IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS, AND IN THE UTILIZATION OF THE IMPURE PRODUCTS RESULTING THERE FROM.
Year: 1878

page_text: LETTERS PATENT to Archibald Miller, senior, Engineer, and Archibald
Miller, junior, Architect, both of Glasgow, in the County of Lanark, North
Britain, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
ILLUMINATING GAS, AND IN THE UTILIZATION OF THE IMPURE PRODUCTS
RESULTING THERE FROM.
"
Sealed the 2nd May 1879, and dated the 19th November 1878.
PROVISIONAL SPECIFICATION left by the said Archibald Miller and Archibald
Miller at the Office of the Commissioners of Patents on the 19th November
1878.
ARCHIBALD MILLER, senior, Engineer, and ARCHIBALD MILLER, junior, Architect,
both of Glasgow, in the County of Lanark, North Britain. "IMPROVEMENTS IN
THE MANUFACTURE OF ILLUMINATING GAS, AND IN THE UTILIZATION OF THE
IMPURE PRODUCTS RESULTING THEREFROM."
This Invention has for its object the production of illuminating gas from ordinary
coal dross, whereby a great economy will be effected in the cost of the gas-producing
material, while the gas obtained will be of a superior quality, and the storing of
the waste or impure products of distillation can be utilized as fuel for various
heating purposes.
And the nature and novelty of the Invention consist in charging the gas retort with
common coal dross instead of the expensive coal hitherto used for gas making, and
when the retort has been raised to the necessary heat, the light hydrocarbon gases
evolved during the first fifteen or twenty minutes are led off by a branch pipe from
the ordinary ascension pipe (before it passes through the hydraulic main) into a
separate or special gas holder of ordinary construction, where it is stored for use or
sale as fuel for marine-boiler furnaces, steam cars, land engines and boiler furnaces,
and for other heating purposes.
Or instead of leading the impure gas into a special gas-holder, it may be con-
ducted by a special pipe down into the furnace or fire grate of the retort, where it

page_text: is consumed by mixing with the air, thus greatly economizing the coke used for
firing the retort.
After this impure gas has been allowed to escape into the special gas holder or
into the fire grate, the escape is shut off by an ordinary cock or valve, and the purer
gas then being evolved is allowed to flow into and through the hydraulic main for
the space of about an hour and a half to two hours, when it is again shut off by an
ordinary cock or valve in the ascension pipe, and the heating of the retort being
continued for the space of about thirty to forty-five minutes, the cock in the branch
pipe is again opened, and the impure or residual gases afterwards evolved are led
into the separate gas holder for storage and use, or down into the furnace, as before
described in reference to the first part of the process. By this method of stopping
the flow of the gas before the process reaches the sedimentary stage, a thoroughly
pure gas is obtained, altogether free from the noxious element bisulphate of carbon,
which hitherto has been found to be very deleterious to the gas. It is found that a
ton weight of common dross yields about 10,000 cubic feet of gas of an average
illuminating power of twenty candles; but by our method of taking off 1,000 feet
at the first stage of the distilling process, and leaving 1,000 feet of gas to be taken
off at the last stage of the process, about 8,000 feet of pure is obtained of an illu-
minating power equal to 28 candles. It is to be understood that this process may
be carried out on board ships for example, with good results, and the evolving gases
directly applied as fuel for the boiler furnaces, one set of the furnaces being
preferably fired with the gas and the other with coke or other fuel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Archibald Miller and Archibald Miller in the Great Seal Patent
Office on the 17th May 1879.
ARCHIBALD MILLER, senior, Engineer, and ARCHIBALD MILLER, junior, Architect,
both of Glasgow, in the County of Lanark, North Britain. IMPROVEMENTS IN
THE MANUFACTURE OF ILLUMINATING GAS, AND IN THE UTILIZATION OF THE
IMPURE PRODUCTS RESULTING THERE FROM.'
"
Our said Invention has for its object the production of illuminating gas from
ordinary coal dross, "tripping," or small coal, whereby a great economy will be
effected in the cost of the gas-producing material, while the gas obtained will be of
a superior quality, and the collected waste or impure products of distillation can be
utilized as fuel for various heating purposes. Referring to the accompanying Sheet
of Drawings, Figures 1 and 2 are a front elevation and sectional elevation respec-
tively, the latter taken through the retort and heating furnace of a set or bench of
four gas retorts A and their two heating furnaces B below, all much of the ordinary
construction used for making the illuminating gas from the usual gas coal, but here'
shown as arranged and fitted with one modification or arrangement of the simple
connections or appliances and fittings necessary for converting or making ordinary
arrangements of retorts suitable for carrying out our said Invention or improved
mode and means of making good illuminating gas from ordinary qualities of
coal dross or "tripping." The improvements of this arrangement consist in fitting a
three way cock D in the bend of the usual uptake or syphon drawing-off pipe C, C',
leading the gas from each retort A direct from the cock D to the hydraulic main
C to be conducted as usual to the ordinary arrangement of gasometer or holder
and intermediate purifiers when desired, and all as indicated by the arrows in these
pipes in the Figures. The internal key of each of these new or additional cocks D,
is fitted with a lever or handle d, d', so as to be able to turn it with facility from
the front of the retorts in one direction to conduct the gases from the retort straight
through the key and cock D by the two opposite branches 1, 2, direct into the
hydraulic main, at the same time shutting the communication through the third or
upper branch 3, which is fitted with a branch conducting pipe D' from each cock to
a large or main pipe D", common to the whole set of retorts for conducting the
impure gases either to a gas holder for subsequent use for heating purposes or by
other pipes to the furnaces B for heating the bench of retorts A. When the key of
the cock D is turned in the opposite direction by the lever and handle d, d', it opens
the cock D, so as to conduct the impure gases from the retort through it by the upper
branch 3 and pipe D', to the new main drawing-off pipe D", as stated, at the same
time shutting the communication to the hydraulic main C. And the nature,
novelty, and mode of putting the Invention into effect or practice consists in
charging each gas retort A with common coal dross," tripping," or small coal instead
of the expensive cannel and other coal hitherto used for gas making; and when the
retort A has been raised to the necessary or usual high heat, the light hydrocarbon
gases evolved during the first ten to twenty minutes, according to the quality of
the dross or tripping" used, are led off through the cock D and branch pipe D'
from the ordinary ascension drawing-off pipe C (leading to and before it passes
through the hydraulic main) into a separate main gas pipe D", leading to a special
gas holder of an ordinary construction, where this impure gas is stored for use or
sale for heating purposes, instead of or as an equivalent for fuel, in the furnaces of
marine boilers, steam cars, land engines, or other furnaces, and for other heating
purposes. Or instead of leading the impure gas into a special gas holder from the
pipes C and C, it may be conducted from these by special pipes for the purpose
down into the furnace B or fire grate of the retorts A, where it is burned by com-
bining with the air for heating these retorts, thus greatly economising the amount
of coke used for firing the retorts.

