CLEAN BURN CB-200-CTB, Руководство оператора

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Coil Tube Boiler Operator's Manual: Models CB-200-CTB, CB-350-CTB, and CB-500-CTB
8-1
SECTION 8: ADJUSTING THE DRAFT OVER FIRE
Understanding the Importance of Draft
Draft in the Coil Tube Boiler is created as the hot combustion gases rise up the stack, creating a negative
pressure inside the stack and the boiler. This negative pressure is measured as inches of water column
(W.C.) of draft. A proper draft overfire of -.02 w.c. is essential so that all combustion products travel
away from the burner, down the combustion chamber, through the boiler flues and up the stack.
Checking for Correct Draft Over Fire
NOTE: The CTB's are equipped with an observation/draft reading port to check draft over fire. A qualified
serviceman with proper equipment must adjust your CTB for proper draft. Contact your Clean Burn
dealer for this service.
1. Insert the probe of the draft gauge
instrument into the draft reading port in the
observation port as shown in Figure 8A.
2. Adjust the barometric damper to achieve
the
required draft over fire of -0.02 w.c.
(water column).
3. Record the reading in the Maintenance
Record located in the Appendixes.
4. If correct draft over fire cannot be achieved,
contact your Clean Burn dealer
immediately.
ATTENTION: Only operate your CTB
with a draft over fire of -0.02 w.c. Poor
draft results in back pressure and poor
burner performance. DO NOT operate your
CTB with a draft over fire greater than
-0.04 w.c.; an abnormally high stack
temperature may result from a draft over fire
that is too high.
ATTENTION: Backdraft must be resolved or
your boiler will not operate correctly!
Under backdraft conditions, draft overfire readings
will show positive pressure in the combustion chamber.
Backdraft means that oil spray, combustion products,
and heat are blown back against the burner. Backdraft results in oil-fouled retention heads and electrodes.
Severe backdraft will force heat back against the burner and result in heat damage to the cad cell and
transformer.
I88257
Figure 8A - Checking for Proper
Draft Over Fire