IMPROVEMENTS IN THE FURNACES OF GAS RETORTS, AND IN MEANS AND APPARATUS FOR EFFECTING THE COMBUSTION OF FUEL IN THE. SAID FURNACES
Year: 1869

page_text: LETTERS PATENT to Frank Clarke Hills, of the Chemical Works,
Deptford, in the County of Kent, Manufacturing Chemist, for the
Invention of "IMPROVEMENTS IN THE FURNACES OF GAS RETORTS, AND IN
MEANS AND APPARATUS FOR EFFECTING THE COMBUSTION OF FUEL IN THE.
SAID FURNACES."
Sealed the 13th July 1869, and dated the 12th February 1869.
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills
at the Office of the Commissioners of Patents, with his Petition,
on the 12th February 1869.
I, FRANK CLARKE HILLS, of the Chemical Works, Deptford, in the
County of Kent, Manufacturing Chemist, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE FURNACES OF GAS RETORTS,
AND IN MEANS AND APPARATUS FOR EFFECTING THE COMBUSTION OF FUEL IN THE
BAID FURNACES," to be as follows:-
My Invention consists in improvements on a former Invention, for
which I obtained Letters Patent bearing date 29 April 1864 (No. 1087),
which Invention consisted in the use in furnaces of air heated by the
waste heated, gaseous products of combustion, which air was introduced.
into the closed ash-pit of the furnace instead of cold air. I have found:

page_text: in practice that the heat generated in the furnace by the above method
is so intense as to destroy the furnace bars and furnace too rapidly.
Now my present Invention greatly prevents such intense heat by the
means herein-after described. I introduce into the closed ash-pit of the
furnace air heated by the waste gaseous products of combustion, but I
temper the heat generated by the said air by mixing therewith a portion
of the waste heated gaseous products of combustion which escape from
the furnace through the flue to the chimney. The carbonic acid and
nitrogen contained in the said products when mixed with the atmospheric
air introduced into the furnace diminish the intense local heat which
heated air generates when introduced by itself, and the heat is by this
means the better diffused through the bed of retorts, and a saving of
fuel is effected. The pipes or chambers in which the air to be introduced
into the ash-pit is heated are placed or formed in the escape flue leading
from the furnace to the chimney, so as to be surrounded as much as
possible by the red-hot waste gaseous products of combustion, and the
escape flue communicates with the said air-heating pipes or chambers by.
means of a pipe, in the centre of which a jet pipe is inserted, in such a
manner that when atmospheric air is forced through it from a fan or
an air pump the jet of air will draw a portion of the waste products of
combustion from the escape flue aforesaid, and will force such portion
into the air-heating pipes or chambers. The jet of air thus forced into.
the air-heating pipes or chambers will mingle with the hot waste gaseous
products of combustion drawn or forced in with it, and both together
will pass through the said air-heating pipes or chambers, and from
thence into the furnace, either through the ash-pit or above, the fire.
bars, as herein-after described. I prefer to make the air-heating pipes
or chambers herein-before referred to of fire-bricks, fire-tiles, or fire-clay,
or other such like refractory material, and to place or form the said
pipes or chambers at a lower level than that of the ash-pit. The whole
of the atmospheric air required may be introduced in the form of the
jet described, or a portion may be drawn into the heating pipes or
chambers aforesaid through a separate pipe. The gaseous products of
combustion when sufficiently cooled to pass through a fan or an air
pump may be used as a jet instead of atmospheric air to draw and force
in the hot waste gaseous products of combustion, but in this case all the
atmospheric air required must be drawn through the separate pipe above
described into the air-heating pipes or chambers, there to mingle with

page_text: the said hot waste gaseous products of combustion, and thence to pass
into the closed ash-pit. Steam might be used as a jet to draw and force
the said products of combustion into the heating pipes or chambers, but
would not answer so well as the other means described. Instead of
admitting the hot air mixed with the hot gaseous products of combustion
into the ash-pit a flue may be made around the sides and back of the
furnace about four inches above the fire-bars, and slots or pigeon holes
about two inches deep communicating with the said flue may be made
around the sides and back of the said furnace in order to admit the hot
air and gaseous products aforesaid to the fuel in the furnace, and thus
keep the fire-bars cool.
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 11th August 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANK
CLARKE HILLS, of the Chemical Works, Deptford, in the County of.
Kent, Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of February, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, 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 Olarke
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, an Invention for
"IMPROVEMENTS IN THE FURNACES OF GAS RETORTS, AND IN MEANS AND
APPARATUS FOR EFFECTING THE COMBUSTION OF FUEL IN THE SAID FURNACES,"
upon the condition (amongst others) that I, the said Frank Clarke.
Hills, 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'

