SUMMARY
The fluidised dense-phase (FDP) conveying of powders and low-velocity slug-flow (LVSF) of granular bulk solids are the most common and popular modes of dense-phase used in industry. However, the accurate prediction of conveying performance still is not possible from first principles and relies heavily on empiricism.
The main aim of this project is to develop the necessary understanding, databases, guidelines and models for the purpose of predicting accurate optimal operating conditions for the two modes of dense-phase. However, as was mentioned in the original research grant application, it was unlikely that both the FDP and LVSF sections could be completed thoroughly in a single 3-year period (i.e. due to the amount of work involved). Hence, top priority was given initially to the LVSF section of the project, although some progress was also made with the FDP section of work. However, with the 3-year extension to the research grant a substantial amount of work can now be completed in the FDP section, as well as tying off some loose ends from the LVSF section.
Several difficulties have been encountered during the course of the project (e.g. unexpected results and phenomena) and have delayed progress in various areas. In some cases, it was not possible to complete certain scheduled tasks (e.g. testing aluminium and mild steel pipe and wide range of granular solids). In other cases, it was necessary to pursue new work (e.g. rotary valve air leakage, new pipe friction and stress transmission testers). However, in terms of achieving the main goals, there is no doubt that the project will be successful in terms of improved understanding and the development of new databases and models for the prediction of LVSF performance. Unfortunately, due to the various problems and delays to date, the full range of pipe wall materials and bulk solids will not be able to be tested – such work is necessary to confirm the accuracy and validity of the new models (e.g. majority of work to date has concentrated on poly pellets). Also, a significant amount of additional time will be needed for the relatively more complex FDP section of work (e.g. only one product and a few different pipelines were able to be tested by the end of the initial 3-year period). The 3-year extension is allowing a more concentrated effort in this area, as evidenced by the extensive testing completed over the past 12 months.
This Annual Report summarises the research progress and major achievements to date, as well the forward plan for the next 12 months.