FLK Gas Sampling System - MPIP - Free

SQ254 Heat Exchanger
1.4 Function description of the heat exchanger
The device is designed to operate the gas sampling probe and the sample gas at a temperature above the dew
point of acids (appr. 130 °C).
During the start up the coolant is bypassed by the three-way valve directly to the gas-sampling probe. After
exceeding the setpoint of the minimum temperature for the closed position of the three-way-valve, the coolant is
directed through the heat exchanger. This method ensures a short heating-up-time of the coolant. Sample gas will
not be taken below the minimum temperature. A cooling fan is switched on at coolant temperatures above 180°C
to force the cooling of the radiator. If the coolant temperatures drops below 180°C the cooling fan is switched off
again.
The level switch (6) monitors the “level minimum” in the expansion vessel. In case of low level of the liquid the
circulating pump is switched off.
For troubleshooting please refer to page 7, “level minimum”.
The flow meter (4) monitors the flow of the coolant. If the minimum flow is less than the minimum for more than 5
sec, the circulation pump is switched off and an alarm is generated. For troubleshooting please refer to page 7,
“Flow”.
For thermal overload protection the probe is being retracted from the kiln at coolant temperatures more than
220°C.
For troubleshooting please refer to page 7, “Exceed temperature”.
Faults are indicated on the signal lamps on the cabinet. For further utilization it can be wired to a control system
by means of potential free contacts.(wiring diagram G 3302-A3254-S004)
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