Improvements in Ovens and Furnaces therefor.
Year: 1896

page_text: Date of Application, 18th July, 1896
Complete Specification Left. 17th Apr. 1897-Accepted. 17th July 1897
[Communicated from abroad by CHARLES ANDRÉ of Lyons, in the
Republic of France.]
Improvements in Ovens and Furnaces therefor.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:
This invention relates to improvements in heat economizing furnaces for ovens
having a double circulation, in which the products of combustion pass toward the
interior or toward the exterior. This oven may be employed for numerous
purposes: three special applications heing hereinafter described.
Referring first to the apparatus used as an oven for baking and pastry cooking
in which the gases travel toward the outside of the oven. The apparatus is
composed of an interior oven proper, which is preferably of a circular shape but
may he made oval, rectangular or square. Around this oven which may consist
of metal or refractory material a jacket is placed, which is open at its upper part
and which is surrounded by a second jacket forming the outer wall. This second
jacket is preferably double and encloses between its walls for the purpose of
avoiding loss of heat-any appropriate non-conducting material, such as mineral
cotton, asbestos or the like. This jacket terminates at its lower part in a chamber.
in which the products of combustion meet after having been previously utilized
during their circulation, and whence they finally escape through opposite conduits.
The outer wall or jacket extends, in the manner described, down to the hottom of
the chamber leaving a central space which is partly occupied by a gas burner
serving to heat the said oven.
In order that the products of combustion may yield the maximum amount of
heat before they are allowed to escape to the chimney, a series of alternating Alues
are provided round the walls (including the feed door) inside the jackets, as well
as at the upper part in both jackets.
In this manner the hot gases, following a circuitous route gradually give off
their heat as they circulate between the different ranges of flues which serve to
pass the said gases either forward or backward, thus utilizing them in the most
advantageous and efficient manner.
In order to avoid overheating of the oven a double disc enclosing a refractory
substance is placed directly above the burner and at a small distance from the
bottom of the oven.
A refractory floor is placed directly upon the inner bottom of the oven, in order
to insure a regular baking of the bread, pastry or the like placed thereon.
The said floor is formed by a series of tiles placed all round the circular space
of the oven and joining a central polygonal tile. These different tiles are provided
on their under side with grooves for enabling the heat produced below the floor,

page_text: to be freely disengaged. Upon their outer circumference these tiles are provided
with notches or recesses, the object of which is to enable the heat produced beneath
the floor, to escape to the interior of the oven.
For lighting and regulating the burner, and for the purpose of inspecting its
action at any time two doors--one turning on hinges and the other having a
sliding motion--are arranged at the lower part of each of the jackets. At the
side of the said doors an auxiliary burner is arranged, to be used for lighting the
main burner.
The heating of this oven is effected by the aid of a special double burner having
etween its two constituent parts an annular space for producing an air current.
The inner part of this burner is formed by a tube the top portion of which is
widened and provided with a series of oblique jet nozzles upon its circumference.
The outer part of this burner is formed by a double jacket, elused above by a
widened head, upon the circumference of which another series of jet nozzles are
arranged, occupying an oblique position similar to those beforementioned.
If so desired and according to the size of the oven the power of the burner may
be increased by adding thereto concentrically one or more similar ring burners,
which are in the same manner as those previously described separated from each
other by an annular space in which an air current is produced. These different
concentric burners are each provided, inside their top part and at their base, with
wire gauze or netting, the object of the upper netting being to prevent the gases
from redescending and igniting the gas at the injector nozzle, and the object of
the lower one is to prevent the outer air current from entering ton rapidly.
thereby causing an irregular air supply.
In order to facilitate the lighting of the burner as well as the discharge of cold
air contained in the partitions of the oven and furnace, a cylindrical box is
arranged in the centre of the collecting tube or horizontal part of the chimney
into which the waste gases are led from the aforementioned opposite conduits.
In this cylindrical box a gas burner is arranged which is accessible from outside
by a lighting door.
The whole furnace and oven is preferably supported by a suitable cast iron
frame provided with legs, but it may be arranged on masonry.
The feed door of the oven is provided with a counterweight for facilitating its
actuation.
Admission valves with vanes are provided for regulating the admission of the
gas supplied to the main burners. A gas bracket with a burner serves to light
up the interior of the oven when the latter is heing charged or discharged. A
pyrometer extends into the interior of the oven in order to constantly register the
temperature therein on its dial outside.
