B. - High-duty Apparatus. -
2. Blast-Furnace Blowing-Engines.-
(b) Horizontal Machines. Fig. 134 represents the blowing-engine at Georgs-Marien Hutte near Osnabuck. The steam-piston has two rods, one attached to the connecting-rod of the crank-shaft and fly-wheel, the other communicating with the air-pump piston. The principal dimensions, etc., are as follows: Absolute air-pressure, 1. 33 atmosphere; volume of air furnished at this pressure, 15,421 cubic feet. Motor: Diameter of steam-piston, 4 feet 4 inches; stroke, 85 inches, cut-off at 2/3 stroke. Diameter of fly-wheel, 30 feet 4 inches. Weight, 28 tons. Normal steam pressure, 4.5 atmospheres. Air-cylinder: Diameter of piston, 9 feet; stroke, 85 inches; useful volume of cylinder, 487 cubic feet; revolutions per minute, 21 ; theoretic volume generated per minute, 20,516 cubic feet.
As will be seen from Fig. 135, the air-valves are disposed on
the cylinder-heads. The inlet-valves, seven in number, are placed
in three vertical lines in the upper half of the heads, and are
of iron, with leather packing. Their mode of support by articulated
rods is clearly shown. The total opening is .19 the piston-surface.
The delivery-valves, 16 in number, are placed in six vertical
lines, and are formed of leaves ru her fixed at one side. Their
total opening is .156 that of the piston-surface. The piston is
hollowed.