IMPROVEMENTS IN THE TREATMENT OF GAS TO BE USED FOR ILLUMINATING PURPOSES
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Thomas Sugg and Frank
William Clark at the Office of the Commissioners of Patents on the 11th
December 1879.
WILLIAM THOMAS SUGG, of Vincent Street, in the City of Westminster, and
FRANK WILLIAM CLARK, of Pembury Road, Lower Clapton, in the County of
Middlesex. IMPROVEMENTS IN THE TREATMENT OF GAS TO BE USED FOR
ILLUMINATING PURPOSES."
"
These improvements relate to the treatment of coal gases of low illuminating
power. Such gases usually contain a large percentage of hydrogen and marsh
gases with small quantities of carbonic oxide and hydro-carbons. The illuminating
power of such gases, as determined by the rules and regulations laid down by the
gas referees of London and elsewhere, varies from 10 to 17 spermaceti candles for
5 cubic feet of gas consumed. The gases are sufficiently stable to maintain at
ordinary temperatures sufficient illuminating power for general purposes, but when
compressed into cylinders at a pressure of from 60 to 70 lbs. to the inch, or when
exposed to cold or freezing temperature, or when conveyed in pipes passing from a
warm to a cold atmosphere of 40° Fahrenheit, or lower, the loss of illuminating
power is very great.
In such cases it frequently happens a white crystallising substance is deposited
in the cylinders or pipes; this substance, which is called naptholine, is found to be
largely composed of carbon, an important element in the illuminating value of the
gas.
The removal of this deposit from the mains and sewers is an expensive operation,
and the necessity for making up the illuminating value of the gas by the use of
cannel or other rich gaseous material causes great loss to the gas companies.
Now the object of the present Invention is to prevent the formation of the
naptholine, and also to supplement and fix the illuminant hydrocarbons in these
gases.
This we effect by adding to the gas (consisting as before said for the most part
of hydrogen, marsh gas, and carbonic oxide) hydrocarbon vapour, which possesses
the property of preventing the formation of the naptholine crystals by holding the
naptholine in solution. It also supplements the hydrocarbon already contained in
he gases and thereby greatly increases their illuminating power.

page_text: The mode in which wo propose to treat the gas to obtain this result is to pass
the poor coal gas after purification, or before any deposit of the naptholine takes
place, over the surface of a liquid hydro-carbon (such as light petroleum oil or
spirit distilled from coal tar, and having a specific gravity of about 600 at the
mean temperature of the air) contained in suitable vessel enclosed in a jacket and
heated to about 60 or 70 degrees by means of hot water. The gas in its passage
over the hydrocarbon takes up the vapour which is given off, and it is then con-
ducted by suitable pipes to a retort and heated to about 900 degrees. After
heating the gas is drawn off by a pump, and either passed to the gas holder or
direct into the mains for the purpose of enriching the gas therein, or is compressed
in any suitable manner into cylinders for use.
The object of thus heating the combined gases in the retort is to fix the
hydro-carbons in the gas and prevent their condensation through changes in the
temperature.
The gas so treated is capable of being subjected to very low temperatures, and
also to compression of from 70 to 80 lbs. per square inch without any practical
loss of its illuminating power.
An obvious inodification in the process of enriching poor gas according to our
Invention would be to conbine with the poor gas a gas rich in carbon before any
deposition of napthaline crystals takes place, and then to submit the combined
gases to heat in a retort as above mentioned.