IMPROVEMENTS IN THE MANUFACTURE OF GAS FOR THE PURPOSES OF ILLUMINATION, AND OF IMPROVEMENTS IN THE PURIFICATION OF GAS
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
Lowe, of Finsbury Circus, in the City of London, Civil Engineer, and
FREDERICK JOHN EVANS, of Horseferry Road, in the City of Westminster,
Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twentieth day of January, in the fifteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said George Lowe and Frederick John Evans, Her especial license, full
power, sole privilege and authority, that we, the said George Lowe and
Frederick John Evans, our exors, adñiors, and assigns, and such others as
we, the said George Lowe and Frederick John Evans, our exors, admors, or
assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plantations
abroad, and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, our
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GAS FOR THE PURPOSES OF
ILLUMINATION, AND OF IMPROVEMENTS IN THE PURIFICATION OF GAS;" in which
said Letters Patent is contained a proviso obliging us, the said George Lowe
and Frederick John Evans, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, particularly to describe and
ascertain the nature of our said Invention, and in what manner the same is

page_text: to be performed, and to cause the same to be enrolled in Her Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
George Lowe and Frederick John Evans, do hereby declare that the nature
of our said Invention, and the manner in which the same is to be performed,
is particularly described and ascertained in and by the following description
thereof, reference being had to the Drawing hereunto annexed, and to the
letters marked thereon (that is to say):-
-
The first part of our Invention refers to certain means of enriching or
improving the quality of gases, so as to render them fit for the purposes of
illumination.
In carrying out this improved manufacture of gas we propose to pass gas
obtained from any of the sources herein-after specified through heated retorts
containing cannel coal, coal, lignite, resin, pitch, tar, oil, retinite, or other
substance or substances capable of yielding carburetted hydrogen gas, by
which means such a combination of rich and poor gases may be produced as
will be exactly suited to the purposes of illumination. For this purpose we
propose to use retorts open at both ends, as shewn in the Drawing forming
part of this our Specification. In this Drawing but one retort is exhibited,
but a similar arrangement of retorts may be adopted to that in general
use in gasworks. a, a, represents a retort in longitudinal section, set in
a suitable furnace for heating the same; and b, b, are mouthpieces and
lids fitted to both ends of the retorts. c is the pipe for carrying off the
gaseous products generated in the retort; and d is a pipe for introducing
into the retort the gas which is intended to combine with the gaseous products
of the substances under distillation in the retort. As soon as the retort is
charged with coal or other carbonaceous matter a cock e in the pipe d is
opened, which allows the gas to flow into and pass through the retort. It
then passes in the direction of the arrows, and mingles with the gas that is
evolved from the carbonaceous matters contained in the retort, whereby a
compound gas is formed, possessing a much higher illuminating power than
could have been obtained had the combination taken place after instead of
at the time of the generation of the gas in the retort a. The gas, which is
brought to the retort by means of the pipe d, may be either forced into the
retort so as to overcome the internal pressure put on the retort by means of
the bydraulic main, or instead thereof an exhauster may be applied to draw
off the gas from the retort. Should tar, oil, resin (previously melted), or any

page_text: liquid hydro-carbon be employed for the generation of the gas, it is to be run
into the retort in the way generally adopted for making oil or resin gas.
The sources from which we propose to obtain inflammable gases to be applied
as above indicated are wood, sawdust in a damp or dry state, spent tanners'
bark, and other like substances capable of yielding an inflammable gas.
These substances must be put into a red hot retort, and distilled like coal.
The resulting gases may be either purified at once, or passed directly to the
retort containing the coal or other carbonaceous material. As a general rule,
however, we prefer that these gases should be stored up in gasholders for use,
as in that case a more uniform and constant supply to the coal retort may be
relied on.
Another source of inflammable gas is from coal of an inferior
description, or from peat. These substances having been distilled in a retort,
the resulting gas can be then employed as above indicated.
We also propose to conduct carbonic oxide gas into retorts containing
carbonaceous matters under distillation. This gas we obtain from carbonic
acid by passing the latter gas (which may be obtained from any convenient
source) through a retort or furnace containing red or white hot coke. Or we
utilize a portion of the gases generated in furnaces by collecting these gases,.
and converting the carbonic acid they contain into carbonic oxide, by passing
them through a retort or furnace as described for treating carbonic acid; or
the gases may be conducted directly into retorts wherein carburetted hydrogen
is being generated, for the the purpose of effecting the desired combination.
From the foregoing description it will be understood that the object of this
part of our Invention is to obtain gas of an uniform quality, that is, possessing
a definite amount of illuminating power. Now it is well known that if the
gas be too rich in carbon it will burn with a dull flame, and give off a large
amount of smoke, and that if deficient in carbon it will burn with a blue
flame, and possess very little illuminating power.
We therefore propose to
mix the rich and poor gases obtained as above described in such proportions
as will be needful to produce a highly illuminating quality of gas. As. the
proportions will depend entirely on the quality of the gases to be combined,
no rule can be laid down for the amount of the gas required to be passed into
the retorts wherein the distillation is proceeding. The mode, however, in
which the gas burns on issuing from the retort will be a sufficient test for the
workman in attendance.
The second part of our Invention refers to the purification of coal gas from
sulphuretted hydrogen. This operation we effect by the use of what has been
considered by chemists to be the ferrate of potash, but what is now found to be
a peroxide of iron in a peculiar state, and such as results from the employment
of the following means.