page_text: 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 be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
My Invention consists in improvements on a former Invention, for
which I obtained Letters Patent bearing date 29 April 1864 (No. 1087),
which Invention consisted in the use in furnaces of air heated by the
waste heated gaseous products of combustion, which air was introduced
into the closed ash-pit of the furnace instead of cold air. I have found
in practice that the heat generated in the furnace by the above method
is so intense as to destroy the furnace bars and furnace too rapidly.
Now my present Invention greatly prevents such intense heat by the
means herein-after described. I introduce into the closed ash-pit of the
furnace air heated by the waste heated gascous products of combustion,
but I temper the heat generated by the said air by mixing therewith a
portion of the waste heated gaseous products of combustion which escape
from the furnace through the flue to the chimney. The carbonic acid
and nitrogen contained in the said products when mixed with the
atmospheric air introduced into the furnace diminish the intense local
heat which heated air generates when introduced by itself, and the heat
is by this means the better diffused through the bed of retorts, and a
saving of fuel is effected. The pipes or chambers in which the air to be
introduced into the ash-pit is heated are placed or formed in the escape flue
leading from the furnace to the chimney, so as to be surrounded as much
as possible by the red-hot waste gaseous products of combustion, and the
escape flue communicates with the said air-heating pipes or chambers by
means of a pipe, in the centre of which a jet pipe is inserted, in such a
manner that when atmospheric air is forced through\it from a fan or air
pump the jet of air will draw a portion of the waste products of com-
bustion from the escape flue aforesaid, and will force such portion into
the air-heating pipes or chambers. The jet of air thus forced into the
air-heating pipes or chambers will mingle with the hot waste gaseous
products of combustion drawn or forced in with it, and both together
will pass through the said air-heating pipes or chambers, and from
thence into the furnace, either through the ash-pit or above the fire-

page_text: bars, as herein-after described. I prefer to make the air heating pipes
or chambers herein-before referred to of fire-bricks, fire-tiles, or fire-clay,
or other such like refractory material, and to place or form the said pipes
or chambers at a lower level than that of the ash-pit or fire-place. The
whole of the atmospheric air required may be introduced in the form of
the jet described, or a portion may be drawn into the heating pipes or
chambers aforesaid through a separate pipe. The gaseous products of
combustion when sufficiently cooled to pass through a fan or an air
pump may be used as an jet instead of atmospheric air to draw and force
in the hot waste gaseous products of combustion, but in this case all the
atmospheric air required must be drawn through the separate pipe above
described into the air-heating pipes or chambers, there to mingle with
the said hot waste gaseous products of combustion, and thence to pass
into the closed ash-pit. Instead of admitting the hot air mixed with the
hot gaseous products of combustion into the ash-pit a flue may be made
around the sides and back of the furnace about four inches above the
fire-bars, and slots or pigeon holes about two inches deep communicating
with the said flue may be made around the sides and back of the said
furnace in order to admit the hot air and gaseous products, aforesaid
to the fuel in the furnace, and thus keep the fire-bars comparatively
cool.
Having now described the nature of my Invention, I will proceed to
describe the manner in which the same is to be performed, reference
being had to the Drawing hereunto annexed, and to the letters and
figures marked thereon.
Figure 1 is a transverse vertical section (taken on the line X,
Figure 2), Figure 2 is a longitudinal vertical section (taken on the
line Y, Figure 1), and Figure 3 is a horizontal section (taken on the
line Z, Figure 1) of so much of one of the retort beds comprised in a
"bank" or series of them as is necessary to illustrate the application of
my Invention. The retorts, hydraulic main, and other details, the con-
struction and arrangement of which are well known, are not. shown.
The same letters indicate the same parts in all the Figures.
A is the arch of the bed of retorts, within which the retorts are set
in any convenient manner; B is the fire-place; O is the ash-pit;
D, E, are flues through which the volatile products of combustion pass
on their way to the chimney. Within the flue E are built air-heating
flues F, F, the said flues being divided from one another by fire-

