Counterpoise weights are also attached to such
machines; the steam is allowed to follow full stroke, steam cylinders
are placed at awkward angles to the air-compressing cylinders and the
motion conveyed through yokes, toggles, levers; and many joints and
other devices are used, many of which are entire failures, while some
are used with questionable engineering skill and very poor results."
[Illustration: FIG. 7.]
Fig. 7 illustrates the theory of Duplex Air Compressors. The hydraulic
piston or plunger compressor is largely used in Germany and elsewhere on
the Continent of Europe, but the duplex may be said to be the standard
type of European compressor at the present time. It is also largely used
in this country. Fig. 7 shows the four cylinders of a duplex compressor
in two positions of the stroke. It will be observed that each steam
cylinder has an air cylinder connected directly to the tail rod of its
piston, so that it is a direct-acting machine, except in that the
strains are transmitted through a single fly wheel, which is attached to
a crank shaft connecting the engines. In other words, a duplex air
compressor would be identical with a duplex steam engine were it not for
the fact that air cylinders are connected to the steam piston rods.
Pages:
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62