| 0.167
9 | 11.740 | 2.329 | 0.179
10 | 12.301 | 2.440 | 0.188
11 | 12.813 | 2.542 | 0.195
12 | 13.278 | 2.634 | 0.202
13 | 13.706 | 2.719 | 0.209
14 | 14.102 | 2.798 | 0.215
15 | 14.471 | 2.871 | 0.223
_______________|_________________|__________________|____________________

Objections to water injection are as follows:

(1) Impurities in the water, which, through both mechanical and chemical
action, destroy exposed metallic surfaces.

(2) Wear of cylinder, piston and other parts, due directly to the fact
that water is a bad lubricant, and as the density of water is greater
than that of oil, the latter floats on the water and has no chance to
lubricate the moving parts.

(3) Wet air arising from insufficient quantity of water and from
inefficient means of ejection.

(4) Mechanical complications connected with the water pump, and the
difficulties in the way of proportioning the volume of water and its
temperature to the volume, temperature and pressure of the air.

(5) Loss of power required to overcome the inertia of the water.

(6) Limitations to the speed of the compressor, because of the liability
to break the cylinder head joint by water confined in the clearance
spaces.

(7) Absorption of air by water.

Before the introduction of condensing air receivers, wet air resulting
in freezing was considered the most serious obstacle to water injection;
but this difficulty no longer exists, as experience has conclusively
demonstrated that a large part of the moisture in compressed air may be
abstracted in the air receiver. Even in the so-called dry compressors a
great deal of moisture is carried over with the compressed air, because
the atmosphere is never free from moisture. This subject will be
referred to more fully when treating of the transmission of compressed
air.

By far the most serious obstacle to water injection, and that which
condemns the wet compressor, is the influence of the injected water upon
the air cylinder and parts. Even when pure water is used, the cylinders
wear to such an extent as to produce leakage and to require reboring.
The limitation to the speed of a compressor is also an important
o