Product Details
It is industry proven and worldwide recognized that the multiple
hearth furnaces are the best tool to produce high grade activated
carbon and they have the highest efficiency as well with very
little carbon loss (Efficiencies as high as 95% could be attained)
. More than 400 multiple hearth furnaces are installed worldwide
and half of them are dedicated to activated carbon production and
regeneration of spent carbon. Calgon, Norit and Chemivron use
widely those furnaces for producing activated carbon.
Basics of thermal activation of carbon
Activated carbon can be made from a wide range of source materials,
such as coal, coconut shells , wood etc. The material is often
carbonized then activated in a high temperature environment to
produce an extensive network of pores. These pores provide sites
for the adsorption of chemical contaminants in gases or liquids.
The activation of carbon is carried out at high temperatures (up to
1000°C) with steam for gasification of a part of the fixed carbon
as per the following reactions :
C+H2O >> H2 + CO
C+CO2 >> 2CO
The gasification process can be manipulated to produce desired
characteristics in the product..
The gasification phase is influenced by the following parameters,
that also determine the quality of the final product.
- chemical nature and concentration of the oxidizing gases
- temperature of reaction
- length of the activation and rate of reaction
- nature of the raw material
Description of a Typical Installation
At this stage , we have made the assumption that the coconut shell
is carbonized and its content on volatile matters is approximately
20%. The carbonized product would go through the following
processing steps :
- Grinding: The raw material is ground to the size distribution that
is required. (between 1 an 3 mm depending on the use)
- The Activation: The product is carried to the top of the furnace
through a bucket elevator. The furnace has a diameter of
approximately 6 meters and 7 hearths. The furnace is essentially
composed by a cylindrical shell (carbon steel) supported by steel
or concrete legs. The total height of the furnace is approximately
15 meters.
See the MHF for full description of the furnace.
Each hearth is supplied with minimum 3 gas burners . There is a
steam injection foreseen also on each hearth. An automatic control
of the burners and the temperature on each hearth is supplied. - Cooling of Activated Carbon: The activated carbon is cooled down at
the furnace exit thru water or indirectly via heat exchangers.
- Storage and Packing: The activated carbon is transported via a
conveyor or pumping system to the screening equipment . From there
it fills the silos of different size distribution. The bags are
filled from the bottom of the silos.
Advantages of Rotary Furnaces
The activation of the carbon, requires a control of the gaseous
atmosphere and un good distribution of the air. It is necessary
that all air is burned in gaseous phase and that it does not reach
the carbon bed. From their design , the rotary furnaces are the
ideal equipment for producing activated carbon.
- They are completely sealed , preventing parasite air from entering
the furnace and burning the carbon, thus reducing the efficiency of
the furnace.
- It easily allows the introduction of combustion and activation
products at different points of the furnace. Their introduction at
different points , allows to control the reaction rate, and avoid
to have a maximum rate of activation at the product entry as is the
case with a rotary kiln.
- It allows to have the desired temperature profile and reduce carbon
losses.
- Rotary furnaces have a big flexibility of operation. They can use
for carbonisation, activation and regeneration in continuous
operation.
Estimated Investments
Our plants come at different sizes from 50 tons per month to 1000
tons per month.
- The furnace includes:
- Refractory parts
- Metallic parts (steel shell and platforms)
- Gas burners and auxiliary piping around the furnace
- Raw material storage silo (15 m3)
- Extractor and raw material conveyor from storage silo to top of the
furnace
- Chute and double sealed valve at furnace top inlet
- Activated carbon discharger and quenching device.
- Staircases, access ladders and floors around the furnace
- Fans, ducting, motors and mechanical equipment
- PLC - and electrical cabinets.
- The rough schedule for the erection of a 200 MT plant is as
follows:
- Engineering and fabrication of equipment: 8 to 10 months
- Packing and transportation : +/- 2 months
- Mounting on site: 6 to 8 months
- Drying, testing , heating up and start up : +/-2 months
Company Profile

Hengyang Industry is an Chinese Company based in Zhengzhou city that manufactures,
on proprietary technology, plants and equipment for waste recycling
and recovery with energy production, material recovery or
production of finished goods.
Innovation, R&D, passionate and skilled team along with the
customer satisfaction have always been the success of Hengyang and
they still are the peculiarities of our Company. Besides the
historical Hengyang equipment, like single and double shafts
shredders, Crushing machine, briquetting machines, separators,
squeezers and centrifuges, the Company offers a wide range of
turn-key plants, among which:
• briquetting and pelletizing plants
• shredding plants
• Waste Sorting Plants
• Bio-fuel Plants
• Waste to Power Recycling Plants
• Mining Plants
• OEM Equipments
……..
Hengyang is able to develop customized solutions too.
Designed, constructed and assembled by the same Hengyang
The Company policy focuses on product quality: robustness and
functionality of the machines that maintain their value over time.
The ability to challenge ideas and concepts and to interact with
partners worldwide has allowed and still allows Hengyang to stay
highly competitive and to be an ideal partner for the world market.