Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1907-05-12

fame then was not comparable in uumin-
ating power 20 the gas today.
Making Coni Gas.
Coal gas Is made from particular kind
OF bituminous coal that Is known In the
trade as gas coal II yields from as cubic
feet to 5 cubic feet Of gas to the pound. and
most Of the best grades come from tho
Pittsburg fields. West Virginia, Tennessee.
Indian Territory and Colorado.
The machinery and processes for making
coal gas are rather intricate. but they are
entirely automatic, at least where the re-
torts are stocked by machinery. and they
rarely get out Of order. The gas Is gem
Grated In fire clay retorts which are usually
set up in sections or benches Of six.
Undef these benches are glowing fires OF
coke. which often are not allowed to die
down in years and which heat the retorts
to a temperature Of about 1900 degrees Fab
renheit Into these white hot retorts is
projected the gas coal.
In some Of the plants OF the Consolidated
company this work is done by machine
invented by William II. Bradley, the vet
eran chief engineer Of the company. In
others the shovelling Is done by hand.
Each retort holds about 300 pounds and as
II must be filled quickly It is a job requir-
ing great deal of alertness and physical
strength
AS each retort is filled an iron door is
closed over the mouth and locked with
gas tight joints. AS the coal is being re-
duced to coke by the great heat the gas
loaded with tar and other byproducts as
lends through a bel-shaped funnel which is
fastened on the end of a standpipe leading
to the hydraulic U-shaped main which is
placed over the long row of retorts.
On the top Of the standpipe there is a
bridge or arch pipe from which hangs a
dip pipe which is bolted TO the hydraulic.
Passing down into this main the gas dips
below the ammoniacal liquid with which
the hydraulic main is partly filled and by
being thus sealed the gas is prevented from
returning to the retorts when they are
opened.
washing the GINS.
But this is only one step in the process
through which Illuminating coal gas must
go before it is ready for the consumers.
1t is drawn from the hydraulic main by an
exhauster, which is operated by a rotary
steam pump. to relieve the back pressure
on the retorts, thrown by the holders and
the friction Of gas as 1t passes through
/ the apparatus
On the next stage of the intricate ma
cbinery the gas goes to the tar extractor
and has its face partly washed-that is, 1t
| is/releved Of all the heavy tar that was
not dropped in the hydraulic main. BY
! this time the gas has fallen in temperature
TO about 100 degrees, but 1t is further cooled
to 80 or 60 degrees in the condenser.
This part of the apparatus resembles a
tubular boiler. The water passes through
! the tubes in one direction, while the gas
passes outside in the opposite direction.
Having been sufficiently cooled the gas
goes to the scrubber for final bath.
| As near as possible all of the ammonia
gas is washed out and then the product is
| sent along to the purifiers to get whatever
sulphur there may be out of it. These
purifiers are cast iron boxes with covers
| sealed in water to prevent the escape Of
! gas. They are filed in layers with either
slack lime or oxide of iron and through
| these layers the product passes, leaving
the sulphur behind
| The next journey of the gas, which is
now ready for consumption is to the sta
| ton meters, huge recording instruments
! showing precisely how much gas Is passing
! to the holders at any minute of the day
1t is from these figures that the Consoli-
dated company gets the gross total of gas
made.
The net total of the illuminant sold is
ascertained from the total of individual
| meters throughout the city, and the differ
ence between the two. making due allow
ance for condensation in the street mains,
constitute the leakage. II the readers ever
notice men drawing very black and highly
odorous water from a tap in the streets
| they will know that the sweet scented
mess was once Illuminating gas which has
| condensed in the mains.
Storing the Gas.
But to go back to the journey of the
manufactured product. From the station
meters the gas is sent to the holders. the
exhauster still getting in its fine work and
urging the illuminant along the way that
leads to gas bills and many swear words.
This holder proposition is one of the most
puzzling Of all to the lay mind.
How does the gas get in and how does 1t
| get out2 If II is the weight of the holder
that forces the gas into the mains. why
does not the same pressure drive back the
gas to the retorts. blowing on the covers
and making a merry time generality Well,
| It is right here that the exhauster is on
the job again.
Ever since the gas left the retorts in
crude form this machine has been drawing
It away and forcing 1t along all through
the apparatus. The same force dives It
| through the intake OF the holueT anu pre-
vents IT from backing up when the gas Is
pouring into the mains for distribution.
The giant holders in New York are tele-
scopic, as they are in all other big cities.
The capacity at present OF the largest Is
often 100000 cubic feet but there is one
in England which holds 100000 cubic feet,
Gas is admitted to these holders and
drawn from them by pipes which go down
under the foundations and up on the inside
20 a point above the water level. The
holders are seated in water which seals
them and makes impossible the escape OF
gas from the bottom.
When gas is admitted to a holder that is
empty Il nils first the space between the
closed ton and the water in the tank. As
} Il continues to enter the pressure increases
until It is sufhcient to overcome the weight
! of the holder, which then begins to rise.
, When the supply coming in gets smaller
than the supply going out the holder begins
to go down again The lifts which make
the holders telescope are so arranged that
they rest I'm cups which are filled with suf-
icient water TO seal them Just as the main
body OF the holder is sealed.
From the holders the gas passes to the
valve house. where the pressure Is regu-
lated on the mains. In some plants the