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Outer Mantle

The lower part of the outer mantle is a cylinder with a solid bottom. The walls are partly double. The intake air flows into the combustion chamber between the two walls. With this construction the waste heat generated in the process is made to heat the intake air to improve the overall efficiency. The generated gas passes into the filter from the upper end of the lower part (3) where there is only single wall. The combustion air is taken in through the one way flap valve (2) and it is led around the generator through the air channel and further to the air channel of the combustion chamber at the point of the ignition opening (6).

The air channel of the combustion chamber and the air channel of the outer mantle are connected together with a flange connection. The ignition opening is quite large to make it possible to tighten the bolts of the flange connection through it. In the lower part there is also a cleaning opening (5) which is led gas tight into the lower part through the air channel. This opening is covered with tightly closed cap. The gasket of the cap can be made of asbestos string treated with graphite. The upper part of the outer mantle is connected to the lower part with a flange with bolts (M8) mounted upwards. In the lower part there is also operating shaft for the hearth moving mechanism. The shaft goes through the wall and in the opening there is a seal made of asbestos string.

The one way flap (2) is an oval steel plate fitted in the pipe with an axle connected to the upper part. It opens inwards and closes automatically. The flap prevents air from entering the generator and produced gas from exiting the generator when not in use.

Auxiliary devices
To produce air flow in the generator during start-up a suction or blowing fan is needed. A fan with a power of 200-300W and producing 15 kPa under or over-pressure meets the requirements. A fan like this is for example one used in car heaters. The length of the starting period depends on the power of the fan:

Translated by Olli.