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Experiences with retrofitting of planetary and rotary coolers to grate coolers
The fuel consumption and environmental impact of each cement plant is predominantly determined by the technical standard of the kiln line. Due to the counter-current flow operation of the burning process, the cooler operation has a crucial impact on the operating performance, especially on the energy consumption, the clinker quality and the productivity of the kiln line. Grate coolers, planetary coolers and rotary coolers are used in order to cool the cement clinker. New kiln lines are predominantly equipped with grate coolers but some older kiln lines are still equipped with planetary or rotary coolers. Continuous optimization and careful maintenance of those coolers was the only way to achieve acceptable performance but limited to a certain extent. Further improvements require the complete replacement of the cooler. This article deals exemplarily with four kiln modification projects where a rotary cooler or a planetary cooler was replaced by a grate cooler. The following conclusions can be drawn from the four grate cooler projects: These grate coolers are designed with a specific surface load of approximately 43 t/m(exp2).d to 47 t/m(exp2).d and and with a cooling air supply of approximately 1.9 Nm3/kg clinker to 2.2 Nm3/kg clinker. A clinker temperature from 100 deg C to 140 deg C (above ambient temperature) was reached with these design figures. Due to differences of the local plant layout and restrictions the specific width load of the coolers varies between 750 t/d.m and 1250 t/d.m. A replacement of a planetary cooler results always in changes in static kiln loads and therefore often the kiln shell and kiln tyre and - pier have to be reinforced and/or replaced. These measures are not necessary when replacing a rotary cooler. The time table for dismantling the old cooler and erection of the new cooler strongly depends on the local conditions and the scale of the project. However a disruption in production of at least 7 weeks has to be anticipated. The complexity of such a big modification requires a particular coordination of all aspects of health and safety within the work process on site. Operational experiences with modern grate coolers demonstrate that these grate coolers are nowadays state-of-the-art. Expectations regarding wear of grate plates and refractory lining were met with these projects. In some plants the material flow was sporadically disturbed by a snow-man formation at the cooler inlet. A formation of bigger clinker balls in the kiln may disturb the throughput of a roller crusher, however, not cause a blockage as it can happen with hammer crushers. A decrease of the fuel consumption of 6% to 10% was reached with these examples, resulting in some cases in increased kiln production rates. The training and instruction of the plant personnel is of utmost importance for a successful commissioning and operation of the modified plant.
Experiences with retrofitting of planetary and rotary coolers to grate coolers
The fuel consumption and environmental impact of each cement plant is predominantly determined by the technical standard of the kiln line. Due to the counter-current flow operation of the burning process, the cooler operation has a crucial impact on the operating performance, especially on the energy consumption, the clinker quality and the productivity of the kiln line. Grate coolers, planetary coolers and rotary coolers are used in order to cool the cement clinker. New kiln lines are predominantly equipped with grate coolers but some older kiln lines are still equipped with planetary or rotary coolers. Continuous optimization and careful maintenance of those coolers was the only way to achieve acceptable performance but limited to a certain extent. Further improvements require the complete replacement of the cooler. This article deals exemplarily with four kiln modification projects where a rotary cooler or a planetary cooler was replaced by a grate cooler. The following conclusions can be drawn from the four grate cooler projects: These grate coolers are designed with a specific surface load of approximately 43 t/m(exp2).d to 47 t/m(exp2).d and and with a cooling air supply of approximately 1.9 Nm3/kg clinker to 2.2 Nm3/kg clinker. A clinker temperature from 100 deg C to 140 deg C (above ambient temperature) was reached with these design figures. Due to differences of the local plant layout and restrictions the specific width load of the coolers varies between 750 t/d.m and 1250 t/d.m. A replacement of a planetary cooler results always in changes in static kiln loads and therefore often the kiln shell and kiln tyre and - pier have to be reinforced and/or replaced. These measures are not necessary when replacing a rotary cooler. The time table for dismantling the old cooler and erection of the new cooler strongly depends on the local conditions and the scale of the project. However a disruption in production of at least 7 weeks has to be anticipated. The complexity of such a big modification requires a particular coordination of all aspects of health and safety within the work process on site. Operational experiences with modern grate coolers demonstrate that these grate coolers are nowadays state-of-the-art. Expectations regarding wear of grate plates and refractory lining were met with these projects. In some plants the material flow was sporadically disturbed by a snow-man formation at the cooler inlet. A formation of bigger clinker balls in the kiln may disturb the throughput of a roller crusher, however, not cause a blockage as it can happen with hammer crushers. A decrease of the fuel consumption of 6% to 10% was reached with these examples, resulting in some cases in increased kiln production rates. The training and instruction of the plant personnel is of utmost importance for a successful commissioning and operation of the modified plant.
Experiences with retrofitting of planetary and rotary coolers to grate coolers
Erfahrungen mit einer Ausrüstungsoptimierung von Satellitenkühlern und Rohrkühlern zu Rostkühlern
Braig, Thomas (author) / Mrowald, Ulrich (author) / Rosemann, Holger (author) / Seglias, Marius (author)
2009
7 Seiten, 7 Bilder, 1 Tabelle, 2 Quellen
Conference paper
English
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