In a modification of my invention, the products of combustion circulate toward
the interior of the oven. the interior of the said oven being in this case made
entirely of refractory material and the floor tiles carry at their periphery an
upwardly extending flange and a series of notches serving for the same purpose
as the notches in the tiles hereinbefore referred to. The tiles forming the vertical
jacket or wall. are provided externally with ribs which, while maintaining the
exact distance hetween the refractory material and the wall. permit the passage
of the hot gases between them. The tiles forming the arch of the furnace are also
provided with ribs for the purpose of directing the passage of the gas and for
directing the heat on the articles to he baked.
This second oven has the advantage of bring less costly in construction than
that before described, moreover a greater amount of heat is developed therein by
the same amount of heating gas.
The vertical hurner hereinbefore described, may be arranged horizontally, in
this position it has a glass covered inspection hole arranged at its upper extremity.
through which the action of the burner may he seen: for ascertaining whether
the gas is well ignited or burning properly. This horizontal burner device also
comprises an automatic regulator for the admission of air to the Iurner: the

page_text: regulation being obtained by the aid of a damper device connected to the plug of
the gas cock and to the regulating valve situated at the lower part of the inlet
for cold air. By this arrangement the gas cock is caused to automatically control
the air feed, since the different positions in which its handle is placed are
transmitted to the damper device connected with the regulating valve.
As the proportions of gas and air are always the same, the combustion will be
consequently always perfect.
This gas cock has fixed to it a graduated horizontal segment upon which a
hand fixed to the plug of the cock is moved, thus indicating the amount of gas
consumed per hour, at a given pressure. By means of this valuable indicating
device, and without using the inspection door hereinbefore referred to, the flame
can be regulated instantly at the burner at any time.
In ovens for kitchen and household use one modification is preferably supported
on legs and heated by a double gas burner with an auxiliary burner, and another
modification does not rest on legs and may be heated by either a gas or charcoal
furnace.
Each of these ovens, which are in these cases made oval shaped, are arranged
so that the heating gases will circulate toward the outside of the furnace, in
a manner similar to the first described baking oven. For this purpose alternate
flue passages are similarly arranged upon the periphery of the furnace as well as
at its upper part. In these two household ovens, the products of combustion are
discharged into the open air. As the said ovens are to be manufactured and sold
cheaply, they are not provided with outer non-conducting material, but may be of
course if required.
The two parts of the door which overlap each other, are provided like the walls
of the oven with alternating flue passages corresponding with those before referred
to. A double disc enclosing non-conducting substance, such as mineral cotton,
asbestos or the like, is likewise arranged at a small distance above the burner in
order to prevent overheating of the articles to be baked. A refractory floor with
ribs is arranged on the bottom of the oven in order to obtain a steady and gradual
baking effect.
In the same way as in the first described arrangement household ovens may
also be constructed according to the second described modification, that is to say
with a circulation of the gases toward the interior of the oven. For this purpose
the bottom of the oven proper is provided with a large number of circular holes,
through which the heating gases arrive at the interior of the oven, and which
heating gases are subsequently discharged into the atmosphere after passing along
the chimney. In this case a grate with a movable plate is employed instead, and
in the place of the above mentioned floor; this grate may also be adapted to the
nature of the material to be baked.
In the modification used for the third form of application of this oven, that is
to say, for heating the "forms" or moulds employed by spectacle makers, the
general arrangement must of necessity be adapted to the special purpose in view.
As the "forms" or moulds to be heated, have the shape of a spherical cap, the
oven is of spherical shape. In the same manner as before, the inner jacket or
wall is open at its top in order that the heating gases may follow the double course,
already referred to. This inner jacket or wall extends downwardly to a flat
bottoni provided with a central opening leaving sufficient room for the head of
the burner to pass through. The outer jacket or wall is preferably a double one,
and encloses between its sides an appropriate non-conducting substance.
Alternating flue passages are likewise placed between each of the walls of the
jacket in order to compel the heating gases, as they successively circulate between
these Hue passages, to give off the maximum amount of heat before arriving at
the chamber whence they are discharged into the chimney through horizontal
flues.
In this heating device the gases of combustion impinge directly on the bottom
of the "form" or mould to be heated, subsequently redescending to its base, then

page_text: rising again and passing along the exterior of the form or mould: by this
arrangement any loss of heat is practically avoided.
