IMPROVEMENTS IN KILNS, OVENS, AND FURNACES
Year: 1862

page_text: LETTERS PATENT to Michael Henry, of 84, Fleet Street, in the City of
London, Patent Agent, for the Invention of "IMPROVEMENTS IN KILNS,
OVENS, AND FURNACES."-A communication from abroad by the "Société
Coignet Père et Fils et Compagnie," of 33, Boulevard Saint Martin,
Paris, France.
Sealed the 5th September 1862, and dated the 22nd March 1862.
PROVISIONAL SPECIFICATION left by the said Michael Henry at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
March 1862.
I, MICHAEL HENRY, of 84, Fleet Street, in the City of London, Patent
Agent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN KILNS, OVENS, AND FURNACES," communicated to me from abroad by
the "Société Coignet Père et Fils et Compagnie," of 33, Boulevard Saint
Martin, Paris, France, to be as follows:-
These improvements relate to kilns, furnaces, and ovens, or apparatus
suitable for calcining lime, plaster, and bones, revivifying animal charcoal,
baking or firing bricks, pottery, porcelain, and retorts, and performing various
other operations in which materials or articles are to be subjected to fire
or to heat.

page_text: In one arrangement the kiln, oven, chamber, or portion of the apparatus
containg the materials to be subjected to fire or to heat is constructed with a
sole or floor, through which numerous orifices or openings are formed, and
furnaces or fire-places are placed directly under this sole or nearly so, so that
the flames, products of combustion, or heat from the fires rise through the
openings in the sole into the chamber, kiln, or oven, and act on the materials
or articles therein, and other orifices may also be sometimes formed through
the sole for the outlet of the gaseous products escaping from the kiln, oven,
or apparatus to the chimney or elsewhere, and in that case it is preferred that
the rows of inlet orifices, or those through which the heat or flame ascends,
should cross the row or rows of these outlet orifices, which may generally be
arranged at, across, or near the middle of the sole, for then films or layers
of heat or flame instead of curved tongues or bows of fire are obtained. It is
preferred also that the whole surface of the sole should be perforated with
the orifices, and that the inlet holes (or those through which the gases ascend)
should be of small section, the heat being thereby more uniform than when
it enters through broad flues. Blocks or other contrivances may be used for
opening and closing the orifices, to any required extent, and thereby, for
example, the inlet holes farthest from the fire may be rendered largest; also
the size of the outlets may be regulated by their proximity to the main exit
flue. For cooling down kilns, ovens, or chambers, passages, or openings with
removable doors, plugs, or plates opened and closed, as required, may be
formed in the sides or walls at or just above the sole, and through these when
opened atmospheric air enters, and rising to the top of the kiln, oven, or
chamber escapes thence through an outlet in the roof with a removeable cover
opened when required. Doors or panels mounted on wheels or rollers which
travel on rails may be used for opening and closing the apparatus to admit
and remove the charges, and passages may be provided under the openings
through the sole to receive cinders or extraneous matters.
In another arrangement a receiver or matter to be subjected to heat is
rested on an arch extending over the fire, and is thus kept from injurious
action of flame. The gases and heat rise from the fire through flues, of which
there are one or more at each end or corner of the apparatus. These flues,
which generally pass through the arch lead up into, and preferably, to the top
of a flue, oven, or chamber, which surrounds the receiver or article to be
heated, and may sometimes have its sides sloping inwards towards the top.
The heat and gases escape thence through other flues, which are situated
midway between the ends or corners, or between and equidistant from the

page_text: first-named or corner flues, and are opened and closed by valves, registers, or
dampers. The grate or fire-place and the ash-pit are closed by plates, doors,
or covers, which exclude the air, but are provided with valves, cocks, or other
means for admitting a regulated draft of air when opened. This apparatus is
especially applicable when the matters are held in one or more vessels or
receivers, and may be used whether the vessel or receiver be wholly enclosed
or not, and among the purposes to which it is applicable may be mentioned
the manufacture of manure. Openings may be sometimes formed in the roof
to divide the draft and keep the temperature uniform, for which purpose a
blast or draft of air may sometimes be forced in.
In a third arrangement several improvements are included. Air may be
forced in or introduced under pressure above and below the fire-bars. The
hot gases from the fire are brought into the kiln, oven, or chamber (containing
the materials to be treated), at the top or upper part thereof a valve, register,
damper, or similar contrivance is fitted in the passage, through which the hot
gases pass on their way out of the apparatus, whereby their escape may be so
controlled as to maintain them within the apparatus under a pressure slightly
above the external pressure. The hot gases in escaping may pass through a
hopper, feed box, or receiver containing the charge to be fed into the kiln,
oven, or chamber. These improvements may be thus combined. Two draft
pipes fitted with cocks or like contrivances lead one above and the other
beneath the fire-bars; through these pipes air may be forced (preferably
by causing them to communicate with an air reservoir). Two arches are
generally constructed over the fire-bars above the upper draft pipe. These
arches are one above the other, and have numerous openings through them,
through which (or otherwise if if the furnace be of other construction) the
heated products of combustion pass from the fire to the upper part of a kiln,
oven, or chamber, herein-after called "main chamber," containing the materials
to be subjected to heat, and thus first attain the upper portion of the heap or
mass of those materials, and after passing down through them escape from the
bottom through a flue or passage leading upward to a hopper, feed shoot, or
charging box, herein-after called hopper only. At the top of the apparatus
or main chamber, through which hopper they escape, and in their passage
warm or heat the charge or supply of material temporarily placed therein
the escape of these gases through their exit flues is regulated by a valve or
like contrivance fitted therein, by which means the gases may be kept in the
apparatus at a pressure in slight excess of that upon or over the hopper, so
that the heat instead of passing in a direct current from inlet to outlet acts as

page_text: a fluid under pressure, and descends in a sort of films or layers. It is preferred
that the main chamber should be oval and of fire-clay, or other refractory or.
ceramic substance, and that it should be opened and closed at top and bottom.
by slides or plates, the upper opening for the feed and the lower for the.
discharge. The feed may thus be continuous, and the products may be dis-
charged into a wheeled truck below the apparatus or other receiver. The heat:
rising from the fire may be subdued by forcing air through the upper draft.
pipe, or the fire rendered more intense by forcing air through the lower
draft pipe.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Michael Henry in the Great Seal Patent Office on the 22nd
September 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
HENRY, of 84, Fleet Street, in the City of London, Patent Agent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Michael Henry, Her special licence that I, the said Michael Henry,
my executors, administrators, and assigns, or such others as I, the said
Michael Henry, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
KILNS, OVENS, AND FURNACES," communicated to me from abroad by the "Société
Coignet Père et Fils et Compagnie," of 33, Boulevard Saint Martin, Paris,
France, upon the condition (amongst others) that I, the said Michael Henry,
my executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.

page_text: NOW KNOW YE, that I, the said Michael Henry, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, as communicated to me, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon, that is
to say:-
These improvements relate to kilns, ovens, and furnaces, suitable for
calcining lime, plaster, and bones, revivifying animal charcoal, burning bricks,
baking or firing pottery, porcelain, and retorts, and performing other operations
in which materials or articles are subjected to fire or heat.
In one arrangement the kiln or oven, or rather the chamber or portion
thereof containing the materials to be subjected to fire or heat, is constructed
with a sole or floor, through which numerous openings, herein called inlet
holes, are formed; furnaces or fire-places are placed directly under this sole (or
nearly so), and from them the flames and hot gases or products of combustion
rise through the openings in the sole into the kiln, oven, or chamber, and act
on the materials or articles therein. Other openings, herein called outlet holes,
may sometimes be formed through the sole for the escape of the gaseous
products from the kiln, oven, or apparatus to the chimney or elsewhere, and in
this case the rows of inlet holes should cross the row or rows of outlet holes,
which
à may mostly be arranged across or near the middle of the sole, the object
being that the products of combustion, when acting on the matters, may be in
the form of films or sheets of heat or flame rather than in that of tongues or bows
of fire. It is preferred that the whole surface of the sole should be provided
with openings or holes, and that the inlet holes should be of small sectional
area, as heat is more equally diffused when entering through narrow openings
than through broad flues. Blocks of brick or other ordinary contrivances
may be used for reducing the sectional area of the passage through the holes
to any required extent, by which means the inlet holes farthest from the fire
may be opened widest and the area of passage through the outlet holes may
be regulated according to their vicinity to the main exit flue.
Doors or panels
mounted on wheels or rollers which travel on rails may be used for opening
and closing the kiln or oven to admit and remove the charges. For cooling
down kilns or ovens, whether constructed as described or otherwise, passages or
openings with removeable doors, plugs, or plates opened and closed as required,
may be formed in the sides or walls at or just above the sole, and through
these, when opened, atmospheric air will enter and will. rise to the top of the
kiln, oven, or chamber, and thence escape-through an outlet in the roof filted

