Solar Distillation Apparatus

Description of Solar Distillation Apparatus:  

Solar Still Basin Type:  This includes a shallow square evaporating tray, the base of which is fitted with removable heat insulating material which assists in the evaporation process. This contains the brine liquid to be studied and is covered by a sheet of flat plate glass, set at an angle of 12½º to the horizontal, so that water condensing on it readily runs down to the lower edge. Water evaporating from the tray condenses on the inside surface of the glass cover, runs down to the lower edge and collects in a channel alongside the evaporating basin, from whence it drains to a volumetric measuring vessel. Temperature measurement by multi-point thermocouple instrument is provided at the following points: - feed, brine (output), ambient, glass (outside), glass (inside), the vapour space, centre of tray (under mat), mat (top side). An optional pen recorder is available to continuously record these temperatures. The whole top section of the still may be turned horizontally through 180º, so making it possible to alter the angle of incidence of sunlight on the absorbing pad.

Experimental Capability of Solar Distillation Apparatus:    

1. Measures output and efficiency against solar energy input, amount of base insulation, brine depth  
2. Effect of different absorbent surfaces
3. Effect of inclination, ambient temperature, wind velocity and the effect of cooling the glass cover  
4. Demonstrates the onset of reflux
5. Investigate the effects of varying the inclination of the absorption surface and the flow rate, recording at the same time the film thickness
6. Investigate the comparison between all characteristics of the two units under identical conditions

Features of Solar Distillation Apparatus:      

1. Temperature measurement at eight points
2. Pen recorder to continuously record temperatures
3. Removable solar radiation mat
4. Extendable tray angles and hence flow rates
5. Variable angle of incidence of sunlight on the absorbing pad  Variable thermal insulation material mounted horizontally on a rigid steel stand  
6. Ability to tilt base continuously by +5º and -5º to the horizontal  
7. Horizontal rotation of basin through 180º
8. Non corrosive materials used in all critical areas