Fountain Geometry of Beds Consisting of Plastic Wastes in Shallow Spouted Beds

Abstract

The fountain is especially important in the design of spouted beds for the treatment of plastic wastes. The height and structure of the fountain in shallow spouted beds have been determined by means of an optical fiber as well as by an image treatment system. The effect of the operating variables on the fountain geometry (height and amplitude) has been analyzed by carrying out the operation with different values of the geometric factors of the contactor (base angle and gas inlet diameter) and of the operating conditions (stagnant bed height, particle diameter, particle density, particle shape, and air velocity). The materials studied are different plastic wastes (polyethylene, polypropylene, and polystyrene, both extruded and expanded). In the fountain, the core or solid ascending zone and the periphery or solid descending zone have been delimited. The experimental results prove the validity for plastic materials of the equation proven previously for prediction of the height of the fountain in cylindrical spouted beds of a conical base for glass spheres. An original equation has been proposed for prediction of the amplitude of the fountain in cylindrical spouted beds of a conical base for materials of varying density and shape.

An application of factor analysis in wet particle systems: Rolling friction and cohesive liquid controlling performances

“…Our dependence on fossil fuels as primary energy sources has caused both an energy crisis and serious environmental problems. Renewable energy sources (solid municipal waste and biomass) must be employed, and spouted fluidization has been widely applied to recover energy from such materials 1,2 . In Japan, fluidized beds are used to incinerate 12% of municipal solid waste 3 .…”

Effects of Reactor Configuration on the Yield of Solid Carbon from Pyrolysis of Low-Density Polyethylene

“…Recently, some processes have been developed for thermal conversion of waste plastics. Among the tested processes, pyrolysis is considered as one of the most promising because of the potential for upgrading waste plastics into valuable products. − …”

“…Among the tested processes, pyrolysis is considered as one of the most promising because of the potential for upgrading waste plastics into valuable products. [3][4][5][6][7] Most of the studies on pyrolysis of polyolefins have focused on the composition of the liquid and gas products, because of their potential use as fuels or chemicals. [8][9][10][11][12][13] The conversion of polyolefins to solid carbons by pyrolysis is an interesting alternative that has received scarce attention.…”