Here’s how a simple tin can be turned into a steam engine
Steam engines are devices that employ heat to create steam, which then conducts some mechanical processes. The functioning of a steam engine can be compared to a huge kettle on top of a coal stove. The water in the kettle boils and transforms into steam as a result of the heat from the fire. Unlike the steam from a kettle, which is wasted by blowing into the air, the steam from an engine is captured and used to power a machine. Making a DIY steam engine at home is a fun activity which can help school goers learn about conversion of thermal energy (heat) to mechanical energy (work). Let's take a look at how we can do it through an easy-to-do experiment.
What you’ll need
- 1 tin can
- Soldering iron
- Copper pipe or tube
- Pencil
- Scissors
- Pliers
- Candles
- Water
- Glass bowl
How-to
Get these on a table, call your child, and start the experiment. Here’s a step-by-step description of the experiment:
- Cut aluminium can to a height of about 2.5 inches. Make a neat horizontal cut about one-third of the way up from the can's base and around the circumference with tin snips or scissors.
- To reduce the sharp edges on each section of the can, fold the rim in on itself.
- The round base of most soda cans curves in its interiors. Smooth it out with the bottom of a small glass or jar or by flattening it with your fingertips.
- Punch two holes on opposite sides of the can half an inch from the top. You can either use a paper punch or a nail or hammer to create the holes. A hole somewhat larger than 3.2 mm in diameter is required here.
- Crumple the aluminium foil and place it under and around the candle to hold it in place. Tea light candles come in small tins, so the wax should not melt and spill into your aluminium can.
- To build a coil, wrap the centre of a 6–8 inch long piece of copper pipe around a pencil two or three times. The 3.2 mm pipe should be able to bend around the pencil with ease.
- Place the pipe's ends through the holes of the can. Ensure that the coil is centred over the candle's wick and that each side of the can has roughly the same length of straight tubing protruding out of it.
- With pliers, bend the ends of the copper pipe into 90 degree angles on either side of the can, so that they face in opposing directions. Bend them again so that they are just below the can's base.
- Set the can in a large bowl of room temperature water with both the ends of the copper pipe submerged in it.
- Water should be poured into the pipes. Placing one end in the bowl of water and sucking through the other like a straw is the easiest way to do this. You can also place your finger over one end while holding the open end under a running faucet.
- The candle should be lit by now. See what happens.
What is happening in this experiment?
As the candles are lit, the water in the copper pipes begins to heat up and boil over time. It will shoot out of the jets of the tube/pipe as it evaporates into steam, spinning the entire can in the bowl. Thus, heat energy gets converted into mechanical energy.