IMPROVEMENTS IN THE MANUFACTURE OF GAS
Year: 1857

page_text: LETTERS PATENT to James Wright, of 10, Alfred Place, Newington
Causeway, Southwark, County of Surrey, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GAS."
Sealed the 12th January 1858, and dated the 16th July 1857.
PROVISIONAL SPECIFICATION left by the said James Wright at the
Office of the Commissioners of Patents, with his Petition, on the
16th July 1857.
I, JAMES WRIGHT, of 10, Alfred Place, Newington Causeway, Southwark,
County of Surrey, Civil Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF GAS," to be as
follows:-
In placing an inuer lid or door to each retort so as to form a partition
between the mouth of the retort proper and the mouthpiece attached to the
retort from which the ascension pipe branches; this door may be of iron,
brick, or tile, properly made, and having an aperture near the top, where it
is prolonged in a tubular form inwards, or a tube may be inserted into this
aperture. This passage may be filled with wire or other non-destructible
matter so as to form interstices throughout, or it may have a number of small
pipes or tubes open at both ends throughout its length, or a series of
reticulated plates may be fixed in it so as to increase the internal surface.
The advantages supposed to flow from this arrangement are, an increase in
the quantity of gas, the formation of less tar, diminished pressure on the

page_text: retorts, prevention of the formation of naphtaline, and all stoppages in the
ascension pipes.
I further propose to improve the form and action of the hydraulic main
by fixing or casting division plates so as to separate the mouth of each dip
pipe from the others, and so that easy access may be had to the interior of
each division. I form an aperture to each in the cover of the main, having
a lid or valve to it; I propose also to attach an equilibrium reservoir to the
throttle valve of the engine used for working the exhauster so as more equally
to regulate the pressure on the retorts. In order to obtain water free from
acids for the scrubbers and washers I make use of the waste steam from the
engine and pass it through them.
When napthaline is formed in preparing the gas, I propose to purify the
latter and separate the naphtaline from it by passing the gas through a vessel
containing oil, or oil and water, or the thin watery liquor which comes off
first from the still in the distillation of tar or resin; the napthaline will bo
dissolved in these, and may be afterwards separated and the oil or other liquid
used for the same purpose again. When I use the oil purifier, I prefer to
pass the gas through it before the sulphur and sulphuretted hydrogen have
been removed from the former. I make use of the oil and other mentioned
fluids for dissolving and removing napthaline when deposited anywhere in s
the purifiers, mains, services, or about the works.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Wright in the Great Seal Patent Office on the
16th January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
WRIGHT, of 10, Alfred Place, Newington Causeway, Southwark, County of
Surrey, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of July, in the year of our Lord Onc
thousand eight hundred and fifty-seven, in the twenty-first year of Her reign
did, for Herself, Her heirs and successors, give and grant unto me, the
said James Wright, Her special licence that I, the said James Wright, my
executors, administrators, and assigns, or such others as I, the said James
Wright, 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 s
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 MANU-
FACTURE OF Gas," upon the condition (amongst others) that I, the said James
Wright, 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 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 Wright, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say:-
The first part of my Invention applies to an improved means and arrange-
ment for distilling the coal in the retort, the object of which is to diminish
or absolutely prevent the formation of tar, and to increase the quantity of the
gas obtained. I effect this in the following manner :-First, in retorts whero
the charge of coals is put in at one end, and the gas escapes at the same end,
the opposite end being closed. In this case I propose, in addition to the
usual lid or door placed over the front of the mouthpiece, to insert or fix
an inner door to each retort, so as to form a partition between the actual
mouth of the retort and the mouthpiece from which the ascension pipe
branches, that is to say, the said door or partition must always be placed so
as to separate the mouth of the ascension pipe from all communication with
the interior of the retort. By ascension pipes I mean the pipes or tubes useḍ
for conveying the gas from the retorts to the hydraulic main. This door may
be of iron, or brick, or tile, properly made so as to fit accurately the retort
mouth, or it may be luted; near the top of the said door in an aperture where
it is prolonged inwards for a short space, varying in length from six to twenty.
inches, or even a little more; the diameter being about one-fourth (or a
little more or less) of the diameter of the door. Instead of prolonging the
door inwards, a pipe or tube open at both ends may be inserted in the said
aperture of the door. The aperture or part of the door projected inwards
or the tube, where inserted in the opening, is to bo filled with iron wire
thrust losely into it, or any other open or porus non-destructible body; or
a series of small tubes open at both ends may be inserted in the tube; or a
series of reticulated or pierced plates may be substituted; or, lastly, and
preferably woven asbestos in layers or even in a fibrous state may be put
in the said tube The object of this arrangement being to cause all the

