OPTIMIZATION OF PROCESS PARAMETERS OF PRESSURE-SWING ADSORPTION CYCLE IN A SILICA GEL DESICCANT DEHUMIDIFICATION SYSTEM

Parametric study on pressure-swing adsorption cycle desiccant dehumidification system is a continuous engineering task with the aim of analyzing its effects and attains target quality of dry air for an industrial process. An experimental setup is developed with a dehumidification tower, regeneration tower,and flow control valve.The effect of process air inlet moisture content, cycle time ratio, and regeneration air flow rate on the adsorption performance is studied to evaluate the potential of the dehumidification system suitable for drying applications. The optimal dehumidification parameters are found, and a regression equation is also developed for the process. It is concluded that, process air inlet moisture is the most influencing parameter compared to regeneration air flow rate and cycle time ratio for the silica gel desiccant dehumidification system.&nbsp

AN EXPERIMENTAL STUDY ON THE PERFORMANCE OF VERTICAL BASIN SOLAR STILL

In the present study, a new experimental approach is proposed to enhance the performances of the conventional single slope solar still using vertical basin at inner wall surfaces. Main objectives of this study are, to increase the distilled output of solar still by utilizing heat energy available inside vertical surfaces and to find out the optimum thickness of vertical basin experimentally. The experimental system involves six identical solar stills, one of the stills is conventional and remaining stills have vertical basin with different thicknesses (3, 6,9,12 and 15 mm). Solar stills are fabricated with an effective area of 0.009 m2 and the transparent glass angle is 11°. The experiments were conducted on 19.02.2016 with depth of water 20 mm. The results show that (i) productivity of vertical basin solar stills are higher than the conventional still, (ii) heat loss from inner wall surfaces to outer wall surfaces are reduced considerably in vertical basin still  (iii) optimum thickness of vertical basin is 12 mm. To conclude introducing vertical basin in conventional still improves the performance of the still

EXPERIMENTAL INVESTIGATION ON DRYING OF BLANCHED BITTER GOURD SLICES IN A TRIPLE PASS SOLAR DRYER

This paper involves with the experimental performance study of a triple pass solar flat plate collector integrated with  thermal energy storage medium for drying of blanched bitter gourd slices. The experimental setup consists of a blower, triple pass flat plate collector and a drying chamber. The experimets were carried out in the meterological conditions of Coimbatore, Tamil Nadu, India. The mass flow rate of air through the system was set as 0.06 kgs-1. From the results, it could be comprehended that, (i) triple pass arrangement of air improves the performance of flat plate collector (ii) thermal energy storage medium played an important role in consistent outlet air temperature and the thermal efficiency (iii) triple pass solar dryer took 5 hours to reach the final moisture content of bitter gourd (9% on wet basis) which is 29 % and 37.5% faster than without thermal storage and open sun drying system. It could be concluded that triple pass solar air collector performs better than without thermal storage and open sun drying

Experimental Investigation on the Effect of Casting Parameters on Thin walled Castings of Metal Matrix (LM21-SiC) Composite

 Metal matrix composites (MMCs) are widely used in several applications owing to their high strength, high specific stiffness, greater wear resistance and light weight. Normally, MMCs are processed through stir casting which exhibits poor wet ability and bonding between metal matrix and ceramic reinforcement, porosity and hot tears. These drawbacks can be overcome by squeeze casting process. Here an attempt was made on processing LM21-Sic composite for making hollow casting through squeeze casting process. Four process parameters are chosen namely squeeze pressure, stirring speed, melt temperature and reinforcement percentage. The primary objective was to experimentally investigate the influence of casting parameters on hardness & wear. Samples were cast for each experiments condition based on L9 orthogonal array. From the analysis of variance (ANOVA), it was observed that stirring speed, reinforcement percentage and Squeeze load were the process parameters making a noticeable improvement in hardness and wear. The mechanical properties such as hardness and wear are evaluated and optimum casting condition was obtained

AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF MASS FLOW RATES ON THE PERFORMANCE OF FLAT-PLATE SOLAR WATER HEATING SYSTEM USING CuO/WATER NANOFLUID

One of the effective ways of increasing the efficiency of flat plate solar collector is to utilize nanofluids which are having high thermal conductivity. In the present study, an attempt is made to investigate the effect of mass flow rates on the performance of flat plate solar collector using CuO/water nanofluid. The experimental set up consists of flat plate solar collector; storage tank and ladder type heat exchanger. The instantaneous efficiency of solar collector is calculated by taking lower volume fraction of 0.01% with average particle size of 30 nm and varying the flow rate from 1 lpm to 3 lpm, as per ASHRAE standard, with and without Triton X-100 surfactant. The experimental results reveal that utilizing the nanofluid with mass flow rate at 1.5 lpm increases the collector efficiency by 19.7%.Â

Status of solar desalination in India

The work was motivated by the increasing awareness of the need for enhancing water supplies schemes in arid lands featuring an appropriate technology for solar energy use in the desalination field in India. The fresh water crisis is already evident in many parts of India, varying in scale and intensity at different times of the year. India's rapidly rising population and changing lifestyles also increases the need for fresh water. Fresh water is increasingly taking centre stage on the economic and political agenda, as more and more disputes between and within states, districts, regions, and even at the community level arises. The conventional desalination technologies like multi stage flash, multiple effect, vapor compression, iron exchange, reverse osmosis, electro dialysis are expensive for the production of small amount of fresh water, also use of conventional energy sources has a negative impact on the environment. Solar distillation represents a most attractive and simple technique among other distillation processes, and it is especially suited to small-scale units at locations where solar energy is considerable. India, being a tropical country is blessed with plenty of sunshine. The average daily solar radiation varies between 4 and 7 kWh per square meter for different parts of the country. There are on an average 250-300 clear sunny days in a year, thus it receives about 5000 trillion kWh of solar energy in a year. In spite of the limitations of being a dilute source and intermittent in nature, solar energy has the potential for meeting and supplementing various energy requirements. Solar energy systems being modular in nature could be installed in any capacity as per the requirement. This paper consists of an overall review and technical assessments of various passive and active solar distillation developments in India. This review also recommended some research areas in this field leading to high efficiency are highlighted.Distillation Fresh water Economic Research Solar energy

Active solar distillation--A detailed review

All over the world, access to potable water to the people are narrowing down day by day. Most of the human diseases are due to polluted or non-purified water resources. Even today, under developed countries and developing countries face a huge water scarcity because of unplanned mechanism and pollution created by manmade activities. Water purification without affecting the ecosystem is the need of the hour. In this context, many conventional and non-conventional techniques have been developed for purification of saline water. Among these, solar distillation proves to be both economical and eco-friendly technique particularly in rural areas. Many active distillation systems have been developed to overcome the problem of lower distillate output in passive solar stills. This article provides a detailed review of different studies on active solar distillation system over the years. Thermal modelling was done for various types of active single slope solar distillation system. This review would also throw light on the scope for further research and recommendations in active solar distillation system.Active solar still Desalination Flat plate collector Review Solar pond Thermal modelling