REDUCTION OF FINE PARTICULATE EMISSIONS FROM ESPs Karsten S. Poulsen Carsten R. Lund FLSmidth Airtech Ramsingsvej 30

2. AgendaAgenda

3. For as long as I remember curves showing the required emission vs time have had a declining tendency. Originally this came in focus for production loss reasons, later on for purely visual reasons and now for more idealistic and environmental reasons As zero-emissions were approached and further reductions became difficult - without going into negative values � the legislators came up with inventive ideas of challenging the ESP product Most recent focus has shifted more towards the actual particle size of matter leaving the stack � and this is for good and public healt reasonsFor as long as I remember curves showing the required emission vs time have had a declining tendency. Originally this came in focus for production loss reasons, later on for purely visual reasons and now for more idealistic and environmental reasons As zero-emissions were approached and further reductions became difficult - without going into negative values � the legislators came up with inventive ideas of challenging the ESP product Most recent focus has shifted more towards the actual particle size of matter leaving the stack � and this is for good and public healt reasons

4. But that�s one of the things that keeps us in the business When plates & electrodes are made in the right manner and you do your particle charging efficiently, you are on the right path You may cheat a little by adding certain devices � or water � to achieve the goal, but I will leave that for the other speakers For purely dry ESPs the way is to remove the disturbances to achieve low emissions and thereby also reduce the fine particle emissionBut that�s one of the things that keeps us in the business When plates & electrodes are made in the right manner and you do your particle charging efficiently, you are on the right path You may cheat a little by adding certain devices � or water � to achieve the goal, but I will leave that for the other speakers For purely dry ESPs the way is to remove the disturbances to achieve low emissions and thereby also reduce the fine particle emission

5. In the laboratory the working hours normally are better than site-work, but the food usually is better on site !In the laboratory the working hours normally are better than site-work, but the food usually is better on site !

6. In order to meet the increasing demands on particulate removal the dry ESP is challenged in many ways ESP manufacturers have had a constant focus on improving the product by elimination of non-ideal effects reducing the performance We have seen in our laboratories that extremely low emissions are indeed possible with our hand made small scale units � upgrading this knowledge to full scale is sometimes more difficult And when focus is set on particle size emission, the build-in deficiency of ESP � and other dust collectors � in the critical range below 1 �m simply becomes more interesting�but there�s no safe place for any of themIn order to meet the increasing demands on particulate removal the dry ESP is challenged in many ways ESP manufacturers have had a constant focus on improving the product by elimination of non-ideal effects reducing the performance We have seen in our laboratories that extremely low emissions are indeed possible with our hand made small scale units � upgrading this knowledge to full scale is sometimes more difficult And when focus is set on particle size emission, the build-in deficiency of ESP � and other dust collectors � in the critical range below 1 �m simply becomes more interesting�but there�s no safe place for any of them

7. At earlier conferences we have presented results of performance improvement by means of electrodes or pulse generators but as good democrats lately we in FLSmidth Airtech have had great success in treating all the gas and all the particles in the same way We have seen many ESPs � including our own - working in with reduced performance � for no particular reasons Baffle plates have either been missing, installed in an improper manner or have lost some of their purpose due to accumulations All of these facts will reduce the performance of the ESP. So the only thing to do is to remove the non-ideal phenomenon to approach laboratory conditions. When this is done, field testing becomes increasingly important to develop our understanding of the ESP collection of fine particlesAt earlier conferences we have presented results of performance improvement by means of electrodes or pulse generators but as good democrats lately we in FLSmidth Airtech have had great success in treating all the gas and all the particles in the same way We have seen many ESPs � including our own - working in with reduced performance � for no particular reasons Baffle plates have either been missing, installed in an improper manner or have lost some of their purpose due to accumulations All of these facts will reduce the performance of the ESP. So the only thing to do is to remove the non-ideal phenomenon to approach laboratory conditions. When this is done, field testing becomes increasingly important to develop our understanding of the ESP collection of fine particles

8. Elimination of sneakageElimination of sneakage

9. Conv bafflesConv baffles

10. We in FLSmidth Airtech have found a way to eliminate turbulence behind the baffling system in top and bottom of the ESP casing The new Vortex Free Baffles have been installed as a quick fix on some trouble shooting jobs � and it worked� Today it is part of our standard design for both retrofit jobs and new ESPsWe in FLSmidth Airtech have found a way to eliminate turbulence behind the baffling system in top and bottom of the ESP casing The new Vortex Free Baffles have been installed as a quick fix on some trouble shooting jobs � and it worked� Today it is part of our standard design for both retrofit jobs and new ESPs

11. Vortex Free BafflesVortex Free Baffles

12. Field tests � influence on particle sizeField tests � influence on particle size

13. In order to gain more knowledge on fine particle behavior more field testing is required For one of he cement processes � the alkali bypass � having most fine particles we have recently conducted some tests which we would like to share with you At this particular plant there is a recirculation of the gases passing the gas conditioning tower which gives a controlled temperature to the ESP at a very high moistureIn order to gain more knowledge on fine particle behavior more field testing is required For one of he cement processes � the alkali bypass � having most fine particles we have recently conducted some tests which we would like to share with you At this particular plant there is a recirculation of the gases passing the gas conditioning tower which gives a controlled temperature to the ESP at a very high moisture

14. After the ESP we have made a series of measurements in the duct Among these � on line measurement of the particle size distributionAfter the ESP we have made a series of measurements in the duct Among these � on line measurement of the particle size distribution

15. By-pass resultsBy-pass results

16. And the results as described in the paper speaks for themselves� On a selection of applications, the dust emission is very low. The reasons for the low emissions in the cases shown is a combinations of the Vortex Free Baffles, discharge electrode optimisation and other control features for the ESP other equipment on the plants As you see both the total dust emission are low and where data is available also the fine particle levels are lowAnd the results as described in the paper speaks for themselves� On a selection of applications, the dust emission is very low. The reasons for the low emissions in the cases shown is a combinations of the Vortex Free Baffles, discharge electrode optimisation and other control features for the ESP other equipment on the plants As you see both the total dust emission are low and where data is available also the fine particle levels are low

17. ConclusionConclusion