It is a vacuum furnace series of medium dimension for laboratory
and industrial applications.
The hot zone has a cylindrical shape and top loading
VLT U.H.V. furnaces are completely metallic and
at the state of the art in the U.H.V. technology.
The use of metals as Tungsten, Molybdenum, OFHC Cupper, AISI
304L and the use of Turbo and dry pumps, allows to perform
high vacuum processes in an oil-free atmosphere
The high efficient metallic hot zone allows
very fast heating and cooling cycles. With a very low power
consumption. The cooling time can be greatly reduced with
the input of inert gas.
The furnaces can operate in automatic or manual, and the
operator interface is very simple.
Process data can be transmitted to a remote
VLT can supply different furnace configurations , responding
to specific client needs.
This U.H.V. Furnace series is supplied for working temperature
of 1200°C, 1500°C and 1800°C, the useful volume
can be from 20lt to 100lt, with a maximum diameter of 420mm.
The overall dimension of the furnace is related to the Hot
Zone dimension. On request VLT can supply bigger furnaces
and with horizontal loading.
Furnaces lay-out is made of three modules:
Working : Automatic and,or manual
Working temperature : 1200°C, 1500°C, 1800°C.
Temp.uniformity : +/- 5°C
Useful volumes : From 20lt to 100lt
Power : 380V 3F+N+G. from 10 to 45 Kw(depending of useful
volume and temp.)
Ultimate Vacuum : See table 1.
Cooling : water 20°C, 40lt/min.
Compressed air : 6/8 bar
Max dim. : See fig.1.
Max weight : 800 Kg.
Fast cooling : By inert gas flow.
1) AISI 304L vacuum chamber cooled wall
- Main cylindrical body max diam.900mm, max height 1000mm,
on it there are vacuum flanges for vacuum pump, vacuum instruments,
thermocouples, vacuum valves, inert gas valve, power feedthroughs
- AISI 304 L cover double wall water cooled, hydraulic
open and 120° rotation. On request a viewport can be
mounted for optical measurement.
- AISI 304L bottom double wall water cooled.
2) Hot zone 1200°C
the Molybdenum resistor, 7 thermal shields (5Mo+2AISI) for
cylinder, top and bottom. The hot zone is easy to remove for
2a) Hot zone 1500°C
It includes the Molybdenum resistor,
9 thermal shields (8 Mo+1 AISI) for cylinder, top and bottom.
The hot zone is easy to remove for maintenance operations.
2b) Hot zone 1800°C
It includes the Tungsten
resistor 9 thermal shields (2 Wo+6Mo+1 AISI) for cylinder,
top and bottom. The hot zone is easy to remove for maintenance
3) Power supply cabinet
and control system / PC
The cabinet includes:
Electrical power supply system; power triphase transformer
(400/12Vac), triphase thyristors Unit Eurotherm Mod TC3001,
chart record Eurotherm Mod. 4103M/6CH six channel for
Vacuum and temperatures, automatic triphase circuit breaker,
protection fuses, voltage-current instruments, door interlocks.
Control system/ PC; programmer temperature-vacuum controller
Eurotherm Mod. 2704 serial port to PC. The software is
upper graded at the state of the art. The control system
allow to operate in automatic or manual, and can be settled
to a prefixed safety vacuum value, so if this value is
reached the program will stay in “ hold ”
condition until the vacuum value start to decrease.
4) Service module
The service module is a complete unit in a wheeled metallic
closed cabinet, it is connected to the Vacuum Chamber by the
high vacuum Electropneumatic Valve.
The module includes:
Vacuum pump systems as the table 1
Vacuum control and monitoring instrumentation for the
Service fluids flow rate and pressure instrumentation
Hydraulic system to open the Vacuum Chamber
Water cooled trap or chiller for vacuum pump system
with diffusion pump
The vacuum system use Varian or equivalent pumps, in figure
2 a typical scheme of Vacuum Furnace with diffusion pump is
A wide range of safeties are included: