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1 INTRODUCTIONAs mentioned in our previous paper impinging stream contactor(ISC)is aninnovative device for phase contact operations and has proved itself capable to en-hance transfer processes in heterogeneous systems effectively,...
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1 INTRODUCTIONAs mentioned in our previous paper impinging stream contactor(ISC)is aninnovative device for phase contact operations and has proved itself capable to en-hance transfer processes in heterogeneous systems effectively,and thus is of poten-tial application in many chemical engineering processes,such as drying of solidparticles,solid-solid,liquid-liquid and gas-gas mixing,absorption and desorptionof gases into or from liquids with or without chemical reactions,combustion of
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For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from ...
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For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from the stand pipe into the cyclone was specially focused. A semi-empirical model was developed for the predic tion of the pressure drop of the cyclone separator at different operate pressures with the effect of air leakage and inlet solid loading. The operate pressure, air leakage and inlet solid loading act as significant roles in cyclone pressure drop. The pressure drop increases with the increasing of pressure and decreases with the increasing of the flow rate of air leakage from the standpipe and with the increasing of the inlet solid loading.
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This paper experimentally analyzes the causes of cavitation damage in the in vert of an open channel. Results show that cavitation in the invert is mainly du e to the maximum boundary shear occurring at the downstream tangential p...
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This paper experimentally analyzes the causes of cavitation damage in the in vert of an open channel. Results show that cavitation in the invert is mainly du e to the maximum boundary shear occurring at the downstream tangential point of the invert, and the critical hydraulic condition causing cavitation occurs when the dimensionless parameter η=q/(Gh3/2) is equal to 0.015. An improved configuration of the invert is then developed.
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Plate heat exchanger can obtain higher thermal performance because of its advantages in high heat transfer coefficient, small scale, and can realize pure counter current flow. It has been widely applied in HVAC industry. In this p...
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Plate heat exchanger can obtain higher thermal performance because of its advantages in high heat transfer coefficient, small scale, and can realize pure counter current flow. It has been widely applied in HVAC industry. In this paper, the numerical research of plate heat exchanger in solar heating system has been proposed. Aimed at the type of herringbone corrugated plate which has better thermal performance and been widely used, the three dimensional model is established by Gambit software. Using FLUENT software for numerical calculation, by studying the effect of corrugated inclination angle, corrugated depth, corrugated spacing and inlet velocity of heat exchanger on internal temperature, pressure, velocity distributions of domains, the relationship between the above parameters and the Nusselt Number and the pressure drop was obtained by simulation data. Heat transfer coefficient and pressure drop correlations used to measure the overall performance of the heat exchanger. The result shows that the optimal structure parameters is corrugated angle 60°, corrugated depth 4 mm and corrugated spacing 16 mm.
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A series of 250 mm lengths of copper tubing, of 15 mm outer diameter and 0.7 mm wall thickness, were studied to determine their deformation if they were pinched or crushed between rigid objects applying a given force, to replicate...
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A series of 250 mm lengths of copper tubing, of 15 mm outer diameter and 0.7 mm wall thickness, were studied to determine their deformation if they were pinched or crushed between rigid objects applying a given force, to replicate potential accidental damage suffered by the copper pipes during service. A finite element modelling framework was developed to simulate the crushing of a copper pipe the same dimensions as that used for experiments, and the experimental data allowed for a validation of the pipe crushing at approximately room temperature, to consider copper pipe carrying cold water. The FE modelling activity was then extended to consider the deformation of copper pipe at 80℃, carrying heated water at this temperature. The modelling agreed reasonably well with experiment, and applied forces of 1.5 kN began to deform the cold pipe, with the pipe collapsing on itself at loads of 6 kN. The heated pipe began to deform at roughly 1.25 kN. Lastly, theoretical flow calculations were performed to determine the Reynolds value, the flow velocity and the pressure loss and head loss per unit length of the deformed pipes, according to classical pipe flow calculation methods.
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Viscous behavior is important for the process design, especially for the non-Newtonian fluid. In this study, the viscous behaviors of slurry, i.e., 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)im ide([Hmim][NTf_(2)])/ti...
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Viscous behavior is important for the process design, especially for the non-Newtonian fluid. In this study, the viscous behaviors of slurry, i.e., 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)im ide([Hmim][NTf_(2)])/titanium dioxide(TiO_(2))-polyethylene glycol(PEG200), were determined experimentally and systematically. The pressure drop was estimated when [Hmim][NTf_(2)]/TiO_(2)-PEG200 was used as the solvent in the absorption/desorption towers. The results show that the slurry belongs to the non-Newtonian fluid with shear-thinning behavior. High temperature and low solid content are beneficial to reduce the viscosity of [Hmim][NTf_(2)]/TiO_(2)-PEG200, and the presence of [Hmim][NTf_(2)] can effectively reduce the viscosity of the slurry. In addition, high temperature is preferable for reducing the pressure drop, and the pressure drop of slurry with the solid content value of 8.0%(mass) can reduce by 28.0%when the temperature increases from 313 to 333 K.
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1 INTRODUCTIONGentry,Yong and Small [1-3]have described their Rodbaffle heat exchangers,whichare geometrically shell-and-tube exchangers consisting of a series of shell-side bafflesas an array of supporting rods.The supporting-rod...
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1 INTRODUCTIONGentry,Yong and Small [1-3]have described their Rodbaffle heat exchangers,whichare geometrically shell-and-tube exchangers consisting of a series of shell-side bafflesas an array of supporting rods.The supporting-rod matrix creates an unobstructedflow path and makes the flow field in the shell-side of the heat exchangerpredominantly longitudinal bringing along flow-induced tube vibration in a cross flowheat-exchanger.With neither bundle cross flow form drag nor repeated flow reversal ef-fects being present,the shell-side pressure losses in Rodbaffle heat exchangers are low.Rodbaffle heat exchangers also offer an enhanced thermal performance.Stagnant
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