SHOCK PULSE GENERATORS BOILER CLEANING

Transcription

1 SHOCK PULSE GENERATORS BOILER CLEANING

2 THE PROBLEM In Energy from Waste and Biomass plants, severe fouling of boiler walls and tubes can occur after short operating periods. This can cause many problems, such as: Blockages that lead to unplanned outages High pressure differentials Reduced heat transfer High flue gas temperatures Fouling filmed from inside the boiler with KRR ProStream s High Temperature camera All these will contribute to reduced production, higher maintenance costs and less power generated, which all lead to lower profits. Fouling filmed from outside the boiler 6 mbar 0 mbar This is an example of pressure drop, del(p), as a result of fouling build up over 8 months, leading to repeated cleaning interventions being required. 2

3 THE SOLUTION Installing a Shock Pulse Generator on the boiler near areas of high level fouling will keep both tubes and boiler walls clear until the next outage. Shock Pulse Generators: Replace sootblowers, reducing valuable steam consumption Have a compact design that reduces the platform space required Have a smaller footprint than sootblowers Provide constant cleaning to prevent unplanned outages due to severe fouling By constantly keeping surfaces inside the boiler clean they maximize heat transfer for higher boiler efficiency Reduce ID fan power consumption Help to increase plant profitability and reduce operational cost Fouling remains when cleaning with 6 soot blowers Results when cleaning with 2 EG10s The TwinL, the largest SPG in the current range, with a small footprint (left) 3

4 DESIGN AND FUNCTION 24/7 continuous boiler cleaning with automatically generated shock pulses 277 units installed in 15 countries a reference list is available Extremely efficient online boiler cleaning technology Small and compact design, easily retrofitted into existing plants or designed into new builds SPG Schematic EG10 Model 4

5 HOW IT WORKS 1. STANDBY MODE: The natural gas and oxygen dosing tanks are filled to a pre-set pressure. The nitrogen pressure presses the piston against the valve seat keeping the empty combustion chamber sealed 2. FILLING: Upon the start of the cycle, the filling valve opens. The dosing tanks are filled to a set pressure, and the valves close 3. TRANSFER: The transfer valves open and the two gases flow via non-return valves and flame backstroke barriers, where they are mixed and then enter the main and pre-combustion chambers 4. IGNITION: The glow plug is activated, igniting the mixture in the pre-combustion chamber. The expansion of gases forces the piston away from the valve seat 5. COMBUSTION: By the time the piston has retracted, the flame from the pre-combustion chamber has travelled to the main combustion chamber igniting the main body of gas generating a shock pulse, which is discharged through thenozzle into the boiler 6. END OF CYCLE: Once the gases have been fully discharged from the combustion chamber, the nitrogen pressure forces the piston against the valve seat, resealing the unit. The shock pulse generator is then ready for the next cycle 5

6 TYPICAL LOCATIONS FOR SPGs EfW Plant Empty Passes EfW Plant Empty pass and Superheater EfW Plant Superheater and Economiser EfW Plant Sludge and Medical Waste Key for page 6 Shock Pulse Generator EG10L on side wall Shock Pulse Generator EG10L on opposite side wall Shock Pulse Generator EG10L on front wall 6

7 CASE STUDY AT LUCERNE EfW PLANT DETAILS: 17 t/h steam capacity 2 nd pass: W 3.1 x L 1.6 m + 4 panel evaporators Cleaned by 1 SPG in 3rd pass since 11/2009, instead of manual explosion cleanings every 2-4 months 3 rd pass: W 3.1 x L 2.1 m 2 SPGs since 06/2009, instead of 8 sootblowers 4 th pass: W 3.1 x L 1.9 m 1 SPG since 02/2010, instead of shot ball system Cleaning effect very good Improvements in boiler operating & maintenance cost Plant supplier: Von Roll (HZI) Plant operator: Real Luzern Key Shock Pulse Generator EG10L on side wall Shock Pulse Generator EG10L on rear wall The Shock Pulse Generators were the sole method of cleaning the boiler for five years, performing more than 500,000 shock pulses. The graph below demonstrates the improved plant perfomance after SPG installation 7

8 CASE STUDY AT ZURICH JOSEFSTRASSE Key Shock Pulse Generator TwinL on side wall KRR PROSTREAM Home Farm Business Unit 7, Loseley Park, Guildford, GU3 1HS Tel: