MANUFACTURE OF COAL GAS 
Condenser 
This is fitted with tubes surrounded by tyater and arranged so gas 
goes through the tubes and|jb||water absorbs the heat in the passing gas. 
Scrubber 
This consists wgiji cylindrical tower containing a number of wooden 
trays having slats running crosswise in checker board fashion and where 
a water spray at the top of the tower keeps tide slats wet and washes the 
impurities down over the wet surfaces. 
Purifier 
This is a large box containing two trays pf oxide of iron where the 
sulphur impurities in the gas are absorbed by the iron and removed from 
the gas. The top or lid of the purifier can be raised, as shown by the 
dotted lines "above, for changing the oxide. A pile of oxide undergoing 
airing is shown on.ithc floor underneath the purifier. 
Gas Holder 
This is merely an open top circular tank filled with water in which a 
smaller open bottom tank is placed so that the gas can fill the space be- 
tween the water and the top of the smaller inside tank called a “lift.” 
When the gas volume is increased, the lift risds, when the gas decreases, 
the lift descends. The weight of the lift produces pressure on the gas. 
Station Meter 
This is merely a large meter which measures the volume of gas manu- 
factured as it goes to the storage holder. 
Coal Gas 
This is made by heating bituminous coal about 4 hours in extremely 
heated, air tight, retorts. Gas is driven off and a residue called “gas 
house coke” is left in each retort. This is withdrawn and a fresh charge 
of coal added. The gas evolved is withdrawn by the exhauster and pushed 
to the condenser where the tar and oil are precipitated and drained out 
at the bottom. The gas then goes to the scrubber where the ammonia is 
washed out and the resulting ammonia solution removed at the bottom. 
The gas now goes to the purifier where the sulphur is removed and then 
passes through the station meter and into the storage holder. 
Water Gas 
If water in the form of steam is brought into intimate contact with 
red hot carbon, hydrogen and carbon monoxide will be made. This is the - 
basic feature of the water gas process. The steam will soon chill the 
carbon and the carbon must be heated again by shutting off the steam and 
blowing with air, making the process intermittent. 
Carburetted 1 — That is, Oil Enriched — Water Gas 
In order to increase the heating value of the blue gas and sometimes 
give it luminous qualities — although this is obsolete — oil under pressure 
is sprayed down over the hot brick work in the carburetter. The hot 
checker brick work in the carburetter and super-heater converts the oil 
in|o a fixed gas, this is known as carbureting and the gas is called “car- 
buretted water gas.” 
The gas then enters the bottom of the scrubber by bubbling through 
a water seal which prevents the return flow of the gas. The scrubber 
washes the gas clean from its tar and carbon particles. The gas then goes 
to the condenser where the tar vapor carried is condensed and then drained 
out at the bottom. The gas then goes to the relief holder which equalizes 
the delivery beyond on account of the intermittent operation of the process. 
One complete cycle of getting the fuel bed ready and making a “run-of-gas” 
takes about 7 minutes. 
The gas is pulled out of the relief holder by the exhauster, passes 
through the purifier which removes the sulphur and then through the 
station meter to the storage holder. 
Storage 
Gas is made at practically a uniform rate for 24 hours. The rate 
of use of the gas varies largely during different hours of the day. The 
function of the holder is to equalize the input and output. ' 
Governor 
As the gas comes into the holder and raises the telescoping sections, 
the weight of the metal that the gas must support increases and this 
increases the pressure on the gas, therefore, the higher the holder is 
raised the greater must be the resulting gas pressure. 
To furnish a more uniform pressure to the consumer, the gas now 
I goes through a governor which is merely a mechanical device where a 
1 variable intake pressure is changed to a practically uniform pressure in 
I the. distributing mains. 
; Delivery of Gas 
From the governor the gas goes into the street mains, through the 
I curb cock, service line, house meter and to the consumer’s appliance. 
Like the realization of an alchemist’s dream, we have a serviceable 
j transmutation of a baser substance into one of greater value in the unno- 
I ticed transmutation of crude, dirty, inert coal into energetic gas which 
j can then be transmitted to a consumer far away where the turning of a 
I gas cock makes it instantaneously available. 
.-..^Official Spelling of the American Gas Association. 
39277—23. 
MODEL SHOWING HOW COAL IS TRANSMUTED INTO GAS AND DELIVERED TO THE HOME 
