A satisfactory result

After having characterized the structure of liquid flow and the spatial distribution of the corresponding speeds, the quantitative analysis of the data and the comparison of this with the hydrodynamics of cylindrical tanks, the researchers were able to demonstrate that the speed of the fluid was sufficiently high in all areas of the tank. The conditions were favorable to optimal development of the cells. “Despite its unusual shape, the speeds we observed were comparable to those obtained by a traditional reactor. This rectangular form then became a great advantage as opposed to a limitation. When we are dealing with stainless steel, molding a cylindrical tank with a concave bottom is not difficult. On the other hand, for plastic reactors this is more difficult because it involves soldering the membranes in a certain way. A rectangular shape is a lot easier to manufacture and therefore less costly. But from our point of view, we were happy to be able to show that this system was not iconoclastic and that very different geometrical shapes could correspond with similar flow and mixture performances”.

Between two worlds

The study might seem very particular and to be intended for a very precise target audience but it was carried out without any diktat from the companies involved. This was one of the initial conditions, the results were able to be published freely. Beyond the positive result for this rectangular reactor, the study illustrates the procedure followed by a chemical engineering laboratory which develops basic tools at the cutting edge of science in an industry that faces economic challenges. Dominique Toye and her team are tracing a joint pathway between research and the industrial sector. If the laboratory continues to develop hydrodynamic characterization tools for reactors, service supplies similar to those in this study will become common. “Though they enable us, from an alimentary point of view, to finance our research and therefore to employ researchers, they also impose very clear demands on us. They require us to develop advanced experimental tools which can also be used for technological and practical ends in order to remain close to questions linked to industry. It is pointless to develop methods and tools that are no use to anyone. It is this perspective which drives our work in the laboratory, the overall aim is to be able to understand and characterize what happens in reactors on an industrial scale, so that the microenvironments where cells grow are favorable."