IMPROVEMENTS IN PROCESSES FOR PURIFYING ILLU- MINATING GAS AND APPARATUS THEREFOR
Year: 1873

page_text: LETTERS PATENT to William Henry St. John; of New York, in the
County and State of New York, United States of North America, -
for the Invention of "IMPROVEMENTS IN PROCESSES FOR PURIFYING ILLU-
MINATING GAS AND APPARATUS THEREFOR.
COMPLETE SPECIFICATION filed by the said William Henry St. John
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 24th July 1873, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY ST. JOHN, of New York, in the County and State of New York,
United States of North America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN PROCESSES FOR PURIFYING ILLUMINATING GAS, AND APPARATUS THEREFOR," and
have petitioned Her Majesty to grant unto me, my executors, adminis-
trators, and assigns, Her Royal Letters Patent for the same, and have
made solemn Declaration that I am the true and first Inventor thereof.

page_text: brought over with the gas may be conducted to the chamber or vessel B
by means of the pipe D placed at a slight inclination from the horizontal.
The chamber B is divided horizontally by a partition b, as represented in
Figure 2, in which partition are fixed a number of downwardly extending
3 dip tubes c, as also indicated in Figure 3. The gas space *f of the
main A communicates with the upper part of the chamber B by means
of the pipe C, in which intermediate between the main and the chamber
is the usual exhauster E operated in any appropriate manner. That
end of the pipe D which enters the main A is at such distance from
the bottom of the latter as to ensure the sealing of the lower extremities
of the dip pipes a. The opposite end of the pipe D enters the chamber B
below the partition b, and is extended downward nearly to the bottom c*.
Provided to the lower part of the chamber B is a valve F, as shown in
Figure 2. This valve comprises an upright shell or chest d, through
the bottom of which works water-tight the hollow piston e, open at
bottom but closed at top, formed with the orifice a¹, and capable of
vertical adjustment by the screw f working through a threaded nut in
the top of the piston, and itself turned by an external hand wheel 6'.
By adjusting the height of the orifice a¹ with reference to the bottom c¹
of the chamber, the liquid contents of the latter may be retained at any
desired level to seal to any requisite degree the lower ends of the dip
tubes. When such adjustment is not desired the chamber may be
furnished with a simple syphon, as shown at J, in Figure 1. That
portion of the chamber B below the partition, but above the highest at
which the liquid just mentioned is to be retained extends a gas conduit G
to a tank I, from which a pipe G* extends to a gasometer, or, should
there be an exceptional case where such may be desired, to a purifier of
ordinary construction. This tank I is furnished with a syhpon y, to
permit the outflow automatically of any liquid which may accumulate in
the tank beyond a given depth.
The retorts being put in operation, and the exhauster E being put in
motion, the gas from the retorts passes through the dip pipes a to the
main A, and thence to the upper compartment of the chamber B, the
same action of the exhauster that insures the passage of the gas from
the retorts forcing it into the aforesaid compartment with a pressure
sufficient to force it down through the dip tubes c, sealed by dipping in
the liquid in the lower compartment of the chamber, as indicated in
Figure 2. This liquid comprises that produced or evolved from the coal

page_text: or other gas producing material in the retorts, and which passing from
the retorts in the state of vapor is condensed in the main A. This
liquid consists for the most part of water, and amounts to about ten
gallons per ton of coal distilled, a quantity sufficient to absorb all the
ammonia, sulphurous gases, etc., carried over with the illuminating gas.
to the chamber B. This liquid, as previously specified, passes from the
main to the lower part of the chamber, and is there maintained by means
of the valve F at such height as to seal to any desired extent the lower
ends of the dip tubes c. When the illuminating gas is forced through
the dip tubes into and through the aqueous liquid in the lower part of.
the chamber it is distributed into intimate contact with the said liquid,
and the ammonia, the sulphurous acid, and the carbonic acid arc
absorbed by the liquid, owing to the intense solvent power of water on
these gases. The illuminating gas is therefore freed or purified from
the deleterious ingredients named. Furthermore, the ammonia being
chemically a base unites with the acids named to form ammoniacal
salts, which dissolved in the liquid, are fixed against liability of volatili-
zation during the subsequent passage of gas through the same. As tho
liquid from the main flows into the upper portion of this compartment
of the chamber the surplus lower down is displaced and flows out
through the valve F.
.
The tar deposited with the liquid in the main A is carried with tho
former to the lower compartment of the chamber B, and inasmuch as
the particles of tar are of like character they cohere and sink gradually,
and finally flow out with the displaced liquid through the valve F.
Meanwhile, the tar particles being distributed throughout the liquid, the
gas while being forced through the latter is brought in intimate contact
with the tar particles, and whatever carbonizing effect can exert upon
the gas is given thereto, and its candle power proportionally increased.
As the gas rises from the liquid it passes into the space immediately
below the partition b, and thence through the conduit G to the tank I,
wherein the temperature is such as to condense whatever moisture may
remain in the gas, which done, the gas passes through the outlet
pipe *G to the gasometer, either with or without any intermediate
purifying adjunct.
Having thus fully described my said Invention, and the manner of

page_text: 1st. The process herein described of purifying illuminating gas by
causing it to pass through the liquids derived from the gas producing
material during distillation, the water absorbing the soluble impurities,
and the acids fixing the ammonia absorbed by the water from the gas,
substantially as herein set forth.
2nd. The chamber B constructed with the horizontal partition b
and the dip tubes c, in combination with the pipes C and D and the
main A, substantially as and for the purpose specified.
3rd. The combination with the chamber B, constructed and operating
as set forth, of the tank I, substantially as and for the purpose specified.
4th. The combination with the main A and chamber B, constructed
and operating substantially as set forth, of the exhauster E, arranged to
serve the double purpose of withdrawing the gas from the main and
forcing it into and through the dip tubes of the chamber, substantially
as and for the purpose specified.
5th. The combination with the chamber B, constructed and operating
substantially as described, of an adjustable valve F, whereby the sealing
of the lower ends of the dip tubesc may be regulated, substantially as
herein set forth.
In witness whereof, I, the said William Henry St. John, have here-
unto set my hand and seal, this Ninth day of July, One thousand
eight hundred and seventy-three.
WILLIAM HENRY ST. JOHN. (L.S.)