Compact Coil Furnace (CCF)
Compact Coil Furnace (CCF).
Green Gautschi technology for heat treatment.
During the continuous evolution of Gautschi heat treatment facilities for coils, the company has been able to optimize annealing technology by adapting the design – without forgoing the use any proven technologies.
Customer requirements for low investment costs, as well as low production costs, were the driving forces behind the need to build a furnace that was as compact as possible. Although one must usually invest in measures designed to reduce energy consumption and production costs, this is not the case with a Gautschi Compact Coil Furnace (CCF).
CCF furnace technology has now been augmented by the incorporation of an electric heating system This not only supports the EBNER GROUP’s strategy for “Driving Green Technologies”, but also meets the market’s increasing demand for alternative solutions to conventional gas-heated facilities.
THE LAYOUT OF A CCF
The cylindrical central section accommodates the coil that is to be heat treated. By opening a double-leaf door, a coil can be charged/decharged from above. Recirculation fans and the heating system are installed in the two end sections positioned to the left and right. Heating can be carried out using either a gas-fired or electric system. Circulation air is distributed across the surface of a coil by a system employing round nozzles.
After a coil is charged, the two leaves of the door are closed. The end sections are then pneumatically shifted up to the central section. All furnace components are designed with dual seals, preventing the loss of thermal energy and making them air-tight. The annealing process can be carried out with or without process atmosphere. A cooling circuit can also be integrated at need. Control cabinets and the rack for the electric heating system can be installed near or alongside the furnace, as requested by the customer. Should the product mix be changed at a later date, the relatively simple design of the central section allows it to be easily replaced.
The heating elements are designed as modular units, and consist of tubular heating elements (12.5 mm) fabricated from stainless steel. All heating elements are installed in the end sections of the furnace, and are easy to replace. The temperature in each end section is controlled separately, using thyristor power controllers. The patented design of the furnace allows the customer’s existing coil handling system to be used for charging. Either a coil grab or a C-hook may be used.
A CCF is an extremely energy-efficient and eco-friendly technology, and thus a solution that reduces costs. Savings are achieved through the reduction of energy and atmosphere consumption, with these reductions leading to a reduction in emissions or potentially even their elimination.
During development, the following advantages of a CCF became apparent:
- The reduced external surface area leads to a reduction of around 75 % in the energy consumption during holding.
- The reduced volume of the furnace leads to a savings of around 55 % in atmosphere consumption.
- The electric heating system reduces emissions to zero.
- The facility is completely pre-assembled and tested in the Gautschi workshop.
- The minimal requirements for the foundation allow the facility to be easily moved to a different location at a later date.
- A customer’s existing coil handling system can be used to charge/decharge coils; a special charging system is not required.
- Should multiple CCFs be installed in a battery, a fully-automated charging system with a gantry crane can be used to charge and decharge the furnaces.
A) REDUCED ENERGY CONSUMPTION
Compared to a conventional single-coil furnace, a new Compact Coil Furnace (CCF) has a significantly smaller exterior surface area. Despite the similar structure of the furnace walls, the consumption during holding at a temperature of 450 °C can be reduced by an impressive 75 %*. (*The savings that are achieved depend on the actual annealing temperature and the composition of the customer’s product mix.)
Energy consumption of a single-coil furnace: 61.5 kW
Energy consumption of a CCF/Compact Coil Furnace: 15.3 kW
Assuming that an annealing temperature of 450 °C is required on 300 days out of the year, the savings that are achieved are as follows:
15 euro cents/kWh: € 49,900/year
20 euro cents/kWh: € 66,500/year
B) REDUCED ATMOSPHERE CONSUMPTION
Due to the significantly smaller volume of the furnace in comparison to a conventional single-coil furnace, process atmosphere consumption can be reduced by up to about 55 %. The gas that is saved does not need to be heated up, leading to additional energy savings. Single-coil furnace: 473.9 m³ at s.t.p. of process atmosphere would require 56.0 kWh per coil to be heated up to 450 °C
Compact Coil Furnace: 214.9 m³ at s.t.p. of process atmosphere would require 25.4 kWh per coil to be heated up to 450 °C
The energy savings for the reduced amount of process atmosphere that is required thus total:
15 euro cents/kWh: € 4.60/coil
20 euro cents/kWh: € 6.10/coil
C) REDUCED/ELIMINATED EMISSIONS
When equipped with a gas-fired heating system, the carbon footprint will be significantly reduced due to the energy savings described above. When equipped with an electric heating system, the emissions fall to zero (assuming the electrical power comes from a green source).
Compact Coil Furnace (CCF)