The Dino-Stove

When we were assigned the task of creating a charcoal stove out of sheet metal and other materials, it felt like an overwhelming task initially. But, as my group spent some time brainstorming and getting inspired from existing models online, we were able to develop a game plan. Our sketch ended up looking like this.

We choose this design for a few reasons. It would do a good job of redirecting the smoke away from the user, and would provide safety from smoke inhalation. Also, the box within a box approach would contain the flames and the heat, minimizing danger from burning. We wanted to include the sunken cooking surface in order to provide a more direct heated surface, and to be able to use the rim to hold a pot or pan in place. Finally, we wanted our design to incorporate insulation in order to maximize heat with minimal fuel.

We built a prototype out of cardboard- and got remarks that it looked like a dinosaur!

After creating the cardboard model, we noticed a few design things that could be improved for our actual model. There wasn't a particular reason for the rectangular shape, and we found that by making the cooking surface into a square we could provide a larger area for a pot or a pan to fit in. Also, we realized that to successfully redirect the smoke, our chimney needed to be larger and located higher up. Finally, we needed to ensure a better air flow to keep the flame going, so we decided to include a grate at the bottom to allow the air to reach the flame.

Going to actually build the stove, we first needed a lot of planning to ensure things would fit together and to make sure we were constructing things in an order that made the most sense.

My group probably spent a total of 9.5 hours making the stove out of metal, aluminum, and wood. We very quickly realized sheet metal was neither easy to work with, nor the most sturdy material. We also ran into some trouble with riveting, but ended up with a model pretty similar to our design.

             


















After testing the stove, we realized that while we succeeded in redirecting smoke and protecting users from the flames, the heat source was too far away from the pot, meaning that our stove never really got hot enough to boil water. This could be solved by making the outer and inner boxes a lot shorter, or by using a lot more fuel to create a hotter chamber. The latter solution probably isn't the best, however, as it requires more resources.

All in all, making the stove was frustrating and rewarding at the same time, frustrating because we weren't used to working with a lot of the materials/tools, but rewarding because we ended up with a semi-functional project. Also, testing the stove meant we got to have hot chocolate and s'mores, which was rewarding in itself.

Making It Personal

To estimate my own personal energy use over 3 days is no easy feat. Trying to record every single time I use (or think I do?) energy suddenly seems daunting. Basically, I realized that I use energy (on average) about 20/7; save for a few hours each day.

To begin this task, here's a list of things that use energy. I'll make my best guess as to how long I used each one...

Day One- Monday 10/5

lamp- 20 minutes

bathroom light- 20 min

phone- 2 hours use, 4 hours "use-lite" (listening to music)

phone charger- 2 hours

computer- 4 hours

comp charger- 1 hour

classroom/academic building lights- 8 hours

food prep-3 hours? 

dining halls- 2 hours 

lampposts-30 min

shower (hot water)- 15 min

string lights- 20 min

Day Two- Tuesday 10/5

lamp- 40 minutes

bathroom light- 20 min

phone- 2 hours use, 4 hours "use-lite" (listening to music)

phone charger- 2 hours

computer- 2 hours

comp charger- 1 hour

classroom lights- 6 hours

food prep-3 hours 

dining halls- 2 hours 

observatory (flashlights, dim light)- 1 hour

lampposts-30 min

hoop- 2 hours

shower (hot water)- 15 min

string lights- 30 min

fan- 8 hours

Day Three- Wednesday

lamp- 40 minutes

bathroom light- 20 min

phone- 2 hours use, 4 hours "use-lite" (listening to music)

phone charger- 2 hours

computer- 4 hours

comp charger- 2 hour

classroom lights- 4 hours

food prep-3 hours 

dining halls- 4 hours 

library- 2 hours

lampposts-20 min

auditorium- 1.5 hours

string lights- 2 hours

fan- 8 hours

I didn't account for energy used for less than 1 minute...such as walking through a building to get somewhere else. One of the trickiest parts was estimating how much time I used with my phone, as I play music constantly and check the screen on and off all day. Also, for food prep energy use I took a completely wild guess. I don't eat a lot of hot food on campus, and really have no idea how to estimate something like this...

Estimations:based on a typical lightbulb and typical LED light

>assume typical lightbulb uses ~60 Watts per hour

>assumes typical LED light uses ~6 Watts per hour

Averages for 3 days

lamp ~30 min > 30 Watts

phone(~ 2 LED)~ 3 hours > 36 Watts

computer (~1 lightbulb) ~ 3 hours > 180 Watts
charging (~1 lightbulb)~ 4 hours> 240

all public lighting( equiv. of 2 lightbulbs)~ 11 hours > 1,320 Watts

food prep~ 2 hours > 240 Watts

string lights (~30 LED)~ 1 hour > 180 Watts

lampposts (~2 lightbulbs)~ 30 min > 60 Watts

hot water~ 15 min > 30 Watts

fan (1/2 lightbulb)~ 5 hours > 150 Watts

Total Daily Use Estimation ~2,500 Watts

Estimations!

Estimation is hard. I worked with Callie on some of these, and between the two of us, we figured some things out.

