scholarly journals Design procedures for a passive pyramid solar still with an automatic feed water system

Author(s):  
Mahmoud Elgendi ◽  
Mohamed Y.E. Selim ◽  
Aysha Aldhaheri ◽  
Wafa Alshehhi ◽  
Houreyah Almarshoodi ◽  
...  
2017 ◽  
Vol 68 (6) ◽  
pp. 1302-1305
Author(s):  
Ali A. A. Al Janabi ◽  
Oana Cristina Parvulescu ◽  
Bogdan Trica ◽  
Tanase Dobre

The paper aimed at studying the performances of pervaporation separation of isopropanol-water system using a Pervatech ceramic membrane at various values of feed mixture flow rate (F=1000 kg/hr), feed water mass fraction (xF=0.1-0.2), operation temperature (t=60-90 �C), permeate pressure (pP=1000-9000 Pa) and water separation degree (sW=0.9, 0.95). Membrane total flux and separation factor were predicted applying a second order response surface model with 3 factors, i.e., xF, t and pP. An algorithm for estimating the membrane surface area was presented. Membrane area increased with sW and xF and its lowest values (A=13 m2 for xF=0.1 and A=24 m2 for xF=0.2) were attained for t=60 �C and pP=9000 Pa. These findings could be applied for optimizing the process of isopropanol dehydration by pervaporation.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Naresh Yarramsetty ◽  
Naveen Sharma ◽  
Modumudi Lakshmi Narayana

Purpose This study aims to investigate the effect of porous material (clay pots) and it is facing on the productivity performance of a pyramid type solar still. The clay pots are placed in the basin facing up and facing down. The numbers of clay pots considered were 9 and 25, and its performance was compared with normal (0 clay pots) solar still. Design/methodology/approach The pyramid solar water distillation system has been designed, fabricated and tested under the actual environmental conditions of Kanchikacherla (16.6834 0N, 80.3904 0E), Andhra Pradesh, India. The solar still is used to produce the fresh water and hot water simultaneously from the brackish (i.e. containing dissolved salts) feed water for domestic applications. From open literature, it was established that the rate of evaporation is higher when the flowing water is held for a longer duration on the black color absorber plate, thereby leading to an increase in productivity of freshwater. Therefore, the pyramid solar still has been tested for smooth absorber plate and the absorber plate with porous heat storage material. Findings The porous material increases the production rate of freshwater compared to a base plate. However, the pyramid still with clay pots has higher productivity at a lower temperature because of the porosity effect. Originality/value The total dissolved solids, electrical conductivity and pH of the distilled water and the saline water have also been measured and compared.


2019 ◽  
Vol 6 (2) ◽  
pp. 91-102
Author(s):  
R. Sivakumaran ◽  
P. Jdihesh

The world is facing the state of being scarce of fresh or drinking water and it is the major problem and global challenge. Along with air and food, water is a basic necessity for human. Solar energy is the biggest source of energy available on earth. A solar distillation is one of the methods for purifying salt water to drinking water. In this method fresh water is obtained by exposing a small layer of salt water to solar radiation and the water vaporized from the basin is condensed on the bottom side of a taper transparent cover. It can be collected in receiving troughs at the end of the still. For this research, a solar still has been designed, fabricated and tested under the climate condition of Coimbatore (11.01680 N, 76.9550 E), India from December 2016 to March 2017. The still basin area was 1m2 and the glass cover of still is inclined at 13 degree based on the city latitude. Solar still is integrated with thermal system such as solar photovoltaic system and then with solar pond in order to preheat the feed water thereby increasing the productivity considerably. Experiments were carried out on the still using different parameters and tested for performance. The results showed that the daily production of the conventional solar still was 2 Lit/m2/day and integrated with photovoltaic system and solar pond was 3.1 Lit/m2/day and 2.54 Lit/m2/day respectively.


Author(s):  
Suyog Patil ◽  
Anand Bewoor ◽  
Rajkumar Patil

Abstract The demand of steam in process industries is increasing rapidly, and this demand can be met by increasing the capacity utilization of steam boilers. Many of the process industries depend on industrial steam boilers as a vital component for their operation. The availability of the boiler can be improved by identifying critical mechanical sub-systems/components concerning failure frequency, reliability, and maintainability and minimizing their likelihood of occurrences. The selection of appropriate technique for data collection and reliability analysis is essential. The time between failure (TBF) and time to repair (TTR) of all components and sub-systems were collected to carry out Reliability, Availability and Maintainability (RAM) analysis. The best-fit distribution and distribution parameters were calculated using ReliaSoft software Weibull++10 after performing trend testing. The preventive maintenance intervals of all components and sub-systems and the availability of the system were evaluated. The analysis reveals that the combustion system, feed-water system, and blow-down system are the critical sub-systems from a reliability perspective and are still the biggest reasons for the boiler downtime. The research study also showed that TTR was longer for the combustion system than the other sub-systems, and thus, to enhance its availability, it is suggested that maintenance resources should be allocated at the appropriate moment to the combustion system. The study also shows the usage of RAM analysis in deciding the preventive maintenance intervals of components/sub-systems of the boiler. It also provides a reference for the preparation of the maintenance plan for the boiler system.


Author(s):  
Michele Compare ◽  
Michele Bellora ◽  
Enrico Zio

This article investigates the aggregation of rankings based on component importance measures to provide the decision maker with a guidance for design or maintenance decisions. In particular, ranking aggregation algorithms of the literature are considered, a procedure for ensuring that the aggregated ranking is compliant with the Condorcet criterion of majority principle is presented and two original ranking aggregation approaches are proposed. Comparisons are made on a case study of an auxiliary feed-water system of a nuclear pressurized water reactor.


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