Energy Efficiency & Cost Reduction Through the Implementation of Low Pressure Sootblowing System

Energy Efficiency and Cost Reduction through the implementation of low pressure sootblowing system Danny S. Tandra Jim Hinman Marc Olson Steve Breaux - Clyde Bergemann, Inc, Atlanta, GA, USA - Weyerhaeuser Company, Federal Way, WA, USA - Weyerhaeuser Company, Portland Engineering, OR, USA - Weyerhaeuser Company, Valliant mill, OK, USA

ABSTRACT Sootblowers in a kraft recovery boiler consumes a large amount of valuable high-pressure steam to maintain high thermal efficiency and prevent costly unscheduled shutdowns due to plugging of flue gas passages. For the past eight years, extensive research and mill trials have been carried out to explore the feasibility of utilizing less expensive low pressure steam for sootblowing. Results of numerous laboratory experiments, Computational Fluid Dynamic (CFD) simulations, and several mill trials have shown that low pressure sootblowing is technically and practically feasible, providing that the sootblower is properly designed and its nozzles are engineered to produce a cleaning power that is comparable to that of high pressure sootblowers. Weyerhaeuser has implemented the first complete low pressure sootblowing system on a new 6.3 million lb/day (2,860 ton/day) DBLS recovery boiler. The steam pressures at the sootblower poppet valve range from 107 psig (7.4 bar) in the economizer sections to 170 psig (12 bar) in the superheaters. This paper discusses the underlying technology of low pressure sootblowing, its full implementation at Weyerhaeuser –Valliant Mill, the cleaning performance, and the economic benefits of the system.

INTRODUCTION The accumulation of fireside deposits on recovery boiler heat transfer surfaces not only creates an insulating barrier that reduces the boiler thermal efficiency, but also can lead to costly unscheduled shutdown due to the plugging of the gas passes. Control of the deposit accumulation is attained by sootblowers, which periodically blast deposit off the tube surfaces with high pressure...