Abstract: 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.

Abstract: The invention comprises a method and apparatus (1) for drying bulk material, especially bark, sawdust, pretreated sludge or a mixture of these. The invention also comprises a method and apparatus for cooling waste water produced in a pulp or paper production process. The invention furthermore comprises a pulp mill, paper mill and a novel way of using a wire (21). According to the invention, in one and the same heat exchanger (13) both waste water produced in a pulp or paper production process is cooled and, simultaneously, gas that cools the waste water is heated. Heated gas extracted from the heat exchanger (13) is conducted through one or several drying conveyers (15) and through the material to be dried that is conveyed on the drying conveyer (15), whereby said material is dried with the heated gas.

Abstract: An unloader for discharging material stored in a silo or similar through an outlet opening in the bottom of the silo has a frame which pivots around a vertical axis and on which is supported a horizontal transport screw rotating around its longitudinal axis. The pivot frame is provided with an upper protecting hood which, in order to prevent arching of material located on top of it, is mounted on the pivot frame so that it does not rotate, as the pivot frame rotates, but continuously is inclined back and forth.