IMPROVEMENTS IN FURNACES AND FIREPLACES
Year: 1879

page_text: LETTERS PATENT to George Frederick Redfern, of the General Patent Office,
A com-
4, South Street, Finsbury, in the County of Middlesex, Patent Agent, for
the Invention of "IMPROVEMENTS IN FURNACES AND FIREPLACES."
munication from abroad by Antonio Palma, of Rome, in the Kingdom of
Italy.
Sealed the 30th May 1879, and dated the 3rd January 1879.
PROVISIONAL SPECIFICATION left by the said George Frederick Redfern
at the Office of the Commissioners of Patents on the 3rd January 1879.
GEORGE FREDERICK REDFERN, of the General Patent Office, 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent. "IMPROVEMENTS IN
FURNACES AND FIREPLACES." [A communication from abroad by Antonio Palma,
of Rome, in the Kingdom of Italy.]
This Invention relates to improvements in furnaces, fireplaces, and stoves in
which the heat both from the fire and from the steam or smoke of all kinds of
boilers, and from the burning or baking of materials such as lime, bricks, bread, bis-
cuits, the cooking of vegetables and the drying of tissues is concentrated; also for
the manufacture of metals, glass, gas, and in general for all such operations as
require concentrated heat.
In carrying out this Invention each furnace or fire place for the boiler, frying pan,
or other kitchen utensil is provided with a platform of iron in its upper part raised
about two feet to three feet three inches above the floor, but if the boilers be for use
in liquorice works the platform is set at the level of the floor, and around and above
it is erected a parapet or wall to protect the workmen. A small staircase from the
higher floor descends to the lower floor where the fire grate is placed. The platform
is covered all round its lower part with one or more rows of refractory bricks laid
flat and joined obliquely. Between the bricks and the platform is put a quantity
of ashes or sand in order to protect it from the reverberated heat of the flame, so
that the smoke only and not the reverberation of the flame may reach it.
In stoves with vertical tubes for the formation of hot air in boilers, for heating
water by the smoke, in stoves for drying linen, in ovens, in furnaces for baking
bricks and the like, and in places where it is required to retain the heat from the
fire grate to the platform, refractory bricks are placed edgewise with oblique joints
so as to face the interior of the grate, each of the bricks being of the greatest possible
length and breadth.

page_text: In a series of boilers of circular form each must have its own furnace. One of
the boilers may serve for cooking, the other in front for water heated by the smoke
passing from the first to the second furnace or grate, or for hot water by leaving an
oblong opening which may be closed by a valve, so that the smoke may come out
with more or less heat and rapidity.
Circular boilers are preferable to those of other shapes owing to the more uniform
and regular ebullition from the bottom to the centre and circumference, but more so
on account of the power of the vertical heat concentrated by the furnace, which is
the main part of this Invention.
Square bricks of earthenware (majolica) are used to cover the outside of the plat-
forms for ranges because they can easily be cleaned every day. Such platforms have
outside projections to hold the bricks. Sand or ashes are placed between the bricks
and the iron surface in order that the bricks may not be heated by their contact
with the platform.
In some stoves the platforms, the iron roof, the iron plate, and the board are
moveable, being enclosed in iron frames, whence they may be removed at the upper
part for cleaning away the soot.
Stoves and ovens from which the aforesaid parts can be removed horizontally are
similarly constructed, but the platforms are concave or flat, but double and separated
by an empty space, and stand on four supports fixed upon the walls or parapets ;
the bread is placed on two moveable wire rings divided into five separable
segments.
The surplus heat may be turned to advantage by introducing cold air into the
ovens, stoves, or ranges through a tube, and discharging it when hot through a suit-
ably placed valve.
In a cooking range for an establishment of sixty persons the oven may be heated
by the smoke, by water heated or warmed by the smoke, and from the stove heated
by the smoke.
In this case there are two boilers for boiling meat, wood being used for fuel, a
small boiler heated by wood, a stew pan heated by charcoal, a frying pan heated by
wood, a pipe for introducing water into the boilers, a pipe for conveying water to
the baths, and large and small air pipes.
The flame should always be directed vertically from the centre of the grating
towards the centre of the boiler, The smoke remains a certain time in the side zones
surrounding the boiler and then passes out by an opening. The vertical column of
the flame impetuously and unceasingly pressing against the bottom of the boiler is
compelled to bend back upon itself until it turns up again towards the bottom of
the boiler, or in furnaces for glass or gas towards the hereinbefore described iron
plate.
These furnaces have the form of a section of a reversed cone from the grating to
the platform. In boilers for a limited, or determined, or special purpose, such a
section extends as far as the middle of the boiler or thereabouts, according to the
shape of the latter and the object to be attained.
It is frequently advantageous to employ only one spiral pipe through which the
smoke passes before entering the opening either through one mouth or through two
mouths, the second one being smaller and perpendicular to the door of the fire placo
when a more powerful draught is required, whereas the smoke should egress gently
but rapidly.
Between the wall of the grate and the lower part of the boiler there must be only
a small space, so to give room only to the side flames detached from the vertical
one, which serve to make the refractory bricks red hot in order that these may keep
the heat in constant equilibrium.
In all grates the smoke must remain but for a short time in the upper zones sur-
rounding the boiler, and then egress through the side opposite to the door of the
fire place; the draught is regulated by the valves according to the quality of the
fuel and to the degree of ebullition which is required.