For the TV, I assumed the voltage to be 120V as it would plug into a basic electrical outlet. I then tried to draw on knowledge of an LED light to estimate current. Using the basic P=IV function, I came up with 85 watts.

I used basically the same process for the computer, as it still might use an electrical outlet (120 V), so the power would be about the same.

For the car, it was a bit more difficult as I tried to first determine work in Joules, then used a random unit of time (1 hour), as we weren't given anything to go on. I assumed the mass of a car to be about 2000 kg. to find acceleration, I just estimated values based on what I know about driving...

For the motorcycle, I used the same process, but changed the mass to be about 500 kg.

For the fridge, I used a similar process as for the TV, but since the fridge is a larger appliance, I used 220V for the voltage.

Since a standard microwave is around 1000 watts, it's probably safe to estimate an oven is between 1000 and 5,000 watts, as it is a lot bigger.

For the radio, I assumed it was around the same as the computer, but its power might be a little less, as the computer does a lot more tasks. From what I determined earlier, I estimate the radio is about 50 watts.

Field Trip!

Today we were able to visit Olin College for part of their Tech Day event. While I wasn't able to stay for very long, what I heard/saw was really cool.

Multiple presenters described a certain technology being implement in a developing country, with products ranging from food storage containers to sanitary napkins. The format was great, because I got to hear a bit about every product before I had to leave.

My favorite product that I heard about was probably the "charcoal" briquettes made from agricultural waste. Not only were they developed/ sold by women (snaps to that!), but they recycled material that was just going to waste anyway. I think a lot of engineering efforts must go to the development of products to serve the needs of people in developing countries, but not as much emphasis is placed on the sustainability or environmental impacts (disclaimer: this is an assumption, not a statement of fact). The bottom line is, creating fuel from waste products benefits all involved, and I hope it becomes more widespread until an even better solution is developed.

All in all, I got a taste of a more comprehensive look at global engineering efforts. The program was was great opportunity.

A dim outlook- reflection on working without light

As an exercise, we spent a good portion of Tuesday's class working without light. Well, technically we were working by candlelight but in technologically advanced nations such as the United States, we would barely classify candlelight as usable light. Unfortunately, working by candlelight is the norm in many places still around the world.

The purpose of the exercise was to gain insight into life without access to reliable electricity, and it proved a stark reminder of the advantages we have in this country. Trying to write with a small light source shared by several others was challenging, as we had to fight physical and mental effects of the dark: eye strain and our brain's association of darkness with sleep. I can only imagine what it must be like for those relying on candlelight-aside from the dangers of fire and smoke, they must struggle to accomplish even the most basic of tasks.

Completing the quiz in "normal" lighting was much easier, as it was what I'm used to and I only had to focus on the answers rather than fighting to see. The exercise definitely inspired me to count my blessings.

Time management

I'll be the first to admit, my time-management skills are subpar. I'm usually the type to wait until the last minute to complete an assignment. For these two projects, the group aspect of the sharps container helped hold me accountable for making sure I had that project done early. We set meeting times to solely focus on the container, and we all worked during that time to create the project.

Having a really busy schedule this semester, it wasn't easy finding time to work on my lantern project, but I set aside several hours one night a few days before the due date to get the framework down, so the final days would just be touch-ups and smaller alterations. Allotting a specific evening just for the project was the best use of my time, as that period was focused on that one thing.

Once I got the initial part of the project to be successful, that is, creating a reliable circuit, it was easy to find smaller blocks of time to tweak smaller aspects of the project.

Overall, it was a bit stressful having 2 projects due on the same day, but since I was finished before the night before, and didn't have to panic at the last minute, I would call this a successful job of time management.

Playing with knives

Ok, so maybe we weren't actually playing with knives, but for a group assignment, we had to create a container for sharps, or dull knife blades. The challenge was to create something practical, safe, and to work as team to accomplish these objectives.

My team, Diana, Ananya, and Kavi had these grand ideas originally about using a combination of heat and pressure to crush and melt discarded blades into sheet metal, completely recycling the pieces. But when it came time to actually creating the product, we realized we would have to scale down our approach to come up with a more feasible idea. We decided on something that would double as a container, and as a tool for safely breaking off the sharps from the Olfa knives.

We used an old can as the container for 2 reasons: it was an easily acquired and cheap item, and it was made of metal so it could be recycled along with the blades. We discarded the lid to the can, and replaced it with a much stronger piece of metal with a small slit in one end so that we could slide the tip of the knife in and brace the blade against the can and break off the sharp part. Ananya came up with the idea to also attach a small piece of metal to the side of the can to prevent the blades from falling out of the container, should we accidentally drop the can.

The end result was a working container that we could successfully use to break off the blade, and safely hold the sharps. However, one of the major drawbacks of our design was the fact that when it filled up with sharps, we would have to recycle the whole thing and make a new one. It was a relatively easy assembly, though. It might be practical with a little perfecting.

I consider myself as someone who works better alone, but I found that working in a group on this project was really beneficial, because the other members came up with lots of ideas I never considered. The experience was definitely positive.