The furnace is not recommended for burning off carbonaceous materials. Other
Carbolite Gero furnaces are available for this application.
When an optional gas inlet is fitted there is a label near the inlet saying "INERT GAS
ONLY".
The chamber is not gas tight, the gas usage may be high and the chamber is always
likely to contain some air. Residual oxygen of approximately 1% to 2% is to be
expected.
Periodically operate the furnace in air at 1500 °C for an hour to ensure the protective
glaze on the elements surface is maintained.
The hearth can be protected from abrasion, if required, by the provision of a secondary
plate. This consumable item can either be in lightweight ceramic fibre or in dense, hard-
wearing alumina refractory.
6.7
Pesting
The furnace is fitted with molybdenum disilicide elements and is therefore susceptible to
pesting. Pesting can be seen as a yellowish crystal growth on the surface of the
element. It occurs when the element surface temperature is around 450 °C and is
caused by the air oxidising with the molybdenum in the element compound. Under
normal operating conditions (above 800 °C) pesting is not a problem and can often be
seen occurring naturally on the element terminals.
operating the furnace for prolonged periods at temperature below 600 °C will cause
pesting to occur on the element surface and will eventually damage the elements.
Heating on a slow ramp rate or dwelling at temperatures below 600 °C for short periods
will not cause a problem providing the furnace is operated above 1400 °C at regular
intervals to recondition the element surfaces.
Large amounts of pesting occurring on the element terminals must be removed in
accordance with good health and safety practices.
6.8
Explosive Materials
The product must not be used to heat materials which could explode, or which could
emit gases that could form explosive mixtures.
6.9
Notes on Temperature Control
This product is designed for heating and cooling at controlled rates. The heating and
cooling rates can be set in the temperature programmer. The programmer enables the
furnace to heat or cool at slower rates as desired and variable "hold" (dwell) periods
can be programmed as required.
The programmer is used in conjunction with a phase angle thyristor power controller,
which incorporates a current limit potentiometer pre-set by Carbolite Gero, but which
will require adjustment in the event of change of supply voltage.
45
6.0 Operation
Summary of Contents for CARBOLITE GERO HTF 17/10
Page 7: ...Caution Double Pole Neutral Fusing 7 1 0 Symbols and Warnings ...
Page 38: ...4 0 3508 Dual Loop Cascade Power Limit View 38 ...
Page 60: ...8 0 Repairs and Replacements 60 ...
Page 65: ...G Grey GR Y Green Yellow 65 10 0 Wiring Diagrams ...
Page 69: ...Notes Service Record Engineer Name Date Record of Work ...
