second gas supply pipe. It is fed with coal-gas and is surrounded by a larger
tube d adapted to supply air for the combustion of the coal gas at the jet in the
end of the tube c. The combustion of the coal gas furnishes the flame which is
relied upon for igniting the heating gas supplied through the pipe b. ff are two
ventilators in the frame a, and are provided for the purpose of automatically
regulating the supply into the oven, of air necessary for the combustion of the
heating gas. y is the heating-gas jet. It is circular in cross-section at its rear
end, which is screwed on to or over the end of the pipe b, but its cross-section
is gradually modified into that of a horizontal and narrow slit h through which the
heating gas flows into the oven in a thin but broad and fan shaped stream. It will
be noticed that the igniting jet is under, but a little further into the oven than, the
nose of the jet g, so that the heating gas will be lighted the moment it begins to
issue from the slit h.
In order that the ventilators ff may close on to their seats automatically, the
axes i. i of their hinges are inclined out of the vertical so that the weight of the
ventilators will close them. Further, in order that the latter may be easily turned,
each is adapted to turn on a vertical conical point or centre j. Opposite to the
point j, the gudgeon & projects into a suitable hole. Suitable apertures 1, 1, fitted
with suitable transparent material, are provided through which the combustion can
be watched. Further spy-holes with swinging covers n may also be formed in
the plate.
To prevent the ventilators ff being opened by the draught into the oven beyond
a certain limit, a stop m (Fig. 3) is provided for each of them, on which is a
revolving arm p which, by striking against the plate a, limits the opening of the
door. The arm may however be turned up when it is desired to open the door
wide, e.g., when the igniting jet is to be lighted.
The apparatus is used as follows. After the igniting jet has been lighted, the
flue dampers are opened, and the heating gas turned on. When the oven has

page_text: been raised to the proper temperature, the heating gas and the igniting flame are
turned off. The ventilators, will then automatically close down upon their
scats.
Referring to Fig. 5, A. is the baking part of the oven, i.e., the oven proper, and
B is its door. E, G, G are the flues, the former being the combustion chamber,
and the latter, the flues through which the products of combustion are led away
through the flue to the chimney stack.
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 apparatus for heating bakers' and similar ovens by gas, the combination
with the heating-gas supply pipe, of a fan-shaped jet, an igniting jet, and auto-
matic ventilators adapted to turn on conical points or centres, in one direction, to
admit air, before the draught, and in the other, to close upon their seats, by their
own weight, as set forth.
2. In automatic oven ventilators, the combination therewith of conical points or
centres as and for the purpose set forth.
Dated this 6th day of June 1891
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.