Solar stillSolar still

Submitted by YOGESH PATIL 11031m02060

Solar Water Distillation Device

Overview/Outline

IntroductionNecessityDesignSystem DevelopmentWater distillationWorkingAdvantages DisadvantagesApplication

A solar still is a simple way of distilling water, using the heat of the Sun to drive evaporation from humid soil, and ambient air to cool a condenser film. Two basic types of solar stills are box and pit stills. In a solar still, impure water is contained outside the collector, where it is evaporated by sunlight shining through clear plastic. The pure water vapor condenses on the cool inside plastic surface and drips down from the weighted low point, where it is collected and removed. The box type is more sophisticated. The basic principles of solar water distillation are simple, yet effective, as distillation replicates the way nature makes rain. The sun's energy heats water to the point of evaporation. As the water evaporates, water vapor rises, condensing on the glass surface for collection. This process removes impurities, such as salts and heavy metals, and eliminates microbiological organisms. The end result is water cleaner than the purest rainwater.

Introduction

NECESSITY

Over 1 billion people without access to clean water worldwide

26.8% in Africa

Clean water essential to stop spread of disease & improve overall health

Solar energy = untapped resource

Design Outline

Input Tank

ReflectiveWalls

Adjustable Legs Output Tank

Float Valve

Troughs

Collection Unit

Insulation

System development

Water Distillation

Process that removes impurities & contaminantsHow?

Heat water to point of vaporizationWater vapor condenses on cooler surfacesCondensate runs off into collection bin

Working

1. Once you have the contraption in place you will need to fill the center trough with the water you are trying to purify.  The center trough usually will have a black bottom, which helps to attract sunlight.

2. The heat from the sun evaporates the salt water that is sitting in the center trough.  The process of evaporation only lifts pure molecule of H2O into the air of the container, leaving the dirty parts of the water sitting in the trough.

3. Next, the process of condensation occurs.  This is when the water vapor molecules hit the glass or plastic ceiling of the solar still and turn into water droplets.  This is the same type of condensation you see when you are drinking cold water out of a glass or cold can.

4. After condensation, the water droplets are forced by gravity and to slide down the glass or plastic ceiling into a second clean trough along the inside edge of the solar still.  They cling to the edge of the glass or plastic and follow it all the way down into an outer rim that flows into the ‘clean water’ area.  Because the water is clinging to the angled glass or plastic, it does not get mixed back in with the dirty water.

5.  After a certain amount of time enough water is collected and the water is ready to drink.  This is usually done with a hose that is connected from the clean trough to the outside of the contraption.

Advantages

Cost Effectiveness

Free of charge sun energy (during sunlight it eliminates 500 Watt electric consumption per one hour of sunlight)

We provide quality water for personal and industrial use

Disadvangs

Low production capacity, not enough for the drinking water needs of the average family

Solar distillers don’t kill bacteria and they don’t break down harmful chemicals because they don’t boil the water

The large area tilted glass cover might be an attraction to bugs and insects

Application

For industrial process

For sterilization

For battery maintanance and radiator