page_text: matters passing from the retorts to the ascension pipes to circulate through
the aperture, which by means of the matter inserted has a large surface at a
high temperature which thus decomposes it thoroughly. When the retorts
are charged at one end and discharge the gaseous products at the other, the
before-described door is fixed at the same end where the gas leaves the retort,
and in a similar manner isolates the ascension pipe from the interior of the
retort, the aperture with the heated material inserted constituting the passage
through which the gaseous matter passes to the ascension pipes. When the
coal is charged, and the gas discharged from the same end in the retort, tho
above-described door is inserted always after each charge; in the other case
this is unnecessary, for after being inserted it need only be removed to clean out,
repair, or renew. In addition to the before-described arrangement, I propose
also to introduce, by means of a tube bent twice upon itself, and one extremity
passing into the retort, small quantities of the ammonaical liquor which has
been previously produced; the amount of liquor introduced should be about
the quantity produced from an equal and similar charge of coal to that in the
retort. The liquor on passing into the retort is decomposed, the hydrogen
it contains taking up the superabundant carbon in the retort. When retorts
are used having the charge of coals taken in at one end, and the gas
discharged at the other, the ammonaical liquor is introduced at the end where
the coal is charged. I further propose to improve the action of the hydraulic
main by casting or fixing division plates so as to form compartments to
seperate the mouth of each dip pipe from the other; and also to attach a lid
to each compartment in order that easy access may be had. I propose also
to connect an equilibrium reservoir to the throttle valve of the engine used
for working the exhauster so as to regulate more equally the back pressure
on the retorts; this reservoir must be placed so as to receive and pass
through it all the gas from the retorts immediately after leaving the condensor
and before passing into the purifiers.
I propose also the following methods of purifying the gas; the object being
to remove the carbonic acid, the sulphur, and sulphur compounds. To a
solution of sulphate of iron I add a solution of carbonate of potash, using the
latter as long as any precipitate is formed; the precipitate is of a gray color. I
then saturate with it a quantity of sawdust or other similar matter which will
produce a large surface; through this I pass the gas which has been purified
by the ordinary methods; this changes the color of the sawdust red, and
the gas loses its carbonic acid. Having now prepared a stock of this saw-
dust after the above-described manner, I place it in the purifiers and pass the
crude gas through it, and I find this has the effect of removing the sulphur.

page_text: and sulphur compounds from it; the sawdust may be used until it becomes
black, when the purifiers may be re-charged.
Having now described my Invention, and the mode of carrying it into
effect, that which I claim and wish secured by the before in part recited
Letters Patent, are,―
First, the application of a door to the retort as described, so as to isolate
the ascension pipe from the interior of the retort, the only passage being
through the internal projecting tube filled with non-destructible matter so
as to increase the heating surface and hence decompose all matters passing
through it.
Second, the application of the ammonaical liquor for the purpose describd.
Third, the improved construction of hydraulic main, as described.
Fourth, the application of an equilibrium gasholder as described, placed
between the condensor and the exhauster and purifier.
Fifth, the method of purification as described.
In witness whereof, I, the said James Wright, have hereunto set my
hand and seal, this Sixteenth day of January, in the year of our Lord
One thousand eight hundred and fifty-eight.