IMPROVEMENTS IN " AND CONNECTED WITH FURNACES OR APPARATUS FOR THE COMBUSTION OF. FUEL
Year: 1881

page_text: LETTERS PATENT. to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of IMPROVEMENTS IN
"
AND CONNECTED WITH FURNACES OR APPARATUS FOR THE COMBUSTION OF.
FUEL." A communication from abroad by Michel Perret, of Paris, in the
Republic of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 12th January 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN AND CONNECTED WITH FURNACES OR APPARATUS
FOR THE COMBUSTION OF FUEL." A communication from abroad by Michel
Perret, of Paris, in the Republic of France.
This Invention relates to improvements in and connected with furnaces or
apparatus for the combustion of fuel, whereby the utilization of fuel of every
description is facilitated.
It is well known that a pulverulent or dusty condition constitutes a serious
impediment to combustion in the case of most descriptions of fuel. Natural or
spontaneous agglutination when exposed to the action of fire is a property possessed
by certain kinds of fuel only, and artificial agglutination is a costly process which
cannot be applied to fuel of inferior quality.
According to this Invention these difficulties are obviated by the employment of
a furnace constructed as hereinafter described with shelves, which performs the
double function of burning without any preparation both pulverulent combustible
materials and combustible materials of poor quality within very wide limits of
tenuity and poverty in the said materials.
The furnace or apparatus for producing combustion is composed of a series of
shelves arranged one above the other, the same being formed by beds of refractory
or fire proof material presenting solid or unperforated surfaces, upon which the
fuel or combustible material is spread, and is burnt at its surface in contact with
atmospheric air.
The number of shelves or beds so employed may be varied according to the quality.

page_text: of the fuel or combustible material employed, and the nature of the purposes to which
the apparatus is to be applied.
The manipulation consists in moving or stirring up the materials upon the beds
or shelves by means of rakes or rubbles worked by hand or mechanically. The same
result may also be obtained by the employment of moving beds or surfaces which
move the materials automatically.
The materials used as fuel may be renewed as required, the interval of time
between each charging being varied according to requirements, and may even be
extended to twenty four hours. The said variation is obtained by suitably
regulating the supply of air.
The supply of air is controlled, with precision, by means of suitable registers,
dampers, or valves, and may be heated either by causing it to circulate about the
furnace or by employing a furnace constructed with a fire grate arranged above or
below the apparatus according as the latter is worked with an upward or downward
draft, or again by utilizing the waste heat.
Thus by employing solid or unperforated surfaces the finest dust. may be
burned in this improved apparatus, the said surfaces being arranged at a small
distance apart, so that a high temperature is obtained producing the combustion of
even the most dense and poor materials, and by suitably heating the air incineration
is carried out to the utmost extent possible.
Anthracite, inferior coal, coke, turf, or peat, sawdust, and other materials in an
absolutely pulverulent condition may be burned by means of the improved arrange-
ment, and the extraordinary capacity of the improved furnace for burning fuel
.extremely poor in quality is evident from the fact that it may even be caused to
consume the refuse of other furnaces..
The power of burning very inferior descriptions of fuel enables all kinds of
matter to be economically submitted to elevated temperatures by mixing them with
a certain proportion of fuel. Moreover, by regulating the supply of air the com-
position of the products of combustion may be modified so as to obtain at pleasure
oxidizing or deoxidizing gases capable of producing a corresponding effect upon the
materials or substances mingled with the fuel.
The improved furnace with shelves is consequently, capable, according to the
manner in which it is worked, of producing carbolic acid and oxide of carbon or
carbonic oxide in different proportions with the admixture of varying quantities
of atmospheric.air.
If desired the products of combustion from the improved furnace may be caused
to pass through a mass of fuel in lumps or fragments in order to absorb the excess
of air, decompose the carbonic acid, and thus produce oxide of carbon, the subsequent
⚫.combustion of which yields the maximum of useful effect.
The Invention also embraces the combination of a gas generator employing fuel
in lumps or fragments with the improved furnace for burning pulverulent fuel
as a means for effecting the conversion of all descriptions of combustible materials
into gas.
In carrying the Invention into effect the shelves or beds are arranged in the
manner of baffle plates so as to cause the gases resulting from the combustion to
follow a zig zag course and pass over all the shelves or beds in succession before
leaving the furnace.
Each shelf or bed is formed by moulded blocks fitted or connected together
laterally by a step joint, and supported at each extremity upon suitable ledges or
projections provided on the side walls of the furnace. The strength of the beds
may be increased by imparting to them a slightly arched form.
A fire grate is provided at the lower part of the front of the furnace for the
purpose of lighting and starting the apparatus, and suitable apertures are also
provided in the fore part of the furnace corresponding to the shelves in order to
enable the combustible material to be introduced and spread upon the said shelves
or beds and for removing the contents of the furnace when required. The front of
the furnace is also provided with an aperture for charging the fire grate herein-

