The presentation is regarding the use of membrane distillation for getting pure water from sweat. The mechanism of UNICEF sweat machine is explained in this presentation

1. Case Study – Membrane Distillation
used in UNICEF Sweat Machine
Guide – Pradip Kumar Mishra
Presented by – Utkarsh Sethia
27th January , 2017

2. UNICEF Sweat Machine

3. UNICEF Sweat Machine
• The device spins and heats the material to remove
the sweat, and then passes the vapor through a
special membrane designed to only let water
molecules get through
• Built by - Andreas Hammar (Swedish engineer)
• Technology developed by - Sweden's Royal
Institute of Technology and the water purification
company HVR

4. UNICEF Sweat Machine

5. Mechanism of UNICEF Sweat Machine
• Sweat Machine works by using membrane
distillation (MD) to separate water from other
components of sweat.
• MD is a thermally-driven process that employs a
hydrophobic, microporous membrane
• The water (or sweat) to be processed is heated,
while the water on the permeate side of the
membrane is kept cool.

6. Mechanism of UNICEF Sweat Machine
• The temperature difference across the
membrane creates a corresponding difference
in pressure which pulls water, in the form of
vapor, over to the permeate side of the
membrane.
• Water’s naturally high surface tension keeps
the liquid phase of the water out of the
membrane’s pores.

7. UNICEF Sweat Machine

8. Why Membrane Distillation
• It is a good choice for compact desalination and
water purification units
• The process doesn’t require the energy and
equipment to create the extreme pressures
needed for reverse osmosis.
• Heating the feed water can be done with the
waste heat of a power plant or factory or with
renewable energy sources like solar power.

9. UNICEF Sweat Machine
• The amount of water it produces depends on
how sweaty the person is - but one person's T-
shirt typically produces 10ml
• Water extracted from the machine is actually
cleaner than the ordinary swedish tap water

10. What Andreas Hammar has to say
• "We use a substance that's a bit like Gore-Tex
that only lets steam through but keeps
bacteria, salts, clothing fibres and other
substances out.”
• "They have something similar on the
International Space Station to treat
astronaut's urine - but our machine was
cheaper to build.”

11. What is Gore-Tex

12. References
• Article (http://www.mynewsdesk.com/)- The worlds
first sweat machine produces clean water for children
• Article (http://www.npr.org/) - Thirsty? 'sweat
machine' turns perspiration into drinking water
• Article (http://www.bbc.com/) - Machine turns sweat
into drinking water for Unicef
• Article (http://www.sterlitech.com/) - Unicef uses
membrane distillation to make sweat drinkable
• Article (http://www.independent.co.uk/) - Unicef's
'sweat machine' turns perspiration into drinkable water

13. Thank you