________
38
________________________________ _________________ ____________
MESSRS. SCHNEIDER AND CO.’S WORKS.
_____ __________ _______________________ ______________
The coal used is a mixture of three qualities, supplied
by neighbouring mines, and containing less than 15 per
cent, of ash. The grates are arranged in groups of
four, united by collecting flues placed above them, and
in which the greater part of the soot is deposited.
Their sizes are :
The average composition of the smoke, taken at the
foot of the chimneys, is as follows :
Length of grate 1.700 m. 5 ft. 7 in.
Width „ 1.000 m. 3 ft. 3 in.
Area „ 1.70 sq. ni. 18.3 sq. ft.
Carbonic acid... ... ... ... ... .. 16.90
Oxygen _______________________________ 1.40
Carbon oxyde ... ... ... ... Q. 10
Free hydrogen ... ... ... ... ... __
Carburet of hydrogen ... ... ... ... __
Nitrogen _______________________________81.60
100.00
Fig. 88. Wrought-iron Chimney of the Siemens-Martin Steel Foundry.
The average composition of the gas, in volume, is as
follows :
Carbonic acid 3.60
Oxygen 0.60
Carbon oxyde 26.60
Free hydrogen 8.80
Carburet of hydrogen 2.60
Nitrogen 57.80
100.00
A series of underground passages leads the gas to the
steel furnaces. In flowing through these, the gas loses a
part of its heat, and reaches tlie furnaces under a relatively
high pressure. The Condensed tar which collects in the
generator chimneys, and the flues, is removed only about
once in twenty months.
Main Casting Pit.—The main casting pit to which
reference has already been made, is provided with two