Batch homogenizing for round logs

Many major aluminum producers combine continuous and batch homogenizing systems for ultimate flexibility.
Even when they replace obsolete batch homogenizing equipment with continuous homogenizers, most customers retain some of their existing batch plants to process certain special alloys.

Operating labor for a combined plant is typically limited to:

  • Data storage on log entry
  • Quality control at visual/UT inspection station
  • Billet saw
    Available here are furnaces for round logs, rolling slabs, and combination furnaces (slabs & logs).
  • Single-chamber furnace up to 60 t
  • Double-chamber furnace up to 120 t
    These plants achieve top homogenizing quality with accurate temperature control (+/-3°) and reversing air flow for near-uniform heating and cooling.
Picture - Typical plant layout (Batch&Conti)
Typical plant layout (Batch&Conti)
Picture - 2x Stack - Storage - 2x - Homogenizer - 1x Cooler
2x Stack - Storage - 2x - Homogenizer - 1x Cooler
Picture - Plant overview

HE variable spacer system

Combined with a moveable bottom in the furnace and cooler, single spacers are arranged at equal distances for the best possible log support. Furthermore, they are designed to prevent overhanging of log ends. Another key function of the moveable bottom is to compensate heat expansion or contraction. That avoids surface marks on the logs. These single spacers are lighter than spacer frames, which contributes to lower energy consumption.

Picture - Automatic Log Handling

Automatic log handling

Modern plants include automated stacking and destacking equipment for lean production and better safety. They often feature a spacer manipulator, spacer magazines, and a crane for handling log layers. Ideal for this process automation are spacers made of heat-resistant steel square tubes. They are extremely durable, as demonstrated by spacers supplied in 1990 which are still in use today. 

Furnace design

Conventional batch homogenizing furnaces apply the principle of mono-directional airflow, as shown by the illustration on the left. You know all about the problem of uneven heating of logs in a stack. Now, our new-generation furnaces with reversing air heat the logs some 20% faster. You benefit because the reversing airflow drastically reduces temperature deviation between the outer and inner logs. Vital to the process is an intensive airflow and perfect heat distribution to achieve near-uniform log temperature throughout the stack. Typically, reversing-air batch homogenizing furnaces come with reversing-type ventilators. However, this is not particularly efficient, because every change in flow direction costs time and puts mechanical strain on units such as motors and fan wheels. Bidirectional fan wheels are less efficient and reach only around 70% of the nominal airflow in one direction. The solution? Our high-efficiency furnaces and cooling stations. They feature flaps that switch the airflow direction within 3 - 5 seconds without extra strain on motors and fan wheels. That ensures 15 - 20% faster heating up.

SMSgroup Image
Monodirectional airflow furnace
SMSgroup Image
HE flap type reversing air furnace