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Optimization of cyclone geometry for maximum collection efficiency . Yunardi; Ilham Maulana; . Elwina; . Wusnah; Novi Sylvia; Yazid Bindar
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 1, No 2 (2011): Engineering
Publisher : Syiah Kuala University

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This paper presents the results obtained from the application of both computational fluid dynamics (CFD) Fluent 6.3 and Design Expert codes to modelling and optimizing a gas-solid cyclone separator based upon its geometrical parameters. A pre-processor software GAMBIT was employed to set up the configuration, discretisation, and boundary conditions of the cyclone. A commercial CFD code FLUENT 6.3 was employed to simulate the flow field and particle dynamics in the cyclone. The optimization study was performed under either a constant gas inlet flow rate of 0.075 m3/s or a constant inlet gas velocity of 18 m/s. A response surface methodology with three levels (-1, 0, and +1) was employed as the experimental design. Independent variables to be optimized include the ratio of inlet gas width to diameter of the cyclone, W/D, the ratio of conical length to diameter, Lc/D and the ratio outlet diameter to cyclone diameter De/D. The response variables of collection efficiency and pressure drop were correlated in the forms of quadratic polynomial equations. The simultaneous optimization of the response variables has been implemented using a desirability function (DF) approach, computed with the aid of Design Expert software. The results of investigation showed that at constant flow rate, the following optimum ratios of W/D =0,28, Lc/D =1,5, and De/D =0,52 were obtained to give a collection efficiency of 90% and a pressure drop of 155 Pa. At the constant inlet gas velocity, the following optimum ratios of W/D =0,25, Lc/D =1,5, and De/D =0,57 were obtained to give a collection efficiency of 90% and a pressure drop of 190 Pa. This findings indicate that gas inlet treatment at either constant flow rate or constant inlet gas velocity does not produce significant difference on the collection efficiency, but does give significant influence on the pressure drop.

The Use of Membrane Cellulose from Nata as a Filter of Pliek U Oil . Faridah; . Elwina; . Nadia
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 2, No 2 (2012): Engineering
Publisher : Syiah Kuala University

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The research has been carried out in the laboratory scale to create and assess the ability of membrane cellulose from nata. Nata was produced from coconut-water and nira aren with a ratio 100%: 0%, 0%:100% and 50%:50%, which fermented with the addition of sugar and without the addition of sugar. Acetobacter xylinumwas added in medium as starter. The fermentation process was be done at 5, 7 9 days. The objective of this research was to study the influence of membrane cellulose as filter for Pliek U oil. Pliek U oil was filtered through membrane cellulose. Pliek U oil which was resulted have a good quality than before. Where membrane cellulosehas been able to reduce Free Fatty Acid (FFA), the results showed that the use of membrane cellulose from nata significantly reducesFree Fatty Acid (FFA). The membrane cellulose from coconut-water and nira aren without the addition of sugarat 9 days was reduced Free Fatty Acid from 2,43 % to 1,2%. But for density and index bias of Pliek U oil does not reduced with using membrane cellulose

Analysis of turbulence models performance for the predictions of flow yield, efficiency, and pressure drop of a gas-solid cyclone separator Novi Sylvia; . Yunardi; Ilham Maulana; . Elwina; . Wusnah; Yazid Bindar
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 1, No 2 (2011): Engineering
Publisher : Syiah Kuala University

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This paper presents the results obtained from the application of computational fluid dynamics (CFD) to modelling the flow field of a Lapple cyclone and to optimizing the cyclone based upon its geometrical parameters. A pre-processor software GAMBIT was employed to set up the configuration, discretisation, and boundary conditions of the cyclone. The characteristics of the cyclone being studied was 0.2 m in diameter, receiving a gas flow rate of 0.1 m3/s with a particle mass loading of 0.01 kg/m3. A commercial CFD code FLUENT 6.2.16 was employed to simulate the flow field and particle dynamics in the cyclone. The objective of this research was to investigate the performance of a number of turbulence models on the prediction of the flow field, collection efficiency and pressure drop in the Lapple cyclone. A number of five turbulence models under Reynolds Averaged Navier Stokes (RANS) category, including Spallart-Allmaras, standard k-ε model, RNG k-ε model, standard k-ω model, and Reynolds Stress Model (RSM) were examined in the simulation of the flow field and particle dynamics inside the cyclone. A validation of all calculation was performed by comparing the predicted results in terms of axial and tangential velocities, efficiency and pressure drop against experimental data of a Lapple cyclone taken from literature. The results of the investigation show that out of five turbulence models being tested, the RSM presented the best predicted results. The predictions of axial and tangential velocities as well as cyclone efficiency by this model are in excellent agreement with the experimental data. Although the pressure drop in the cyclone is under-predicted, the RSM predictions are far better than those of other model. Other turbulence models are over-predicted and under-predicted the axial and tangential velocity, respectively. With respect to efficiency and pressure drop of the cyclone, other models are capable of following the trend of the experimental data but they failed to agree with the experimental values. These results suggest that the RSM is the most suitable turbulence model to represent the flow field and particle dynamics inside a cyclone gas-solid separator.

