DESIGN AND CONSTRUCTION OF A PCI RIG FOR EVALUATION OF PULVERIZED FUELS COMBUSTION: EQUIPMENT FEATURES
PROJETO E CONSTRUÇÃO DE UM SIMULADOR DE PCI PARA COMBUSTÍVEIS SÓLIDOS PULVERIZADOS: CARACTERÍSTICAS DO EQUIPAMENTO
René Lúcio Rech, André da Silveira Machado, Claudia Caroline Teixeira Barbieri, Juliana Gonçalves Pohlmann, Janaina Gonçalves Maria da Silva Machado, Maurício Covcevich Bagatini, Nilson Romeu Marcílio, Antônio Eduardo Clark Peres, Antônio César Faria Vilela, Eduardo Osório
Abstract
Pulverized coal injection (PCI) is a technique worldwide used in blast furnaces (BFs) to reduce coke consumption. Burning of pulverized coal injected into tuyeres of BFs takes place under medium pressure (up to 450 kPa), high flame temperatures (around 2500 K), very fast heating rates (105 –106 K/s) and very short residence times, less than 40 ms. Since there are no standard tests for evaluation of coal combustibility at PCI conditions, lab scale injection rigs are usually employed for this purpose. This work shows relevant characteristics of the injection rig developed by LASID-UFRGS, which operates at automated injection mode. The main rig features are direct measurement of pressure and temperature inside the combustion zone during combustion process, temperature measurement with ultra-fast thermocouples (ms), high speed control and data acquisition (ms) and collection of both solid and gaseous combustion products. First results showed pressure and temperature evolution along throughout the combustion test, with and without sample, combustion gas composition and coal burnout for different coals. Experimental data statistics showed good repeatability for all tested coals.
Keywords
Resumo
A injeção de carvão pulverizado (PCI) é uma técnica utilizada em altos-fornos (AFs) para reduzir o consumo de coque. A queima do carvão pulverizado injetado nas ventaneiras do AF ocorre em pressões médias (até 450 kPa), temperaturas de chama elevadas (cerca de 2500 K), taxas de aquecimento muito elevadas (105 –106 K/s) e tempos de residência muito curtos, abaixo de 40 ms. Como não há testes padronizados para avaliação da combustibilidade de carvões nas condições de PCI, simuladores de combustão em PCI são comumente utilizados para esse fim. Este trabalho apresenta as características relevantes do simulador de PCI desenvolvido pelo LASID-UFRGS, que opera com pulso automatizado de injeção. As características principais do simulador são a medida direta de pressão e temperatura dentro da zona de combustão durante o, a medição de temperatura com termopares ultrarrápidos (ms), a aquisição de dados e controle em alta velocidade (ms) e a coleta dos produtos sólidos e gasosos da combustão. Os primeiros resultados mostraram a evolução da pressão e temperatura durante o pulso de injeção, com ou sem amostra, o grau de conversão (burnout) do carvão e a composição dos gases de combustão para diferentes carvões. A análise estatística dos dados experimentais demonstrou uma boa repetitividade para todos os carvões testados.
Palavras-chave
References
1 Babich A, Senk D, Gudenau HW, Mavrommatis K. Ironmaking. Aachen: Mainz Gmbh; 2008.
2 Carpenter AM. Use of PCI in blast furnaces. London: IEA Clean Coal Centre; 2006.
3 Lu L, Sahajwalla V, Harris D. Coal char reactivity and structural evolution during combustion – factors influencing blast furnace pulverized coal injection operation. Metall Mater Trans 2001;32(b):811-820.
4 Wu K, Ding R, Han Q, Yang S, Wei S, Ni B. Research on unconsumed fine coke and pulverized coal of BF dust under different PCI rates in BF at Capital Steel Co. ISIJ International. 2010;50(3):390-395.
5 Osório E, Gomes MLI, Vilela ACF, Kalkreuth W, Almeida MAA, Borrego AG, et al. Evaluation of petrology and reactivity of coal blends for use in pulverized coal injection (PCI). International Journal of Coal Geology. 2006;68:14-29.