page_text: before referred to, and another aperture communicating with the ash pit. These
apertures are closed by means of cast-iron doors or plugs, which may be faced
internally with fire clay.
The furnace constructed as hereinbefore described may be supplied with cold or
heated air, but the latter is preferable in most cases, and for this purpose the
arrangement hereinafter described is adopted.
A certain quantity of heat being radiated from the front of the furnace, and
especially from the doors closing the apertures hereinbefore described, a sheet metal
screen or door is provided which encloses a space or chamber in the front of the
furnace in which the radiated heat is to some extent retained. This space is closed
at the upper part, but an interval is left between the lower edge of the door or
screen, and the ground forming an aperture through which the external air enters
and ascends in the chamber behind the screen where it becomes heated to a certain
extent by absorbing the heat radiated from the front of the furnace. This air then
enters a horizontal flue or channel by which it is conducted first to the sides of
the furnace, where it descends vertically a certain distance along two vertical
channels, then passes along horizontal side passages situate immediately behind
the furnace lining and ascends passages at the back of the furnace which deliver
it into a single passage debouching into the back of the furnace at a level with
the third shelf from the bottom in the case of a furnace with four shelves.
According to this arrangement the two lower shelves are. supplied with cold air
which enters under the screen and passes direct through the ash pit into the lower
part of the furnace, whilst air which has been heated by circulating about the
furnace, as hereinbefore described, is supplied to the two upper shelves and
produces a more rapid combustion thereon.
The combustible materials are spread in a thin layer upon the shelves or beds,
and are ignited by lighting a fire upon the fire grate, which is maintained until the
materials upon the shelves is thoroughly alight, whereupon the fire on the fire grate
is discontinued, and the process of combustion proceeds in the furnace on the beds
or shelves only.
When the apparatus is working normally the fresh supplies of combustible
materials are spread upon the upper shelf in the first place, and caused to pass
over the other shelves in succession whereby the said materials are gradually
exhausted.
In order to charge the furnace the attendant introduces a rake or rubble through
one of the apertures in the front of the furnace, and draws the exhausted material
or ash on the lower shelf into the ash pit, he then draws down the material from
the next or second shelf, and spreads it evenly upon the lower shelf, and so on
until he has cleared the uppermost shelf, which he then recharges with. fresh
combustibles.
A valve or door may be provided in the front of the apparatus for the purpose
of controlling the admission of air to the furnace.
The gases resulting from the combustion leave the furnace through a suitable
aperture, and are conducted to a heating apparatus of any suitable construction,
generally arranged above the body of the furnace. The heat generated is utilized
in this apparatus being transferred to air drawn in from the exterior.
The improved furnace is susceptible of very numerous and varied applications,
it may be employed for heating private houses, public buildings, hot houses, drying
and storing purposes in various manufactures, such as spinning, heating silk worm
houses, roasting and baking purposes, concentrating liquids, and the like, whilst at.
the same time retaining its economical advantages, resulting principally from the
small value of the combustible which it consumes, and the small amount of
attendance which it requires to work it.

