purification of water using solar still

Under the guidance ofSanthosh K.G

Assistant professorMechanical engineering

M.I.T Mysore

A Technical Seminar on

WATER PURIFICATION USING

SOLAR STILL

Submitted by

Mohamed Shakeeb Ahmed

4MH11ME069

1

INTRODUCTION

• A solar still is a simple way

of distilling water.

• It uses solar energy to distill the water.

• It removes impurities such as salt and

other microbiological organisms.

2

Water Impurities

• Suspended particles.

• Dissolved inorganic salts.

• Dissolved organic compounds.

• Micro-organisms.

• Pyrogens.

3

Types of purification

• Distillation.

• Vapour compression.

• Reverse osmosis.

4

Benefits of Distillation

• It produces water of high quality.

• Maintenance is almost negligible.

• Any type of water can be purified into potable water

by means of this process.

• Wastage of water will be minimum.

5

Types of solar still

• Spherical solar still.

• Hemispherical solar still.

• Pyramid solar still.

6

Spherical solar still

7

Hemispherical solar still

8

Pyramid solar still

9

Working of solar still

10

Concept for making a good solar

still• The cover can be either glass or plastic.

• Glass is preferable to plastic because most plastic

degrades in the long term due to ultra violet light

from sunlight.

• The use of the mirror reflector will increase the

temperature of the solar still basin.

• Sufficient Insulations of wool, thermocol, sealants

etc. must be provided inside the basin in order to

prevent loss of heat.

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Estimation of water output

Estimate: 3.91 liters/𝒎𝟐 /day

Q=𝑨.𝑬.𝑮

𝟐.𝟑

A = Aperture area of the still in 𝒎𝟐

E = Efficiency of the still usually taken as 50%

G = Global radiation energy in MJ/𝒎𝟐(Approx. 18 MJ/𝒎𝟐)

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Advantages

• Free of charge sun energy (during sunlight it

eliminates 500 Watt electric consumption per one

hour of sunlight).

• There are no moving parts; it is therefore reliable and

almost maintenance free (cleaning is required

though).

• Water taste is claimed to be better since the device

act as a Solar Water Vaporizer and it doesn’t boil the

water (resembling rain water).

• Neutral pH is claimed (like rainwater), not like the

not neutral pH of steamed distilled water. 13

Disadvantages

• Low distillate output per unit area.

• Leakage of vapour through joints.

• High maintenance.

• Productivity decreases with time for a variety of

reasons.

14

Case study

Fig: 12 Array Solar Still System

1.

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2.

Fig: Flat Plate Solar Still

16

Conclusion

• It was found from the experimental analysis that

increasing the ambient temperature from 32°C to

47°C will increase the productivity by approximate

12 to 23%.

• It was observed that when the water depth increases

from 0.01m to 0.03m the productivity decreased by

5%.

• Solar still productivity can also increase by use of

reflector by 3%.

• Capital cost can be reduced by using different designs

and new materials for construction of solar stills.17

THANK YOU

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