SMELT X WASH -X. Valmet Energy and Environmental (ENE) North America Mike Ward

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Charles Hutchinson
5 years ago
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1 SMELT X WASH -X Valmet Energy and Environmental (ENE) North America Mike Ward

2 SMELT-X

Smelt-X Overview Smelt is extracted by an ejector driven by pressurized air Simple design, No moving parts = Reliable, Reusable 200 + Smelt-X projects have been carried out in pulp mills in Europe,

3 Smelt-X Overview Smelt is extracted by an ejector driven by pressurized air Simple design, No moving parts = Reliable, Reusable Smelt-X projects have been carried out in pulp mills in Europe, North and South America, Asia, Africa and Australia Smelt bed cooling time can be reduced to 4 6 hours from hours. As a result, time spent in recovery boiler washing can be reduced by hours Ejectors remove smelt directly into dissolving tank without exposing spouts to high smelt flow and temperature 3

4 Smelt-X Ejector Operates by entrainment and siphon effect Compressed air acts to shatter smelt Compressed air is preheated before entrainment of smelt Air Pipe Support Coil Air Connection 90 psi Suction Tube Smelt Spout Ejector Tube Mini Hood 4

5 Flexible Design 3 Standard designs are used Insures smelt removal from the deepest point of the furnace floor 5 3 Standard designs are used

6 Compressed Air Compressed air causes a Venturi effect which creates the suction to remove molten smelt The longer the air tube the more the air gets preheated and the less likely it is that the smelt will freeze inside the ejector Optimal distance between ejection tube exit end and air tube exit end Is 12 inches 6

7 Extension Hook & Latch type extension used for some hood styles 7

into spouts and valves controlling air flow are opened Smelt extraction with ejectors is continued until the smelt

8 Smelt X Operations A smelt bed temperature of approximately 1600F is best to maintain the bed molten and flowing Firing black liquor is effective at maintaining the desired extraction temperature Smelt-X ejectors are installed into spouts and valves controlling air flow are opened Smelt extraction with ejectors is continued until the smelt pool is empty Thermocouples are used to monitor bed temperature Firing is stopped, pressure reduction and cooling begins 8

Benefits Reduced Time: - Faster cooling of bed - Less time for cleaning furnace bottom Inspection and maintenance can be started earlier Reduced Cost: Shorter outages

9 Benefits Reduced Time: - Faster cooling of bed - Less time for cleaning furnace bottom Inspection and maintenance can be started earlier Reduced Cost: Shorter outages Lower cleaning costs Less bed chemicals not recovered Better Inspection: Better inspections can be performed on areas where smelt would have otherwise been covering 9

10 Video 10

11 11 WASH-X

12 Wash-X Overview Water is sprayed to the floor as soon as safe bed temperatures have been reached Water can be sprayed to furnace floor through liquor guns or nozzles installed in various openings Several water sources can be used 0 0 Eductors are installed on the furnace floor and operated continuously throughout the whole boiler washing period Once superheaters are clean, the mixing devices are removed and floor is emptied from wash water using smelt ejectors 12

13 Wash-X Operations Salt concentration is used to monitor washing effectiveness Up to 8 eductors are inserted to start floor washing in parallel with superheater washing Hot water results in faster washing and may also be needed to dissolve large ash deposits which fall to the floor The wash pool volume protects the floor from large falling deposits Wash salt concentration density is periodically measured If the wash water density increases above 1.25, higher wash water flow is likely to be beneficial. Densities below 1.1 would indicate that wash water flow rate can probably be reduced without significant reduction in dissolving rate Page 13

14 Typical time schedule for Smelt-X & Wash-X h Bed reduction Oil firing Smelt-X Depressurization Economiser washing Boiler bank washing Superheater washing Floor washing Wash water removal Drying Safety roof installation Scaffolding 15 - Total time spent on cooling and washing Friday Saturday Page 14

15 The outage begins ahead of schedule Page 15

16 References Number of Smelt-X projects Total Smelt-X Projects S Am N Am EMEA Page 16 Total

Wash-X preparations. Timo Karjunen 5/2/2016

Wash-X preparations. Timo Karjunen 5/2/2016 Wash-X preparations Timo Karjunen 5/2/2016 Wash-X service 1. Water is sprayed to the floor as soon as the remaining bed has cooled down to 800ºF and floor tube temperatures are below 300ºF. Water can be