page_text: with a removeable cover opened when required. Passages may be provided
under the opening through the sole to receive cinders or extraneous matters.
In another arrangement a receiver containing matters to be subjected to
heat is rested on an arch extending over the fire, and is thereby preserved
from being injured by the flames. The hot gases rise from the fire through
flues, of which there are one or more at each corner of the apparatus, and
pass into (and to the top of) a flue, oven, or chamber which surrounds the
receiver or article to be heated, and has sides sloping inwards towards the top;
thence the heat escapes through other flues which are situated between and
equidistant from the first-named or corner flues, and are opened and closed by
valves, registers, or dampers. The fire-place and ash-pit are closed by plates
or doors which exclude the air but are fitted with valves, cocks, or other
ordinary contrivances for controlling the flow of air, by which, when opened,
a regulated draft is admitted. By these means of controlling the draft into
the fire, of conveying the products of combustion from it and from the apparatus,
and of regulating their escape, a regular and uniform temperature may be
obtained. This apparatus is mainly applicable for treating matters held in one
or more vessels or receivers whether such vessel or receiver be wholly enclosed
or not. Among the purposes to which it is suitable may be mentioned the
manufacture of manure. Small openings may be formed in the roof to divide
the draft and keep the temperature uniform, for which purpose also, as
before stated, the draft of air is forced in.
In a third arrangement air may be forced into the furnace above and below
the fire-bars. The hot gases from the fire are conducted into the kiln or oven in
such manner as to enter it at the upper part of the space in, or portion of, the
kiln or oven which contains the materials to be treated and is herein-after
called "main chamber." A valve register damper or similar contrivance is
fitted in the passage through which the hot gases travel on their way out of
the main chamber, whereby their escape may be so controlled that they may
be, when within the kiln, oven, or chamber, under a pressure slightly
exceeding the external pressure. The hot gases in escaping pass through a
hopper, feed box, or receiver, containing the charge to be fed into the main
chamber.
These improvements may be thus combined :-Through two draft pipes fitted
with cocks or like contrivances, and leading one above and the other beneath
the fire-bars, air may be forced as required; two arches are set one above the
other over the fire-bars and higher than the upper draft pipe, and have
numerous openings through them through which the hot products of com-

page_text: bustion pass from the fire to the upper part of the "main chamber," and thus
first attain the upper portion of the beap or mass of the materials therein, and
after passing down through them will escape from the bottom through a flue
or passage leading upward to a hopper feed, shoot, or charging box, herein-
after called hopper, only at the top of the main chamber, through which
hopper they escape, and in their passage they warm or heat the charge or
supply of material temporarily placed therein. The escape of these gases
through the exit flue is regulated by a valve or like contrivance fitted in it, by
which means pressure may be put on the gases when in the apparatus a little
in excess of that upon the mouth of the hopper, so that the heat instead of
passing in a direct current from inlet to outlet acts as a fluid under pressure
and descends in a sort of films or layers. The main chamber may be opened
and closed at top and bottom by slides or plates, the upper being opened for
the feed and the lower for the discharge, and the products may be discharged
into a truck or other receiver below the apparatus. The heat may be subdued
by forcing air through the upper draft pipe, and may be rendered more
intense by forcing air through the lower draft pipe.
I now proceed with reference to the accompanying Drawing more
particularly to describe apparatus constructed according to this Invention.
Figure 1 is a vertical section of a kiln constructed according to the arrange-
ment first herein-before described; Figure 2 is a transverse vertical section of
the same; and Figure 3 is a horizontal section above the sole; Figure 4 is a
front elevation. Figure 1 is on the line W, X, of Figure 3, and Figure 2 on
the line Y, Z, of Figure 3.
A, A, are fire-places or furnaces, four in number, for example, placed one at
each side of the kiln beneath its sole or floor B; d, d, are openings which I
call inlet holes, formed through the sole, through which the gaseous products
of combustion from the fires pass into the interior of the kiln; these holes
communicate by flues c with larger flues C, leading from the fire-places and
separated by a partition wall P, but this wall or any such separation may be
dispensed with, as the holes d suffice to diffuse the heat equally. 9, 9, are
other openings which I call outlet openings, formed through the sole for the
escape of the products of combustion from the kiln after acting on the
materials therein. These holes 9 communicate through flues h with a broad
flue G, extending below the sole along the middle thereof, and leading into
the chimney. The flues c and h may be straight, bent, angular, or sloping.
The sectional area of the holes d and g may be varied by the insertion of
pieces of fire-brick or otherwise. The rows of outlet holes are arranged

