Development of a Drop Tube Reactor to Test and Assist a Sustainable Manufacturing Process

Abstract

This work outlines the development of a Drop Tube Reactor (DTR) following a simulation assisted design. The general purpose of the DTR is to simulate the thermochemical conversion process of solid hydrocarbon feedstock, such as coal, coke, biomass, and industrial waste under controlled reaction conditions. It supports the development of more efficient and flexible conversion devices (i.e. reactors, gasifier, etc.) to accommodate none conventional solid fuel, i.e. biomass and solid waste material. The DTR is extensively used in investigating the thermochemical pathways and in the development of high fidelity reactive flow models. As this device is custom made, the thermochemical loading, i.e. thermal flow/heating and exothermic reactivity requires detailed flow analysis. This work attempts to provide guidelines for the DTR development. It details the functionality of the main device components, investigates the flow conditions and suggests the tube material by considering a variable heating flux and mass flow rate in a conjugate heat flow environment. The results demonstrated how basic analytical calculations, CFD simulation, and conjugate heat analysis influence design decisions. In particular, the effect of the heat flux and mass flow rate and their effect on the flow pattern are investigated. Results have shown that the adjustment of the wall heat flux leads to a more predictable change in temperature whereas the variation in the mass flow rate results in a more predictable change in the velocity profile. The residence time varies linearly with mass flow rate and nearly parabolic with wall heat flux. An increase of the heat flux requires adjustment of the mass flow rate to maintain particle residence time at a constant value.