The front convex part of this furnace or oven is provided with a hinge door
which is opened or closed by the aid of a vibrating counterweight, to permit of
the insertion and discharge of the "forms" or moulds. In order to heat these
"forms" or moulds they are placed upon two longitudinal T-shaped iron pieces
fixed to the upper side of the inner jacket or wall. In order to permit of their
being easily inserted or withdrawn without fear of accident, other iron pieces
forming extensions of those first mentioned are so arranged as to slide upon a
table provided for the purpose, so that they may be brought against the first
mentioned iron pieces by means of a manipulating handle, when the door has been
lifted.
Finally the whole apparatus is supported on legs in any appropriate manner,
and the heating of the furnace is effected by the aid of a gas burner, the feed of
which is regulated externally by the aid of a suitable cock.
101 3
1009
HASELTINE LAKE & Co.,
45 Southampton Buildings, London, W.C.. Agents for the Applicant.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 improvements in heat economizing furnaces for ovens
having a double circulation, in which the products of combustion pass toward the
interior or toward the exterior. This oven may be employed for numerous
purposes: three special applications being hereinafter described and illustrated in
the accompanying drawings, in which
Figure 1 represents in elevation and Figure 2 in sectional plan on the line 1-2
of Figure 1, the apparatus applicable as a baking oven for pastry and the like;
the circulation of the gases in this case is toward the outside of the furnace.
Figure represents a modification of this furnace or oven, receiving the gases
at its interior.
Figure 3 indicates in sectional plan, upon its right hand side a refractory
device applicable to a furnace in which the gases pass to the interior of the furnace,
and upon its left hand side a device applicable to a furnace, in which the gases
virculate toward the interior.
Figure is a perspective view of the whole arrangement of the apparatus as
shown in Figures 1 and 3.
Figures 6 and 7 are sectional elevations representing the arrangement of a
kitchen oven, in which the gases circulate toward the outside of the oven and
Figure 8 represents a modification of the apparatus, in which the gases circulate
toward the interior.
Figure 9 represents in sectional elevation a furnace or oven used for heating the
"forms"employed by spectacle makers, and
Figures 10 to 15 represent constructional details which will be hereinafter
referred to.
Referring first to the apparatus used as an oven for baking and pastry cooking
in which the gases travel toward the outside of the oven, as illustrated in

page_text: and the heating of the furnace is effected (see Figure 9) by the aid of a gas burner,
the feed of which is regulated externally by the aid of a suitable cock V.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent. I declare that what I claim is:-
1. An improved heat economizing oven or furnace with double circulation, with
its heating gases passing toward the interior or toward the exterior, applicable
for various purposes, more especially suitable as baker's, pastry cook's kitchen,
spectacle-maker's ovens or furnaces: reserving also the right of employing the
same for other appropriate purposes, and to modify its particular constructional
forms and arrangements according to the nature of the products to be treated;
substantially as described, and as represented in the accompanying drawings.
2. The hereindescribed arrangement of the flue-passages and the application of
the same to ovens or furnaces, substantially as above described and shown in the
drawings and for the purpose specified.
3. The improved constructional arrangement of the vertical burner represented
in Figures 1, 12 and 13, whereby burner devices of any required size and power
can be obtained; also the improved constructional arrangement of horizontal
burners such as represented in Figures 14 and 15, comprising a transparent
inspection hole, a graduated dial, indicating the amount of gas consumed and a
regulating device for always ensuring a proportional regulation of the quantity
of air and gas admitted.
4. The arrangement of the ribs beneath the refractory floor of the oven, and the
openings upon the periphery referred to, enabling the heat disengaged through
the base to freely circulate and to arrive at the interior of the oven without any
obstacle.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.

page_text: are arranged so that the heating gases will circulate toward the outside of the
furnace, in a manner similar to the first described with reference to
Figures 1 and 2. For this purpose alternate flue passages r r are similarly
arranged upon the periphery of the furnace as well as at its upper part. In these
two household ovens Figures 5 and 7, the products of comaustion are discharged
into the open air. As the said ovens are to be manufactured and sold cheaply,
they are not provided with outer non-conducting material, but may be of course
if required.
The two parts of the door which overlap each other, are provided like the walls
of the oven with alternating flue passages, corresponding with those before
referred to as represented in Figures 5, 6 and 7. A double dise Genelosing non-
conducting substance such as mineral cotton, asbestos or the like, is likewise
arranged at a small distance above the burner in order to prevent overheating of
the articles to be baked. A refractory floor L with ribs (see Figure 10) is
arranged on the bottom of the oven in order to obtain a steady and gradual baking
effect.
