IMPROVEMENTS IN STEAM GENERATOR. AND OTHER FURNACES
Year: 1881

page_text: LETTERS PATENT to Josiah Swain, of Oldham, in the County of Lancaster,
Engineer, for an Invention of "IMPROVEMENTS IN STEAM GENERATOR. AND
OTHER FURNACES,"
PROVISIONAL SPECIFICATION left by the said Josiah Swain at the Office
of the Commissioners of Patents on the 17th March 1881.
JOSIAH SWAIN, of Oldham, in the County of Lancaster, Engineer. " IMPROVE-
MENTS IN STEAM GENERATOR AND OTHER FURNACES."
My Invention relates principally to the furnaces of steam generators, and has for
its objects to obtain a more perfect combustion of the fuel and of the gases generated
therefrom, and to prevent or lessen the emission of sınoke, and also to obtain a
better equalisation of the action of the furnaces. To this end I place upon or in or
behind the bridge or in a combustion chamber a mass or masses of metal, such, for
example, as iron or steel, which is or are intended to absorb heat during the times
when the furnace is highly heated, and to give out heat at the times when the
furnace is less heated. To provide for the possible melting of the metal I place it
in a lined ladle or receptacle, or I form a hollow place lined with refractory
material upon or in the bridge or in the combustion chamber. I may make the
bridge or a perforated wall of blocks or lumps of metal. In the flue and to the
rear of the said combustion chamber I arrange bridges, grids, or bars, which may
be of iron or steel, and which are set at distances apart so that the dust can pass
through to a space below, from whence it can be removed at intervals. The heated
gases and products of combustion from the furnaces pass over or between the said
bridges, grids, or bars, which absorb and give out heat as in the case of the afore-
said mass or masses of metal. In the said combustion chamber I place incombustable
material, through or over which the heated gases pass, and which becomes highly
heated at the times when the heat of the furnace is most intense. I consider cotton
silicate or slag-wool, abestos, and pumice stone to be suitable substances for my
purpose. In some cases I may employ the incombustible material without the said
mass or masses of metal. I may also place a combustible material, such as
charcoal, in the said chamber. I provide passages for the flow of air into and
through the combustion chamber, which air becomes highly heated by contact with
the substances in the said chamber and mingling with the gases issuing from the
furnace promotes the combustion of the same. I may use a charcoal or other fire
to heat the air before it passes into the said combustion chamber.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Josiah Swain in the Great Seal Patent Office on the
17th September 1881.
JOSIAH SWAIN, of Oldham, in the County of Lancaster, Engineer. "IMPROVE-
MENTS IN STEAM GENERATOR AND OTHER FURNACES."
My Invention relates principally to the furnaces of steam generators, and has for
its object to obtain a more perfect combustion of the fuel and of the gases generated
therefrom, and to prevent or lessen the emission of smoke, and also to obtain a
better equalisation of the action of the furnaces. To this end I place upon or in or
behind the bridge or in a combustion chamber a mass or masses or peces of metal,
such, for example, as iron or steel, which is or are intended to absorb heat during
the times when the furnace is highly heated, and to give out heat at the times when
the furnace is less heated. In the said combustion chamber I place incombustible
material, through or over which the heated gases pass, and which becomes highly
heated at the times when the heat of the furnace is most intense. I consider
clinkers, cotton silicate, or slag-wool, asbestos, and pumice stone to be suitable
substances for my purpose. In some cases I may employ the incombustible material
without the said mass or inasses of metal. I provide passages for the flow of air
into and through the combustion chamber, which air becomes highly heated by
contact with the substances in the said chamber and mingling with the gases issuing
from the furnace promotes the combustion of the same. I may use a charcoal
or other fire to heat the air before it passes into the said combustion
chamber.
And in order that my Invention may be fully understood, I have attached
hereunto a Sheet of Drawings made to a scale of about one inch to the foot, and
marked with letters of reference. In the said Drawings Fig. 1 represents a vertical
longitudinal section of a boiler fitted with my improved arrangements, Fig. 2
being a cross section of the internal flue taken on the line A, and Fig. 3, a cross
section on the line B. In the said Figs. a is a bridge corresponding to the ordinary
fire bridge, and b is a wall which is situated at a distance behind the said bridge so
that space to constitute a combustion chamber is provided. Between the bridge
and the wall extend several iron gratings c, d, and e. One of these gratings is seen
in plan in Fig. 4. The lower grating e is fitted with a sliding shutter f, which is
slotted to correspond with the said grating, so that it acts as a grid-iron valve to
close and open the passages through the said grating. Upon the upper grating c is
placed a layer g of clinkers or of pieces of fire-brick or other incombustible
substance of the nature hereinbefore indicated. The number and forms of the
gratings may be varied, and if preferred masses or pieces of iron or steel of any
other form may be substituted for the gratings, or be placed thereon, or used in
conjunction therewith; or instead of the said gratings or masses of metal I may
use perforated blocks or slabs of fire clay. The valve fis connected by means of a
rod h with a crank i, which is on an extension of the hinge pin of the furnace
door, the arrangement having the effect of opening the passages for the flow of air
through the grating each time that the said door is opened for firing. An
apparatus indicated by ; of any ordinary or suitable construction may be used to
cause the valve to close or partly close slowly after the furnace door has been shut.
Below the grating e is a layer of charcoal or saw-dust k, which is kept burning or
smouldering, and is renewed at intervals as it becomes consumed. When the boiler
is at work the grating or masses or pieces of metal become hot and heat the air
which is permitted to flow upwards into or through the combustion chamber, as
indicated by the arrows, the air also receiving heat and gases from the burning

page_text: material k. The air issues through the highly heated bed of clinkers g, and
mingling with the products of combustion passing over the said bed aids in effecting
the combustion of the said products. In some cases I may use the arrangements
without the bed of clinkers or incombustible material g. I may dispense with the
bed of sawdust or charcoal k, and I may also dispense with the sliding valve or
shutter f and the connected parts, as the employment of such valve forms no part
of my Invention. In some cases, and especially in cases wherein the boilers are
formed with water bridges, I apply the additional bridge in front of the ordinary
bridge instead of behind it, leaving a space between the two bridges to contain the
metal gratings or the pieces or masses of metal and the bed g, if such be used.
Having now fully set forth and indicated the nature of my said Invention,
and the manner in which I carry the same into practical effect, I would have
it to be understood that I claim,-
First. The apparatus for promoting the combustion of the products of combustion
in furnaces, substantially as set forth and indicated hereinbefore and in and by the
accompanying Drawings.
Secondly. The bed g of clinkers, slag-wool, pumice-stone, or other incombustible
material, through which air is permitted to flow, substantially as and for the purpose
set forth and indicated.
Thirdly. The use of metal to absorb heat and to impart heat to a current of air
flowing into the combustion chamber, substantially as and for the purpose set forth
and indicated.
And, Lastly. The bed g, the metal air heaters c, d, and e, or other metal pieces
substituted therefor, and the bed of burning charcoal or sawdust, over which the
air passes on its way to mingle with the products of combustion issuing from the
furnace, substantially as and for purpose set forth and indicated.
In witness whereof, I, the said Josiah Swain, have hereunto set my hand
and seal, this Fifteenth day of September, in the year of our Lord One
thousand eight hundred and eighty one.
Signed, sealed, and delivered in
the presence of
EDWARD K. DUTTON,
41, John Dalton Street,
Manchester,
(Agent for the Patentee).
JUSIAH SWAIN. (L.S.)