Secondary Fuels

Precut sample material was used for this test. We prepared a batch of 250 ml of sample and slowly transferred the sample into the mill which was equipped with sieve shells of 0,5 mm (cutting mill conversion). The speed was set to its maximum (18.000 rpm).

During the feeding process, no metal fragments were found; the sound of grinding was typical and vanished almost instantly after the last fragment was fed into the mill.

There was no significant clogging of perforations, surely even higher amounts of this sample could be fed and ground.

Cleaning was performed rapidly with a soft brush. Also compressed air could be helpful to remove traces of sample from sieve shells and holder, too.

With this trial, we used 0,5 mm precut sample material. 22 grams (~ 250 ml) were fed slowly into the feeding funnel. The grinding sound was typical until ~ 50 seconds of feeding were performed. A change in sound indicated that a bit of sample already started melting.

The few last fragments were fed within a total grinding time of 70 seconds. A few melted fragments were removed afterwards (mainly located in front of the static knives). Eventually a previous embrittlement might allow to comminute somehow more of sample.

For intensive cleaning, the sieve shell holder was disassembled. After using our Ultrasonic Cleaner LABORETTE 17, stuck particles inside the sieve shell perforations were removed with a wired brush.

We do not recommend using such fine perforated sieve shells for comminution of secondary fuels. Also the optical properties of the ground sample do not differ significantly from the output which passed the 0,5 mm sieve shell set.