Linn High Therm GmbH
HT-1500-GT-VAC-Spezial GRAPHITE
page
18
operating instruction issue 30.10.2018
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4. Description of system
4.1 Furnace housing
The proper furnace housing is made of stainless steel and is provided in touchproof
condition in the outside housing. It is cooled by a fan (plugged sideways on the
bottom on a separately stored housing) so that also during continuous operation a
wall temperature of 180°C is not exceeded. Because of changed position of the fans
the cover will additionally be designed watercooled. The correspondingly designed
outer housing remains relatively cold (max. 40°C over ambient temperature), except
the door front plate. On both sides a blind flange DN 40 is provided which serves as
lead through for 9 customer
– provided thermocouples. For the enforcement of max.
9 thermocouples two adapter DN for max. Ø 1,5 mm thermocouples with vacuum
tight fittings will be installed. The swivelling door with silicone rubber sealing is
provided with turn-locks (spring press capacity). The door flange is water - cooled.
The door is locked until the temperature in the furnace is less than 250°C
(temperature programmable). The status of the door switch can be controlled over a
potential free signal. The furnace door has a guidance in order to avoid damages of
the door insulation during opening and closing. The current connections are installed
on the furnace rear side. The furnace housing is connected separately over feet with
the furnace. Under the furnace housing will be placed a second housing for gas
installation, vacuum, fan for furnace housing, oxygen measuring device etc.
The transformers get an additional housing and will be positioned behind the
furnace.
This housing has legs with a length of appr. 160 mm. A guidance for the customers
loading device is welded or screwed by Linn High Therm. The guidance part is
supported by Corning.
The cover sealing will be designed as circular O-ring sealing. To this the cover and
the furnace housing will be adjusted correspondingly.
The tube lines will be provided with compensators in order to reach a low vibration
load.
4.2 Insulation
The inner housing is lined with graphite fibre boards. The use of this lightweight, low
heat storage material enables extremely short heating up
– and cooling down times.
The bottom insulation is reinforced by fibre light bricks and designed for a max. 50 kg
loading on an area in the furnace centre of 300 x 400 mm.
Additionally the furnace chamber contains an outside wall water cooling (cooling
coil).
The joints (labyrinth) of the insulation will be treated with graphite coating in ordert o
minimize a fibre input in the useful chamber.
4.3 Furnace prepared for the lead
– in off three extrusion die
In the centre of the furnace roof a water
– cooled blind flange DN 40 KF is provided.
On demand it can be used for lead
– in of an extrusion die (pressure force max. 80
kg). From the centre of the furnace roof 2 other water
– cooled blind flanges DN 40
