Metso shredders offer results in combined heat and power applications

Metso Waste Recycling, Helsinki, announced the company has developed a solution to boost the capacity of combined heat and power (CHP) plants.

The size of the waste burned in a CHP plant is essential to the operation. If the fragments of waste are too large, it can lead to downtime during which the facility must be left idle for days until the temperature is low enough to allow the work to be performed. This can be avoided with Metso Waste Recycling’s series solution, which meets bubbling fluidized bed (BFB) requirements for input material, the company says. Metso says its first M&J preshredder in the system handles the coarse shredding, while the following one fine-shreds it, thus ensuring that the input for combustion is small and homogeneous. Tests show that 95-96 percent of the waste can be reduced to under 120 mm in size, the company says.

Metso Waste Recycling’s solution has been installed in several CHP plants in Scandinavia. The company says these solutions have succeeded in reducing the cost of operation and maintenance (typically by 50 percent), as well as helped increase the processing capacity at every site. Another advantage, the company says, is that the plants can handle larger waste fragments and are, therefore, less dependent on receiving the waste in specific sizes. More waste can then be run through the system with even greater reliability and a better residual product.

"Customers using our solution in BFB boilers tell us that the residue is of a higher quality. Most metal can be separated for recycling without shredding," Laila Sondergaard, project manager of marketing, waste and recycling at Metso, says.