| 摘要 |
<p>Forced convection is established inside the oven by hot air output from a centrifugal turbine (4) in a compartment connected to it. Cleaning by pyrolysis is controlled by an electrical circuit contg. a bimetallic switch (1) connected to a control thermostat (2) and the heating resistance (RG). The turbine (4) directs air on to a safety switch (5) and preset 460 deg. C thermostat (14). During the cleaning process the turbine comes into operation at a predetermined critical temp. and its exhaust closes the safety switch (5) and cools the thermostat (14) while the heating resistance is alternately supplied and isolated by the contacts (3a,3b) of the bimetallic switch (1) so that the max. temp. remains at about 460 to 500 deg. C. The turbine is pref. equipped with a second rotor for ventilation throughout the operation. It is assured of adequate cooling without the provision of an isolating shutter.</p> |