page_text: After this impure gas has been allowed to escape into the special gas holder for
collecting it, or into the fire grates B, the escape through the pipe 3, D' is shut off by
the three way cock D, and at the same time allows the purer gas then being
evolved to flow in the usual direction into and through the hydraulic main C" for the
space of about an hour and a half to two hours, when it is again shut off by reversing
the said three way cock D, fitted between the ascension and dip syphon pipe C, C¹,
at the same time opening the communication from the retort through the cock D
and branch pipe 3 D for the residuary impure gases afterwards evolved to be led
into the separate gas holder fór storage and use, or down into the furnace B, as
before described in reference to the utilization of the impure gas evolved in the first
part of the process; the heating of the retort being then continued for the space of
about thirty to forty-five minutes. By this method of stopping the flow of the gas
from the retorts before the distillation or process reaches the sedimentary stage, a
thoroughly pure gas is obtained, altogether free from the bisulphate of carbon, the
noxious qualities of which are found to be very deleterious in or to the use of illumi-
nating gas aş ordinarily made. We find that a ton weight of common coal dross
yields about 10,000 cubic feet of gas of an average illuminating power of twenty
candles, but by our method of taking off the gas from the retorts about 1,000 feet
at the first stage of the distilling process, and leaving about 1,000 feet of gas to be
taken off at the last stage of the process, as described, about 8,000 feet of very pure
gas is obtained of an illuminating power equal to about 28 candles. It is to be
understood that this process may be carried out on board of steam ships or other
sailing vessels for example, with good results, and the evolving gases directly applied
as fuel for the steam boiler furnaces, one set of furnaces being preferably fired with
the gas, and the other with coke or other fuel; or this impure gas may be utilized
on board of such ships or vessels for the heating of their galley stoves or cooking
ranges.
And although only an ordinary three way cock has been shown and described as
applied for the conducting of the impure gases from the retorts to the new pipes,
and for shutting off the communication to the hydraulic main, and vice versa,
opening the communication to the hydraulic main, and shutting off the connection
with the impure gas conducting pipes, it will be understood that any other equiva-
lent arrangement of pipes and cocks, or it might be valves, as in the case of separate
pipes, may be used for effecting the same purpose. In carrying out this process of
manufacturing illuminating gas from the dross of common coal or
66 tripping," the
present arrangements of retorts and their purifiers and gas holders may all be the
same as heretofore used for making illuminating gas from cannel or other gas coal,
so that the only change required is the use of special separating pipes and reversing
cocks or valves, as D. D. D, for the drawing off of the impure from the pure or the
low from the high illuminating gases or products of distillation in this new process,
and it may be observed that with the better qualities of "tripping or dross, the
middle or intermediately separated gases distilled are of so pure a quality that in
many cases, or for small gas works, little or no purification would be required.
"
Having now described the nature of our said Invention, and the manner of per-
forming the same, we have to state that we do not confine ourselves to the precise
details herein described or delineated, but what we consider novel and original and
therefore claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,-
First. The mode of and means or arrangements of apparatus for manufacturing
illuminating gas from ordinary coal dross or "tripping." by drawing off the first and
last impure products of distillation and separating the same from the middle or
intermediate or purer and richer illuminating gases, and collecting and utilizing the
impure gases for heating purposes, all substantially in the new or improved manner
herein described in reference to and shown in the accompanying Drawings, or any
mere modification thereof.
Second. The production of a superior and pure illuminating gas from the dross
of common coal or tripping," by separating or drawing off the impure products or
"6

page_text: gases evolved during the first and last stages of the process of distillation, and the
mode and means employed for effecting the same, substantially as herein
described.
Third. The arrangement and use of special reversing and leading off cocks, or it
might be valves and pipes, as D, D, D", for separating and drawing off the first
and last impure products from the middle or pure gases in the distillation of illu-
minating gas from the dross or tripping of common coal, substantially as herein
described in reference to and shown in the accompanying Drawings, or any mere
modification thereof.
"
The collecting and utilizing of the first and last separated products of distillation
of the dross of common coal or tripping" in the manufacture of illuminating gas,
all substantially in the manner and for the heating purposes generally, as herein
described.
In witness whereof, we, the said Archibald Miller, senior, and Archibald
Miller, junior. have hereunto set our hands and seals, this Fifteenth day
of May, in the year of our Lord One thousand eight hundred and seventy
nine
ARCHIBALD MILLER, SENT. (L.S.)
ARCHP. MILLER, JUNE.
(L.S.)