Feasibility of Using Low Pressure Steam for Sootblowing, 2004 International Chemical Recovery Conference

Sootblowers typically consume 5 to 12% of the total superheated steam produced by a kraft recovery boiler. With properly designed fully-expanded nozzles the sootblower nozzle steam pressure can be reduced from 300 psig (20 bars) to 150 psig (10 bars), without significantly jeopardizing the cleaning effectiveness of the sootblower jet. Laboratory tests showed that a 20% increase in flow rate makes a low pressure nozzle (150 psi) even more effective at greater distances than 300 psi nozzles. Since low pressure steam extracted from the steam turbine is much less expensive than high pressure steam, the flow rate increase is economically justified. This offers the possibility of using steam from downstream side of the turbine for sootblowing, with the advantage of significant energy savings. However, because of inevitable pressure losses in the steam delivery tubes and valves, the turbine extraction steam pressure, suitable for low pressure sootblowing, should be at least 210-230 psi.