page_text: transversely to the rows of inlet holes, the inlet and outlet holes may be distri
buted in such transverse rows over the whole surface of the sole, but it will be
be sufficient if the row of outlets is only along the middle of the sole, as shewn
in the Drawings. To give an idea of a suitable number of holes I may
mention that there may be 120 holes in a kiln of 20 feet long, 16 feet broad
and 11 feet high (internal dimensions), however, I do not restrict myself to
this number or proportion. q are small passages extending from end to end
of the kiln under the bend of the flues h and c, for cinders and dirt to drop in
they are closed while the kiln is at work and only opened to rake them out
and clean the kiln. E is the roof; J are doors which are mounted on rollers
travelling on rails, and are opened to fill and empty the kiln; M is an opening
in the roof communicating with the chimney; L are openings in the side
walls. While the kiln is at work these openings L and M are kept closed,
but when it is to be cooled down they are opened, and drafts of atmospheric
air rush through the holes L into the kiln and escape through the opening M,
thereby rapidly cooling the kiln. The limestones or similar materials to be
burnt when piled on the sole to be burnt should be arranged over the holes d
änd 9, but so as not to stop them up, and the largest lumps should lie at bottom
and the lumps as they rise towards the roof be of less size, so that the smallest
may be at top. I have mentioned four furnaces or fire-places A, but any
other convenient number may be used.
Figures 5, 6, and 7, are views of furnaces constructed according to the
arrangement of apparatus secondly herein-before described; Figure 5 is a ver-
tical section, and Figure 6 a plan of a furnace for producing red or amorphous
phosphorous; and Figure 7 a longitudinal section of a furnace for coating iron
with fusible metal; the latter differing from the former of these two forms only
in being open instead of closed at top, and having two fire-places instead of one.
The apparatus Figures 5 and 6 is furnished with thermometers a and b, to
indicate the internal temperature. I have supposed merely by way of example
'that these furnaces are for producing red phosphorous, and for coating metal,
but the improvements inay be applied in similar manner to furnaces or ovens
when used for other operations of subjecting materials to heat or fire. A is a
metal vessel or receiver containing the matters to be treated; B is an arch
or bridge on which the vessel rests within the chamber or recess J, the sides
'of which slope inwards towards the top; D, D, are fire-places, shut in by
-air-tight doors C; E are ash-pits, closed by plates F, in which are air-tight
doors G, furnished with cocks, valves, or like contrivances M, which afford
the only means whereby atmospheric air can obtain access to the fire, so that

