We are currently developing a small-scale clean RDF (Refuse Derived Fuel) combustion technology, that enables the medium and small self-governing bodies by themselves to recover the energy effectively from their own refuses. The system features the cyclone furnace that burns the pulverized RDF at high temperature.

It's expected as an effective method for reduction of dioxins, becsuse of its high combustion efficiency compared to conventional small-scale combustion system. And it can reduce noxiouseness, as well capacity, of the burned ash and other residues, by melting them directly in the furnace.

In addition, the recovered slag can be used as recycled materials.

The test facility was built in 1997, and the results of proofing test have evidenced the high combustion temperature, low emission of noxious gases, and direct ash melting. But some problems appeared, such as blocking up of slag tap, some wasteful use of auxiliary fuel (oil) owing to a little combustion instability.

In 1998, we tried to solve these problems.

The outlines of our last year test results are:

1.We made modifications on slag tap, slag recovering conveyor (air slag cooling), pulverized RDF feeder.

The problem of slag tap blocking was almost solved, but the refractories of around this found to be not durable.

This problem is left unsolved.

2.We built test facility of drying refuses (one process of the refuse fuelizing), using RDF combustion energy.

3.We evidenced stability of combustion of pulverized RDF only, no use of auxiliary fuel except on starting.

Under 4mm pulverized RDF burned well.

But under 6mm did not, the combustion was unstable and CO concentration altered frequently.

4.We analyzed solid-gas two phase flow in the furnace numericaly, by using PHOENICS, a marketted software. We studied about RDF-particle motion, by using PSI-cell model.

We intend to solve these remained problems, such as durability of slag tap, and to fix terms of clean combus tion in the year 1999.