[1] A mechanistic model is derived for the rate of fluvial erosion into bedrock by abrasion from uniform size particles that impact the bed during transport in both bed and suspended load. The erosion rate is equated to the product of the impact rate, the mass loss per particle impact, and a bed coverage term. Unlike previous models that consider only bed load, the impact rate is not assumed to...

In present paper, dynamic behavior and control of a fluidized bed reactor for polyethylene production has been considered. A double active sites model for Ziegler-Natta catalysts is used for simulation of polymerization reaction. Hydrodynamic behavior of the bed is modeled using a two phase model including bubble and emulsion phases in which bubble phase has plug flow pattern with different...

Effect of interparticle force on the hydrodynamics of gas-solid fluidized beds was investigated using the combined method of computational fluid dynamics and discrete element method (CFD-DEM). The cohesive force between particles was considered to follow the van der Waals equation form. The model was validated by experimental results from literature in terms of bed voidage distribution and Eule...

Low-temperature gasification of black liquor is a new alternative to the conventional Tomlinson recovery boiler for recovering pulping chemicals and energy from black liquor in pulp and paper mills. This process can be carried out in a fluidized bed based on steam reforming at 600 C using indirect heat supplied via heat exchangers built into the fluid bed. As black liquor is injected into the b...

The rising popularity of incineration of municipal solid waste (MSW) calls for detailed mathematical modelling and understanding of the incineration process. In this paper, governing equations for mass, momentum and heat transfer for both solid and gaseous phases in a moving bed in a solid-waste incineration furnace are described and relevant sub-models are presented. The burning rates of volat...

The process of fluidized bed spray granulation unites the steps of solid formation and product formulation in one apparatus and is used to produce granules out of a liquid. Thereby, a melt is atomized into small droplets and sprayed into the fluidized bed, which consists of seed particles of the same material. Droplets deposit on the particles near the spray zone and form a film which solidifie...