Method and apparatus for drying bulk material, especially bark, sawdust, pretreated sludge or a mixture thereof

摘要

Method and apparatus are provided for drying bulk material, especially bark, sawdust, pretreated sludge or a mixture of these. Also provided are a method and apparatus for cooling waste water produced in a pulp or paper production process. Certain embodiments include a pulp mill, paper mill and a novel way of using a wire. Other embodiments provide for cooling in one and the same heat exchanger the waste water produced in a pulp or paper production process while simultaneously heating the gas that cools the waste water. Heated gas extracted from the heat exchanger is conducted through one or several drying conveyers and through the material to be dried that is conveyed on the drying conveyer so as to dry the material with the heated gas.