Comparative performance study of two simple soot models for the prediction of soot level in atmospheric turbulent non-premixed flames . Elwina; . Yunardi; Novi Sylvia; . Wusnah; Yazid Bindar
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 1, No 2 (2011): Engineering
Publisher : Syiah Kuala University

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The increase of current fossil fuel consumption has led to an increase of soot emission into atmosphere. Accurate prediction of soot production and destruction in a combustion system is not only important for the purpose of the design of the system, but also vital for the operation of the combustor. Numerous soot models have been proposed to predict the soot production and destruction in a flame, categorized as empirical, semi-empirical and detailed soot models. Although the detailed model represents the highest level of soot modelling, its use has been impaired by substantial requirement of resources of computer and time. Therefore, empirical and semi-empirical approaches still have their position in soot modelling of practical combustors. In this study, two soot models, single-step and two-step models are examined in the simulation of atmospheric turbulent non-premixed sooting flames. The soot models are compared and evaluated for their performance in predicting soot level in methane and ethylene non-premixed flames. The commercial software Fluent 6.3 was used to perform the calculations of flow and mixing fields, combustion and soot. Standard k-ε and eddy dissipation models were selected as solvers for the representation of the turbulence and combustion, respectively. The two soot models used in the study are available directly from the code for evaluation. The results show that the two-step model clearly performed far better than the single-step model in predicting the soot level in both methane and ethylene non-premixed flames. With a slight modification in the constant a of the soot formation equation, the two-step model was capable of producing prediction of soot level closer to experimental data. In contrast, the single-soot model produced very poor results, leading to a significant under-prediction of soot levels in both flames.

Computational fluid dynamics of crosswind effect on a flare flame . Wusnah; . Yunardi; Ilham Maulana; . Elwina; Novi Sylvia; Yazid Bindar
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 1, No 2 (2011): Engineering
Publisher : Syiah Kuala University

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This paper presents the results obtained from the application of computational fluid dynamics (CFD) to modelling the crosswind effect on a turbulent non-premixed flame. A pre-processor software GAMBIT was employed to set up the configuration, discretisation, and boundary conditions of the flame being investigated. The commercial software Fluent 6.3 was used to perform the calculations of flow and mixing fields as well as combustion. Standard k-ε and eddy dissipation models were selected as solvers for the representation of the turbulence and combustion, respectively. The results of all calculations are presented in the forms of contour profiles. During the investigation, the treatment was performed by setting a constant velocity of fuel at 20 m/s with varied cross-wind velocity and by keeping the cross-wind velocity constant at 1.1 m/s with varied fuel velocity. The results of the investigation showed that the standard k-ε turbulence model in conjunction with Eddy Dissipation Model representing the combustion was capable of producing reliable phenomena of the flow field and reactive scalars field in the turbulent non-premixed flame being investigated. Other results of the investigation showed that increasing the velocity of the crosswind, when the fuel velocity was kept constant, significantly affected the flow field, temperature and species concentrations in the flare flame. On the other hand, when the velocity of the fuel was varied at the constant crosswind velocity, the increasing velocity of the fuel gave positive impact as it enabled to counteract the effect of crosswind on the flare flame

Simulation of the crosswind and the steam addition effect on the flare flame . WUSNAH; . YUNARDI; NOVI SYLVIA; . ELWINA; YAZID BINDAR
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 4, No 1 (2014): Engineering
Publisher : Syiah Kuala University

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This paper presents the results obtained from the application of computational fluid dynamics (CFD) to modelling the crosswind and steam addition effect on a turbulent non-premixed flame. A pre-processor software GAMBIT was employed to set up the configuration, discretisation, and boundary conditions of the flame being investigated. The commercial software Fluent 6.3 was used to perform the calculations of flow and mixing fields as well as combustion. Standard k-ε and eddy dissipation models were selected as solvers for the representation of the turbulence and combustion, respectively. The results of all calculations are presented in the forms of contour profiles. During the investigation, the treatment was performed by setting a velocity of fuel at 20 m/s with varied cross-wind velocity at 3.77 m/s, 7.5 m/s and 10 m/s, and steam/fuel ratio at 0.14, 0.25 and 2.35. The results of the investigation showed that the standard k-ε turbulence model in conjunction with Eddy Dissipation Model representing the combustion was capable of producing reliable phenomena of the flow field and reactive scalars field in the turbulent non-premixed flame being investigated. Other results of the investigation showed that increasing the velocity of the crosswind, when the fuel velocity was kept constant, significantly affected the flow field, temperature and species concentrations in the flare flame. On the other hand, when the velocity of the fuel was varied at the constant crosswind velocity, the increasing velocity of the fuel gave positive impact as it enabled to counteract the effect of crosswind on the flare flame. The velocity of the crosswind very influence of combustion efficiency, from result of the investigation showed that increasing the velocity of the crosswind significantly affected the combustion efficiency, other result of the inverstigation showed that steam addition will very influencing combustion, excelsior the steam/fuel ratio results the combustion efficiency decrease

Effect of plasticizer and fermetation time on cellulose membrane production and analysis of material property . FARIDAH; ALFIAN PUTRA; . ELWINA; M. SAMI; NUR AZIZAH
Proceedings of The Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter Vol 4, No 1 (2014): Engineering
Publisher : Syiah Kuala University

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This research has been carried out in cellulose membrane production from bacterial cellulose. Bacterial cellulose is produced from the fermentation process. The purpose of this study was to analysis the effect of cmc, glycerol and fermentation time towards cellulose membrane characteristics. Cellulose membrane made of a combination of coconut water and palm sugar juice as medium fermentation by using Acetobacter xylinum at 2, 4 and 6 days for fermentation time. Cellulose membrane obtained from a mixture of bacterial cellulose, cmc and glycerol. The addition of cmc and glycerol to improve cellulose membrane characteristics and performance. Based on the analysis results obtained the best performance at 4 days of fermentation time with a concentration of 1.5% cmc and 1.5% glycerol. The thickness of the cellulose membrane was almost the same for all samples and does not affect significantly towards the fermentation time for cellulose membrane production. Cellulose membrane has an asymmetric shape based on morphological analysis using SEM. Besides cellulose membrane has a similar pattern to the weight reduction and has the addition of heat resistance of the membrane. While the results of the IR spectra of cellulose membrane to detect the presence of OH groups, CO, C=C and CH groups that are characteristic of the polymer

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