Despatch S Type - Manual (Page 34)

I-235 (9/03)
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OVEN AIRFLOW ADJUSTMENT
1.
THE PURPOSE OF ADJUSTABLE AIRFLOW
a. Ability to get the best temperature and airflow uniformity.
b. Ability to "spot heat" special areas or specific parts of load.
c. Ability to prevent air flowing out or sucking in through the entrance and exit
openings in the oven.
2.
NO FACTORY ADJUSTMENT
Most ovens that have final assembly in the field have not had the louvers adjusted at all
since the heater boxes have not been installed on the oven before shipment. The
louvers on some of the smaller, shipped assembled, more standard ovens (models RS,
S (PS), PW, PC, and VR), where ductwork is already installed or heater source is
incorporated with the oven, have been basically pre-set to baseline adjustments (no
uniformity tests have been performed unless it is purchased as an extra).
3.
PREFERRED METHOD—FACTORY SPECIALISTS
We recommend using our factory specialists for start-up and adjustment. Our people are
well trained and have many years of experience. We feel that an experienced Despatch
field supervisor will save the customer inconvenience, confusion and costs besides
getting a proper installation that will be covered under warranty and give many years of
trouble free operation. If this service has not been purchased with the equipment it may
be obtained by contacting the Despatch Field Service Department for price and
availability.
4.
GENERAL GUIDELINES—SUPPLY AIR ADJUSTMENT
The adjustment of supply louvers is directly related to temperature uniformity in the work
chamber. A general guideline is that more heat is required next to doors, windows and
outside walls so, therefore, more air is required to deliver that heat. The supply duct
chart shows the relationship of slot openings in several different shapes of ducts.
5.
GENERAL GUIDELINES—RETURN AIR ADJUSTMENT
The return ducts are not as critical in setting as long as they are opened up enough to
eliminate a restrictive condition that may cut down the amount of air being handled by the
fan or result in a pressurized condition within the work chamber. Initial setting of return
louvers should be 50% more open than supply louvers—final adjustment may be
required.
6.
Refer to the following pages for baseline settings that match your ductwork discharge
options (louvers or diamond nozzle options). Use adjustment tool (P/N 211834) for
adjusting diamond nozzle ports as noted on the following pages