IMPROVEMENTS TH THE CONGREDIAN ADD
Year: 1853

page_text: LETTERS PATENT to James Robertson, of Kentish Town, in the
County of Middlesex, Cooper, for the Invention of "IMPROVEMENTS
TH THE CONGREDIAN ADD"
Sealed the 6th February 1854, and dated the 5th December 1853.
PROVISIONAL SPECIFICATION left by the said James Robertson
at the Office of the Commissioners of Patents, with his Petition,
on the 5th December 1853.
I, JAMES ROBERTSON, of Kentish Town, in the County of Middle-
sex, Cooper, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSUMPTION OR PREVENTION OF SMOKE" to be
as follows:-
This Invention consists in placing either all round or partially
around the furnace or fire-containing chamber or grating, a series of
air-admitting apertures, so as to allow the air to act directly from
different sides upon the burning fuel. I also propose to use in con-
nection with this Invention a suitable apparatus, by which the entire
body or any part of the furnace may be let down, upon a new supply of

page_text: fuel being introduced, so as to allow the level of the top of the fuel
to be always in the same position with the grating or air-admitting
apertures around; this being effected by weights, so that as the fuel
is consumed, and consequently diminished in weight, it will itself
rise up again to its position, and the attendant will thus be enabled
to see, by the state of the weights outside, the exact state or weight
of the fuel in the furnace. By a similar arrangement, it is obvious
that by lowering or raising one portion of the furnace, the whole of
the fuel or ashes may be at once discharged from it. The bars of
the furnace may also be arranged with apertures in them at any
convenient distances apart, into which jets may be inserted, each
jet having an aperture below, so as to receive the air from under-
neath the fire, and terminating in a species of rose, or series of small
holes or apertures, or in a single aperture, above the level of the
burning fuel, by which means air will be let in throughout the whole
body of the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Robertson in the Great Seal Patent Office
on the 5th June 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JAMES ROBERTSON, of Kentish Town, in the County of Middlesex,
Cooper, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of December, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said James Robertson, Her special
license that I, the said James Robertson, my executors, administrators,
and assigns, or such others as I, the said James Robertson, my execu-
tors, administrators, or 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

page_text: vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE CONSUMPTION OR PREVENTION OF SMOKE," upon the condition (amongst
others) that I, the said James Robertson, by an instrument in writing
under my hand and seal, 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.
NOW KNOW YE, that I, the said James Robertson, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is
to say:-
My said Invention relates to an improved construction of furnace
for effecting the consumption of smoke, and consists in placing either
all round or partially around the furnace or fire containing chamber
or grating, a series of air-admitting apertures, so as to allow the air
to act directly from different sides upon the burning fuel. I also
propose to use in connection with this Invention a suitable apparatus,
by which the entire body or any part of the furnace may be let down,
upon a new supply of fuel being introduced, so as to allow the level
of the top of the fuel to be always in the same position with the
grating or air-admitting apertures around; this being effected by
weights or any other convenient arrangement, so that as the fuel is.
consumed, and consequently diminished in weight, it will itself rise
up again to its position, and the attendant will thus be enabled to
see, by the state of the weights outside, the exact state or weight of
the fuel in the furnace. By a similar arrangement, it is obvious
that by lowering or raising one portion of the furnace, the whole
of the fuel or ashes may be at once discharged from it. The bars
of the furnace may also be arranged with apertures in them at any
convenient distances apart, into which jets may be inserted, each jet
having an aperture below, so as to receive the air from underneath the

page_text: fire, and terminating in a species of rose, or series of small holes or
apertures, or in a single aperture, above the level of the burning fuel,
by which means air will be let in throughout the whole body of the
furnace, or a portion of it.
Figure 1 on Sheet 1 of the Drawings, represents a horizontal
section of a cylindrical steam boiler with internal flue, the greater
portion of the fire bars being removed to shew the elevating levers.
Figure 2 is a transverse vertical section of the boiler and furnace,
taken through the dead plate. Figure 3 is a horizontal section of
the boiler, shewing the furnace bars and burner in plan. Figure 4
is a longitudinal vertical section of the boiler and smoke-consuming
apparatus, taken along the centre line thereof; and Figures 5, 6, 7, 8,
and 9, are separate details of the smoke-consuming apparatus, which
will be herein-after described.
Fig. 1 on Sheet 2 of the Drawings represents a horizontal section
of a steam boiler furnace with external flues, the grate bars being
removed to shew the elevating mechanism. Figure 2 is a transverse
section of the furnace taken through the front of the grate bars; and
Figure 3 is a longitudinal vertical section of the same shewing the
whole of the smoke-consuming apparatus. The same letters refer to the
corresponding parts in the different Figures of the Sheets of Drawings.
The boiler A is of the ordinary cylindrical class, with internal cylindrical
flue B. The greater number of the bars C are moveable, their inner
ends resting upon the fixed transverse support D, whilst their front
ends bear upon the moveable support E, which is connected by links F
to the pair of balance levers G, G. These levers work on the fixed
transverse rod II, which serves as a centre, and are weighted at I, I, to
balance the weight of the grate bars. The moveable portion of the
grate is enclosed in a fixed cast iron frame J, shewn in detail at
Figure 5. This frame projects downwards a short distance, and is per-
forated at the front end and sides by a number of perforations which act
as air inlets to supply the air for combustion. By this means, the air
entering from the ash pit is divided into a number of thin streams or
currents, which impinge directly upon the upper surface of the burning
fuel in the grate bars, and thereby assists in the combustion of the