6 Wu Z. Fundamentals of pulverized coal combustion. London: IEA Clean Coal Centre; 2005.
7 Machado AS, Mexias AS, Vilela ACF, Osório E. Study of coal, char and coke fines structures and their proportions in the off-gas blast furnace samples by X-ray diffraction. Fuel. 2013a;114:224-228.
8 Machado JGMS. Estudo de reatividade e combustão de carvões minerais, carvão vegetal e misturas [thesis]. Porto Alegre: Universidade Federal do Rio Grande do Sul; 2009.
9 Barbieri CCT, Osório E, Vilela ACF. Combustibility and reactivity of coal blends and charcoal fines aiming use in ironmaking. Materials Research. 2016;19(3):594-601.
10 Yamaguchi K, Ueno H, Tamura K. Maximum injection rate of pulverized coal into blast furnace through tuyeres with consideration of unburnt char. ISIJ International. 1992;32(6):716-724.
11 Hutny WP, Giroux L, Macphee A, Price JT. Quality of coal for blast furnace injection. In: Proceedings of the Blast Furnace Injection Symposium; 1996 Nov 10-12; Cleveland, Ohio, United States of America. Warrendale: Association of Iron and Steel Engineers; 1996. p. 1-31.
12 Ueno H, Yamaguchi K, Tamura K. Coal combustion in the raceway and tuyere of a blast furnace. ISIJ International. 1993;33(6):640-645.
13 Wippermann S. Kombiniertes Einblasen von Kohle und Feinerz oder eisenhaltigen Hüttenreststoffen in den Hochofen [thesis]. Aachen: IEHK, RWTH; 1996.
14 Khairil D, Katsuya N, Naruse I. Fundamental reaction characteristics of pulverized coal at high temperature. ISIJ International. 2001;41(2):136-141.
15 Haywood RJ, McCarthy MJ, Truelove JS, Mason MB, Thomson AD. An experimental and theoretical investigation of pulverized coal combustion in blast furnaces. Proceedings of the Fourth Australian Flame Days; 1995 Nov 9-10; Adelaide, Australia. Adelaide: University of Adelaide; 1995.
16 Mathieson JG, Truelove JS, Rogers H. Toward an understanding of coal combustion in blast furnace tuyere injection. Fuel. 2005;84(10):1229-1237.
17 Wu L, Paterson N, Dugwell DR, Kandiyoti R. Simulation of blast-furnace tuyere and raceway conditions in a wire mesh reactor: extents of combustion and gasification. Energy & Fuels. 2007;21:2325-2334.
18 Babich A, Senk D, Knepper M, Benkert S. Conversion of injected waste plastics in blast furnace. Ironmaking & Steelmaking. 2016;43(1):11-21.
19 Machado JGMS, Osório E, Vilela ACF, Babich A. Senk, D Gudenau, HW. Reactivity and conversion behaviour of Brazilian and imported coals, charcoal and blends in view of their injection into blast furnaces. Steel Research International. 2010;81(1):9-16.
20 Reis HMB. Estudo da combustão de misturas de carvões de baixo e alto ranks [dissertation]. Belo Horizonte: Universidade Federal de Minas Gerais; 2003.
21 Assis CFC, Tenório JAS, Assis PS, Nath NK. Experimental simulation and analysis of agricultural waste injection as an alternative fuel for blast furnace. Energy & Fuels. 2014;28:7268-7273.
22 Silva AM. Estudo da utilização da biomassa em substituição parcial ao carvão mineral no processo de fabricação do ferro-gusa em alto-forno [thesis]. Guaratinguetá: Universidade Estadual Paulista; 2008.
23 Pohlmann JG, Osório E, Vilela ACF, Diez MA, Borrego AG. Pulverized combustion under conventional (O2 /N2 ) and oxy-fuel (O2 /CO2 ) conditions of biomasses treated at different temperatures. Fuel Processing Technology. 2017;155:174-182.
24 Girolamo AD, Lameu NK, Zhang L, Ninomiya Y. Ignitability and combustibility of Yallourn pyrolysis char under simulated blast furnace conditions. Fuel Processing Technology. 2017;156:113-123.
25 Kim JH, Kim RG, Kim GB, Jeon CH. Effect of coal fragmentation on PCI combustion zone in blast furnace. Experimental Thermal and Fluid Science. 2016;79:266-274.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email