IMPROVEMENTS IN AND APPLICABLE TO FURNACES TO BE USED IN THE MANUFACTURE or GAS
Year: 1864

page_text: LETTERS PATENT to Frank Clarke Hills, of Deptford, in the County of
Kent, Manufacturing Chemist, for the Invention of "IMPROVEMENTS IN
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills at
the Office of the Commissioners of Patents, with his Petition, on the
29th April 1864.
I, FRANK CLARKE HILLS, of Deptford, in the County of Kent, Manu-
facturing Chemist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN AND APPLICABLE TO FURNACES TO BE USED IN THE MANUFACTURE
or GAS," to be as follows:-
My improvements are as follows: First, instead of admitting cold atmo-
spheric air into the ash-pits of the furnaces for the combustion of the coke in
the fire-places above, the said combustion is effected by air heated by what is
now the waste heat of the furnaces, and brought into the ash-pits, which must
be closed by doors in front to exclude the external cold air. From the ash-
pits the heated air ascends through the fire-bars to the fuel above. By thus
using hot air instead of cold in the ash-pits the ordinary fire-bars would be
liable to be constantly clinkering over with hard clinkers, and would soon be

page_text: destroyed. To prevent these evils, pans about 6 or 8 inches deep, and
covered with plates or tiles to keep out the ashes, and which I call water
pans, are placed in the bottoms of the ash-pits; water, preferably heated by
the waste heat as herein-after referred to, is to be run into these water pans
in a regulated stream, so as to keep a few inches of water in the pans.
These water pans are to be placed at such a distance below the fire-bars that
by the comparative coolness of the water therein contained, and the steam
generated by its evaporation, the fire-bars may be kept from becoming too
hot. When the ash-pits are shallow, tiles may be placed on the tops of the
water pans to prevent their becoming too hot and making too much steam.
Water in a regulated quantity may be run into the ash-pits themselves
without any pans, but this does not answer so well as having the water pans.
The fire-bars themselves also should be considerably deeper than those at
present used, so that by their conducting power, their lower parts being
exposed to the more moderate temperature in the ash-pits, will greatly prevent
their upper parts from becoming too hot, clinkering over, and burning away.
The steam generated from the water in the water pans will be mostly
decomposed by coming in contact with the burning coke on the fire-bars, and
sufficient heated air is to be admitted into the fire-place and above the fuel to
effect the combustion of the hydrogen of the decomposed steam, as well as of
any carbonic oxide formed by the combustion of the coke. If only thin
fire of coke is used on the fire-bars, sufficient air will pass from the ash-pits
through the fire-bars and coke to effect the combustion of the said hydrogen
and carbonic oxide; but if the fire on the bars is thick, a sufficient quantity
of the atmospheric air heated by the said waste heat is to be admitted into
the fire-places above as well as into the ash-pits to insure the combustion of
the hydrogen and carbonic oxide produced. The best way of admitting the
heated air into the fire-place and above the fuel is to take it from the ash-
pits through a sufficient number of holes of about an inch in diameter made
in the dead plates of the fire-places, to allow the hot air from the ash-pits to
pass through them to the fire-places above, but to prevent steam from the
water pans passing undecomposed with the air into the fire-places, above a
thin fire of coke should be kept over the said holes in the dead plates. Bars
with narrow openings between them may be substituted for the said dead
plates. Instead of having the water pans in the ash-pits with loose covers;
tight water pans with inlet and outlet pipes for taking in water and letting
out steam may be used. These pipes should be placed at the front ends of
the pans, the steam pipe at the top and the water pipe at the bottom. These
pans also, like those before mentioned, may be about 6 or 8 inches deep to.

