Dew Point Verification; Maintenance; Desiccant Dusting - Sigma HRD Serie Manual De Instrucciones

responds to the desired purge rate as indicated
on the purge flow calibration graph. Turn the set
screw counterclockwise to increase the purge
flow; clockwise to decrease the purge flow.
• Remove the allen wrench.
• Replace the petcock wing.
CAUTION
Inlet air temperatures higher than 100°F will
reduce the design dew point of the dryer.
The dryer can now be put into service. No further ad-
justments are necessary unless there are changes in op-
erating conditions. Within limits, changes in inlet flow
rate can be compensated for by adjusting the purge ad-
justment valve (repeat Steps 1 through 5 above).

Dew Point Verification

After the dryer has operated for a minimum of five
days, check the dew point of the outlet air with a pres-
sure dew point instrument. Follow the directions for
the instrument used.
Model 30
HRD56 / HRD56EM 21
HRD100 / HRD100EM 39
HRD160 / HRD160EM 62
HRD200 / HRD200EM 78
HRD275 / HRD275EM 107
HRD350 / HRD350EM 136
HRD475 / HRD475EM 185
HRD600 / HRD600EM 234
HRD800 / HRD800EM 312
HRD1000 / HRD1000EM 390
HRD1200 / HRD1200EM 468
HRD1450 / HRD1450EM 565
HRD1710 / HRD1710EM 666
HRD2010 / HRD2010EM 783
HRD2250 / HRD2250EM 877
HRD2600 / HRD2600EM 1013
HRD3250 / HRD3250EM 1267
Average Purge Rate
38.5
(% inlet air)
1
Maximum inlet air pressure, 150 psig. Higher pressures available as an option on some models; consult your local distributor
2
Based on 100°F inlet air temperature and –40°F pressure dew point. Maximum recommended inlet temperature, 120°F. For capacity at inlet temperature higher than
100°F, consult your local distributor.
HRD and HRD-EM Series (Bulletin 378)
Table 3
INLET AIRFLOW AT VARIOUS INLET AIR PRESSURES
40 50 60
Average Inlet Airflow (scfm)
26 31 36
48 56 65
76 90 104
95 113 130
131 155 179
167 197 228
227 268 309
286 338 391
382 451 521
477 564 651
572 677 782
691 818 944
815 965 1114
959 1134 1309
1073 1269 1465
1240 1467 1693
1550 1833 2117
31.5 26.6 23.0
Use only metallic tubing when checking dew point
since plastics, rubber and similar materials absorb
moisture from the ambient air and give false readings.

MAINTENANCE

Desiccant Dusting

The dryer vessels for models 56 through 600 scfm are
shipped filled with desiccant. Some dusting will occur
from movement of the desiccant during shipping. Dust
carried by the purge air eventually plugs the mufflers
preventing complete depressurization of the offstream
vessel and proper airflow switching. When this occurs,
the muffler cores must be replaced. Replace muffler
cores when the pressure gauge on the offstream vessel
indicates a pressure higher than 0 psig. Replacement
interval depends on dryer usage and the quantity of
desiccant dust formed.
Inlet Air Pressure (psig)
70 80 90
2
41 45 50
74 83 91
118 132 146
148 165 183
203 227 251
258 289 319
351 392 434
443 495 548
591 661 730
738 826 913
886 991 1095
1071 1197 1324
1263 1412 1561
1484 1660 1835
1662 1858 2054
1920 2147 2373
2400 2683 2967
20.3 18.2 16.4
1
100 110 125
55 60 67
100 109 122
160 174 195
200 217 244
275 299 335
350 381 426
475 516 579
600 652 731
800 870 974
1000 1087 1218
1200 1305 1462
1450 1576 1766
1710 1859 2083
2010 2185 2448
2250 2446 2740
2600 2827 3167
3250 3533 3958
15.0 13.8 12.3
150
79
144
230
287
395
503
682
862
1149
1436
1723
2082
2455
2886
3231
3733
4667
10.4
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