Pressure Drop in the Blast Furnace Hearth with a Sitting Deadman

摘要

1. Introduction The extraction of a liquid through a lateral orifice is commonly encountered in a wide range of industrial applications. In the ironmaking blast furnace (BF), the tapping process is far more complex because of issues related to the multiphase flow characteristics and the role of the packed bed of coke (deadman) in the hearth. An efficient and strictly controlled tapping is necessary for guaranteeing a stable operation and high productivity of the BF. Many recent investigations on this subject have revealed that the pressure drop caused by fluid flow through the deadman in the hearth is a significant factor governing hearth drainage. However, due to the hostile environment, the possibilities to directly measure internal variables are practically nonexistent. Instead, knowledge on and a better understanding of the conditions in BF hearth can be gained by mathematical modeling and small-scale experiments. A simple but reliable predictive model of the pressure drop in the BF hearth could form an integral component of a tapping guidance system for on-line process estimation and control. Such a model may also be useful for other purposes. With this aim, the Kozeny-Carman (KC) equation,10' which is a well-established expression for the pressure loss of a fluid flowing laminarly through a packed bed, was rearranged into a generic form to quantify the pressure drop in the BF hearth, applying both computational fluid dynamics (CFD) and physical modeling to verify the expression for one-phase flow through a sitting deadman.