The unit comprises a Primary Chamber into which the waste is continuously fed through slow-moving augers and a Secondary Chamber underneath where combustion takes place. The floor of the Primary Chamber forms a hot hearth under the incoming waste. In addition, each unit has an inlet arrangement for the primary feed, an outlet chamber for the ash residual and a stack for final emissions. The operating temperature in the primary chamber is usually between 800 and 900⁰C. Ash from the hearth exits the chamber at the end of the feed augers to a receiving hopper.
Afterburning, or the complete oxidation of volatile gases, takes place in the secondary chamber. The Brookes Gasifier has a “cracking zone” which is unique and is a product of the special geometry of the system. The residual ash from the gasifier is completely oxidised and inert. On average, the ash constitutes about 5 to 7% by weight of the original waste.
Considerable amounts of surplus heat are generated in the gasification process as the temperature in the outlet chamber of the gasifier can reach 1,000⁰C. This surplus heat can be exploited in several conventional ways e.g. to produce steam for downstream power generation, hot water for process or washing down, or hot air for heating poultry-rearing units, all depending on the user’s requirements. Any power generated qualifies for premium rates paid for alternative energy in whatever location the gasifier is installed.
The gasifier is particularly suited to single industrial installations where it can be used to convert a difficult waste to a product which provides recoverable energy for use on site in whatever form required. Where applicable, surplus energy can be sold to the grid and the residual ash disposed of beneficially. It has a small footprint and requires only a single-phase 220/240V power supply.