HPH® Bell-type Annealing Furnaces for non-grain-oriented Silicon Steel Strip (NGO)
For over 60 years LOI, has been a technical and economical market leader in Bell-type Annealing technology. A wide variety of innovative details and comprehensive process technology expertise are the result that customers can build on.
Bell-type furnaces are the most economical, most flexible alternative for the heat treatment (homogenization and recrystallization) of non-ferrous metals. Bell-type annealing plants are suitable for the treatment of all types of rolled nonferrous products including strips, foils, wire, and wound tubular products.
Coils of copper-based alloy products are heat treated in a controlled atmosphere. The atmosphere used depends on the specific alloys and the annealing process which is required. The gases, which are available, include pure hydrogen, nitrogen or mixtures of the two. For the homogenization of certain alloys, nitrogen is selected as the atmosphere gas for economic reasons as hydrogen is more expensive and offers no advantages for this process.
In contrast, nonferrous metals are normally recrystallized using pure hydrogen as an atmosphere gas in order to obtain a bright metal surface by way of the high chemical reducing potential of the gas. In addition, the high thermal conductivity of hydrogen enables considerably higher heating and cooling throughputs compared to nitrogen.
Value for Money
- Low operating costs
- Low shop floor space consumption due to high efficiency
- High efficient burner-individual recuperators
- High convective heat transfer
- Excellent temperature uniformity
- Sophisticated process control
- O2 concentration monitoring during prepurging
- TÜV proven safety strategy
- Long service life
- Sturdy cast diffusor system
- > 60 years of experience in Bell-type Annealing
- > 8,500 bases worldwide (>3,500 HPH®)
- Selection of alternative cooling systems i.e. for low water quality or extended energy recovery
- Fully automated control system
- Various software modules for optimization
- World's first fully automated BAF plant
- HPH®-Flameless combustion technology
Multi-stack Bell-type Annealing Furnaces (MBAF) for Silicon Steel StripTenova LOI Thermprocess, with its predecessors Matthias Ludwig and Nassheuer, has been building bell-type annealing plants for more than 60 years. Throughout the world, more than 500 LOI multi-stack annealing bases have been installed. The world-wide market share during the past 10 years is virtually 100%.