Perma Pure Mini-GASS - Manual (Page 13)

13
Mini-GASS User Manual | Original Instructions
PERMA PURE LLC
Mini-GASS™ User’s Manual
Doc. #212: Revision: 00A
Page 13 of 32
Steam Temperature Control
Steam heated systems are regulated by a thermostatic steam control valve located in the
purge air exhaust stream. This valve is preset at the factory to an appropriate temperature
determined by sample conditions. A typical setpoint temperature is 180° F which is the
approximate temperature of the purge air exhaust indicated by analog thermometer located
in the purge air exhaust stream.
Safety Interlocks
Systems equipped with the SIVS2 interlock option automatically shuts off the sample pump
in the event of low purge airflow or low temperature in the system. To accomplish this, a
differential pressure switch in the purge air inlet senses the flow of purge air and energizes
a relay. This relay then sends power to the contacts of a second relay which will energize
only when temperature set point has been reached. Under normal operating conditions both
safety relays will remain energized (When the system is operating normally, open contacts
will close and remain closed). Alarm relays may be field wired to initiate an external alarm.
See Appendix F for additional information.
Preheating the system
1. Turn on AC power or steam to system.
WARNING!
On AC powered units, temperature control display should light. DO NOT BEGIN SAMPLE
FLOW AT THIS TIME! Check purge air is flowing immediately after turning on AC power or
steam. If, for any reason, there is no purge air or flow is inadequate, turn off AC power or
steam before attempting to locate problem. OPERATING SYSTEM WITH LITTLE OR NO
PURGE AIR CAN CAUSE DAMAGE TO MEMBRANE DRYER ASSEMBLY.
2. Set purge air pressure to 15 psig.
3. Adjust purge air flow to 20 L/min.
4. Set purge air educator vacuum level to 5 in-Hg (if applicable).
5. Ensure purge air is exhausting from system.
6. The temperature controller will be alternately displaying –AL– and actual purge air
exhaust temperature until purge air temperature comes within 5° C of setpoint
temperature.
7. Allow 15 – 30 minutes of additional heating time after system has come to setpoint
temperature. Sample flow may be started. For Mini-GASS with a pump, when set on
“AUTO” mode, pump will turn on when unit has reached temperature and purge gas is
sensed.