Title

Reduction of Pulverized Coal System Injection Drops

Reduction of Pulverized Coal System Injection Drops

Authorship

FRANKLIN, FABIAM; REINALDO, JOSÉ MARIA; ZANETTI, CARLOS HILTON; MOTTA, RICARDO SEBASTIÃO NADUR; SILVA, ALCIDES JOSE DE LUCENA

FRANKLIN, FABIAM

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REINALDO, JOSÉ MARIA

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ZANETTI, CARLOS HILTON

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MOTTA, RICARDO SEBASTIÃO NADUR

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SILVA, ALCIDES JOSE DE LUCENA

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DOI

10.5151/2594-357x-34Red-469-484

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Abstract

CSN Blast Furnaces 2 & 3 Pulverized Coal Injection System – PCI was designed by Claudius Peters to inject at maximum, 200 Kg/Thm to produce 4500 and 9500 Thm/day, respectively. Therefore, the injection stations were designed for rates of approximately 40 and 80 Tons/h of pulverized coal for the blast furnaces. The pulverized coal constant flow shall be the most stable possible, with no occurrence of injection drops, that is, through faults in the equipment or in the process. The consequence of an injection drop, or interruptions on coal flow, goes since from blast furnace reduction, CTE boilers quenching, lances clogging and vapor/oxygen flow control loops that are cascaded with the injection rate. After improvements and developments performed in equipment and control logic along these 9 years experience, the number of monthly pulverized coal injection drops was reduced at about 36%, making possible a zero injection drop index, in December, 2003. Thus, nowadays, PCI injection plants are more stable and reliable, achieving average availability indexes of 99,98%, or it is, 10 minutes drop per month through each injection station. It provides an operational stability for the blast furnace originating opportunities for bigger PCRs, with injection rates of 90 Ton/h for the blast furnaces current productivity. Besides, there were considerable improvements on the equipment useful life due to this optimization.

CSN Blast Furnaces 2 & 3 Pulverized Coal Injection System – PCI was designed by Claudius Peters to inject at maximum, 200 Kg/Thm to produce 4500 and 9500 Thm/day, respectively. Therefore, the injection stations were designed for rates of approximately 40 and 80 Tons/h of pulverized coal for the blast furnaces. The pulverized coal constant flow shall be the most stable possible, with no occurrence of injection drops, that is, through faults in the equipment or in the process. The consequence of an injection drop, or interruptions on coal flow, goes since from blast furnace reduction, CTE boilers quenching, lances clogging and vapor/oxygen flow control loops that are cascaded with the injection rate. After improvements and developments performed in equipment and control logic along these 9 years experience, the number of monthly pulverized coal injection drops was reduced at about 36%, making possible a zero injection drop index, in December, 2003. Thus, nowadays, PCI injection plants are more stable and reliable, achieving average availability indexes of 99,98%, or it is, 10 minutes drop per month through each injection station. It provides an operational stability for the blast furnace originating opportunities for bigger PCRs, with injection rates of 90 Ton/h for the blast furnaces current productivity. Besides, there were considerable improvements on the equipment useful life due to this optimization.

Keywords

drops reduction, pulverized coal injection, PCI, blast furnace, process stability

drops reduction, pulverized coal injection, PCI, blast furnace, process stability