Hazardous waste is a potential danger for our environment and our
health if not treated appropriately. Some hazardous waste examples
are solvents, aerosols, pesticides, oil sludges, varnishes, or
medical waste from hospitals. Their treatment by incineration
offers the advantage that organic, toxic substances are decomposed,
and waste volume is highly reduced. Furthermore, energy can be
recovered and steel recycled.
The rotary kiln has become the most common technology to incinerate
hazardous waste, thanks to its high capacity (up to120 000 t/a) and
versatility; rotary kilns can treat solid, pasty and liquid wastes
all together. Typical dimensions are lengths of 5–15 m and
diameters of 3–5 m.
Solid wastes reach the kiln through a feed chute in the stationary
front wall. Auxiliary fuels, liquid, and pasty wastes are injected
through different nozzles placed next to the chute. The kiln is
slightly inclined (~3 %) and rotates with 0,05–0,7 rpm, resulting
in a mean residence time of 30–90 min for solid waste. While
travelling slowly through the kiln, wastes transform into gases and
a solid/liquid inorganic combustion ash, called “bottom ash”.
Combustion gases are treated in a secondary combustion chamber and
neutralized through different gas cleaning devices.
The mean temperature at the rotary kiln lining’s hot face was
measured to be 900–1000 °C in the inlet and outlet zones, and
1000–1200 °C in the combustion zone, However, these temperatures
fluctuate due to varying waste inputs, which cause thermal shocks.
In addition, the kiln rotation induces a thermal cycling, since the
temperatures at the top of the kiln differs from the temperatures
at the bottom by approx 300 °C.
Medical Waste Incineration Plant for Hazardous Was...
ROTARY KILN INCINERATORS are typically applied in the following KEY
MARKETS:
- Medical and infectious waste incineration,
- Thermal desorption (soil cleaning),
- Hazardous waste incineration, including:
- Solid wastes,
- Sludge, slurries,
- Combustible liquids,
- Waste waters,
- High chlorinated hydrocarbons and PCB’s,
- Petrochemical wastes,
- Refinery wastes,
- Pharmaceutical wastes.
