Loesche Energy Systems Ltd was contracted to retrofit a high efficiency dynamic classifier to a coal-fired power station in Kentucky to improve pulverizer performance. The original static classifiers were limiting raw coal throughput to 87,000lb/hr. The Loesche dynamic classifier installation increased throughput by 19.3% while maintaining fineness levels. It also reduced the pulverizer's specific power consumption by over 10%. The retrofit successfully improved the pulverizer's stability and throughput.

1. E N E R G Y S Y S T E M S L T D
High Efficiency Dynamic Classifier – USA Retrofit Project
Increasing throughput on an MPS 89 mill
Loesche Energy Systems Ltd were contracted to design, manufacture and supply high efficiency dynamic classifiers for a coal
fired power station in Kentucky, USA.
The objective of the project was to improve the pulverizer performance by increasing the raw coal throughput by 15% whilst
maintaining the same pulverised fuel fineness operating levels.
The MPS 89 pulverizers at this plant were fitted with the OEM static classifiers. The testing 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 efficiency Loesche LSKS 39 (6 outlet) dynamic classifier was selected for the retrofit to this pulverizer to resolve this
throughput issue. The Loesche LSKS high efficiency dynamic classifier retrofit resulted in a significant 19.3% improvement in
pulverised coal throughput. This major improvement in pulverizer performance allows for greater fuel flexibility along with
affording the possibility of operating the plant with a spare pulverizer (N+1 basis), whilst maintaining MCR.
The new Loesche dynamic classifier also successfully reduced the specific power consumption of the pulverizer motor by over
10% allowing the plant an added heat rate benefit. Dependant on classifier rotational speed an additional 10% improvement
in fineness was observed.

2. E N E R G Y S Y S T E M S L T D
Project Summary
During an initial site
inspection, Loesche carried
out a laser scan using their
in-house laser scanning
facility. This allows for the
existing geometry to be
fully modelled showing
exactly how the new
classifier will fit. The picture
on the near left shows the
resulting 3D model and the
installed classifier.
The laser scanning, in
combination with onsite
Loeschesupervision,resulted
in the new classifier being a
perfect fit.
The retrofit of the Loesche high efficiency dynamic classifier successfully:
• Increased the throughput by 19.3%
• Eliminated the pulverizer reject/dribbling issues
• Reduced the specific power consumption by over 10%
Loesche Energy Systems Ltd
185 Plumpton Avenue
Washington, PA, 15301
Phone: +1 724 884 5330
Fax: +1 724 229 1185
Contact: Paul Garnham
Email: power@loescheamerica.com
40 400
%Passing
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
distribution of retrofitting
the dynamic classifier.
The blue line shows the pre-
conversion distribution and
the red line shows the post-
conversion distribution.