Effect of Horizontal Air Jet Penetration on the Combustion of Coal in a Fluidized Bed

Abstract

Experiments have been conducted to investigate the influence of a horizontal air jet on the performance of a fluidized bed coal combustor. Cold flow model studies were first made to visually and photographically study the effect of jet penetration on bed solids circulation patterns and mixing characteristics. Using these cold flow model studies as a basis, the influence of jet penetration and jet induced solids circulation on the combustion characteristics of a high sulfur coal has been investigated in an identical fluidized bed combustor. The experiments show that the combustion efficiency and bed temperature are usually higher at low jet air mass flow rates. The importance of the synergistic influence of bed solids blending rate, the elutriation rate, the superficial velocity, and the chemical reaction rate in realizing high combustion efficiencies is demonstrated. Pf PP Nomenclature= nozzle diameter, m = mean particle diameter, m = gravitational constant jet penetration depth from end of nozzle, m = jet air velocity, m/s = bed void fraction = gas density, kg/m 3 = bed solid particle density, kg/m 3

Dry cleaning aluminum cell gases from Söderberg cells

“…These results, combined with the previous results for fluidized-bed combustion in a reactor of relatively large diameter (25 cm inner diameter), show an adequate similarity with those for bench-scale reactors (9 cm and 10 cm inner diameter) used by Rajan 9 and Shafey. 10 This gives confidence for the present results to be applied to the design and operation of commercial large-scale reactors.…”

Numerical simulation of horizontal jet penetration using filtered fluid model in gas–solid fluidized bed

“…The effect of horizontal injection of gas into fluidized beds on flow behavior of gas and particles is widely investigated [1][2][3]. When gas with high velocity is injected into the fluidized bed from a horizontal nozzle, a permanent jet plume with bubbles will be formed in the bed.…”

Numerical simulation of single and multiple gas jets in bubbling fluidized beds

“…The feed injection is usually used to enhance the mixing, stimulate solids flow, and control NO x emission and bed temperature (Rajan and Christoff, 1982;Varol and Atimtay, 2007). It is important to ensure the jet penetration is sufficient to distribute the feed reactant across the cross-section of the column to minimize the lateral gradient in reactant concentration.…”