On-Load Boiler Cleaning with Steam CBW Clyde Bergemann Wesel 10.2007 - Rev. 5 March 16, 2017 FPK II Combustion Chemistry II Åbo Akademi University, Åbo
The Cleaning Systems at a Glance 1 Furnace 5 Air heater/ Gas heater 6 DeSOx Wall blower Water cannon Rake sootblower Jetblower Part retractable sootblower Optimisation 2 Superheater/ Re-Heater Retractable sootblower Oscillating sootblower Axial sootblower Jetblower Part retractable sootblower SMART Helix 2 3 4 SMART Clean Automation SMART Control Remote Control 3 ECO 6 Part retractable sootblower Rotating element sootblower 1 5 4 DeNOx Rake sootblower 2
Sootblower 3
Sootblower in operation 4
Sootblower Solutions - Types Sootblower Description Principle Wall Blower Cleaning of wall heating surfaces with heavy slagging As steam or water blowers Retractable Sootblower cleaning of heating surface banks with heavy fouling and high flue gas temperatures Part Retractable Sootblower Cleaning of heating surface banks with heavy fouling Blowing tube remains in the flue gas pass 5
Content Sootblower solutions Sootblower technology for the furnace Wall blower VS-H Sootblower technology for convective heat exchangers Retractable sootblowers - PS-H, RSG-H, RXC-H Part Retractable sootblowers - PS-HB, RSG-HB Important design features 6
Wall blower VS-H Nozzle head is axially moved into the boiler. Blowing process begins as soon as the nozzle head has passed through the tube wall. During the process, the tube wall is cleaned in circular form. On reaching the front end position, the direction of movement changes and the nozzle head returns to its starting position. 7
Wall blower VS-H Blowing arc: 30 to 360 Blowing medium: Steam, air Blower valve: Screw spindle: Cast steel with adjustable throttle disc for varied blowing pressure Threaded tube with stuffing box casing Feed tube: Stainless steel; Ø60 mm Nozzle head: Heat resistant steel 8
VS-H Functional aspects Gear Motor Sealing & Scavenging Air Fan Valve Actuating Mechanism Valve Electrical Equipment (not shown in fig. above) Wall Box Nozzle Head Construction Kit Screw Spindle Feed Tube 9
VS-H Cleaning pattern Clenaing pattern of VS-H wall blower Spiral cleaning pattern due to wall blower type that advances into the boiler as it cleans On-Load Boiler Cleaning Systems 10
Content Sootblower solutions Sootblower technology for the furnace Wall blower VS-H Sootblower technology for convective heat exchangers Retractable sootblowers - PS-H, RSG-H, RXC-H Part retractable sootblowers - PS-HB, RSG-HB Important design features 11
Operating principle Retractable sootblower Blowing medium Steam, air The lance with two opposite, highperformance nozzles helically moves into the flue gas pass. The blowing process may begin as soon as the two nozzles have passed through the boiler wall. During the blowing process the lance tube continues to move helically into the flue gas pass. On reaching the front-side end position the direction of movement changes and the lance tube returns to its starting position. 12
Cleaning mechanism Retractable sootblower 13
Retractable sootblowers PS-H RSM-H 14
Retractable sootblower Travel: Blower valve: Feed tube: 0,3m - 20m over single or double rack (heavy-duty) Cast steel with adjustable throttle disc for varied blowing pressure Stainless steel; Ø60 mm or Ø70 mm Lance tube: Creep resistant or high alloy steels O.D. Ø88,9 mm, Ø101,6 mm and Ø114,3 mm 15
Retractable sootblowers (PS series) Lance Tube Guidance Electrical Equipment Covering System Rear Suspension Sealing & Scavenging Air Equipment Valve Actuating Mechanism Valve Wall Box Lance Tube Lance Tube Track Beam Blower Carriage Gear Motor Feed Tube Support Feed Tube Support 16
Cleaning mechanism - Part Retractable sootblower 17
Part Retractable sootblower Travel: Blower valve: Blowing tube: 0,3m - 8m over single or double rack (heavy-duty) Cast steel with adjustable throttle disc for varied blowing pressure Of material creep resistant steel or of higher alloyed steel O.D. Ø60,3 / Ø 76,1 / Ø88,9 mm With welded-in nozzles and element bearings Feed tube: Stainless steel; Ø60 mm (or Ø70 mm in special cases) Lance tube: Creep resistant or alloy steel O.D. Ø88,9 mm (or Ø101,6 mm in special cases) 18
Failure due to axial crack formation Mussmann, UoToronto 2009 19
Failure due to surface pitting/axial crack formation Mussmann, UoToronto 2009 20
Failure due to spalling Mussmann, UoToronto 2009 21
Deposit break-up by steam jet Mussmann, UoToronto 2009 Thin deposit Distance = 9 cm Soft deposit Break-up duration: 3 ms 22
Deposit break-up by steam jet Mussmann, UoToronto 2009 Thick deposit Distance = 9 cm Soft deposit Break-up duration: 9.50 ms 23
Deposit asymmetry Actual deposits in boilers Boiler tubes Deposit Carry-over Flue gas Mussmann, UoToronto 2009 24
Deposit asymmetry Symmetric Asymmetric Deposit Steel tube Mussmann, UoToronto 2009 25
Deposit asymmetry 90 JET Mussmann, UoToronto 2009 26
Deposit asymmetry (0º vs. 90º) Mussmann, UoToronto 2009 27
Content Sootblower solutions Sootblower technology for the furnace Wall blower VS-H Sootblower technology for convective heat exchangers Retractable sootblowers - PS-H, RSG-H, RXC-H Part Retractable sootblowers - PS-HB, RSG-HB Important design features 28
Sootblower Design Toolbox System design Official Release 1.0 29
Sootblower Design Toolbox Project specific input parameters Calculation of fluid flow and mechanical stability including heat transfer Calculation of droop correction, steam consumption and jet profile 30
Quality of steam 31
Quality of steam 32
Recommended design principals for steam feeding systems Piping arrangement: Inclination for proper draining. Avoid Christmas Tree piping layout. Pre-heating control: Draining temperature controlled, not time controlled. Cleaning sequence: Start with sootblower nearest to the drain station. Short connecting pipe: Secure complete pre-heating; avoid cold pipe parts. 33
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