OBSERVATIONS ON THE DYNAMICS AND EFFICIENCY OF SOOTBLOWING IN KRAFT RECOVERY FURNACES .2. EFFICIENCY - LOCATION AND TIMING DICTATE EFFECTIVENESS

Flue gas and steam temperature data collected on-line using infrared p yrometers and thermocouples were used to examine the dynamics and effe ctiveness of sootblowing. These studies indicated thar sootblowers wer e relatively ineffective dye at removing fouling deposits from convect ion section tube banks in the test furnace and were not able to remove carryover deposits that accumulated on the front of the tubes. Foulin g was not reduced after a week using a double-blowing sequence with so otblowing concentrated in the heavily-fouled secondary superheater. Op eration of certain sootblowers in the economizer section of this parti cular furnace was found to be crucial to prevent furnace draft loss al though these sootblowers had little effect on the observed heat transf er efficiency in the economizer, Since sootblowing had little effect o n heat transfer efficiency after tile first two to three weeks of oper ation following a crater wash, it should be used primarily to maintain furnace draft. If these results are confirmed in other furnaces, soot blowing steam consumption can be dramatically reduced in many recovery furnaces without significantly affecting furnace throughput or tile o perating time between water washes.