MAC AVR, Installation, Operation & Maintenance Manual

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Publication: MAN3002G MAC Equipment, Inc. 9
Compressed Air Dryers:
1. In applications where the compressed air piping is indoors or where
the installation is in a warm or moderate climate and a compressed
air dew point of 35
 to 50  F is sufficient to prevent moisture
condensation in the pipe lines, the following types of equipment are
available: the deliquescent desiccant non-regenerative type for
small to medium volumes of air, and the mechanical refrigeration
type with or without an after warmer for large volumes of air.
2. In applications where the compressed air piping is outdoors or
where the installation is in a cold climate and a compressed air dew
point of-10
 F to
-40
 F is required to prevent moisture condensation
in the pipe lines, the following types of equipment are available: the
in-line desiccant type with manual regeneration for small volumes of
air; the desiccant type with heatless automatic regeneration for
medium volumes of air; and the dual tower desiccant type with
automatic regeneration by heat for large volumes of air.
Oil Free Compressed Air
1. Much of the above mentioned equipment used to remove liquid
moisture can also be used to remove condensed oil and oil mist.
2. For installation where condensed oil and oil mist are the major
problems, special in-line filters are available that use desiccant
absorptive elements or packed beds of an oil absorbing granular
organic polymer.
Compressed Air Piping
The compressed air header on the AVR filter should be connected with at
least 1" diameter pipe. The air piping for multiple units should be sized in
relation to air consumption. A drain should be installed at the lowest
point in this piping.
The following table is a guideline for selecting the proper pipe size and is
based on 80-100 PSIG air.
Recommended Piping Sizes
Total Free Air Consumption
Pipe Length Up to 50 SCFM 50 - 100 SCFM
up to 100 ft. 1" dia. 1-1/4" dia.
100 to 500 ft. 1-1/4" dia. 1-1/2" dia.
500 to 1000 ft. 1-1/2" dia. 2" dia.
Air Volume Requirements
The AVR filter typically requires the following SCFM at 80 to 100 PSIG:
Model Number SCFM Required
AVR 7 3.3
AVR 14 4.7
AVR 21 5.4
AVR 32 6.5
AVR 39 7.5
AVR 52 9.1
AVR 62 10.6
AVR 80 13.2
SYSTEM START-UP AND OPERATION
The following inspection should be made before the initial start-up of the
system and for normal operation thereafter.
1. Check filter bags for proper installation
.
2. Check all air and electrical connections for proper routing. The
compressed air supply should be connected to the 3/4" FNPT port
on the air header. Turn on the compressed air supply to the header.
Pressure should be 80-100 PSIG.
3. Check out and start up any auxiliary equipment such as an airlock,
screw conveyor, or fan and see that any control interlocks are
operating properly.
4. Energize the timer panel. Listen for the sound of pulsing of the
solenoids and diaphragm valves to verify that they are operating. (If
the filter is equipped with a photohelic gauge, decrease the high
pressure setting on the gauge to zero to activate the timer. Restore
the pressure setting to its normal value after pulsing is verified.)
5. When all components are operating correctly, start the dust laden air
through the filter and observe the differential pressure at the gauge.
(The differential pressure is the air resistance across the filter bags).
The pressure should stabilize between
½" and 4" H
2
O. Never allow
pressure drop across the filter to exceed 17" H
2
O; this may damage
the bag cages.
6. If the pressure continues to rise over 5" H
2
O and does not stabilize,
shut off flow of dust laden air and decrease the "time-off" setting by
one-half the initial setting. This will result in a more frequent
cleaning cycle. Restart the system.
7. When collector stabilizes between
½" and 4" H
2
O, you may then
"fine tune" for least air consumption by gradually increasing "time-
off" setting. Do not exceed 4" to 5" H
2
O on clean bags because as
the filter bags become "dirty" the differential pressure will increase.
Note: If a photohelic switch/gauge is in use, do not change the
"time-off" setting. (With the photohelic gauge the cleaning cycle is
initiated by pressure differential, not time.) Set the pressure set
points on the photohelic switch/gauge at 1.5" H
2
O for the low
pressure setting and 4" H
2
O for the high pressure setting. If the unit
pulses continually, decrease both pressure set points to lower the
differential pressure and initiate the cleaning cycle sooner.
MAINTENANCE
It is recommended that one individual be assigned to monitor the
operation of the dust-collection system. The individual assigned should
have maintenance manuals and manufacturer
’ s documentation for all
components readily available. He(she) should be thoroughly familiar with
the manuals so as to be able to pinpoint trouble should it occur.
The individual responsible for the system should follow a regular
schedule of inspection and maintenance. The exact schedule will
depend on the particular system and the number of hours it operates per
day or week. A typical maintenance schedule is shown below.
Disconnect and properly lockout-tagout the
electrical and compressed air service before
performing any maintenance or service
procedures on the filter.
Disconnect and properly lockout-tagout the
electrical and compressed air service before
performing any inspection procedures.