Improvements in or relating to Baking or like Apparatus.
Year: 1897

page_text: Date of Application, 26th Mar., 1897
Complete Specification Left, 29th Nov., 1897-Accepted, 15th Jan., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Baking or like Apparatus.
I, ELLEN MATHILDA SJÓHOLM, of Östgötagatan 18, Stockholm, in the Kingdom
of Sweden, Artist, do hereby declare the nature of this invention to be as follows:
This invention relates to baking or like apparatus which in consideration of its
size, is very efficient in working. It may be provided with a series of compartments
in which baking takes place, said compartments being heated by a system of zigzag
or serpentine tubes issuing from a fire box, located under the oven.
The com-
partments are provided with doors, for the insertion of the substances to be treated,
into or removing them from, one compartment while baking is proceeding in
another. The apparatus in question may suitably be made portable.
Preferably centrally under the bottom of the apparatus which may be mounted
on wheels there is arranged a fire-box whence tubes issue preferably in two rows,
those belonging to one row or half of the oven, being situated opposite the intervals
between the other tubes of the other half. Between the bottom and an inner
bottom located just above the former, one set of tubes run forwards and the other
set backwards, all the tubes then passing backwards and forwards in zigzag or
serpentine fashion between the walls, so as to form say four compartments sur-
rounded by the tubes.
At the top the tubes enter into a chamber next to the roof of the chamber and termi-
nate in two rows, as in the fire box. Over these rows are dampers which cover the
ends of the tubes and which may be opened at will by rotating their damper shafts
protruding through the wall of the chamber. The compartments are encased
with sheet metal at the top and bottom as well as at the sides. At one side a door
is provided for each compartment, and at the sides of each door there are sight
glasses or windows which can be opened for ventilation of the oven. From the
top chamber there ascends a smoke stack, and from the fire box another smoke-
stack is provided having a damper. The latter is kept open at the commencement
of firing and is shut off more or less when the fire has been inade. The combustion
gases traverse the sets of tubes and heating the compartments around which they
circulate. The bread or other substance placed on metal plates, as usual, is
inserted in the compartments for baking.
Opposite the ends of the horizontal sections of the tubes there are cleaning holes
or openings. These are closed by means of plugs which, especially for the lower
tubes, are long so as to allow the tubes to be shut off more or less by pushing in
said plugs. It is thus made possible to regulate the heat accurately so as to
obtain the same degree of heat at both ends of the oven. Also by opening the
chimney damper more or less a higher or lower degree of heat, can of course, be
obtained. The plugs are preferably hollow and filled with an insulating material
or non-conductor of heat. The sides of the oven are likewise double, the inter-
mediate space being filled with any suitable non-conductor of heat.
The fire box is provided with interior plates both at the sides and at the ton.
Between said plates and the outer walls of the oven, as well as between the upper
"

page_text: plate and the bottom of the oven there are spaces into which cold air can enter for
being heated. In the last mentioned space, perforations are made in the tubes
just before they enter the oven through which perforations the air can enter said
tubes for ensuring complete combustion of fuel.
The arrangement of these perforations in the tubes and of a jacket around the
fire-box serves to prevent excessive heating of the walls of the "fire-box and thus
to make the latter more durable. Moreover the jets of air entering into the tubes
from the jacket-space serve to regulate automatically the draught in the fire-box,
thus preventing excessive temperatures in the latter. This is explained by the fact
that as the draught in the fire-box increases, the temperature and consequently
the velocity of the air passing through the jacket-space is also increased. The jets
of air entering crosswise into the tubes then becoming more powerful, tend to shut
off the passages from the fire-box, thus reducing the draught in the latter.
It has been proved by experiments that an even temperature can thus be main-
tained in the tubes leading from the fire-box of this description and that the fire
box can thus be insured from destruction by intense firing.
Dated this 26th day of March 1897.
BOULT & WADE,
Agents for the Applicant.
improvements in or relating to Baking or like Apparatus.
I, ELLEN MATHILDA SJÓHOLM, of Östgötagatan. 18, Stockholm, in the Kingdom
of Sweden, Artist, 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:
This invention relates to baking or like apparatus which, in consideration of its
size, is very efficient in working. It may be provided with a series of compartments
in which baking takes place, said compartments being heated by a system of zigzag
or serpentine tubes issuing from a fire-box or heating chamber located under the
oven. The compartments are provided with doors, for the insertion of the sub-
stances to be treated into, or removing them from, one compartment while baking
is proceeding in another. The apparatus in question may suitably be made
portable, an oven so arranged being shown on the annexed drawing, in which
Figure 1 shows a longitudinal section, Figure 2 a cross-section and Figure 3 a
horizontal section of the oven. Figure 4 shows a diagrammatic elevation of the
same.
Preferably centrally under the bottom 1 of the apparatus which may be mounted
on wheels 2 there is arranged a fire-box 3, whence tubes issue preferably in two
rows, those belonging to one row or half of the oven 4 being situated opposite the
intervals between the tubes 5 of the other half. Between the bottom 1 and an
inner bottom 6, located just above the former, one set of tubes 4 run forwards and
the other set 5 backwards, all the tubes then passing backwards and forwards in
zigzag or serpentine fashion between the walls 8 so as to form
sav, four
ments 9, 10, 11, and 12, surrounded by the tubes, as shown in Figures 1 and 2.
compart-
At the top the tubes enter into a chamber 13 next to the roof of the oven and
terminate in two rows, as in the fire-box. Over these rows are dampers 14 and 15,
which cover the ends of the tubes and which may be opened at will by rotating
their shafts 16 protruding through the wall of the chamber. The compartments
are encased with sheet metal at the top and bottom as well as at the sides.
At one
side a door 17 is provided for each compartment, and at the sides of each door

