IMPROVEMENTS IN OVENS FOR BAKING AND COOKING
Year: 1885

page_text: We, WILLIAM HENRY THOMPSON, and DAVID THOMPSON, of Queen Square, Leeds,
in the County of York, Gas Engineers, do hereby declare the nature of our
Invention for "IMPROVEMENTS IN OVENS FOR BAKING AND COOKING " to be as
follows:-
•
The object of our invention is to construct Smokeless Ovens in an improved
manner.
The whole structure, forming our invention, is herein described under the general
term "oven;" and the same is usually divided into three principal portions, viz:-
The "proving oven," near the ground. Above this is the chamber containing the
heating apparatus; and above the latter is the "baking oven," for baking and
cooking.
The external walls, or casing, of the oven, is formed of iron plates placed a certain
distance apart (usually about two inches) the spaces thereby formed being filled
with slag wool, asbestos, sand, kieselguhr, or other non conducting substances.
The front, door frames, and doors, are made of cast iron, as usual.
The bottom of the baking oven is formed of iron plate, with or without a layer
of tiles upon the same. tubes are fitted to the sides of this plate, rising therefrom
to, or near to, the roof. The ends of these tubes pass through the bottom, and are
secured by nuts or other suitable means. The tubes may be formed of copper,
brass, iron, or solid drawn steel. These tubes form a considerable portion of the
heating surface, the heated gases passing through them from one end to the other.
In the heating chamber we fit iron boxes, into which gas is supplied, such boxes
being fitted with burners. These boxes contain a considerable quantity of gas,
which arrangement affords sufficient time for the gas contained therein to become.
beated, previous to its combustion.
The heated gases pass upwards to the underside of the iron plate forming the
bottom of the baking oven. From thence they are carried upward through one end
of the tubes and downward by the other end to a flue at the side of the heating
chamber. From thence the gases are carried by horizontal flues, under the heating
chamber, to the chimney.
The chimney is formed of iron, and is surrounded for some distance by an air
flue, leading to a perforated plate in the heating chamber. This arrangement

page_text: provides and supplies warm air to the underside of the gas boxes, and utilises some
of the heat which would otherwise be lost up the chimney; the entering air
descending by the annular or surrounding flue to the heating (or combustion)
chamber, and thereby become heated.
The proving oven is placed under the combustion chamber, and receives sufficient
heat from above. In very small ovens the proving oven may be omitted; and the
arrangements as well as the materials are varied to suit special requirements.
The fuel may be common coal or other gas, petroleum, or oil, as preferred.
The essential features of our invention are:-The extended heating surface
arising from the use of tubes: the means of heating the gas and air, previous to
combustion; and the general economy of fuel arising from such arrangements.
ated 90th 1002
GEO. DOWNING,
Agent for Applicants.
We, WILLIAM HENRY THOMPSON, and DAVID THOMPSON, of Queen Square, Leeds,
in the County of York, Gas Engineers, do hereby declare the nature of our said
Invention for "IMPROVEMENTS IN OVENS FOR BAKING AND COOKING" and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The object of our invention is to construct smokeless ovens in an improved
manner.
The whole structure, forming our invention, is herein described under the general
term "
oven;" and the same is usually divided into three principal portions, viz:-
The "proving oven," usually near the ground, but sometimes placed above the
baking oven; the chamber containing the heating apparatus, and the baking
oven," for baking and cooking.
"
The external walls, or casing, of the oven, is formed (by preference) of iron
plates placed a certain distance apart (usually about two inches), the spaces thereby
formed being filled with slag wool, asbestos, sand, kieselguhr, or other non-con-.
ducting substances.
The front, door frames, and doors, are made of cast iron or other suitable
materials.
The bottom of the baking oven is formed of iron plate, with a layer of tiles
placed upon the same: or of fireclay or tiles, or of a combination of the foregoing
or any other suitable materials. tubes are fitted to the sides of the floor of the
oven, rising therefrom to, or near to, the roof. The ends of these tubes pass
through the floor, and are secured thereto by nuts or other suitable means.