page_text: Preparation of the Material.-First, we heat together peroxide of iron and
caustic potash or soda to a dull red heat, by which a kind of ferrate or ferrite
of potash or soda is produced, and when this substance is washed in water it'
undergoes decomposition, with the reproduction of caustic potash or soda which
remains in solution, and the precipitation of peroxide of iron in the state fit for
the purification of gas. All or any of the peroxides of iron may be used
for the above purpose, and will, by its means, become useful for purifying gas,
though previously inert; and the solution of potash or soda, when evaporated
to dryness, may be again and again employed upon fresh portions of peroxide
of iron, so as to communicate to them the peculiar property desired.
Or we
heat together peroxide of iron with a smaller quantity of caustic potash or
soda and a portion of common salt, by which means we economize the potash
or soda. The heat in this case should be as before, a dull red, and the same
measures must be adopted for recovering the potash or soda and common salt,
which may be used over and over again with fresh portions of peroxide of iron.
Or we heat to a temperature of about 600° Fahrenheit the common bydrated
peroxide of iron, taking care that the leat never reaches a bright red, and in
this way we obtain a. peroxide of iron having the requisite properties. Or we
heat in the same way, and with the same precautions, such of the native ochres
or ferruginous compounds as will, after such treatment, become rapidly black
upon being subjected to the action of a stream of sulphuretted bydrogen.
Having, by any of the means thus indicated, procured a quantity of peroxide
of iron fit for purifying gas, this oxide is next to be mixed with sawdust or
other convenient material, and damped slightly with water, and the mixture
spread in a dry lime purifier, and used in the way employed with hydrate of
lime or it may be mixed with water and run into a wet lime purifier, and
used in the way adopted with regard to lime when employed in this kind of
apparatus.. In both cases it will be necessary, after the peroxide of iron has
ceased to act upon the gas, to expose it to the air, by which its energies are
renewed, so that it may be again and again used for the purification of gas.
With the dry lime purifier simple exposure is all that is required, but with the
wet lime purifier the mixture must be run out and left at rest for some time.
When the fluid has entirely separated from the solid part the fluid may be
allowed, to escape, and as the solid portion dries its power will become
renewed, after which it may be mixed with water and employed as before.
The renewal of the peroxide of iron, in both these cases, is known by its
changing from black to red or deep brown.
Another part of our Invention relates to the use of the sulphite and bisul-
phite of lead for the removal of the sulphuretted hydrogen of coal gas. These
substances we employ singly or together, mixed with water, in a wet lime purifier,

page_text: exactly as is practised with regard to lime, and when they cease to purify the
gas we run the mixture out, and having removed the water by subsidence
and decantation, or by a filter, we dry the residue and burn it, so as to make
sulphurous acid, which is employed in the manufacture of fresh sulphite or
bisulphite of lead, as the case may be, or in the production of sulphuric acid,
as is well known to chemists. The matter which remains after this burning
process is carefully roasted, and thus converted into oxide of lead or litharge,
from which sulphite or bisulphite of lead may be again produced.
Having now described our Invention, and the manner of carrying the same
into effect, we wish it to be understood that under the above in part recited
Letters Patent we claim the combining of gases which possess different
degrees of illuminating power, by the introduction of gas obtained in any of
the ways above indicated, into retorts or vessels containing carbonaceous
matters under distillation.
We claim as of our improvements in the purification of gas,-
First, the use of anhydrous peroxide of iron, prepared as above described;
and,
Secondly, we claim the use of sulphite and bisulphite of lead for the
removal of sulphuretted hydrogen from coal gas.
In witness whereof, we, the said George Lowe and Frederick John
Evans, have hereunto set our hands and scals, this Twentieth day
of July, in the year of our Lord One thousand eight hundred and
fifty-two