page_text: there are sight-glasses or windows 18 which can be opened for ventilation of the
oven. From the top chamber 13 there ascends a smoke-stack 19, and from the
fire-box 3 another smoke-stack 20 is provided having a damper 21. The latter is
kept open at the commencement of firing and is shut off more or less when the fire
has been made. The combustion-gases traverse the sets of tubes 4 and 5, and heat
the compartments 9-12, around which they circulate. The bread or other sub-
stance placed on metal plates, as usual, is inserted in the compartments 9-12 for
baking etc.
Opposite the ends of the horizontal sections of the tubes there are cleanin' holes
or openings 22. These are closed by means of plugs which, especially for the lower
tubes, are long, so as to allow the tubes to be shut off more or less by pushing in
said plugs. It is thus made possible to regulate the heat accurately, so as to
obtain the same degree of heat at hoth ends of the oven. Also by opening the
chimney damper 21 more or less a higher or lower degree of heat can, of course,
be obtained. The plugs are preferably hollow and filled with an insulating
material or non-conductor of heat. The sides of the oven are likewise preferably
double, the intermediate space being filled with any suitable non-conductor of
heat.
The fire-box is provided with interior plates both at the sides and at the top.
Between said plates and the outer walls of the oven, as well as between the upper
plate and the bottom 1 of the oven there are spaces into which cold air can enter
to be heated. In the last mentioned space, perforations 25 are made in the tubes
and 5, just before they enter the oven, through which perforations the air can enter
said tubes for ensuring complete combustion of fuel.
The arrangement of these perforations 25 in the tubes 4 and 5 and of a jacket
around the fire-box 3 serves to prevent excessive heating of the walls of the fire-
box and thus makes the latter more durable. Moreover, the jets of air entering
into the tubes 4 and 5 from the jacket-space serve to regulate automatically the
draught in the fire-box, thus preventing excessive temperatures in the latter. This
is explained by the fact that, as the draught in the fire-box increases, the tempera-
ture and consequently the velocity of the air passing through the jacket-space
is also increased. The jets of air, entering crosswise into the tubes 4 and 5, then-
becoming more powerful, tend to shut off the passages from the fire-box, thus
reducing the draught in the latter.
It has been proved by experiments that an even temperature can thus be main-
tained in the tubes leading from a fire-box of this description and that the fire-box
can thus be insured from destruction by intense firing.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A baking-oven provided with a series of compartments in which baking takes
place, said compartments being arranged one above the other and located between
parallel branches of zigzag tubes (as 4, 5), ascending from a fire-box situated
beneath, a portion of said tubes, preferably every alternate one, first passing forward
above the bottom plate of the oven, then turning upwards along one of the sides
of the oven, then passing between the lowest and the next higher compartment to
the opposite wall of the oven, then upwards along the latter and so on, thus sur-
rounding the compartments referred to, the remainder of said tubes first passing
rearwards then in a zigzag path like the other tubes, though in the reverse direction,
up to a smoke-outlet common to all the said tubes, each compartment being encased
with sheet-metal and provided with a door substantially as described.
2. In a baking oven of the character described, a chamber (as 13) provided with
a smoke-outlet, in which charaber the tubes terminate in such a manner that the
projecting ends of each set of tubes, form a row over which dampers are placed by
means of which all the tubes belonging to each row can be simultaneously opened
or shut off, substantially as described.

page_text: 3. In a baking oven of the character described, double bottoms (as 1, 6) between
which the tubes pass in the beginning of their course in two rows, the tubes in one
row passing forward and those in the other backward on leaving the fire-box, said
tubes ascending through the lower bottom (1) of the oven substantially as described.
4. In a baking oven of the character described, valves situated in front of the
ends of the horizontal tubes and consisting of adjustable plugs, said plugs being
made hollow and filled with an insulating material and being adapted to be pushed
in and out, more or less, for the purpose of closing the tubes more or less and thereby
regulating the heat, substantially as described.
5. In a baking oven of the character described, an intermediate chamber between
the bottom of the oven and an interior plate located above the hearth and through
which the heating tubes pass, cold air entering into said space, the heating tubes
having perforations in their circumference at the portions entering said air-space,
for the purpose of allowing the cold air to enter into the tubes, thus ensuring a
more complete combustion, substantially as described.
6. The combination and arrangement of parts constituting the complete baking
oven, substantially as described and illustrated in the accompanying drawings.
Dated this 29th day of November 1897.
BOULT & WADE,
Agents for the Applicant.