page_text: 21
SPECIFICATION in pursuan of the conditions of the Letters Patent filed by
the said John Henry Joson in the Great Seal Patent Office on the
9th July 1881.
2
JOHN HENRY JOHNSON, of 47 lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN AND CONNECTED WITH FURNACES OR APPARATUS
FOR THE COMBUSTION OF FUEL A communication from abroad by Michel
Perret, of Paris,. in the Republic France.
The said Invention relates to improvements in and connected with furnaces or
apparatus for the combustion of fuel, whereby the utilization of fuel of every
description is facilitated.
It is well known that a pulverulent or dusty condition constitutes a serious
impediment to combustion in the case of most descriptions of fuel.
Natural or spontaneous agglutination when exposed to the action of fire is a
property possessed by certain kinds of fuel only, and artificial agglutination is a
costly process which cannot be applied to fuel of inferior quality.
According to this Invention these difficulties are obviated by the employment
of a furnace constructed as hereinafter described with shelves, which performs the
double function of burning without any perforation both pulverulent combustible
materials and combustible materials of poor quality, within very wide limits of
tenuity and poverty in the said materials.
The improved furnace or apparatus for producing combustion is composed of a
series of shelves arranged one above the other, the same being formed by beds of
refractory or fire proof material, presenting solid or unperforated surfaces upon
which the fuel or combustible material is spread, and is burnt at. its surface in.
contact with atmospheric air.
The number of shelves or beds 80 employed may be varied according to the
quality of the fuel or combustible material used and the nature of the purposes to
which the apparatus is to be applied.
The manipulation consists in moving or stirring up the materials upon the beds
or shelves by means of rakes worked by hand or mechanically. The same result
may also be obtained by the employment of moving beds or surfaces which move
the materials automatically.
The materials used as fuel may be renewed as required, the interval of time
between the operations of charging being varied according to requirements, and
this interval may even be extended to twenty four hours. The said variation is
obtained by suitably regulating the supply of air.
The supply of air is controlled with precision by means of suitable registers,
dampers, or valves, the air may be heated either by causing it to circulate about
the improved furnace, or by employing a separate furnace constructed with a fire
grate arranged above or below the apparatus, according as the latter is worked
with an upward or downward draft, or again by utilising the waste heat..
Thus by employing solid or unperforated surfaces the finest dust may be burned
in this improved apparatus, the said surfaces being arranged at a small distance
apart so that a high temperature is obtained, producing the combustion of even the
most dense and poor materials, and by suitably heating the air the process of
incineration is carried out to the utmost extent possible.
Anthracite, inferior or poor coal, coke, turf, or peat, saw dust, and other materials
in an absolutely pulverulent condition may be burned by means of the improved
arrangement, and the capacity of this furnace for burning fuel extremely poor in
quality is evident from the fact that even the refuse of other furnaces may be
consumed in it.

page_text: The power of burning very inferior descriptions of fuel enables all kinds of
matter to be economically submitted to elevated temperatures by mixing them
with a certain proportion of fuel. Moreover by regulating the supply of air the
composition of the products of combustion may be modified, so as to obtain at
pleasure oxidising or deoxidising gases capable of producing a corresponding effect
upon the materials or substances mingled with the fuel.
The improved furnace with shelves is consequently capable, according to the
manner in which it is worked, of producing carbonic acid, and oxide of carbon, or
carbonic oxide in different proportions, with the admixture of varying quantities
of atmospheric air.
If desired the products of combustion from the improved furnace may be caused
to pass through a mass of fuel in lumps or fragments in order to absorb the excess
of air, decompose the carbonic acid, and thus produce oxide of carbon, the
subsequent combustion of which yields the maximum of useful effect. A gas
generator employing fuel in lumps or fragments is thus combined with the improved
furnace for burning pulverulent fuel as a means for effecting the conversion of all
descriptions of combustible materials into gas.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
'
Figure 1 of the accompanying Drawings represents a longitudinal section of a
furnace constructed according to the said Invention, the section being taken along
the line 1, 2, Figure 2.
Figure 2 is a corresponding transverse section taken along the line 3, 4, Figure 1,
and Figure 3 is a horizontal section of half of the furnace, the section being taken
along the line 5, 6, Figure 1.
1
This furnace is constructed in the form of a rectangular chamber, built of brick
or other suitable materials, and provided with a fire brick or other fire proof
lining H. This chamber is divided into any convenient number of compartments
by horizontal fire proof partitions I, forming shelves or beds arranged in the manner
of baffle plates, so as to cause the flame and gases resulting from the combustion to
follow a zig zag course and pass over the materials on all the partitions or beds I
in succession before leaving the furnace.
Each shelf or bed is formed by moulded blocks fitted or connected together
laterally by a step joint, as shewn in Figure 1, and supported at each extremity
upon suitable edges or projections A provided on the side walls of the furnace.
The strength of the beds may be increased by imparting to them a slightly arched
form.
A fire grate J is provided at the lower part of the front of the furnace for the
purpose of lighting and starting the apparatus, and suitable apertures K are also
provided in the fore part of the furnace in order to enable the combustible materials
to be introduced and spread upon the beds or shelves I, and for removing the
contents of the furnace when required. The front of the furnace is also provided
with an aperture L for charging the fire grate J and another aperture M
communicating with an ash pit D.
These apertures are closed by means of cast iron doors or plugs, not shown in
the Drawing, which may be faced internally with fire clay. A passage or chimney V.
is provided for the escape of the products of combustion.
The furnace, constructed as hereinbefore described, may be supplied with cold or
heated air, but the latter is preferable in most cases, and for this purpose the
arrangement illustrated in the Drawing and next hereinafter described is adopted.
A certain quantity of heat being radiated from the front of the furnace, and
especially from the doors closing the apertures K and L, a sheet metal screen or
door N is provided, which encloses a space or chamber O in the front of the furnace
in which the radiated heat is to some extent retained. This space is closed at the
upper part, but an interval is left between the lower edge of the door or screen and

