E N E R G Y S Y S T E M S L T D
High Effi ciency Dynamic Classifi er – USA Retrofi t ProjectIncreasing throughput on an MPS 89 mill
Loesche Energy Systems Ltd were contracted to design, manufacture and supply high effi ciency dynamic classifi ers for a coal fi red power stati on in Kentucky, USA.
The objecti ve of the project was to improve the pulverizer performance by increasing the raw coal throughput by 15% whilst maintaining the same pulverised fuel fi neness operati ng levels.
The MPS 89 pulverizers at this plant were fi tt ed with the OEM stati c classifi ers. The testi ng prior to conversion showed that the pulverizer was severely limited with a coal output of 87,000lb/hr. Beyond this load point the pulverizer became unstable and “coal dribble” at the table reject indicator port was clearly visible.
A high effi ciency Loesche LSKS 39 (6 outlet) dynamic classifi er was selected for the retrofi t to this pulverizer to resolve this throughput issue. The Loesche LSKS high effi ciency dynamic classifi er retrofi t resulted in a signifi cant 19.3% improvement in pulverised coal throughput. This major improvement in pulverizer performance allows for greater fuel fl exibility along with aff ording the possibility of operati ng the plant with a spare pulverizer (N+1 basis), whilst maintaining MCR.
The new Loesche dynamic classifi er also successfully reduced the specifi c power consumpti on of the pulverizer motor by over 10% allowing the plant an added heat rate benefi t. Dependant on classifi er rotati onal speed an additi onal 10% improvement in fi neness was observed.
E N E R G Y S Y S T E M S L T D
Project Summary
During an initi al site inspecti on, Loesche carried out a laser scan using their in-house laser scanning facility. This allows for the existi ng geometry to be fully modelled showing exactly how the new classifi er will fi t. The picture on the near left shows the resulti ng 3D model and the installed classifi er.
The laser scanning, in combinati on with onsite Loesche supervision, resulted in the new classifi er being a perfect fi t.
The retrofi t of the Loesche high effi ciency dynamic classifi er successfully:• Increased the throughput by 19.3%• Eliminated the pulverizer reject/dribbling issues• Reduced the specifi c power consumpti on by over 10%
Loesche Energy Systems Ltd185 Plumpton AvenueWashington, PA, 15301Phone: +1 724 884 5330Fax: +1 724 229 1185Contact: Paul GarnhamEmail: [email protected]
40 400
% P
assi
ng
Sieve size(micron)
70
60
90
99
80
99.9
99.98
(200 mesh) (50 mesh)
Post-Conversion
Pre-Conversion
(100 mesh)
This chart shows the results of the Rosin Rammler distributi on of retrofi tti ng the dynamic classifi er.
The blue line shows the pre-conversion distributi on and the red line shows the post-conversion distributi on.
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