Numerical Simulation Study of Gas-Solid Heat Transfer and Decomposition Processes of Limestone Calcined with Blast Furnace Gas in a Parallel Flow Regenerative Lime Kiln

Abstract

Quicklime is an essential reducing agent in the steel smelting process and its calcination from limestone is accompanied by considerable energy consumption. As a relatively economical lime kiln, the Parallel Flow Regenerative (PFR) lime kiln is used as the main equipment for the production of quicklime by various steel industries. PFR lime kilns generally use natural gas as the fuel gas. Although natural gas has a high calorific value and is effective in calcination, with the increasing price of natural gas and the pressure saves energy and protect the environment, it makes sense of exploring the use of cleaner energy sources or other sub-products as fuel gas. The use of blast furnace gas (BFG) as a low calorific value fuel gas produced in the steel smelting process has been of interest. This paper therefore develops a set of mathematical models for gas-solid heat transfer and limestone decomposition based on a Porous Medium Model (PMM) and a Shrinking Core Model (SCM) to numerically simulate a PFR lime kiln using BFG in order to investigate the feasibility of calcining limestone with low calorific fuel gas and to provide a valuable reference for future development of such processes and the kiln structure improvement.

Numerical Simulation Study of Mixed Particle Size Calcination Processes in the Calcination Zone of a Parallel Flow Regenerative Lime Kiln

“…Mohammadpour started to use a porous medium model(PMM) to study the gas flow in a lime shaft kiln [10]. Hallaka couple a DPM based on the SCM by comprising differential equations in a single shaft kiln [11], then Duan established a combined porous medium model and shrinking core model to investigate the gas-solid heat transfer and limestone decomposition process of an annular shaft lime kiln and a PFR lime kiln [12,13]. Kashyap analyzes the performance of a regenerative evaporative cooler with all the possible configurations of the air-flow direction by keeping the water flow in a natural (gravitydriven) downward direction [14].…”

Metallurgical Process Simulation and Optimization

“…The function of an Electric Arc Furnace is essentially to melt metals, and Moskal et al [ 5 ] optimized the melting process using statistical-thermodynamic modeling based on, among other things, multiple linear regression (MLR). In the work of Duan et al [ 6 ], the gas–solid heat transfer and decomposition processes of limestone calcined with blast furnace gas were studied in a parallel-flow regenerative lime kiln; a Porous Medium Model (PMM) and a Shrinking Core Model (SCM) were used to examine the feasibility of calcining limestone with low-calorific fuel gas. The software ANSYS was used in Deng et al’s [ 7 ] study to simulate the temperature field and stress–strain distribution on the working layer of a four-strand tundish under three preheating stages through the indirect coupling method.…”