Expansion furnace

The controlled expansion

The vertical expansion furnace used in the innovative BUBLON expansion technology is heated electrically; energy transfer is achieved through heat radiation.

The expansion furnace consists of several identical heating zones in which the temperature is individually and finely adjustable. The expansion rate of the final light fillers can be optimized by setting an exact temperature profile and through an optional air-stream sorting.

The expansion rate of the final lightweight material can be optimized through the number of modules used and optional air-stream sorting. This controlled expansion ensures lightweight materials with excellent product properties such as the glazed and closed surface. The expansion furnaces can be expanded by additional modules and it is even possible to operate several units in parallel.

The specific advantages of the BUBLON expansion furnace:

  • the temperature can be individually adjusted in different zones
  • this allows for a targeted variation of product qualities
  • in combination with the pneumatic conveying of fully expanded materials, the operation of the expansion furnace takes place under a slight vacuum, avoiding the emission of dust and parti-culate matter
  • the expansion rate of the raw material can be increased by way of optional wind shifting
  • the flow rate can be individually adjusted
  • the number of modules in the shaft furnace is balanced with the quality of the final product
  • the system is adaptable and expandable to several modules and parallel shaft furnaces

The starting point in the BUBLON-Technology is the raw sand silo. This is where the mechanically processed (crushed and screened) raw material is stored. The material is then fed through the down-stream rotary feeder.

The elevator feeds the fluidised bed dryer. The fluid bed is operated in a closed cycle and is fuelled either electrically or with natural gas.

After the thermal preparation, the raw sand is moved from the fluid bed into a container from where the raw sand is continuously conveyed further into the electrically heated expansion furnace. The energy input is transformed entirely into heat for the expansion of the granulate. The usually inevitable hot and dusty exhaust gases are avoided.

In further processing stages the final BUBLON® spheres can be packaged, palletized and stored.