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Investigation the Effect of additives on Effective Parameters in Design and Production of Agricultural Sulfur Formulation

Abedini, Hassan | 2014

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46241 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Safekordi, Ali Akbar; Ahmadi, Amir Naser; Pakseresht, Saed; Roozbehani, Ahmad
  7. Abstract:
  8. Nowadays, different processes are designed in order to convert raw materials to value added products. One of these is the Bentonite sulfur production process. The most important equipment in this process are stirred tanks where mixing operation of molten sulfur with some additives such as functionalized Bentonite and oxides of iron, zinc and manganese are performed.
    In this thesis, following the design and making of a laboratory scale glass baffled stirred tank, the viscosity of molten sulfur and additive suspension has been measured at different temperature (125, 130 and 135oC) and several formulations. Concentration profile of Bentonite has also been obtained by means of local sampling from molten sulfur and Bentonite suspension in laboratory stirred tank. This operation has been done with a sampler designed and made in this project. In another section of the thesis, simulation of stirred tanks in laboratory and pilot scale has been conducted by using computational fluid dynamics (CFD) based on RNG turbulence model and Eulerian two fluid model. First of all, in order to verify the selected models and numerical method, comparison of experimental results and simulation outputs has been performed. Results show that the selected models can reliably predict the particle distribution of Bentonite in molten sulfur. Also, in this section, minimum required impeller speed for production of 10 and 20 %w/w Bentonite concentration in pilot stirred tank, has been predicted and the essential changes in impeller speed in the case of liquid level and viscosity variations, has been calculated. It is necessary to increase the impeller speed to provide sufficient agitation, when micronutrients, which increase the suspension viscosity, were added. The experimental results indicate that increase in viscosity of molten sulfur and Bentonite suspension due to adding zinc oxide is more than that from other additives. In addition, with increasing the concentration of additives, the effect of temperature on the suspension viscosity increases.
  9. Keywords:
  10. Computational Fluid Dynamics (CFD) ; Bentonite ; Solid-Liquid Suspension ; Molten Sulfur Sampling ; Bentonite Sulfur ; Stirred Tanks

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