page_text: the draft may be regulated with precision; H, H, are flues, of which there is
one (or more) at each angle of the furnace leading into the chamber or
recess J; and L, L, are flues, one at each side of the apparatus midway between
the flues H, H. These flues are fitted with valves or registers. The heated
products of combustion pass through the flues H into the part J, and thence
through the flues L into the chimney.
Figure 8 is a sectional elevation of a kiln exemplifying the arrangement
thirdly herein-before described; G is a furnace into which lead two draft
pipes D and E, provided with cocks d and e. The pipe D opens below the
fire-bars F, and the pipe E above them. Air is forced into these pipes by an
ordinary apparatus such as at A, B, C. A being a blower communicating by.
the pipe B with the air vessel C, from which the pipes D and E proceed;
H, H¹, are bridges or arches, through which are numerous passages h, h¹;
M, M', is the kiln, M being what I call the main chamber or part of the
kiln in which the materials are held while being burned; I is a pipe leading
from the furnace into the top of the chamber M; J is a hopper open, at top,
but closed at bottom by a slide m, which also closes a feed opening at the top,
of the chamber M, the slide being opened for the materials to fall in the
chamber; L is a flue leading from the lower part of the chamber M to the
hopper J, and having in it a slide or valve l; there is a delivery outlet at the
bottom of the chamber M, opened and closed by a slide.n.; P are trucks to
receive the materials delivered from the kiln. The heated products of com-
bustion pass from the fire through the flues h, h³, and I into the chamber M,
down through which they travel, acting on the materials held therein, and they
proceed therefrom up the pipe L, into and through the hopper J, heat the
materials therein, and thence escape. The valve is opened to such extent as
to keep the pressure within the chamber M a little in excess of the atmo-
spheric pressure, or that on the top of the hopper, whereby it is believed that
the air or gases being under such pressure travel down the chamber M in sheets
or films, and heat its internal sides and contents thoroughly before escaping...
The furnace heat may be raised by increasing the draft through the
pipe D, and closing the pipe E, and it may be reduced by diminishing the
draft through D, and forcing air through the pipe E (the cocks d and e regu:
lating the currents as required). The blue lines indicate a modification, in
which the hopper is placed to the side, and the materials.descend from it to the
kiln along an inclined plane.
Figure 9.is a vertical section, and Figure 10 a plan of a modification of
this kiln, in which the kiln is divided into two main chambers or compart-
ments A and B set together, and communicating by an annular. flue. 6, furnished

page_text: with valves or doors so worked that while one chamber is being filled the
firing, burning, or heating is going on in the other. Round the chambers are
flues, through which the heat from the furnace circulates, entering through an
opening a. Supposing the chamber A full, and the chamber B empty, the
valves would be disposed as shown, and the heat would travel in the direction
indicated by the arrows into the chamber A, down which it would pass, and
thence proceed through the flue b into the chamber B, and escape through
the flue c into the chimney. When the chamber B is full, and the chamber A
empty, the disposition of the valves would be reversed. The chambers are
closed at top and bottom by screw plates or covers, which are opened to feed
and empty the materials into and from the kiln. The furnace is not shewn in
Figures 9 and 10.
Having now described the nature of the said Invention, and in what manner
the same may be performed, I declare that I claim in respect of the arrange-
ment first herein-before described :-
First, the employment in kilns or ovens of a sole or floor directly or nearly
directly under which furnaces or fire-places are placed, and through which sole
or floor numerous openings are formed for the passage of flames, and products
of combustion from the fires into the kiln or oven, substantially as described.
Second, the arrangement for cooling kilns and ovens in which openings
with moveable covers are formed in the sides and roof for the passage of air,
substantially as described.
Third, the general arrangement and combination of parts constituting the
improved kiln represented in Figures 1, 2, 3, and 4 of the Drawings, and
herein-before described.
And I claim in respect to the arrangement secondly herein-before described,
First, the arrangement and combination of parts whereby an uniform and
regular temperature is maintained as described.
Second, the general arrangement and combination of apparatus in which
an arch, flues, or passages for the products of combustion, and means for regu-
lating their escape, and controlling the draft, are arranged and combined as
herein-before described and exemplified in Figures 5, 6, and 7 of the
Drawings.
And I claim in respect of the arrangement thirdly herein-before described,
First, the general arrangement and combination of apparatus herein-before
described and represented in the Drawings.
Secondly, causing the products of combustion to enter the main chamber at
the upper part of the materials as herein-before described.
Thirdly, the mode of maintaining a pressure on the products of combustion

page_text: within the apparatus a little in excess of that on the outside as herein-before
described.
Fourthly, causing the escaping products of combustion to pass through anıl
heat the contents of the hopper as herein-before described.
In witness whereof, I, the said Michael Henry, have hereunto set my
hand and seal, this Twenty-second day of September, One thousand
eight hundred and sixty-two.
Witness,
S. E. A. NEWSOME.
M. HENRY. (L.S.)