Estimation of mositure in coke using non-invasive infrared thermography

Abstract

Modern steel industries are driven to produce better quality products and to improve upon current practices, which will in turn reduce the cost of their end product. For optimal blast furnace performance the chemistry of the molten iron being produced should remain under control and the thermal balance of the furnace should remain as constant as possible. One of the fuels used in blast furnace is coke which has composition of ash, carbon, volatile matter and moisture. Variation in coke moisture can have an adverse effect on the thermal control of the blast furnace process and also the chemistry of the iron and slag produced. Real-time online analysis of moisture is necessary for enhancing the productivity of blast furnace. Although several real-time online measurement techniques are available but those are costly and having harmful radiation. Microwave-assisted, IR thermography based non-invasive technique can be employed for real-time online moisture analysis of coke. Different types of coke samples are collected and crushed around the size of 10 mm. Fixed quantity of coke samples is considered in which moisture is added in increasing amount for every sample and uniformly heated in a microwave oven for an optimal time period. Thermal images of heated samples are captured using IR camera and average temperature of each sample is obtained. Through IR imaging of coke samples with varying moisture, a calibration curve is generated which correlates the average temperature of the coke samples with their corresponding moisture content. The moisture content in the coke samples in which the percentage of moisture is not known, can be predicted from this calibration curve