Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer

Solar pond powered liquid desiccant evaporative cooling

Liquid desiccant cooling systems (LDCS) are energy efficient means of providing cooling, especially when powered by low-grade thermal sources. In this paper, the underlying principles of operation of desiccant cooling systems are examined, and the main components (dehumidifier, evaporative cooler and regenerator) of the LDCS are reviewed. The evaporative cooler can take the form of direct, indirect or semi-indirect. Relative to the direct type, the indirect type is generally less effective. Nonetheless, a certain variant of the indirect type - namely dew-point evaporative cooler - is found to be the most effective amongst all. The dehumidifier and the regenerator can be of the same type of equipment: packed tower and falling film are popular choices, especially when fitted with an internal heat exchanger. The energy requirement of the regenerator can be supplied from solar thermal collectors, of which a solar pond is an interesting option especially when a large scale or storage capability is desired

New Method for Removal of Organic Dyes Using Supported Iron Oxide as a Catalyst

In this study, we perform a catalytic decomposition of organic dye over Fe2O3-CeO2-TiO2-γ-Al2O3 catalyst in the presence of molecular oxygen and chlorate ions. The results showed that organic dye acts as a sensitizer during this process. The mechanism of the allover process is hypothesized. Several techniques were employed for the characterization of the catalyst, including XRD, SEM, EDAX, and thermal analysis and catalytic activity. The analysis showed that iron is the main active centers, and we have two types of active centers in this process: surface iron and dissolved iron in titanium dioxide. The dissolved iron was found to be the most active center; however, after Fe/Ti = 2.76, a synergism was observed to be occurring between the two active centers

A thermodynamic review on solar ponds

Solar energy is a clean source of renewable energy and people around the world are getting a lot of benefits day by day through the utilization of solar energy technology. Among various solar energy systems, a solar pond is a good energy device which is liable to be the most economic large-scale solar collector. It also has the benefit of being its own thermal energy storage (TES). The present review article focuses on the design methodology and different thermodynamic aspects of a salinity gradient solar pond (SGSP) along with its socio-economic benefits. Thermodynamic analysis of SGSP for energy, exergy, heat transfer, and shading effect has been discussed in much supportive way to the students, research scholars and solar professionals. Technical and general recom-mendations for future works show the research gap and a great possibility of further research on SGSPs. Overall, through this review study, the one can design a solar pond and carry out a complete thermal analysis of a SGSP with a simple approach