Advance technology for continuous decoating and drying, from 500
kg/hr to 20 ton/hr, complying with the strictest environmental
regulations.
The Hengyang system is designed for removing the volatile organic
(paint, lacquers, oils) and inorganic (water) contaminants from a
wide range of aluminium scraps by a continuous thermal process.
Typical applications . Decoating aluminium shredded scrap such as
UBC, profile, carter ... . Drying machining chips, turnings, swarf,
...
Hengyang system main components are: . The Rotary Kiln for
processing the dirty scraps. . The Post-combustion chamber, for the
incineration of the gases generated in the rotary kiln. . The
recirculation fan between both equipments, in order to reuse part
of the hot gases generated in the Postcombustion chamber. . The
intermediate cyclone, for removing the small particles from the
process, such as fines, dust, ... Economical & environmental
benefits: . Very low overall energy consumption. . Reduce the metal
losses and energy consumption in the melting process. . Improved
the Foundry safety (no water). . Controlled volatilization of the
VOC. . Full incineration of the generated gases. . Reduces
emissions to the environment.
Kiln discharge and temperature
The temperature at the kiln discharge is controlled to ensure a
well cleaned final product. The Hengyang tube, acts as a heat
exchanger giving up heat to the scrap and kiln exit gases by
radiation. The Gases enter the Hengyang tube at afterburner
temperature and by the time they reach the end have been cooled,
and so used to control the temperature at the discharge end of the
kiln, with temperatures below 550º C.
Cyclone & recirculation fan
A high efficiency cyclone unit is employed to remove any
particulate from the kiln prior to the recirculation fan and
afterburner. The recirculation fan provides the required gas flow
from the Afterburner. The fan is fitted with a variable speed drive
unit, and the speed of the fan is modulated automatically to
maintain the kiln gas exit temperature at the selected control set
point.
Kiln Speed and residence time
The kiln rotational speed is adjusted by the kiln drive motor. Each
material has an ideal residence time within the kiln barrel.
Kiln gases pressure control
The Hengyang kiln pressure is controlled to ensure that process
gases remain within the system and that the infiltration of air
into the drum is kept to a minimum. Kiln free O2 level The Hengyang
free oxygen level is controlled to ensure the thermal process
occurs in the required conditions, avoiding the generation of CO
gases.