page_text: opens
smoke and unconsumed gases evolved from the partially consumed fuel.
By the employment of a moveable grate, as described, the size of the
surrounding air inlets will be regulated according to the amount of fuel
on the grate; thus, for example, when the fuel is first fed in, and the
grate full, the weight of the coal will depress it to its full extent, as
shewn in Figs. 4 and 5; consequently a great amount of air will be
admitted as the air inlets will be full open, but as the fuel burns away
and becomes lighter, the weights on the ends of the levers G will
elevate the grate bars, and reduce the supply of air by partially closing
the inlets before mentioned. The combustion of the smoke and uncon-
sumed gases is also further assisted by the perforated burner K, which
is situated near the inner end of the furnace. This burner, shewn in
plan and end elevation at Figs. 7 and 8, may be composed of cast
iron, fire clay, or of any other material suited to stand the fire, and is
so arranged as to be entirely surrounded with burning fuel. Fresh air
is supplied to the interior of the burner by the pipe I, which into
the under side of it. This pipe passes along the bottom of the ash pit,,
and is terminated by an expanded mouth at M, outside the front of
the boiler; if necessary, a regulater or damper may be fitted into the
mouth M, to regulate the supply of air to the burner, according to the
state of the fire in the furnace. An opening N is formed in the air
pipe, which is fitted with a moveable lid, and serves to facilitate the
removal of any dust or ashes which may be deposited in the angle of
the pipe. To prevent the accumulation of dust or fine ash inside the
burner, two longitudinal slots 0, 0, (Fig. 7) are made in the bottom of
the same, through which the dust is blown through into the fire again,
where it is completely consumed, thereby preventing the injurious
deposit of a large amount of dust and fine ash behind the bridge, which
has hitherto been found to take place in smoke-consuming furnaces.
The air enters the furnace in a number of small streams or jets, having
been previously heated by the fire surrounding the burner. By placing
the burner in the fire and bringing the air into direct contact with the
flame and smoke, the consumption is found to be more complete than
when the air is mixed with the gases after they have passed away from
the fire. The cold air which enters the burner counteracts the heat

page_text: steam.
outside, and prevents the burner from being burnt away. Figs. 9 and
6 represent two different forms of burners which may be employed
in place of the one shewn in Fig. 4; the air being introduced at P,
through the pipe L, as herein-before described. As the air is always in
a heated state when issuing from the burner, it will have no tendency
to cool the flues, but on the contrary will assist in the generation of the
I may here observe, that I do not confine myself to any par-
ticular form or position of burner, or of the apertures therein, so long
as it does not interfere with the draught of the furnace. One or more
of these burners or modifications of the same may be placed on the
grate bars, which might be made hollow for that purpose, and receive
a supply of heated air from the ashpit. Fig. 1 on Sheet 2 of my
Drawings represents a horizontal section of a steam boiler furnace with
the bars removed, to shew the elevating or balance weight and chains.
Fig. 2 is a transverse section of the same taken through the front of
the fire bars; and Fig. 3 is a longitudinal vertical section of the
furnace, shewing a portion of the boiler in elevation. This latter
arrangement shows the application of my principle of smoke prevention
to boiler furnaces with external or lateral flues. In this arrangement
the furnace bars are balanced by counterweights A, suspended by the
chains B, which pass over the fixed guide pulleys C and D, and are
attached at E to the rod E', which connects the two brackets F, F,
secured to the moveable transverse bar G, on to which the front ends
of the fire bars rest, as described with reference to the first arrange-
ment, the opposite ends of the bars being supported by the fixed
transverse bar II. The air is admitted round the furnace through the
perforated frame I, as herein-before described, and a burner J may be
employed similar to that lettered K in Sheet 1 of the Drawings. Tho
air, however, in this case is supplied from the ashpit itself, the mouth
of the short supply pipe K being fitted with a self-acting valve or regu-
lator L, which is actuated by the descent or ascent of the grate bars.
This is effected by connecting the valve L to a short chain M, which is
attached to one or both of the elevating chains B, by a cross bar con-
necting the two chains, or by any other suitable arrangement. As the
grate descends with the weight of the newly supplied fuel, the chains B

page_text: will be drawn in the direction of the arrow in Fig. 3, thereby drawing
the short chain M, and effecting the opening of the valve to allow a
proportionally large supply of air to enter the burner. When, how-
ever, the grate rises on account of the burning of the fuel, then the
valve or regulator L will gradually clase, and reduce the supply of air
to the furnace. But I do not claim the regulating of the supply of air
to the rose J, as part of my Invention. It will thus be seen that the
greatest supply of air is obtained when the fire has been supplied with
fresh fuel, and the least supply when that fuel has become partially
consumed.
Although in the Drawings I have represented the air-regulating
valve as being self-acting, it may be closed entirely by hand at any
time when the air is not required. The counterweights A may be fixed
either in the ashpit or in any other convenient part of the furnace.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe, in conclusion, that I do not
confine or restrict myself to the precise details or arrangements
which I have had occasion to describe or refer to, as many variations
may be made therefrom without deviating from the principles or main
features of my said Invention; and I may here observe, that I am
aware that small streams of air have been previously employed in
smoke-consuming furnaces, and that I lay no claim to the same. But
what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent is,
First, the general arrangement and construction of apparatus for
effecting the prevention of smoke, as herein-before described.
Second, the system or mode of admitting air into the furnace by the
employment of a fixed perforated frame in conjunction with moveable
grate bars, as herein-before described.
Third, the application and use of the perforated burner or burners,
herein-before described, placed in the body of the fire at any part
thereof, or as near thereto as the construction of the furnace will admit,
instead of in the flues, for effecting the entire or partial consumption

page_text: of the smoke and unconsumed gases arising from imperfect com-
bustion.
In witness whereof, I, the said James Robertson, have hereunto
set my hand and seal, the Fifth day of June, One thousand
eight hundred and fifty-four.
JAMES ROBERTSON. (L.S.)