page_text: In furnaces for burning lime, bricks, and the like, the base of the cone rests on the
grating, and an iron vault is provided with holes to give vent to the flame and
smoke.
For the baking of bricks the vault may be of clay. When the fuel gives a low
flame only a grating takes the place of the vault, and the lower grating for the fuel
is raised as high as is convenient.
The height of the furnace ought not to be less, but either equal to or greater than
double the diameter of the base.
The top is made of clay and is full of holes. Such furnaces, but especially furnaces
for burning lime, are protected from the influences of the atmosphere by being
enclosed in a building and sunk in the ground, or covered all round with earth while
the fire is burning.
Beneath the grating there is an ash pit, which by means of two small horizontal
pipes placed at the sides of the door communicate with an air conduit parallel to the
pipes and starting from below the door of the ash pit. This door consists of
an iron plate covered with wood, a space being left between the iron and the
wood.
It is sometimes useful to add a vertical tube for the purpose of introducing
air into the horizontal tube by means of a valve for regulating the descent of
the air and preventing its irregular or too rapid movement.
The ash pit must have a free communication with the fuel so that the air may
gradually pass through the grating, aided by the converging walls of the ash pit.
The chimney runs horizontally from the opening for the smoke to the point
where the vertical smoke pipe in inserted. Near the line of this vertical pipe are
placed the boilers for hot water in order that the workmen may be able to work
round half or three quarters of their circumference, whereas in ranges along tho
horizontal line of the opening for the smoke moveable stoves are placed, and the
fixed boilers are placed on a platform so that they may be easily cleaned from the
Boot by taking off first the two boards and then the two iron plates.
In family ranges or in special grates the smoke pipe.may be oblique or vertical,
provided that additional short branches be added to it, the dimensions of the pipe
and of its branches boing always such as is required by the combustion.
With low boilers the opening for the smoke is to be square or a parallelogram,
with the horizontal sides longer than the vertical. With high boilers the horizontal
side of the opening must be shorter than the vertical ones.
The opening itself must be in proportion to the quantity of the smoke and of the
draught necessary for the combustion.
The combustion is regulated by a horizontal iron valve, or a vertical valve is
inserted in the opening for the smoke. The other valves in the air conduit and in
the small air pipes secure the regular motion of the air, or even stop it altogether,
when the heat of the ovens, stoves, or ranges is employed for warming rooms, or
drying linen, or for like purposes.
These are the main conditions required to preserve and reflect the heat with com-
paratively little fuel by using the vertical power of the flame.
The distance from the grating to the bottom of the boiler, pan, still, or other vessel
is determined by various conditions, such as the diameter and height of the vessel
and the height of the flame.
In small boilers the conditions are modified in consequence of the larger space
occupied by the wood employed. When pit coal is used the distance as well as the
diameter of the grating is varied in order to have a determined degree of efficient
hent at the bottom and on the higher part of the vessel, according to the object to
be attained.
In steam engines the boiler should consist of vertical tubes, with ash pits covered
with fire-proof bricks.
The door of the ash pit and that of the fire place ought to have the smallest pos-
sible dimensions, especially when faggots are substituted for wood or coal. The

