Design and function
2017-03-23 / DIS 184_58300000197442_ARA_EN_A
Copyright by BSH Hausgeräte GmbH
Page 25 of 101
3.8
Vapour extraction system
3.8.1
Structure
The vapour extraction system conveys excess vapour out of the cooking
compartment.
Extracting the vapour prevents it from developing an overpressure and escaping
from the cooking compartment at unwanted points (via openings, leaks).
Controlled extraction also prevents the vapour concentration in the cooking
compartment from becoming too high or too low.
In view of the factors explained below, we need an extraction that can be controlled
by volumetric flow with a minimum extraction via bypass of 4 mm or 8 mm:
•
varying amounts of steam arising due to different foodstuffs at the same and
different temperatures
•
varying amounts of steam condensing on cooler surfaces, depending on the
current state of the walls and door of the cooking compartment
Fig. 22:
various bypass openings / minimum extraction
Vapour valve versions
•
Appliances with full steam and microwave have a vapour valve.
•
Appliances without full steam, without microwave and without pyrolytic system
have a vapour valve.
•
Appliances without full steam, without microwave, with pyrolytic system, and/or
added steam and/or cooking sensor and/or drying, have a vapour valve.
•
Appliances without full steam, without microwave, with pyrolytic system, without
added steam, without cooking sensor and without drying, have
no
vapour
valve.
3.8.2
Function
When it is connected to the power supply and when it is reset, the appliance first
checks how long the eccentric takes for a complete rotation. The eccentric rotates
at most three times. The flap is then set to its half-open position (eccentric 90° /
vapour valve 11° = 50 %).
Depending on the operating mode, the flap may remain in the same position until
the cooling fan switches on (at about 80 °C).
For example, if the motor turns the eccentric to 72° - the vapour valve is then 7° =
40 % open.
Fig. 23:
Rotation and opening angle of the vapour extraction motor
Angle of rotation
of the eccentric
Opening angle of
the vapour valve
Vapour valve
opening ratio
0°
0°
0 %
36°
1°
20 %
72°
7°
40 %
90°
11°
50 %
108°
15°
60 %
144°
24°
80 %
180°
28°
100 %
Table 6:
Angle of rotation, opening angle and opening ratio
For each type of heating there is a fixed assigned parameter that governs the valve
position.
The parameters assigned to the various types of heating also depend on the type
of appliance:
•
Conventional appliances
•
Appliances with full steam
•
Appliances with microwave (45 cm, without pyrolytic system)
