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Cooling Water (cooling + water)
Selected AbstractsPhotoelectrochemical Study of Corrosion Resisting Property of Cupronickel B10 in Simulated Cooling WaterCHINESE JOURNAL OF CHEMISTRY, Issue 2 2009Qunjie XU Abstract The corrosion behavior for cupronickel B10 electrode in simulated cooling water has been studied by using cyclic voltammetry, a photocurrent response method and electrochemical impedance spectroscopy (EIS). The cupronickel electrode shows a p-type photoresponse to positive and negative potential scan, which comes from Cu2O layer on its surface, but its iph,max is less than that in borax buffer solution. The corrosion resisting property of the cupronickel B10 electrode appeared worse with the increase in the concentrations of Cl,, SO42, and S2, ions, as well as with increasing pH. The rise in the temperature may result in a photoresponse changes from p-type to n-type, and the corrosion resisting property fell simultaneously. The results of the EIS measurement agree well with those obtained by a photoelectrochemical method. [source] JOURNAL of FOOD PROCESSING and PRESERVATION SEP 2000 Vol-24.4. DEVELOPMENT of A PROCESS FOR DETECTING NONTHERMAL EFFECTS of MICROWAVE ENERGY ON MICROORGANISMS AT LOW TEMPERATURE,JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2000MICHAEL KOZEMPEL We developed an experimental process capable of isolating thermal and nonthermal effects of microwave energy relative to the destruction of microorganisms at low temperature. the concept combines instantaneous energy input to the food system by microwaves with rapid removal of thermal energy. the process used a double tube heat exchanger inside a continuous microwave dryer. the outer tube was transparent to microwaves, whereas the inner tube was stainless steel and was used for cooling the system. the microwave energy, 5,6 kW power, was absorbed by the process fluid in the annulus. the cooling water flowing in the inner tube removed the thermal energy from the process fluid to control temperature at or below 45C. the process was at turbulent flow to assure a uniform temperature and dwell time. There were no detected nonthermal effects from microwave energy for yeast, Pediococcus sp., Escherichia coli, Listeria innocua, or Enterobacter aerogenes in various test fluids, such as water, liquid egg, beer, apple juice, apple cider, and tomato juice. [source] Co-current and Countercurrent Configurations for a Membrane Dual Type Methanol ReactorCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 1 2008R. Rahimpour Abstract A dynamic model for a membrane dual-type methanol reactor was developed in the presence of catalyst deactivation. This reactor is a shell and tube type where the first reactor is cooled with cooling water and the second one with feed synthesis gas. In this reactor system, the wall of the tubes in the gas-cooled reactor is covered with a palladium-silver membrane which is only permeable to hydrogen. Hydrogen can penetrate from the feed synthesis gas side into the reaction side due to the hydrogen partial pressure driving force. Hydrogen permeation through the membrane shifts the reaction towards the product side according to the thermodynamic equilibrium. Moreover, the performance of the reactor was investigated when the reaction gas side and feed gas side streams are continuously either co-current or countercurrent. Comparison between co-current and countercurrent mode in terms of temperature, activity, methanol production rate as well as permeation rate of hydrogen through the membrane shows that the reactor in co-current configuration operates with lower conversion and also lower permeation rate of hydrogen but with longer catalyst life than does the reactor in countercurrent configuration. [source] Photoelectrochemical Study of Corrosion Resisting Property of Cupronickel B10 in Simulated Cooling WaterCHINESE JOURNAL OF CHEMISTRY, Issue 2 2009Qunjie XU Abstract The corrosion behavior for cupronickel B10 electrode in simulated cooling water has been studied by using cyclic voltammetry, a photocurrent response method and electrochemical impedance spectroscopy (EIS). The cupronickel electrode shows a p-type photoresponse to positive and negative potential scan, which comes from Cu2O layer on its surface, but its iph,max is less than that in borax buffer solution. The corrosion resisting property of the cupronickel B10 electrode appeared worse with the increase in the concentrations of Cl,, SO42, and S2, ions, as well as with increasing pH. The rise in the temperature may result in a photoresponse changes from p-type to n-type, and the corrosion resisting property fell simultaneously. The results of the EIS measurement agree well with those obtained by a photoelectrochemical method. [source] A structure/function study of polyaminoamide dendrimers as silica scale growth inhibitorsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2005Konstantinos D Demadis Abstract Dendrimers have attracted immense attention during the last decade due to their interesting properties both from a basic and an applied research viewpoint. Encapsulation of metal nanoparticles for catalysis, drug delivery and light harvesting are only some applications of dendrimers that are breaking new ground. A novel application of dendrimer technology is described in the present paper that relates to industrial water treatment. Industrial water systems often suffer from undesirable inorganic deposits. These can form either in the bulk or on metallic surfaces, such as heat exchangers or pipelines. Silica (SiO2) scale formation and deposition is a major problem in high-silica-containing cooling waters. Scale prevention rather than removal is highly desired. In this paper, benchtop screening tests on various silica inhibition chemistries are reported, with emphasis on materials with a dendrimeric structure. Specifically, the inhibition properties of commercially available STARBURST® polyaminoamide (PAMAM) dendrimers generations 0.5, 1, 1.5, 2, and 2.5 are investigated in detail together with other commonly-used scale inhibitors. Experimental results show that inhibition efficiency largely depends on structural features of PAMAM dendrimers such as generation number and nature of the end groups. PAMAM dendrimers are effective inhibitors of silica scale growth at 40 ppm dosage levels. PAMAM dendrimers also act as silica nucleators, forming SiO2,PAMAM composites. This occurs because the SiO2 formed by incomplete inhibition interacts with cationic PAMAM-1 and -2. The general scope of silica formation and inhibition in industrial waters is also discussed. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||