1. ENGINEERING WORLD HEALTH: COLD BOX Josh Arenth Cynthia Bien Graham Gipson Elise Springer Brittany Wall Group 19 Engineering World Health: Cold Box (Group 19)

2. ENGINEERING WORLD HEALTH Organization background:  Founded in 2001 by Dr. Malkin  Charitable organization that collaborate with collegiate engineering programs  Improves conditions of hospitals in developing nations  Multi-step process: (1) Assessment of hospitals (2) Ship container of refurbished medical equipment (3) Install equipment and train at location (4) Return to location to reinforce training Engineering World Health: Cold Box (Group 19)

3. WHY WORK FOR EWH?  Want to improve healthcare in developing countries  Impact the quality of healthcare in developing countries  Give others an opportunity that was given to us Engineering World Health: Cold Box (Group 19)

4. PROBLEM STATEMENT Build a portable device that:  Keeps a 5-mL fluid volume at 10°C (outside temperature 20°C) for up to 12 hours,  Operates without electricity or outside fuel,  Can be manufactured for less than $0.20 per unit (500 units for less than $100),  Does not require highly skilled labor to assemble. Engineering World Health: Cold Box (Group 19)

5. ASSESSMENT  Determine a unique and efficient way to sustain 10°C for 12 hours Will ice work?  CO 2  Freon  Decide which materials are good conductors and which are good insulators  Ultimately determine which materials are both sufficient and cheap, and can be easily produced in the developing world Engineering World Health: Cold Box (Group 19)

6. Initial Design: Prototype Cold Box Design Specs Outer layer / casing Outer portion of container must be a good insulator (i.e., be an intrinsically poor conductor.) Ideal materials:  Styrofoam  Ceramic  Gas sandwiched between two layers Materials chosen:  Styrofoam with a durable plastic covering Engineering World Health: Cold Box (Group 19)

7. Initial Design: Prototype Cold Box Design Specs Heat sink Cold Box must have a component to remove heat from box contents Ideal materials:  Non-toxic, non-abrasive chemical reaction  Heat-absorbing material with large heat capacity Materials chosen:  Ice and water  Sodium bicarbonate / acetic acid system Engineering World Health: Cold Box (Group 19)

8. Initial Design: Prototype Cold Box Design Specs Inner casing Cold Box must have an inner layer to separate the contents of the box from heat-sink materials, yet still allow for efficient heat transfer (i.e., have high conductivity). Ideal materials:  Non-reactive metal  Glass Materials chosen:  Aluminum Engineering World Health: Cold Box (Group 19)

9. Initial Design: Prototype Cold Box Design Specs Engineering World Health: Cold Box (Group 19) storage cavity heat efflux heat sink heat-conductive inner wall insulating outer wall a + b + Δ → c Schematic description In the cold box, an endothermic chemical reaction (generalized here) consumes thermal energy, thus drawing heat out of the inner cavity. This heat is trapped in the heat sink because of the outer insulating boundary.

10. Initial Design: Prototype A Outer layer / casing: paper-plastic composite (mostly paper) Inner-chamber layer: aluminum Heat sink: Binary mixture described below Cooling Technique: mixture of water (267mL), NaCl (10g), ice Measuring Technique: LabWorks thermistor-based temperature probe Engineering World Health: Cold Box (Group 19)

11. Initial Design: Prototype A Engineering World Health: Cold Box (Group 19)

12. Initial Design: Prototype A Data Engineering World Health: Cold Box (Group 19) At about 10°C for 20 minutes Temperature dropped in less than 20 minutes Problems: –Need to maintain 10°C for 12 hours

13. PAST WORK  Final version of NCIIA design proposal created and posted on website.  Met with Dr List to seek his opinion of protocols.  Each group member presented their own ideas on how to design the cold box to meet specifications.  Discussed lab experiments for first prototype.  Picked materials for our first prototype:  Chose appropriate chemical heat sink  Chose insulating / conducting materials  Researched and could not find Nashville Thermos company Engineering World Health: Cold Box (Group 19)

14. CURRENT WORK  Performing first experiment on Prototype A and collected data in the lab  Performing another experiment on Prototype B  Need to choose best cooling technique - Water, ice, and salt mixture - Chemical reaction Engineering World Health: Cold Box (Group 19)

15. FUTURE WORK  Try Prototype B (trial 1), which is a variation of Prototype A - Vial used will already be cooled - Outer casing / insulator is 100% Styrofoam - Cooling technique still the same  Try Prototype B (trial 2) -Cooling technique used will be a chemical reaction Engineering World Health: Cold Box (Group 19)

16. Inner chamber Cooling mixture Lid Insulating tape Nested foam cups Trapped air CROSS SECTIONOUTER VIEW