page_text: the ground forming an aperture B through which the external air enters and
ascends in the chamber O behind the screen N, where the said air becomes heated
to a certain extent by absorbing the heat radiated from the front of the furnace.
This air then enters a horizontal flue or channel P, by which it is conducted first
to the sides of the furnace, where it descends a certain distance along two vertical
channels Q; it then passes along two horizontal side passages R situate immediately
behind the furnace lining, and after traversing vertical passages S and horizontal
flues T is delivered into a single flue U, debouching into the back of the furnace
opposite, say, the third shelf from the bottom.
According to this arrangement the two lower shelves are supplied with cold air,
which enters under the screen N and passes direct through the ash pit into the
lower part of the furnace, whilst air which has been heated by circulating about
the furnace, as hereinbefore described, is supplied to the two upper shelves or beds
and produces a more active combustion thereon.
The improved furnace is worked in the following manner, videlicet:-The
combustible materials are spread in a thin layer upon the shelves or beds I, and
are ignited by lighting a fire upon the fire grate J, which fire is maintained until
the materials upon the beds I are thoroughly alight, whereupon the fire on the
grate J is discontinued, and the process of combustion proceeds in the furnace on
the beds or shelves I only.
When the apparatus is working normally the fresh supplies of combustible
materials are spread upon the upper shelf in the first place and caused to pass over
the other shelves in succession, whereby the said materials are gradually and
uniformly exhausted.
In order to supply the furnace with fuel the attendant introduces a rake or
rabble through one of the apertures K in the front of the furnace, and draws the
exhausted material or ash on the lowest shelf into the ash pit; he then draws
down the material from the next or second shelf, and spreads it evenly upon the
lower shelf, and so on until he has cleared the uppermost shelf, which he then
recharges with fresh combustibles.
Materials which are most difficult of combustion under ordinary circumstances,
and the most inferior or poorest descriptions of fuel may be burned in these
improved furnaces, being spread in thin layers upon the beds or shelves, in which
position they are exposed to the continued action of flame, whilst being at the same
time submitted on each shelf in succession to the powerful reverberation of the
shelf next above it. Under these conditions an intense heat is concentrated in
the furnace, and gradually penetrates the entire thickness of the layers of fuel,
the immediate result of which is to cause the burning of all the combustible particles
so that the residue which is removed from the ashpit consists solely of a completely
exhausted mineral powder.
The concentration of the heat in this furnace is an essential condition to the
success of the operation, and it is consequently necessary to avoid admitting air too
freely. When it is observed that the temperature is becoming too low it will be
simply necessary in order to increase the heat to partially close a suitable valve or
damper provided in the outlet for the products of combustion for the purpose
of regulating the escape of the said products, and thereby controlling the draft.
In addition to this damper a valve or door may be also provided in the front
of the apparatus for the purpose of controlling the admission of air to the
furnace.
The gases resulting from the combustion are discharged through the aperture V
and are conducted to apparatus of any suitable construction for heating air,
and preferably arranged above the body of the improved furnace, or the said
gases are employed in a furnace for generating gas in combination with suitable
gas producing materials in the condition of lumps or fragments, and they may also
be utilised for any other purpose for which they may be required.
The improved furnace is susceptible of very numerous and varied applications;
it may be employed for heating private houses, public buildings, hot houses, drying

page_text: and stoving purposes in various manufactures, such as spinning, heating silkworm
houses, roasting and baking purposes, concentrating liquids, and the like, whilst
at the same time retaining its economical advantages, resulting principally from the
small value of the combustible which it consumes, and the small amount of
attendance which it requires to work it.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. The peculiar furnace constructed with shelves, as herein set forth, for the
purpose of facilitating the use of fuel or combustible materials in a pulverulent.
condition or of inferior quality, substantially as hereinbefore described.
Second. The combination with the furnace, constructed as herein set forth, of a
gas generator containing combustible materials, in the condition of lumps or
fragments, in order to utilize the waste gases from the furnace in the production
of gas, substantially as herein before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Eight day of July, One thousand
eight hundred and eighty one.
J. HENRY JOHNSON. (L.S.)