Heating elements
Molybdenum disilicide elements are not affected by oxidising atmospheres and by ageing with
a result of simple operation of the furnace and low cost maintenance.
Since elements are not affected by ageing, a single damaged element can be replaced with a
new one without altering the efficacy of the others even though they have been operating for
a long time.
The furnaces with max operating temperature up to 1600°C. are supplied with heating element
with max. surface temperature of 1700°C. (3090°F), while furnaces operating up to 1700°C.
are supplied with heating elements with max. surface temperature of 1800°C. (3270°F).
The furnaces up to 1600°C. and furnaces up to 1700°C. have different thermal insulation and
different voltage input.
Heating elements are hairpin shaped and the heating zone is freely suspended inside the
furnace chamber.
This configuration allows the elements to be removed and replaced by extremely simple
operations.
Power control
The resistivity of the Molybdenum disicide elements substantially increases as the
temperature does, consequently the voltage must be steadily adjusted during the heating up
to the furnace.
SK-M, SK-C are equipped with a solid state power controller which includes a current limited
feedback and ramp. The start up precedure is automatically performed.
In case of power failure the heating elements are not damaged by the electrodynamic forces
when power is restored (soft restrt).
The firing mode of the thyristors prevents the damage of the element at low temperatures by
harmonics.
Temperature control
Microprocessor three term P.I.D. controller is fitted as standard with DC output connected
to the solid state power controller.
Temperature controller incorporates a digital display to show the preset temperature and the
actual temperature.
A sheated Pt-PtRh 13% or 18% thermocouple, which probes the furnace chamber, gives accurate
temperature sensing.
Thermocouple break protection and over temperature cut out are all standard features.
Overtemperature protection is performed by an independent temperature controller connected
to a dedicated thermocouple.
Microprocessor temperature programmer to perform time/temperature controlled cycle is
available as standard option.
Thermal isulation
The furnace chamber is lined with ASTM classified firebricks. Element separators, hearth
supports and hearth are made of high content alumina refractories tiles.
The furnace chaber is surrounded by a graded selecton of insulating refractories which gives
the highest average between thermal conductivity and pyroscopic resistance. Lighweight
insulation minimizes heat losses and gives quick response whenever the setted temperature is
changed.
SK-M, SK-C HIGH TEMPERATURE FURNACE 1600°C - 1700°C
SK horizontal chamber furnace (M) features case splitted in two parts:
- the base which contains the power and temperature controllers;
- the upper part which contains the heating chamber.
SK vertical furnace (C) includes the thermal process chamber in a floor standing case, plus
a remote control cupboard which contains the power and temperature controllers.
Temperature programmer, if requested, is fitted on the same cupboard instead of standard
temperature controller.
The most outstanding characteristic of SK-C furnace is the work access opening situated both
on the bottom and on the top of the heating chamber.
The bottom opening has an insulated lifting device which allows the transfer of the
materials in and out the heating chamber.
APPLICATION ORIENTED OPTIONS
Optional extra are available to comply with the needs of different processes. The optionals
include:
SK-M TYPE: Arrangement for door opening of various design according to the loading
and unloading procedure.
- Gas tight retort made of impervious Alumina tube, to perform atmosphere controller
processes.
SK-C TYPE: Eletrically operated lifting device to transfer the materials in and out
the heating chamber.
- Tilting mechanism foru crucibles (available with electrically operated lifter only).
Model | A mm | B mm | C mm | D mm | E mm | F mm | a mm | b mm | c mm | Peso Kg | Potenza Kw | Temp. °C |
SK5-M | 710 | 1850 | 770 | 380* | 280* | 500* | 100 | 150 | 200 | 380 | 5 | 1600 - 1700 |
SK7-M | 800 | 2000 | 870 | 380* | 280* | 500* | 180 | 200 | 300 | 460 | 9 | 1600-1700 |
SK9-M | 800 | 2000 | 970 | 380* | 280* | 500* | 200 | 200 | 400 | 510 | 12 | 1600 |
SK-C | 600 | 1300 | 650 | 600 | 500 | 1750 | 100 | 150 | - | 370 | 5 | 1600-1700 |
SK-C | 670 | 1450 | 700 | 600 | 500 | 1750 | 120 | 230 | - | 440 | 9 | 1600-1700 |