page_text: bricks should be joined with fire clay; stone and cement should be employed in
basements and stands which are not to be reached by the heat.
It is preferable to place ashes behind the bricks, or to leave an empty space round
them in the case of moveable steam engines, and to put earth or sand behind the
iron-plate, according to the various circumstances.
Besides the advantages with regard to the protection of workmen the economical
advantages of this system are, first, that groat effects may be produced by using a
comparatively small quantity of fuel; second, that cheap and reproductive fuel
such as faggots, straw, and the like, can be substituted for more expensive and
exhaustible ones, such as pit coal or lignite.
SPECIFICATION in pursuance of the conditions of the Letters Patont filed by
the said Georgo Frederick Redfern in the Great Seal Patent Office on the
3rd July 1879.
GEORGE FREDERICK REDFERN, of the General Patent Office, 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent. "IMPROVEMENTS IN
FURNACES AND FIREPLACES." A communication from abroad by Antonio Palma,
of Rome, in the Kingdom of Italy.
This Invention relates to improvements in furnaces, fire places, and stoves in
which the heat both from the fire and from the steam or smoke of all kinds of
boilers, and from the burning or baking of materials such as lime, bricks, bread,
biscuits, the cooking of vegetables, and the drying of tissues is concentrated, also
for the manufacture of metals, glass, gas, and in general for all such operations as
require concentrated heat.
In carrying out this Invention each furnace or fire place for the boiler, frying
pan, or other kitchen utensil is provided with a platform of iron in its upper part
raised about two feet to three fect threo iuches above the floor, but if the boilers be
for use in liquorice works the platform is set at the level of the floor X, and around
and above it is orected a parapet or wall to protect the workmen. A small staircase
from the higher floor descends to the lower floor where the fire grate is placed. The
under part of the platform is covered all round its upper part with one or more
rows of refractory bricks S, a, laid flat and joined obliquely. Between the bricks
and the platform is put a quantity of ashes or sand in order to protect it from the
reverberated heat of the flame, so that the smoke only, and not the reverberation
of the flame, may reach it.
In stoves F with vertical tubes for the formation of hot air in boilers V, I, for
heating water by the smoke, in stoves E for drying linen, in ovens A, B, in furnacos I
for baking bricks and the like, and in places where it is required to retain the heat
from the fire grate to the platform, refractory bricks are placed edgewise with
oblique joints as shewn at b, c, d, Figure S, so as to face the interior of the grate,
each of the bricks being of the greatest possible length and breadth.

page_text: In a series of boilers of circular form each must have its own surface. One of
the boilers may serve for cooking, the other in front for water heated by the smoke
passing from the first to the second furnace or grate, or for hot water by leaving an
oblong opening which may be closed by a valve so that the smoke may come out
with more or less heat and rapidity.
Circular boilers C, L, are preferable to those of other shapes owing to the more
uniform and regular ebullition from the bottom to the centre and circumference, but
more so on account of the power of the vertical heat concentrated by the furnace
which is the main part of this Invention, for the intensity of the heat is not
naturally produced by the flame but is artificially produced by the oven.
Square bricks of earthenware (majolica) are used to cover the outside of the
platforms for ranges because they can easily be cleaned every day; such platforms
have outside projections to hold the bricks. Sand or ashes are placed between the
bricks and the iron surface in order that the bricks may not be heated by their
contact with the platform.
In the stoves E and F the platforms, the iron roof a, the iron plate b, and the
board c are moveable, being enclosed in iron frames, whence they may be removed
at the upper part for cleaning away the soot.
The stoves and ovens A and B, from which the aforesaid parts can be removed
horizontally, are similarly constructed, but the platforms are concave or flat, and the
latter aro composed of two parts, one which is close to the heat, and an upper one
which is limited only at the boards where are laid the said ironwire segments, and
separated by an empty space and stand on four supports B fixed upon the walls
or parapets. The bread is placed on two moveable wire rings divided into six
separable segments. File dust, sand, or other proper matter are placed in 6 of the
Figure B of a convex form for the purpose of concentrating to the centre the greatest
number of heat mys.
In a cooking range shewn at U and V for an establishment of sixty persons the
water of the boiler may be heated by the smoke through g and f by water heated
or warmed by the smoke, and from the stove heated by the smoke at l.
In this case there are two boilers a and c for boiling meat and cooking pastry,
wood being used for fuel; a small boiler b heated by wood, a stew pan or roaster d
heated by charcoal, a frying pane heated by wood. i is a pipe for introducing
water into the boilers; k is a pipe for conveying water to the baths; and m, m,
large, and x, x, small air pipes; y, valve.
A range suitable for cooking for fifteen persons is represented at R.
boiling ineat; b, for frying; c, for pastry; d, for roasting ment.
a is for
These grates have the shape of a section of a reversed cone from the grating g to
the platform p, P. In certain boilers H, M, E, F, for a limited, or determined, or
special purpose such section extends as far as the middle of the boiler or thereabouts,
according to the shape of the latter and the object to be attained.
It is frequently advantageous to employ only one spiral pipe D, K, Q, through
which the smoke passes before entering the opening C, D, either through one mouth a
or through two mouths, the second one b being smaller and perpendicular, to the
door of the fire place when a more powerful draught is required, whereas the smoko
should egress gently but rapidly.
Between the wall of the grate and the lower part of the boiler there must be
only a small space so as to give room only to the side flames detached from the vertical
one which serve to make the refractory bricks red hot in order that these may keep
the heat in constant equilibrium.
In all grates the smoke must remain but for a short time in the upper zones
surrounding the boiler and then egress through the side opposite to the door of the
fire place. The draught is regulated by the valves according to the quality of the
fuel and to the degree of ebullition which is required.
In furnaces I for burning lime, bricks, and the like, the base of the cone rests on
the grating, and an iron crown is provided with holes to give vent to the flame and
smoke.

