ENGINEERING WORLD ENGINEERING WORLD HEALTH:HEALTH:

COLD BOXCOLD BOXGROUP 19

Josh ArenthCynthia Bien

Graham GipsonElise Springer

Brittany Wall

EENGINEERING NGINEERING WWORLD ORLD HHEALTHEALTHOrganization background:

Founded in 2001

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)

WHYWHY WORK FOR EWH? WORK FOR EWH? Want to improve healthcare in developing countries

Impact the quality of life in developing countries

Give others an opportunity that was given to us

Engineering World Health: Cold Box (Group 19)

PROBLEM STATEMENTPROBLEM STATEMENTBuild a portable device that:

Keeps a 5-mL fluid volume at 10°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)

ASSESSMENTASSESSMENT Determine a unique and efficient way to sustain 10°C for 12 hours

Will ice work? CO2

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)

Initial Design: Initial Design: Prototype Cold Prototype Cold Box Design SpecsBox Design Specs

Outer layer / casingOuter 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)

Initial Design: Initial Design: Prototype Cold Prototype Cold Box Design SpecsBox Design Specs

Heat sinkCold 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)

Initial Design: Initial Design: Prototype Cold Prototype Cold Box Design SpecsBox Design Specs

Inner casingCold 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)

Initial Design: Initial Design: Prototype Cold Prototype Cold Box Design SpecsBox Design Specs

Engineering World Health: Cold Box (Group 19)

storage cavity

heat efflux

heat sinkheat-conductive inner wall

insulating outer wall

a + b + Δ → c

Schematic descriptionIn 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.

PASTPAST WORK WORK General agreement on twice-weekly, one-hour meetings

Responsibilities assigned to each group member

Took advice from Dr Roselli (BME) to work with an advisor more knowledgeable about chemistry and materials science.

Met with Dr List (Chemistry) and gained his mentorship for our project.

Final version of NCIIA design proposal created and posted on website.

Engineering World Health: Cold Box (Group 19)

CURRENTCURRENT WORK WORK Each group member has presented their own ideas on how to design the cold box to meet specifications.

Discussion about performing lab experiments for:

Choice of appropriate chemical heat sink

Choice of best insulating / conducting materials

Several experimental set-ups were put on the table

Engineering World Health: Cold Box (Group 19)

FUTUREFUTURE WORK WORK Members offering different experimental set-ups will generate protocols and a brief rationale statement.

Group will meet with Dr List and seek his opinion of protocols.

Experiments will be performed and first sets of data collected.

Engineering World Health: Cold Box (Group 19)