Dynamic characteristics and efficiency of a fluidized bed heat treatment process

The dynamic characteristics of gas bubbles in fluidized beds are important to determine the heat and mass transfer rates at component surfaces and the treated profiles of components. They also have great impact on the components’ structural, mechanical and physical properties. However, it has been very difficult to monitor those characteristics dynamically. In this paper, a specifically designed fluidized bed was introduced to facilitate the capturing of its dynamic characteristics and a new video image processing and analysis algorithm was developed. The algorithm is robust and adaptive in terms of locating both bubbles and components in beds with a single or multiple components. It has many advantages in dynamic characterization of gas bubbles and monitoring component treatment. By using this algorithm, the properties of gas bubbles over any period of time can be accurately obtained. This technology will provide a potential on-line dynamic monitoring and quality control system for the chemical heat treatment processes with fluidized beds.

Mathematical modelling of downflow floating medium filter (DFF) with in-line flocculation arrangement

A laboratory-scale set-up consisting of rapid mixing device and floating medium filter was used to study the use of a downflow floating medium filter (DFF) with an in-line flocculation arrangement as a static flocculator and a prefilter. The semi-empirical mathematical model formulated incorporates flocculation within the filter, particle/floc attachment onto the filter and the detachment of flocs from the medium. The mathematical model for filtration takes into account the expansion of the filter bed. The removal efficiency of DFF and headless development were successfully simulated for different conditions of filtration velocity, filter depth and influent suspended solids (SS). The values of attachment coefficient a(p)β and headless coefficient β1 were found to be independent of filtration velocity, filter depth and influent SS concentration.

CONBPS : an expert system to improve the efficiency of the construction process

The aim of the research outlined in this paper is to develop a best practice process model for building projects based on the use of an expert system. The CONstruction Best Practice System (CONBPS) focusses on projects which are based on the traditional procurement strategy, using the JCT 80 standard form of contract. The model clearly identifies the sequence of construction activities. It also identifies the roles and responsibilities of the major parties on the building team and the issues within the project cycle, which can prove critical to project success. The system incorporates many user-friendly functions, including the provision of multi-choice icons and the provision of an on-line help function. Besides, it also provides interim and final reports which are used to advise the participants on the success factors that they have ignored and to which aspects they should pay more attention. A framework was initially developed focussing on the whole design process with a full knowledge-based system developed for the Inception Stage. CONBPS can be used as a teaching/learning tool to assist teachers and students to better understand the construction process. Also, it could prove useful to project managers and all the participants in the construction process.