Kurt D. Hamman

Bio: Kurt D. Hamman is an academic researcher. The author has contributed to research in topics: Volume of fluid method & Spray characteristics. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Numerical Simulation of Black Liquor Spray Characteristics

Abstract: The performance and capacity of Kraft recovery boilers is sensitive to black liquor velocity, droplet size and flow distribution in the furnace. Studies have shown that controlling droplet size and flow distribution improves boiler efficiency while allowing increased flight drying and devolatilization, and decreased carryover. The purpose of this study is to develop a robust two-phase numerical model to predict black liquor splashplate nozzle spray characteristics. A three-dimensional time dependent numerical study of black liquor sheet formation and sheet breakup is described. The volume of fluid (VOF) model is used to simulate flow through the splashplate nozzle up to initial sheet breakup and droplet formation. The VOF model solves the conservation equations of volume fraction and momentum utilizing the finite volume technique. Black liquor velocity, droplet size and flow distribution over a range of operating parameters are simulated using scaled physical models of splashplate nozzles. The VOF model is compared to results from a flow visualization experiment and experimental data found in the literature. The details of the simulation and experimental results are presented.Copyright © 2002 by ASME

Characteristics of liquid sheets formed by splash plate nozzles

Abstract: An experimental study was conducted to identify the effect of viscosity on the characteristics of liquid sheets formed by a splash plate nozzle. Various mixtures of corn syrup and water are used to obtain viscosities in the range 1–170 mPa.s. Four different splash plates with nozzle diameters of 0.5, 0.75, 1, and 2 mm, with a constant plate angle of 55° were tested. Liquid sheets formed under various operating conditions were directly visualized. The sheet atomization process for the range of parameters studied here is governed by two different mechanisms: Rayleigh–Plateau (R–P) and Rayleigh–Taylor (R–T) instabilities. R–P occurs at the rim and R–T occurs on the thin sheet. The rim instability can be laminar or turbulent, depending on the jet Reynolds number. The R–T instability of the sheet is observed at the outer edges of the radially spreading sheet, where the sheet is the thinnest. It can also occur inside the sheet, due to formation of holes and ruptures.

An atomization model for splash plate nozzles

Abstract: A model for the atomization and spray formation by splash plate nozzles is presented. This model is based on the liquid sheet formation theory due to an oblique impingement of a liquid jet on a solid surface. The continuous liquid sheet formed by the jet impingement is replaced with a set of dispersed droplets. The initial droplet sizes and velocities are determined based on theoretically predicted liquid sheet thickness and velocity. A Lagrangian spray code is used to model the spray dynamics and droplet size distribution further downstream of the nozzle. Results of this model are confirmed by the experimental data on the droplet size distribution across the spray. © 2009 American Institute of Chemical Engineers AIChE J, 2010