Assan Aluminium Installs 4 Vortex® Jet Heated Annealing Furnaces

Jan. 29, 2009 - PRLog -- ASSAN Aluminium Sanayi ve Ticaret A.S.  Turkey recently installed four coil annealing furnaces equipped with high convection Vortex Jet Heating for processing various sizes of coils.  The furnaces are an integral investment in ASSAN ALUMINIUM’s large-scale investment program to renovate and expand the Standart Aluminium (Ex-Nasas) assets to a 100,000 tpy aluminium complex for foil and specialty products.

The heating system incorporates recuperative burners for maximum energy efficiency. The complete installation includes an automatic charging machine for furnace loading, unloading, and load transportation between furnaces and load tables.

Vortex Jet Heating - How it Works

Aluminium annealing requires an advanced convective heating system to obtain the shortest possible cycle without any loss of quality in the material. Quality problems typically appear at the strip edges, and are represented by non-uniform material properties like hardness, and discolorations of the strip surface, as in the case of 5xxx and 7xxx alloys caused by Mg- or Mn-bleeding, cracking of residual milling oil from coil degreasing, or coil surface melting. These problems are caused by overheating at the coil edge resulting from non-uniform impingement of the air flow. The governing parameter describing the temperature uniformity of a convective heating system is the ratio of maximum to minimum heat transfer coefficient (HTC). This parameter limits the heat up time since the smaller the HTC ratio the higher the average temperature that can be obtained without exceeding the maximum tolerable local heat transfer.

The Vortex Jet Heating System incorporates arrays of 4 round inclined nozzles that generate a spiral vortex motion of air that results in high heat transfer without producing hot spots in the coil. The high volume flow of this nozzle system in conjunction with a unique semi-axial fan design allows the coil to be heated more uniformly by a larger mass of atmosphere.  The effective thermal conductivity in a strip coil is much lower in the radial direction than in the axial direction, therefore, the most effective way of heating the coil is through the edges of the coil wraps. The difference between the thermal conductivity for the two directions is caused by the heat insulating effect of the gas and milling oil layers in the coil between the strip layers.

This technology provides many benefits compared to older technologies:
•   Reduced heat-up time without local overheating
•   Improved uniformity of material properties
•   Minimizes local cracking and staining of milling oil
•   Reduced electrical consumption because the fan operates at a lower speed rather than a higher volume flow

ASSAN ALUMINIUM

ASSAN ALUMINIUM, a member of Kibar Holding Group, is a world leader in thin gauge and wide continuous strip casting technology.  The main plant in Tuzla is a benchmark for sustainable growth with investments in advanced technologies. The output from the Tuzla Plant, which was 10,000 tpy sheet in 1988,  shortly evolved to 130,000 tpy by 2006, including 24,000 tpy in foil. Utilizing the widest strip casters in the world and one of the largest cold rolling mills in Europe, the Tuzla Plant exports over 60% of production to international clients and generates an annual revenue exceeding $350 million. In June 2005, ASSAN ALUMINIUM acquired the assets of Standart Aluminium (Ex-Nasas) and subsequently launched a business plan for developing the acquired assets to a 100,000 tpy aluminium complex by 2008. The challenging project for the new site - named as Dilovasi Plant - includes full scale modernization of 7 rolling mills, installation of  5 new strip casters and 8 new annealing furnaces in addition to modernization of existing casthouse and new downstream equipment.

# # #

SECO/WARWICK Worldwide manufactures industrial heat processing equipment including heat treat furnaces, vacuum furnace technology, atmosphere generators and aluminum reverb melting and holding systems. SECO/WARWICK provides heat treating equipment and services worldwide for customers involved with primary aluminum, aluminum recycling, automotive, aerospace, commercial heat treating, HVAC, electronics, lighting, medical equipment and nuclear applications.

The globally integrated organization includes SECO/WARWICK Corp. (USA), Retech Systems LLC (USA), SECO/WARWICK S.A. (Poland), ELTERMA S.A. (Poland), SECO WARWICK Allied Pvt. Ltd. (India) and SECO/WARWICK Industrial Furnace Co. Ltd. (China).

The company is an industry leader in industrial heat processing equipment and processes. More information can be found at www.secowarwick.com.