Temperature measurement of molten iron in taphole of blast furnace combined temperature drop model with heat transfer model

Abstract

The molten iron temperature in the taphole of a blast furnace (BF) is an important variable which reflects the internal heat of the BF. However, there is no method to detect the temperature directly. To solve this difficulty, an approach to measure the temperature of molten iron in taphole is proposed in this paper. First, during the stable tapping period, a heat transfer model is established according to the principle of equal heat flux of the trench walls, which is used to calculate the molten iron temperature at different positions in the main pipeline according to the temperature measured by thermocouples buried in trench walls. Next, a main pipeline temperature drop model is established based on the pipe temperature drop theory. Finally, the output of heat transfer model is used as the data source for parameter identification in the temperature drop model. The least-squares method is adopted to identify the molten iron temperature in the taphole. The proposed approach was validated in a practical industrial experiment at the #2 BF in an iron making plant. The results illustrate the effectiveness and rationality of the proposed approach and provides credible temperature data for the control of the BF.

Hot Metal Temperature Prediction at Basic-Lined Oxygen Furnace (BOF) Converter Using IR Thermometry and Forecasting Techniques

“…Usually, the actual hot metal temperature is intermittently measured by an operator using disposable thermocouples. Since this method only provides partial information, continuous determination of temperature by means of combined modeling and indirect measurements is a growing area of interest in BF [7][8][9][10], but comparable efforts for BOF have not yet been reported [11,12].…”

Influence of Dust on Temperature Measurement Using Infrared Thermal Imager

“…During the burning process of cement clinker, the burning temperature measurement in rotary kiln is also easily affected by dust and smoke [18]. In the process of blast furnace ironmaking, dust is generated randomly near the taphole in the cast field, which have a significant influence on the temperature measurement of molten iron [19]. As far as the authors know, there have been little reports of compensation methods for dust interference when infrared thermal imagers are used for temperature measurement.…”

Projeto De Robô Industrial Para Automação Da Medição De Temperatura Do Ferro-Gusa Em Altos Fornos

“…A medida da temperatura do gusa líquido nos canais de corrida é geralmente realizada por meio de um termopar descartável montado na extremidade de uma haste [3]. Medidas realizadas por sensores de infravermelho (sigla IR, do inglês infrared) também são utilizadas, mas podem apresentar imprecisão no caso de temperaturas demasiado altas e ambientes com alta quantidade de poeira [4]. Têm sido relatadas na literatura várias tentativas de se realizar a medição de temperatura do gusade forma a diminuir a exposição do operador às altas temperaturas, além de se buscar melhorar a precisão dos instrumentos atuais.Usamentiagaet al (2012) [5], desenvolveram um sistema de medição que utiliza a emissividade em IR do ferrogusa.…”

“…O desafio dos autores, neste caso, foi filtrar a emissão de IR proveniente da escória, de forma que a temperatura correta do gusa líquido fosse medida.Sigiuraet al (2014) [3] fez uma investigação similar, porém foi proposta uma medição contínua, utilizando câmeras CCD com obturador de alta velocidade. Jianget al (2016) [4]propuseram uma forma de se medir a temperatura no interior do furo de corrida pela medição de temperatura do canal de corrida, utilizando um modelo de transferência de calor. Neste caso, a medição de temperatura nos canais de corrida ocorreu pela introdução de termopares no interior do dos tijolos e do concreto refratário dos canais de corrida.…”