In the same way as in the first-described arrangement indicated in Figure 1,
the types or systems of furnaces represented in Figures and 7 may also be
constructed according to the modification indicated in Figure S, that is to say with
circulation of the gases toward the interior of the oven. For this purpose the
bottom of the oven proper is provided with a large number of circular holes,
through which the heating gases arrive at the interior of the oven, and which
heating gases are subsequently discharged into the atmosphere after passing along
the chimney. In case a grate H with a movable plate is employed instead,
and in the place of the above mentioned floor : this grate may also be adapted
t the nature of the material to be baked.
In the modification used for the third form of application of this oven that is
to say for heating the "forms" or moulds employed by spectacle makers, the
general arrangement must of necessity be adapted to the special purpose in view.
As the "forms" or moulds to be heated, have the shape of spherical cap, the
oven is of spherical shape as is indicated in Figure 9. In the same manner as before
the inner jacket or wall B is open at its ton in order that the heating gases may
follow the double course, already referred to.
This inner jacket or wall extends downwardly to a flat bottom provided with a
central opening leaving sufficient room for the head of the burner to pass through
The outer jacket or wall is preferably a double one, and encloses between its
sides an appropriate non-conducting substance.
Alternating Hue passages r r are likewise placed between each of the walls of
the jackets B and C in order to compel the heating gases, as they successively
circulate between these flue passages, to give off the maximum amount of heat
before arriving at the chamber whence they are discharged into the chimney
through horizontal flues M".
In this heating device the gases of combustion impinge directly on the bottom
of the "form" or mould to be heated, subsequently re-descending to its base, then
rising again and passing along the exterior of the "form or mould: by this
arrangement any loss of heat is practically avoided.
The front convex part of this furnace or oven is provided with a hinge door Z,
which is opened or closed by the aid of a vibrating counterweight to permit of the
insertion and discharge of the "forms" or moulds. In order to heat these
"forms" or moulds they are placed upon two longitudinal T-shaped iron pieces
fixed to the upper side of the inner jacket or wall. In order to permit of their
being easily inserted or withdrawn without fear of accident, other iron pieces X+
forming extensions of those first mentioned are so arranged as to slide upon a
table provided for the purpose, so that they may be brought against the first
mentioned iron pieces by means of a manipulating handle 0, when the door has
leen lifted.
Finally the whole apparatus is supported on legs in any appropriate manner.

page_text: In order to facilitate the lighting of the burner as well as the discharge of cold
air contained in the partitions of the oven or furnace, a cylindrical box e is
arranged (see rear view, Figure 11) in the centre of the collecting tube E joining
the pipes EE and serving to convey the heating gases through the pipe E to the
flue. In this cylindrical box e a gas burner is arranged which is accessible from
outside by a lighting door e'.
The whole furnace or oven is preferably supported by a suitable cast iron frame
provided with legs, as shown in Figures 1 and 4, but it may be arranged on
masonry.
Figure indicates the whole of such a device as may be advantageously
employed. In this figure, the following is an explanation of those constituent
parts which have not been previously referred to.
M is the feed door of the furnace and is provided with a counterweight M for
facilitating its movements.
N and are admission valves with vanes for regulating the admission of the
gas supplied to the main burners I and I. X" the handle regulating the feed
of the auxiliary burner. P is a gas bracket with a burner serving to light up the
interior of the oven when the latter is being charged or discharged. It is the
pyrometer extending into the interior of the oven in order to constantly register
the temperature therein on its dial outside.
R
In the modification of my invention shown in Figure the products of
combustion circulate toward the interior of the oven, the interior of the said oven
being in this ense made entirely of refractory material and the floor tiles carry, at
their periphery an upwardly extending flange and a series of notches .r, z serving
for the same purpose as the notches in the tiles herein before referred to. The
tiles forming the vertical jacket or wall are provided externally with ribs re
which, while maintaining the exact distance between the refractory material oven
and the wall permit the passage of the hot gases between them. The tiles
forming the arch of the furnace are also provided with ribs re for the purpose
of directing the passage of the gas and to direct the heat on the articles to be
baked.
This second oven has the advantage of being less costly in construction than
that before described, moreover a greater amount of heat is developed therein by
the same amount of heating gas.
The vertical burner I herein before described, may be arranged horizontally,
as illustrated in Figures and 15: in this position, it has a riass covered
inspection hole A arranged at its upper extremity, through which the action of
the burner may be seen: whether the gas is well ignited or burning properly.
