Organic and Inorganic Fouling in Heat Exchangers – Industrial Case Study: Analysis of Fouling Rate

Fouling rates in refinery heat exchangers with mixed organic/inorganic deposits (frequent in practice) are estimated using a comprehensive model-based thermohydraulic methodology combining data-driven measurements analysis with advanced models. An industrial case study for a heat exchanger over 4 years demonstrates the method. Following an analysis of the fouling state, the dynamic analysis here estimates organic and inorganic fouling rates using constant or time-varying proportionality ratios. Base-line organics deposition rate is described by a typical correlation, inorganics deposition as a perturbation with constant or time-varying proportionality ratios. Deposition rate parameters are estimated from measured pressure drops and validated against temperatures. Results show that the deposition rate ratio varied substantially over time, revealing acute inorganic deposition periods; accounting for inorganics explains well both thermal and hydraulic performances; the time-varying ratio provided a good fit of the data. This is a highly promising new method for predictive monitoring, detection, and diagnosis of fouling

Study of Average Static Hold-up Along a Rotary Disc Contactor in the Presence of Nanoparticles

Regarding the important role of static hold-up in both hydrodynamic and mass transfer rate in extraction columns, average static hold-up has been studied in a Rotary Disc Contactor (RDC) as a function of rotor speed, average mother drop size and number of stages using several chemical systems. In the light of the promising potential of nanofluids in mass transfer applications, in a quite novel investigation, nanofluids were applied as dispersed phases to the RDC column. Two types of SiO2 nanoparticles with different hydrophobicities were employed in nanofluids preparation, which stabilities were appraised by sedimentation method and UV-vis spectrophotometry. Transmission Electron Microscopy was also applied to examine the size and shape of SiO2 nanoparticles