page_text: hold a few inches of water.
The steam generated in these tight water pan's
is to be taken into the air heating pipes in the way hereafter described, or
part may be allowed to come into the ash-pits direct through one or two small
holes in the pans. Instead of using furnaces with fire-bars and water pans as
above described, V-shaped fire-places may be used, that is; fire-places having
their sides sloping inwards from the top to the bottom. In this case, instead
of the fire-bars, the sides of the fire-placés support the burning coke. The
bottom opening of the fire-place into the ash-pit is a long slot, and should be
the whole length of the ash-pit, and sufficiently narrow to prevent the burning
coke falling through into the ash-pit in injurious quantities. The dead
plates of these fire-places are to have a number of holes of about an inch
diameter made in them, or they are to be composed of bars as before
described for the other form of furnace, to allow sufficient heated air to pass
through them from the ash-pits to the fire-places above to effect the com-
bustion of the carbonic oxide or other inflammable gases formed by the
combustion of the solid fuel used. Water pans may also be used in these
furnaces, but in this case the holes in the dead plates or bars should be kept
covered with a thin fire of coke as before described, to prevent any steam
passing away undecomposed through the fire-places above. The atmospheric
air to be used to support the combustion of the fuel as before described may
be heated in any convenient way by the waste heat of the furnaces; the way
however which I prefer is one described by me in a former Patent for
improvements in manufacturing gas (No. 13, 912, 1852), and consists in
passing the air to be heated' through iron pipes, say, of about 4 5 inches
diameter, place within other pipes or flues, through which the waste beat
from the furnaces passes away. The interior pipes are thus surrounded
by the waste beat, and the air as it travels along them will become lotter and
hotter by absorbing the waste heat in the exterior pipes, or flues, and when
it arrives at the ash-pits to which the interior heating pipes must be connected,
it will be very hot. If these air heating pipes are placed horizontally on the
tops of the beds of retorts, which in works in operation will perhaps be the
most convenient place for theni, then, instead of drawing the atmosplieric air
to be heated into them on the same level as that on which the pipes are
placed, other pipes are to be connected to them, which descend to the level, or
preferably below the level of the ash-pits. The atmospheric air to be heated
is drawn in at the bottom end of these latter pipes, and is then to pass
through the series of heated pipes into the closed ash-pits of the furnaces
before described. Steam generated in the tight, water pans before described
s also to pass into the bottom end of these pipes with the atmospheric air to

page_text: be heated. This steam will warm the air, and assist, the draught into, the
ash-pits. As there will be some waste heat left in the escape flues after
heating the air for supporting the combustion of the fuel used, a pan for
heating the water to be used in the water pans may be placed on or in the
said flues beyond the air pipes, so that the water may be hot as it, runs in 'a
stream regulated by cocks from this pan through small pipes into the water
pans in the ash-pits. When new beds of retorts are made, prefer placing
the air heating pipes below the level of the ash-pits in waste heat flues
prepared for them.
.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frank Clarke Hills in the Great Seal Patent Office on the
28th October 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANK
CLARKE HILLS, of Deptford, in the County of Kent, Manufacturing Chemist,
send greeting...
1
WHEREAS Her most Excellent. Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Twenty-ninth day of April, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Frank Clarke. Hills, Her special licence that I, the said
Frank Clarke Hills, my executors, administrators, and assigns, or such
others as I, the said Frank Clarke Hills, 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, ap Invention
for "IMPROVEMENTS IN AND APPLICABLE TO FURNACES TO BE USED IN THE MANU-
FACTURE OF GAS," upon the condition (amongst others) that I, the said Frank
Clarke Hills, my executors or administrators, by an instrument in writing
under ny, 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.
"
NOW KNOW YE, that I, the said Frank Clarke Hills, do hereby
declare the nature of the said Invention, and in what manner the same is to
:
9.1

page_text: be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:
My improvements are as follows:-First, instead of admitting cold atmospheric
air into ash-pits of the furnaces for the combustion of the coke in the fire-places
above, the said combustion is effected by air heated by what is now' the waste
heat of the furnaces and brought into the ash-pits, which must be closed by
doors in front to exclude the external cold air. From the ash-pits the heated
air ascends through the fire-bars to the fuel above. By. thus using hot air
instead of cold in the ash-pits the ordinary fire-bars would be liable to be con;
stantly clinkering over with hard clinkers, and would soon be destroyed. To
prevent these evils, pans about 6 or 8 inches deep; and covered with plates or
tiles to keep out the ashes, and which I call water pans, are placed in the
bottoms of the ash-pits; water, preferably heated by the waste heat as herein-after
referred to, is to be run into these water pans in a regulated stream, so as to
keep a few inches of water in the pans. These water pans are to be placed at
such a distance below. the fire-bars that by the comparative coolness of the
water therein contained, and the steam generated by its evaporation, the fire-
bars may be kept from becoming. too hot. When the ash-pits are shallow,. tiles
may be placed on the tops of the water pans to prevent their becoming too hot
and making too much steam.. Water in a regulated quantity may be run' into
the ash-pits themselves without any pans, but this does not answer so well as
having. the water pans: The fire-bars themselves should be considerably;
deeper than those at présent úsed, so that by their conducting power, their
lower parts being exposed to the more moderate temperature in the ash-pits,
will greatly prevent their upper parts from becoming too hot, clinkering over,
and burning away. The steam generated from the water in the water pans!
will be mostly decomposed by coming in contact with the burning. coke on the
fire-bars, and sufficient heated air is to be admitted into the fire-place aud
above the fuel to effect the combustion of the hydrogen of the decomposed
steam as well as of any carbonic oxide formed by the combustion of the coke.
If only a thin fire of coke is used on the fire-bars súfficient air will pass from!
the ash-pits through the tire-bärs and coke to effect the combustion of the said
hydrogen and carbonic oxide; but if the fire on the bars is thick, a sufficient quan-
tity of the atmospheric air heated by the said waste) heat is to be adinitted into
the fire-places above as well as into the ash-pits to ensure the combustion of the
hydrogen and carbonic oxide produced. The best way of admitting the Heatedly
air into the fire places and above the fuel is to take it from the ash-pits through
a sufficient number of holes of about an inch in diameter made in the dead plates