This horizontal burner device also compfis an automatic regulator for the
admission of air to the burner: the regulation obtained by the aid of a
damper device T connected to the plug of the gas cock I and to the regulating
valve 12 actuated at the lower part of the inlet for cold air. By this arrangement
the gas cock R is caused to automatically control the air feed, sinet the different
positions in which its handle is placed are transmitted to the damper device T
connected with the regulating valve Pe
As the proportions of gas and air are always the same, the combustion will be
consequently always perfect.
This gas cock it has fixed to it a graduated horizontal segment are C2 upon
which a hand 12 fixed to the plug of the cork, is moved, thus indicating the
amount of gas consumed per hour, at a given pressure. By means of this valuable
indicating device and without using the inspection doors and s hereinbefore
referred to, the flame can be regulated instantly at the burner at any time.
In one modification ovens for kitchen and household use illustrated in
Figures 5 and are preferably supported on legs and heated by a double gas
burner with an auxiliary burner. and in another modification does not rest on
legs, and may be heated by either a gas or charcoal furnace.
These ovens which are in these cases made oval shaped, as indicated in Figure 6,

page_text: Figures 1 and 2, the apparatus is composed of the interior oven proper A, which is
preferably of a circular shape but may be made oval, rectangular or square.
Around this oven which may consist of metal or refractory material a jacket B
is placed, which is open at its upper part and which is surrounded by a second
jacket C forming the outer wall. This second jacket is preferably double and
encloses between its walls-for the purpose of avoiding loss of heat-any appropriate
non-conducting material, such as mineral cotton, asbestos or the like.
jacket C terminates at its lower part in a chamber D, in which the products of
combustion meet after having been previously utilized during their circulation,
and whence they finally escape through the opposite conduits. The outer wall or
jacket B extends, in the manuer described down to the bottom of the chamber D.
leaving a central space which is partly occupied by a gas burner serving to heat
the said oven.
This
In order that the products of combustion may yield the maximum amount of
heat before they are allowed to escape to the chimney, a series of alternating flues
are provided round the walls (including the feed door) inside the jackets as well
as at the upper part between both jackets.
In this manner the hot gases, following a circuitous route indicated by the
arrows Figure 1; and more especially in Figure 2 gradually give off their heat as
they circulate between the different ranges of flues which serve to pass the said
gases either forward or backward, thus utilizing them in the most advantageous
and efficient manner.
In order to avoid overheating of the oven a double disc G enclosing a refractory
substance, is placed directly above the burner and at a small distance from the
bottom of the oven.
A refractory floor (see Figure 1 and 3ª left hand side) is placed directly upon the
inner bottom of the oven, in order to insure a regular baking of the bread, pastry
or the like placed thereon.
The said floor (see the left hand side of Figure 3) is formed by a series of tiles
placed all round the circular space of the oven and joining à central polygonal
tile. These different tiles are provided on their under side with grooves L' for
enabling the heat produced below the floor to be freely disengaged. Upon their
outer circumference these tiles are provided with notches or recesses the object of
which is to enable the heat produced beneath the floor to escape to the interior of
the oven.
For lighting and regulating the burner, and for the purpose of inspecting its
action at any time two doors s-one turning on hinges and the other having a
sliding motion are arranged at the lower part of each of the jackets B and C.
At the side of the said doors an auxiliary burner is arranged, to be used for
ighting the main burner.
The heating of this oven is effected by the aid of a special double burner I, I,
shown separately in elevation and plan in Figures 12 and 13 and having between
its two constituent parts an annular space for producing an air current. The
inner part of this burner is formed by a tube I the top portion of which is widened
and provided with a series of oblique nozzles upon its circumference. The outer
part of this burner is formed by a double jacket I closed above by a widened head,
upon the circumference of which another series of jet nozzles are arranged
occupying an oblique position similar to those beforementioned.
If so desired and according to the size of the oven the power of the burner may
be increased by adding thereto concentrically one or more similar ring burners,
which are in the same manner as those previously described separated from each
other by an annular space in which an air current is produced. These different
concentric burners are each provided, inside of their top part and at their base,
with wire gauze or netting the object of the upper netting being to prevent the
gases from redescending and igniting the gas at the injector nozzle, and the object
of the lower one is to prevent the outer air current from entering too rapidly,
thereby causing an irregular air supply.