ELECTRIC RADIANT PANEL TESTING:

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ELECTRIC RADIANT PANEL TESTING HARDWARE
MAINTENANCE PARAMETERS
KHANG D. TRAN, Ph.D. THE MEXMIL
COMPANY SANTA ANA, CALIFORNIA, USA
INTERNATIONAL AIRCRAFT MATERIALS FIRE TEST
WORKING GROUP MEETING, 06/2003, HAMBURG, GERMANY
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Water supply
Exhaust
Control panel
Radiant panel
Burner
MEXMIL RADIANT PANEL TESTING SYSTEM
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PARAMETERS THAT COULD AFFECT RADIANT PANEL TEST
RESULTS
EQUIPMENT SETUP PARAMETERS OPERATIONAL
PARAMETERS MATERIALS/SPECIMEN PARAMETERS HARDWAR
E MAINTENANCE PARAMETERS
RADIANT PANEL TESTING RESULTS
This presentation describes how the hard-ware
maintenance parameters affect results of a
radiant panel test
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POWER CONTROLLER CIRCUIT BREAKER
FAILURE ELECTRIC RADIANT PANEL CORROSION
RESISTANCE OF HEATING ELEMENTS BURNER TIP
CLOGGING
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A Watlow electric radiant panel including 6
stainless steel radiant emitter strips are
used in the system. Maximum operating
temperature 1300 ºF Strip resistance 11.2
?/16 Amp each phase
OBSERVATION TEMPERATURE AND HEAT FLUX
READINGS
LEVEL OFF BEFORE REACHING SETPOINTS VERIFICATION
?
Temperature of heating strips is not equal.
? Strips are not
uniformly red hot.
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R

UNPLUG THE POWER CORD TO PERFORM MEASUREMENTS
The electronic circuit of the strips
1. Check the fuses (using an Ohm-meter or a
Continuity Checker) 2. Check the strip
resistance (using an Ohm-meter) Each strip
should read 11.2 ? (Watlow strips) 3. Detect
any corrosion signs High temperature corrosion
occurs due to the interaction at high
temperatures of gases, or solids with
materials. 4. Check the current intensity for
each phase using a clamp-on ammeter
(qualified electrician is required)
A typical clamp-on ammeter
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BURNER TIP MAINTENANCE
Flue way/Air inlets clogged
Flame turns yellow, gets weaker, Burner
orifice dirty and
curves up. Gases are burning off
The inner blue cone becomes blurred
SPECIMEN
THE BURNER TIP SHOULD BE CLEANED USING
ULTRA-SONIC BATCH CLEANING
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A clean burner tip produces blue flame with
bright inner cone
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A BLUE FLAME MEANS
A complete combustion
A higher flame
temperature
A higher heat transfer rate WHEREAS A
YELLOW FLAME EXHIBITS
An incomplete combustion
A lower flame
temperature
A lower heat transfer rate
TEST RESULTS ARE UNPREDICTABLE
Surface burning occurs instead of flame
penetration into supporting layers. This could
make the process of flame propagation (on the
surface of the specimen) unpredictable.