MDBT-MODEL

Technical Data

Drier Housing

The drier consists of cylindrical zones which are made of aluminium (stainless steel as option). These zones are screwed together on the flanges and mounted on a frame.  Each zone is provided with two or three magnetrons (microwave generators) which provide the heating energy. The air which is necessary for cooling of the magnetrons will be sucked from the ambient and led to the respective magnetron. The warm exhaust air will be given back to the ambient.

Absorber tunnels, which bring the leak radiation under the legal limit values, are installed at the inlet and outlet opening of the drier. If needed also absorber curtains can be used. The housing of absorber zones and of the outlet tunnel are also made of aluminium (stainless steel as option). The drier can be flexibly used due to the modular construction. If the furnace should be equipped with additional power then this can be reached through adding of further zones. The transport belt will hereby be enlarged or renewed and the switching unit will be adjusted to the required size.

When individual zones fail, the production will not be interrupted but the failure will be shown optically.

An opening, which is closed with a cover (screwed), is installed on each second zone for cleaning works.

Heating

The heating is effected through aircooled 900 W magnetrons which are mounted on different positions of the individual zones and arranged each above, below and side shifted to each other.

This effects a uniform field distribution and thus a better and more homogeneous heating of the material.

Control Unit

The control unit is in a specially for it provided switching cabinet. A lockable main switch protects the machine against unauthorized operation.

The power adjustment is possible manually over switch (as option also automatically). Hereby the individual magnetrons will be switched on manually and the transport speed will be adjusted over a potentiometer.

Transport system

The to be heated material will be led through the furnace with a microwave penetrable transport belt. The transport belt slides hereby over stainless steel supports which are mounted in each zone. Several deflector rolls are located at the beginning and at the end of the drier as well as below the furnace for guiding of the belt. A clamping fixture provides for a tight transport belt. A drive motor actuates the deflector roll over a toothed belt system. The belt speed is controllable. The loading areas with adjusted length are located at the inlet and outlet of the machine. A sideways wandering of the transport belt is minimized through special technics. The used drive motor has a high IP protection class.

Furnace ventilation

The air quantity for cooling of the individual magnetrons will be extracted from the ambient with each one ventilator and led to the magnetrons. The cooling fans are equipped with air filters in order to protect it against dust loading.  After the cooling air was led over the magnetrons, it will be again given back to the ambient. An additional exhaust system (consisting of a fan) which exhausts the humid air from the microwave chamber, can be mounted optionally to the microwave chamber.

Protection devices

In order to protect the magnetrons against overcharge, they are equipped with a thermo switch which switches off the magnetrons in case of exceeding of a certain temperature. Emergency off switches, which after activating effect an immediate switch off, are installed at the inlet and outlet openings of the furnace.

We recommend to check regularly the leakage radiation with an appropriate measuring device or to use stationary measuring devices which gives alarm when exceeding of the adjustable level or switches off the magnetrons. In usual operation (process operation according to specification of customer) maximal 5 mW/cm2 in distance of 5 cm are allowed and in exceptional operation 10 mW/cm2 are allowed.