page_text: tiles ff. G is a side flue, through which the volatile products of com-
bustion pass from the lower to the upper part of the flue E; and H
is a flue through which the said products pass from the said flue E to
a transverse flue I leading to the chimney; J'is an air pipe, through
which the air required in addition to that supplied by the jet aforesaid
passes into the air-heating flues; K is a flue leading from the flue F* to
the ash-pit C; L is a pipe, the ends of which communicate respectively
with the flues E and F; M is a jet pipe luted into a socket 1¹ in the
pipe L.
The action of the apparatus is as follows: The atmospheric air to
be heated passes through the pipe J into the flue F", and there mingles
with a portion of the heated gaseous products of combustion, which is
withdrawn from the flue E by the pipe L, and forced or drawn into the
said flue F" by means of a jet of air passing through the pipe M. The
air and the carbonic acid and nitrogen in admixture therewith pass from
the flue F through an opening f¹ into the flue F, and thence through
the flue K into the closed ash-pit of the furnace. The heated gaseous
products of combustion pass from the arch of the bed of retorts through
the flue D into the lower part of the flue E, thence through the side
flue G into the upper part of the said flue E, and thence through the
flues Hand I to the chimney. The course of the air is indicated by
blue arrows y, y, and that of the products of combustion by red
arrows z, z. Instead of admitting the hot air mixed with the waste
heated gaseous products of combustion into the ash-pit, as described,
they may be admitted into the furnace above the fire-bars. In this
arrangement the flue K is dispensed with, and a flue is made around
the sides and back of the said furnace, which flue communicates with
the flue F by means of a vertical flue, and slots. or pigeon holes are
made around the said sides and back of the furnace in order to admit
the hot air and gaseous products aforesaid to the fuel in the furnace,
and thus while duly supporting combustion keep the fire-bars com-
paratively cool. The whole of the atmospheric air required may be
introduced in the form of the jet described (the air pipe J being in this
case dispensed with), or a portion may be drawn through hollow fire-
bars, in order to diminish the heat of the said bars. Instead of furnishing
each bed of retorts with pipes through which the air and the products of
combustion respectively pass, as herein-before described, the air may be
introduced into the furnaces through a main air flue running the whole
length of the "bank" or scries of retorts, and having branch flucs

page_text: opening into the fire-places or ash-pits of the said furnaces, and the
requisite portion of the products of combustion may be taken from
the waste heat flue leading to the chimney, and introduced into the
said main air flue by means of a flue communicating with the said
waste heat flue and the said air flue respectively, and provided with a
jet pipe through which a jet of air is forced into the said air flue to
draw in the required quantity of the said products of combustion.
Having thus described the nature of my Invention, and one way in
which the same may be carried into effect, I would have it understood
that my said Invention is not confined to that particular way, nor to
the use of the particular apparatus described and represented otherwise
than as herein-after stated, as such apparatus may be variously modified
according to the construction of the beds of retorts to which it is
applied; but I claim as my Invention,-
Firstly. Mixing with the heated air used for the support of com-
bustion in the furnaces of gas retorts a portion of the waste heated
gaseous products of combustion from such furnaces, and thus lessening
the heat in the fire-places,
Secondly. The application to the apparatus by means of which the air
used as aforesaid is heated of a pipe or flue furnished with a jet pipe,.
through which air is passed, by means of which pipe or flue and jet pipe
a portion of the waste heated gaseous products of combustion is with-
drawn from the waste heat flue and introduced into the flue in which
the said air is heated, or into the flue through which it passes to the
furnace or furnaces, essentially in the manner and for the purpose
described.
In witness whereof, I, the said Frank Clarke Hills, have hereunto
set my hand and seal, this Ninth day August, in the year of
our Lord One thousand eight hundred and sixty-nine.
Witness,
H. H. MURDOCH,
7, Staple Inn.
F. O. HILLS. (L.S.)