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The purpose of this paper is to perform the computational fluid dynamics (CFD) simulation with experimental validation to investigate the particle segregation effect in abrupt and smooth shapes circulating fluidized bed (CFB) risers.

The experimental investigations were carried out in lab-scale CFB systems and the CFD simulations were performed by using commercial software BARRACUDA. Special attention was paid to investigate the gas-particle flow behavior at the top of the riser with three different superficial velocities, namely, 4, 6 and 7.7 m/s. Here, a CFD-based noble simulation approach called multi-phase particle in cell (MP-PIC) was used to investigate the effect of traditional drag models (Wen-Yu, Ergun, Wen-Yu-Ergun and Richardson-Davidson-Harrison) on particle flow characteristics in CFB riser.

Findings from the experimentations revealed that the increase in gas velocity leads to decrease the mixing index inside the riser. Moreover, the solid holdup found more in abrupt riser than smooth riser at the constant gas velocity. Despite the more experimental investigations, the findings with CFD simulations revealed that the MP-PIC approach, which was combined with different drag models could be more effective for the practical (industrial) design of CFB riser. Well agreement was found between the simulation and experimental outputs. The simulation work was compared with experimental data, which shows the good agreement (<4%).

The experimental and simulation study performed in this research study constitutes an easy-to-use with different drag coefficient. The proposed MP-PIC model is more effective for large particles fluidized bed, which can be helpful for further research on industrial gas-particle fluidized bed reactors. This study is expected to give throughout the analysis of CFB hydrodynamics with further exploration of overall fluidization.

Indian Bank, a major commercial bank in South India, has launched Rural Credit Franchisee (RCF) model for lending money to small borrowers in villages. The study aims to study the business model, the profile of ultimate borrowers and their credit requirements and to study the economics of the model.

Data used for the study are mostly primary in nature collected from the RCFs and the rural borrowers. In addition, bank officials were interviewed and also data on loan accounts of RCFs were collected from the sample bank branches and the RCFs.

The RCF scheme is a novel micro finance scheme and it has showcased that the informal institutions can be linked with the formal credit institutions. The scheme has benefited all the stakeholders including the bank, the RCFs and the rural poor.

The study has covered majority of the RCFs of the bank in terms of number and volume of business under the scheme and hence the results indicate the performance of the entire portfolio of the bank under the scheme.

The study finds that the scheme has benefited all the stakeholders. It has particularly helped in creating competition amongst the rural moneylenders and thereby bringing down the cost of credit in rural hinterlands. Findings are strongly in favour of expanding/replicating the model by the other commercial banks and in all parts of the country, rather across the entire world.

The RCF model is one of its kind and the policy makers and regulators may encourage the scheme in order to attain inclusive economic growth. This is a first of its kind study investigating the operation of such a model.