PROCESS AND SYSTEM FOR TREATING BULK MATERIAL UTILIZING FLASH AND LEAKAGE STEAM IN A BULK HANDLING SYSTEM

摘要

The invention relates to a process and system for treating bulk material. In particular the invention relates to drying bulk material in a pneumatic steam dryer and treating the bulk material before and/or after the pneumatic steam dryer in a bulk material handling system. The process for treating bulk material according to the invention comprises -feeding bulk material by an inlet feeding device (131,401) into a steam filled circulation conduit (105) of a pneumatic steam dryer (100) operating above atmospheric pressure -heating said steam by heating means (121), -drying said bulk material in a drying conduit (111) by heat transfer from said steam thereby forming surplus steam, -separating said bulk material from said steam by a first separating means (150), -pneumatically conveying said bulk material suspended in said steam through said drying conduit from said inlet feeding device (131,401) to said first separating means (150), -releasing surplus steam from said circulation conduit (105), -discharging said bulk material by an outlet feeding device (141) from said pneumatic steam dryer thereby generating flash and leakage steam, and utilizing said flash and leakage steam in a bulk material handling system (200;200';200") connected to said pneumatic steam dryer(100).