Comparative Study of Clogging in Valve and Cascade Mixers

Abstract

A cascade mixer and a valve mixer were applied for the precipitation of CaCO 3 . This model reaction has been used for benchmarking both mixer types with respect to their robustness against fouling. The valve mixer was found to be much less susceptible to fouling and clogging. Pressure changes during precipitation in both types of mixers differed significantly. This parameter can be easily used for identification of clogging in the valve mixer and applied as input in clean-in-place (CIP) procedures. The pressure trend in the cascade mixer is quite complex and, therefore, difficult to apply for CIP. Ultrasonic treatment has been evaluated as a measure to prevent clogging.

Study on the Morphologic and Flow State of Polyacrylonitrile Particles in a Microchannel Reactor

“…The use of ultrasonic pulses destroys the agglomerates and prevents them from fusing with the sedimentary layer. The formation of the localized high viscosity zone slows down, and the “bridging” phenomenon cannot occur, thus delaying the clogging. − Another option is to replace the transparent PTFE tube in Figure with a transparent glass tube to reduce the wall friction in this section of the pipeline. A high-speed camera recorded the flow reaction process in the pipe over time, as shown in Figure .…”

Towards process intensification: Remediation of fouling in continuous microscale synthesis of phosphated TiO 2

“…Therefore, this work exemplarily shows the miniaturization of phosphated TiO 2 nanoparticle synthesis as a multistep continuous microreactor process utilizing a modular microreactor setup. Continuous multistep synthesis is achieved by serial setup of a slit plate- [52,53], a comb [54] and a valve mixer [55][56][57]. Both titanium(IV)isopropoxide (TTIP) and titanium(IV)butoxide (TBUT) are investigated as precursors for the reaction in order to elucidate the influence of mixing and reaction speed on fouling in a continuous microreactor process.…”