Review of applications of electrical resistance tomography to chemical engineering

In spite of decades of study and investigation, the research on tomography and electrical resistance tomography (ERT) in particular, remains to be focus of immense scientific significance. ERT provides the ability to measure conductivity distribution inside a process plant and delivers time evolving multidimensional information. Such important and otherwise inaccessible information enhances critical process knowledge whilst improving the design and function of the process equipment. ERT has been employed in a variety of fields including chemical engineering. This paper reviews previous research carried out on the application of ERT within the chemical engineering arena. The applications are classified based on the objective of ERT measurements, the unit operations ERT has been utilized on, the media under examination, and also other technologies and data processing techniques used in combination with ERT. The objective of this taxonomy is to offer the reader with a broad insight into the current situation of ERT related research and developed applications in the chemical engineering field and to assist in the identification of research gaps for future investigation.

Radiotracer technology in mixing processes for industrial applications

Many problems associated with the mixing process remain unsolved and result in poor mixing performance. The residence time distribution (RTD) and the mixing time are the most important parameters that determine the homogenisation that is achieved in the mixing vessel and are discussed in detail in this paper. In addition, this paper reviews the current problems associated with conventional tracers, mathematical models, and computational fluid dynamics simulations involved in radiotracer experiments and hybrid of radiotracer.

A different approach for predicting reaeration rates in gravity sewers and completely mixed tanks

A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analysis was used to fit the rate of oxygen transfer equation against G. The reaeration rate in completely mixed reactors was found to be proportional to G2 (R2 = 0.987). Subsequently, G was linked to headloss in sewers, and the equation was calibrated using a slope-adjustable, 27-m-long, gravity-flow, experimental sewer (internal diameter, D = 0.16 m). Here, the reaeration rate was proportional to G1 (R2 = 0.981). The equation was compared with existing oxygen transfer models and validated against experimental data from the literature, to which the overall mass transfer coefficient for oxygen, K(L)a, derived by the new approach, conformed well.