Introduction - Keison Bibby Scientific Techne Afterburners AB-100 Operator's Manual

introduction

the techne afterburners aB-100 & aB-500 are designed to reduce smoke emission from the exhaust gas
flue of certain sized techne fluidised bath cleaning systems. the afterburner consists of a burner plate
mounted within a thermally insulated combustion chamber. the input to the combustion chamber is
designed to mate directly to a standard techne extraction fan, while the output is suitable for connection
to an insulated exhaust stack.
the system is designed and built to comply with British Gas council regulations, and has an approved
flame control unit, which monitors the flame via a flame probe.
the gas train consists of a pilot line pressure regulator, a control solenoid, a gas flow adjuster and a pilot
burner running in parallel with a main line pressure regulator, two control solenoid valves in series, a gas
flow adjuster, a maximum flow limiter and the main burner.
a safety interlock, in the form of a differential air pressure switch which monitors air flow across the
burner, inhibits operation of the burner upon loss of air flow.
the start up sequence for the burner is as follows:-
With the fume extraction fan running, and the afterburner power switch in the on position, (it is normal
practice to wire the electrical supply to the afterburner via an auxiliary contact of the extraction fan motor
starter), after a pre-purge period of approximately 10 seconds both the ignition system and the pilot
solenoid valves are energised. once the flame probe has detected that the pilot flame is correctly
established, the ignition system is switched off and the burner operates on the pilot flame only for a
period of approximately 15 seconds, after which the main solenoid valves are energised to establish the
main flame.
If the pilot flame is not established correctly during the start-up sequence, the lock out safety circuit
causes the burner to shut down to a safe position. Shut down will occur within 5-6 seconds, after the
initial release of gas.
the lock out lamp on the control panel will illuminate and the burner cannot be restarted until the Start
switch has been depressed.
a compulsory minimum delay of 60 seconds is provided by the flame control system before the unit can
be re-started. this delay allows the afterburner to be purged of any combustible gases which may be
present.
If during normal operation the gas burner flame is extinguished, the flame probe reacts instantly to the
loss of the flame. the solenoid valves are switched off immediately and after a delay period of
approximately 10 seconds, the ignition system and the pilot solenoid are energised in an attempt to
re-establish the flame in the normal manner.
If the re-light attempt is unsuccessful, the flame control system goes to a lock out state as described
above.
the techne afterburner system is one of several fume treatment components that may be used in
conjunction with techne fluidised bath cleaning systems. the components selected will depend upon the
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