page_text: These tubes form a considerable portion of the heating surface, the heated gases
passing through them: from one end to the other.
The sectional form of the tubes may be circular, elliptical, square, corrugated or
otherwise; or one tube or chamber may be adapted to the purpose.
In the heating chamber we fit suitable apparatus for imparting heat to the gas
previous to combustion taking place; such apparatus consisting of boxes or pipes,
or coils of pipes, whereby a large surface is provided to absorb heat; such apparatus
being formed of iron, copper, or other suitable material. This apparatus in the
heating chamber has sufficient cubical area to contain a considerable quantity of
gas, whereby sufficient time is afforded for the gas to become heated, previous to
combustion.
The heated products of combustion pass upwards to the underside of the floor of
the baking oven, From thence they are carried upward through one end of the
tube or tubes and downward by the other end to a flue at the side of the
heating chamber. From thence the gases are carried by horizontal.. flues under
the heating chamber to the chimney.
The chimney is surrounded for some distance by an air flue, leading to a
perforated plate in the heating chamber. This arrangement provides and supplies
warm air to the heating chamber, and utilises some of the heat which would
otherwise be lost up the chimney; the entering air descending by the surrounding
flue to the heating (or combustion) chamber.
The proving oven is placed (preferably) under the combustion chamber;
receiving sufficient heat from above. But in some cases we place the proving oven
above the baking oven; and in very small ovens the proving oven may be
omitted; and the arrangements as well as the materials are varied to suit special
requirements.
The fuel may be common coal or other gas, petroleum, or oil, as preferred.
The essential features of our invention are:-The extended heating surface
arising from the use of tubes: the means of heating the gas and air, previous
to combustion; and the general economy of fuel arising from such arrangements.
And in order that our said invention may be more particularly described and
ascertained, reference is hereby made to the accompanying drawings, in which
similar letters of reference indicate corresponding parts; and which drawings are
intended to illustrate one method of carrying out our invention.
Fig. 1 is a front elevation of one forin of oven constructed in accordance with
our invention, Fig. 2 is a side elevation, Fig. 3 is a sectional elevation on the
liue a b, and Fig. 4 is a horizontal section on the line c d. e is the outer casing of
the oven, is the inner casing, the space g being filled with slag wool, or other
suitable non-conducting material. h is the proving oven; i is the heating chamber,
aud
is the baking oven. I is the floor of the baking oven, which is perforated at
the sides to receive the ends of the tubes m m. The lower ends of these tubes are
open, and the tubes are held in position by nuts or other suitable means.
gas boxes which receive the entering gas, and in which the gas becomes heated
previous to combustion.
n n are
The heated gases pass into the tubes at m¹: they then traverse the tubes m,
parting with the heat by conduction, and descend to m*, from whence they follow
the course indicated by the arrows to the flue o.
We sometimes heat the entering air which is required to support combustion, by
surrounding the flue o with a casing p, and causing the air to enter at the top p¹,
as shewn by the arrows. The casing p terminates below where it opens into a
space covered by the perforated plater below the heating chamber i.
The tubes m m are preferably made of solid drawn steel and of a circular
sectional form, but they may be made rectangular, flat, corrugated, elliptical, or of
any other sectional form suitable for heating the air in the oven with rapidity.
Although we have described the walls of the oven as consisting of iron plates
enclosing a non-conducting material, it is obvious that the same may be built of
bricks, concrete, masonry or any other ordinary material,

page_text: Having now particularly described and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we declare that what
we claim is
1. The method of heating smokeless ovens by means of large heating surfaces
composed of tubes or tubular conductors, whereby the heat arising from the
combustion of the fuel is suitably distributed to the oven; substantially as herein
before described and shewn on the drawings.
2. In the construction of ovens of the description aforesaid, the method of beating
the gas and air previously to combustion, substantially as herein before described
and shewn on the drawings.
3. The general construction, arrangement and combination of parts, together
forming our improvements in Ovens for baking and cooking, substantially as herein
before described and shewn on the drawings.
GEO. DOWNING,
Agent for Applicants.