page_text: For the baking of bricks the vaults b, c, may be of clay and bricks. When the
fuel gives a low frame only a grating takes the place of the vault, and the lower
grating for the fuel is raised as high as is convenient.
The height of the furnace ought not to be less, but either equal to or greater than,
double the diameter of the base.
The top is made of clay, and is full of holes. Such furnaces, and especially kilns
for burning lime, are protected from the influences of the atmosphere by being
enclosed in a building and sunk in the ground, or covered all round with earth while
the fire is burning.
Beneath the grating there is an ash pit P, g, which by means of two small
horizontal pipes x, x, V, and the valve T, v, placed at the sides of the door, coin-
municate with an air conduit N, m, m, V, m, m, parallel to the pipes and starting
from below the door of the ash pit. This door consists of an iron plate covered
with wood, a space T, o, being left between the iron and the wood.
Sometimes it is necessary to dispense entirely with the reservoir of heated water,
and in some cases to substitute to the grate refractory bricks supported by refractory
materials of curved shape.
It is sometimes useful to add a vertical tube for the purpose of introducing air
into the horizontal tube by means of a valve for regulating the descent of the air
and preventing its irregular or too rapid movement.
The air reservoir must have a free communication with the fuel so that the air
may gradually pass through the grating aided by the inclined wall of tho said
grate.
The chimney runs horizontally from the opening for the smoke to the point where
the vertical smoke pipe is inserted.
Near the line of this vertical pipe are placed the boilers N, X, for hot water in
order that the workmen may be able to work round half or three quarters of their
circumference; whereas in ranges V along the horizontal line of the opening for the
smoke, moveable stoves are placed, and the fixed boilers are placed on a platform
so that they may be easily cleaned from the soot by taking off first the two boards
and then the two iron plates.
In family ranges, or in special grates, the smoke pipe may be oblique or vertical,
provided that additional short branches R, v, v, v, v, be added to it, the dimensions
of the pipe and of its branches being always such as is required by tho
combustion.
With low boilers the opening for the smoke is to be square or a parallelogram
with the horizontal sides longer than the vertical sides. With high boilers the
horizontal sides of the opening must be shorter than the vertical ones.
The opening itself must be in proportion to the quantity of the smoke and of
the draught necessary for the combustion.
The combustion is regulated by a horizontal iron valve R, v, T, v, or a vertical
valve N, v, is inserted in the opening for the smoke. The other valves in the air
conduit V, y, and in the small air pipes x, x, (T, v¹) secure the regular motion of tho
air, or even stop it altogether when the heat of the ovens A, B, stoves E, F, or
ranges V is employed for warming rooms, or drying linen, or for like purposes.
The surplus heat may be turned to advantage by introducing cold air through a
tube t and letting it out when heated through the valve v.
The distance a from the grating P, g, to the bottom of the boiler, pan, still, or
other vessel X, is determined by various conditions, such as the diameter and height
of the vessel, and the height of the flame.
In small boilers V, b, the conditions are modified in consequence of the larger
space occupied by the wood employed. When pit coal is used the distance a, as
well as the diameter of the grating, is varied in order to have a determined degree
of efficient heat at the bottom and on the higher part of the vessel, according to
the object to be attained.
In steam engines the boiler should consist of vertical tubes M, O, with a reservoir
of air covered with fire proof bricks.

page_text: The door of the reservoir of air, and that of the fire place ought to have the
smallest possible dimensions, especially when faggots P are substituted for wood or
coal K. The bricks should be joined with fire clay; stone and cement should be
employed in basements and stands which are not to be reached by the heat.
It is preferable to place ashes behind the bricks, or to leave an empty space round
them in the case of moveable steam engines, and to put earth or sand behind the
iron plate, according to the various circumstances.
Besides the advantages with regard to the protection of workmen, the economical
advantages of this system are, first, that great effects may be produced by using a
comparatively small quantity of fuel; second, that cheap and reproductive fuel,
such as faggots, straw, and the like, can be substituted for the more expensive and
exhaustible ones, such as pit coal or lignite.
Having thus described the nature of the Invention communicated to me, and the
manner of performing the same, what is claimed is,―
The improvements in furnaces and fire places, substantially as hereinbefore
described, and represented in the accompanying Drawing.
In witness whereof, I, the said George Frederick Redfern, have hereto set
my hand and seal, this Third day of July, in the year of our Lord One
thousand eight hundred and seventy nine.
G. F. REDFERN. (L.S.)