_of parts of the Imperial Compressor_.
=======+=============================
Number |
of Part| Name of Part
-------+----------------------------
1 | Frame
2 | Main-bearing cap
3 | Main-bearing cap-bushing
4 | Fly-wheel
5 | Fly-wheel key
6 | Fly-wheel key set-screw
7 | Crank-shaft
8 | Crank-disc
9 | Crank-disc key
10 | Crank-pin
11 | Crank-pin cap
12 | Crank-pin cap set-screw
13 | Connecting-rod cap
14 | Connecting-rod cap-bushing
15 | Connecting-rod
16 | Piston
17 | Piston-pin
18 | Piston-pin bushing
19 | Piston-pin set-screw
20 | Piston, inside ring
21 | Piston, outside ring
22 | Adjusting-bolt for piston-pin
| end of connecting-rod
23 | Connecting-rod bolt
24 | Guard-plate
25 | Air-head
26 | Air-head gasket
27 | Air-head studs
28 | Inlet valve and stem
29 | Inlet valve-seat
30 | Inlet valve-spring
31 | Inlet valve-stem head
32 | Inlet valve-stem cotter
33 | Inlet valve-bonnet
34 | Outlet valve
35 | Outlet valve-spring
36 | Outlet valve-bonnet
37 | Water inlet pipe
38 | Water outlet pipe
39 | Air inlet pipe
40 | Air outlet pipe
41 | Unloader
42 | Main-bearing grease-cup
43 | Crank-pin grease-cup
44 | Piston-pin grease-cup
45 | Air-cylinder lubricator
46 | Main-bearing studs
47 | Main-bearing liners
48 | Unloader regulating-cylinder
_The Norwalk standard compressor_ is shown in Figs. 361 and 362, the
latter being a longitudinal section; Fig. 361 is a perspective view;
the two compressors are driven by a single steam cylinder having an
adjustable cut-off. The air valves are operated by a positive crank
motion.
_A view of a Pelton water wheel_ operating a compressor it shown in
Fig. 363. The cut represents a compound air compressor in which the
valves are operated mechanically. The water which drives the wheel
enters through the pipe and nozzle secured in the wheel pit, as
represented.
Fig. 364 exhibits a belted duplex air compressor built by
Allis-Chalmers & Co.
Fig. 365 shows a vertical duplex compressor driven by a belt.
[Illustration: FIG. 369.]
All the latter, as may be seen by the engravings, have the positive
valve motion operated by an eccentric. In selecting an air compressor
the following points need consideration: 1, Number of cubic feet of
free air required per minute; 2, Altitude, _i.e._, the number of feet
above the sea level; 3, Steam pressure and air pressure.
_The use of compressed air for operating mining pumps_, while
having advantages in some cases, _is not to be recommended in all_,
particularly on account of the low efficiency of the plant as a whole.
The loss due to leaks is serious, and the long line of piping with its
numerous joints causes much trouble, delay and expense.
_In Fig. 369 is shown a direct acting steam single air compressor_;
simplicity in its construction is a leading feature and there are few
parts in this pump that are liable to wear.
[Illustration: FIGS. 370 AND 371.]
This apparatus is designed for working pressures up to twenty pounds;
it is intended for use in oil refineries, smelting works, blast
furnaces and in all situations where compressed air of medium pressure
is required. They are variously used for sand blasts, ventilating
purposes, and for pneumatic deliveries.
The steam end and valve motion are the regular Deane pattern, assuring
positive operation. The air cylinder is provided with a water jacket.
[Illustration: FIG. 372.]
_A power wall or post air compressor_ is shown in Figs. 370-372. The
machine is single acting and is recommended where little space is
available, as it can be bolted to the wall or to a post, or on the
under side of the ceiling. The crank shaft and connecting rod are of
cast steel. The bearings are babbitted and adjustable. The piston is of
the trunk form, carrying a pin for the connecting rod, and is of extra
length to act as a guide for the lower end of the connecting rod. The
valves are of the poppet type. These compressors are extensively used
in electric power stations for supplying air for removing dust from
electric machinery, in bicycle shops for inflating pneumatic tires,
maintaining a supply of air in pressure tanks, and for various purposes
where a limited supply of air is needed.
These compressors are of _the “Blake” design_ and the following
particulars will be of interest.