SHOCK PULSE GENERATORS

BOILER CLEANING

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In Energy from Waste and Biomass plants,severe fouling of boiler walls and tubes canoccur 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

All these will contribute to reduced production, highermaintenance costs and less power generated, which all leadto lower profits.

THE PROBLEM

This is an example of pressure drop, del(P), as a result of fouling build up over8 months, leading to repeated cleaning interventions being required.

Fouling filmed from inside the boiler withKRR ProStream’s High Temperature camera

Fouling filmed from outside the boiler

6 mbar

0 mbar

Shock Pulse Generators: Replace sootblowers, reducing valuable

steam consumption

Have a compact design that reduces theplatform space required

Have a smaller footprint than sootblowers

Provide constant cleaning to preventunplanned outages due to severe fouling

By constantly keeping surfaces inside theboiler clean they maximize heat transfer forhigher boiler efficiency

Reduce ID fan power consumption

Help to increase plant profitability andreduce operational cost

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THE SOLUTION

Installing a Shock Pulse Generator on the boiler near areas ofhigh level fouling will keep both tubes and boiler walls clearuntil the next outage.

Fouling remains when cleaning with 6 soot blowers

Results when cleaning with 2 EG10s

The TwinL, the largest SPG in the currentrange, with a small footprint (left)

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

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DESIGN AND FUNCTION

SPG Schematic – EG10 Model

1. STANDBY MODE: The natural gas and oxygen dosingtanks are filled to a pre-set pressure. The nitrogenpressure presses the piston against the valve seatkeeping the empty combustion chamber sealed

2. FILLING: Upon the start of the cycle, the filling valveopens. The dosing tanks are filled to a set pressure, andthe valves close

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HOW IT WORKS

3. TRANSFER: The transfer valves open and the two gases flow via non-return valves and flame backstrokebarriers, where they are mixed and then enter the mainand pre-combustion chambers

4. IGNITION: The glow plug is activated, igniting themixture in the pre-combustion chamber. The expansionof 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 hastravelled to the main combustion chamber igniting themain body of gas, generating a shock pulse, which isdischarged through the nozzle into the boiler

6. END OF CYCLE: Once the gases have been fullydischarged from the combustion chamber, the nitrogenpressure forces the piston against the valve seat, re-sealing the unit. The shock pulse generator is then readyfor the next cycle

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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 6Shock Pulse Generator EG10L on side wall

Shock Pulse Generator EG10L on opposite side wall

Shock Pulse Generator EG10L on front wall

PLANT DETAILS: 17 t/h steam capacity 2nd pass: W 3.1 x L 1.6 m + 4 panel

evaporators Cleaned by 1 EG in 3rd pass since 11/2009,

instead of manual explosion cleaningsevery 2-4 months

3rd pass: W 3.1 x L 2.1 m 2 SPG since 06/2009, instead of 8

sootblowers 4th 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

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CASE STUDY AT LUCERNE EfW

The Shock Pulse Generators were the sole method of cleaning the boiler for fiveyears, performing more than 500,000 shock pulses.

The graph below demonstrates the improved plant perfomance after SPG installation

KeyShock Pulse Generator EG10L on side wall

Shock Pulse Generator EG10L on rear wall

KRR PROSTREAM Home Farm Business Unit 7, Loseley Park, Guildford, GU3 1HSTel: 01483 570 044 | email: info@krrprostream.com | www.krrprostream.com

CASE STUDY AT ZURICH JOSEFSTRASSE

KeyShock Pulse Generator TwinL on side wall