page_text: .
of the fire-places to allow the hot air from the ash-pits to pass through them
to the fire-places above, but to prevent steam from the water. pans passing
undecomposed, with, the air into the fire-places above, a thin fire of coke should
be kept over the said lioles in the dead plates. Bars with narrow openings
Letween them may be substituted for the said dead plates. Instead
of having the water pans in the ash-pits with loose, covers, tight water
pans with inlet and outlet pipes for taking in water and letting out
steam may be used. These pipes should be placed at the front ends of the
pans, the steam pipe, at the top and the water pipe at the bottom. These pans
also, like those before mentioned, may be about.6 or 8 inches deep to hold a
few inches of water. The steam generated in these tight water pan's is to be
taken into the air heating pipes in the way hereafter described, or part may be
allowed to come into the ash-pits direct through one or two small holes in the
pans. Instead of using furnaces with fire-bars and water pans, as above
described, V-shaped fire-places may be used, that is, fire-places having their sides
sloping inwards from the top to the bottom. In this case, instead of the fire: bars,
the sides of the fire-places support the burning coke. The bottom opening of
the fire-place into the ash-pit is a long slot, and should be the whole length of
the ash-pit, and sufficiently narrow to prevent the burning coke falling through
into the ash-pit in. injurious quantities... The dead plates of these fire-places:
are to have a number of holes of about an inch diameter made in them, or.
they are to be composed of bars. as before described for the other. form of
furnace, to allow sufficient heated air to pass through them from the ash-pits:
to the fire-places above to effect the combustion of the carbonic oxide or other.
inflammable gases formed by the combustion of the solid fuel used. Water
pans. may also be used in these furnaces, but in this case the holes in the dead.
plates or bars should be kept covered with a thin fire of coke as before
described, to prevent. any steam passing away undecomposed through the fire-
places above. The atmospheric air to he used to support the combustion:
of the fuel as before described may be heated in any convenient way
by the waste heat of the furnaces, the way however which I prefer is
one described, by me in a former Patent for "Improvements in Manufac-
turing and Purifying certain Gases, and in Preparing certain Substances
for Purifying the same," (No. 13,912, 1852,) and consists in passing. the
air to be heated through iron pipes, say, of about 4 or 5 inches diameter,
placed within other pipes or flues, through which the waste heat from.
the furnaces passes, away.. The interior pipes are thus surrounded by the
waste heat, and the air as it travels along then will become hotter and:

page_text: hotter by absorbing the waste heat-in the exterior pipes or flues; and when it
arrives at the ash-pits to which the interior heating pipes must be connected
it will be very hot. If these air heating pipes are placed horizontally on the
tops of the beds of retorts, which in works in operation will perhaps be the
most convenient place for them then instead of drawing the atmospheric air to
be heated into them on the same level as that on which the pipes are placed,
other pipes are to be connected to them which descend to the level or pre-
ferably below the level of the ash-pits. The atmospheric air to be heated
is drawn in at the bottom end of these latter pipes, and is then to pass through
the series of heated. pipes into the closed ash-pits of the furnaces before
described. Steam generated in the tight water pans before described is
also to pass into the bottom end of these pipes with the atmospheric air to
le heated. This steam will warm the air and assist the draught into the ash-
pits. As there will be some waste heat left in the escape flues after heating
the air for supporting the combustion of the fuel used; a pan for heating the
water to be used in the water pans may be placed on or in the said flues
beyond the air pipes, so that the water may be, hot as it runs in a stream
regulated by cocks from this pan through small pipes into the water pans in
the ash-pits. When new beds of retorts are made, I prefer placing the air
heating pipes below the level of the ash-pits in waste heat flues prepared for
them in any convenient position.
Having now described the nature of my Invention, I will proceed to describe
one way in which the same may be carried into effect, reference being had.to
the Drawings hereunto annexed, and to the letters and figures marked
thereon:
Figures 1 and 2 represent in front elevation and transverse vertical section
respectively as much of one of the retort beds comprised in a series of them as
is necessary to illustrate the means by which I introduce heated air into. the
closed ash-pits of furnaces' used in the manufacture of gas, and the apparatus
by which I prefer to heat the air preparatory to its being so introduced.
With respect to these Figures, I would observe that I have not shown the
retorts, bydraulic main, and other details, the construction and arrangement
of which being well known do not require description or illustration. Figure 3
represents a longitudinal vertical section of the air heating apparatus herein-
after referred to, and the upper part of the retort bed on or in which the said
apparatus is built, the section being taken on the line a, Figure 2; Figure 4
is a plan; partly in section, of the same, the section being taken on the line.b,
Figure 3; and Figure 5 is a plan of the said apparatus and upper part of the
retort bed. Figures 6, 7, and 8 represent in front elevation, side elevation,

page_text: and plan respectively the water pan herein-after referred to. The same letters
indicate the same parts in the several Figures.
A is the arch of the bed of retorts, within which the retorts are set in any
convenient manner; B is a V-shaped furnace, by which the retorts are heated,
and B is the furnace door; C is the ash-pit, and C is the ash-pit door'; D
is a water pan, which is placed in the ash-pit, and is supplied with water from
a reservoir E. by means of pipes d', el, the supply being regulated by means
of the cock The said pan may either be provided with a lid fitting loosely
or it may be made air-tight (with the exception of the holes, into which the
pipes d'; d, are fitted), as représented, in which latter case the steam generated
passes through the piped into the pipe; by which the external air to be
heated is conveyed to the air heating flues, as herein-after explained. F is a
flue built in the brickwork partition between each bed of retorts, through
which flue the. volatile products of combustion pass to the flues G', G², in
which the air heating pipes H, H1, H2, H3, are placed, the said flue having
openings f, f, at its front end. The pipes UI', H', communicate at either end
with flues: 1, I, and the pipes II, H2, communicate at either end with the
flue: 12 and the flue: I. The pipes: H, II, are shielded by fire tiles h, h, from
the direct action of the volatile products of combustion where the latter' enter
the flue G. J. is a pipe through which the external air to be heated enters
the flue I', and K is a pipe which conducts the air when heated from the
flue: 1 to the flue: L, which opens into the ash-pit; M is a flue running, the
whole length of the bench of retorts, and communicating with the stack.or
chimney. The said flue is constructed: with openings. (one of which is shown
at m¹) at those parts of it which pass over the flues G³, through which
openings the: volatile products of combustion pass from the flue G2 into the
flue M; whence they escape to the chimney. Other openings m³ are made in
the flue M, to allow the said products of combustion to impinge on the bottoms
of the reservoirs E,, and thus heat the water which they contain.
.
The action. of the apparatus is as follows:-The external air enters the
apparatus through: the pipe: J. (the draft being promoted by the steam which
passes from.. the water pan D through the pipe d² to the said pipe J), and
passes through the flue I' and pipes H, H', into the flue I2, from' which it
passes through the pipes H2, H3, into the flue Is, from which it is conveyed by
the pipe K to the flue L, whence it enters the ash-pit at a high temperature.
The course; of the air thus introduced into the ash-pit is indicated by arrowsy..
The volatile: products of combustion by, which the air, is heated pass from the
retort bed into the flue F and enter the flue G' by the openings ff. From
this flue they pass through the flue G2 and opening m into the flué, M,.

page_text: where they mingle with the volatile products of combustion which have
similarly escaped from the air heating flues on the other retort beds, and
are passing through the flue M to the chimney. The course of the volatile
products of combustion by which the air is heated is indicated by arrows 2...
Having thus described the nature of the said Invention, and one way in
which the same may be carried into effect, I would have it understood that
my Invention is not confined to such particular mode of carrying it into effect,
nor to the use of the particular' apparatus represented and described otherwise
than as herein-after stated; but what I claim as of my Invention is,-
First, the employment of hot atmospheric air heated by what is now the
waste heat of the furnaces, and brought into closed ash-pits to effect the
combustion of the fuel used in the said furnaces or fire-places, as herein-
before generally described.
And, secondly, when the air heating pipes are placed on the top of the gas
retort settings, or above the furnaces, the use of pipes descending as low as
or lower than the level of the ash-pits, for the purpose of conducting the
atmospheric air to be employed for effecting the combustion of the fuel to
the said air heating pipes, and from thence to the ash-pits.
In witness whereof, I, the said Frank Clarke Hills, have hereunto set
my hand and seal, this Eleventh day of October, in the year of our
Lord One thousand eight hundred and sixty-four.
Witness,
H. H. MURDOCH,
7, Staple Inn.
F. C. HILLS. (L.s.)