A methodology to obtain a Nusselt correlation for stirred tank reactors is presented. The novelty of the approach is the use of a validated computational model to obtain the heat‐transfer coefficients. The advantages of this new approach are many, including the possibility of testing different heat‐transfer configurations to obtain their Nusselt correlation without performing experimental runs. Physical phenomena involved was represented both qualitatively and quantitatively. The classical experimental work of (Oldshue and Gretton, Chem Eng Prog. 1954;50(12):615–621) illustrates the procedure. A sufficient number of virtual points in the whole range of the Reynolds number should be obtained. Results strongly depend on mesh refinement in the boundary layer, so a procedure is suggested to guarantee heat‐transfer coefficients are accurately estimated. The final Nusselt correlation was compared against all the 107 experimental points of the work by (Oldshue and Gretton, Chem Eng Prog. 1954;50(12):615–621), and an average deviation on the results of 10.7%. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3912–3924, 2017
The heat exchange in stirred tanks occurs mainly due to the impeller rotation and overall circulation of the fluid that promotes a more effective heat transfer between fluid and heat transfer surfaces. The type of impeller used and the size of the vessel (that affects the relation heat transfer area and volume of the vessel) have significant effects on the heat transfer. The heat transfer coefficient is very much dependent on the impeller and the speed of rotation. Empirical correlations are usually used to estimate the process side heat transfer coefficient. However, its dependence on the geometrical parameters restricts the use of those correlations to specific tank configurations. In this respect, the use of computational fluid dynamics (CFD) has recently emerged as an alternative to experimental studies. The procedure proved to be faster and lower cost, and the results proved to be accurate. In this study, CFD was applied to obtain a Nusselt number correlation for a jacketed stirred tank equipped with a six‐blade Rushton turbine impeller. The Nusselt number correlation obtained from the simulated model agrees with experimental data providing a reliable representation of the heat transfer in the tank.
Biocorrosion is a phenomenon that strongly affects the integrity of the materials used in the oil and gas industry. Different types of biocides are currently used to control bacteria in industrial water; however, they have disadvantages such as microbial resistance to these chemical compounds and possible impact on biodiversity due to eventual contamination of natural water. There are several alternatives for the elimination or control of bacteria, among which one is the use of type C ultraviolet (UV-C) radiation. Nevertheless, the use of these micro-organism removal systems could be affected by water quality and its efficiency can be improved by using LED diodes of lower energy consumption and greater versatility in exposure to high temperatures. This work was aimed to evaluate the use of such radiation as a strategy for the control and/or elimination of sulfate reducing bacteria (SRB), and acid producing bacteria (APB) present in both corrosion and souring processes. For this purpose, injection water from oil and gas industry and a dynamic system which flow variation enabled the evaluation of different water exposure times to UV-C light (1-20 minutes) were used. Efficiencies ranging between 99-100% were achieved in the elimination of SRB and APB from produced water measured by two different techniques, selective culture media for these microbial populations, and qPCR detecting a specific gene from the SRB population.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.