Air compressors and blowers for the operation of industrial furnaces

              AIR COMPRESSORS AND BLOWERS
FOR THE OPERATION OF
INDUSTRIAL FURNACES
SELECTION OF
BLOWER
There is no one air pressure
or type of blower that can be
properly employed for all fur­nace
operations. The pressure
to be carried is determined by
the design of the furnace and
the nature of the work. In
some cases it is desirable to
maintain air pressure below 8
oz. per square inch, but in others
it is necessary to employ a higher
pressure to properly burn the
fuel in the space available for
the operation. Operating con­ditions
govern the pressure of
the air, and the type of blower
should be adapted to these con­ditions.
In order to conserve
power the general rule is to maintain as low a
pressure as is permitted by the operating condi­tions.
Except under very unusual circumstances,
air pressures beyond the limits of the blowers
Fig. 2. Typical centrifugal
air per minute at
Fig. 1. Centrifugal air compressor, bottom intake, top discharge, or
m a d e vice-versa
compressor installation. Each machine delivers 3300 cu. ft. of free
IV2 lb. pressure. Machines are bottom intake, top discharge
herein illustrated are unnecessary. Higher pres­sures
are also open to the objection that high
pressure machines involve a high cost of instal­lation
and operation. Their use should be avoided
whenever possible.
The accompanying cuts illustrate some of the
different types of blowers that are successfully em­ployed
in connection with furnaces operated with
oil or gas fuel.
CENTRIFUGAL COMPRESSORS
Figs. 1, 2 and 3 illustrate a type of centrifugal
air compressor very well adapted to the require­ments
of a majority of furnace installations using
oil or gas fuel. This type of machine makes a very
simple and compact installation. The design is
such that a uniform pressure is maintained at all
times, with a power input in proportion to the air
volume delivered, also making for economical oper­ation
when all of the air is not being utilized. They
may also be subjected to considerable sustained
overloads without injury. These machines are
furnished only direct connected to alternating or
direct current motors, or to turbine or steam drive.
DECEMBER, 1918 No. 38