There are two basic options for the type of apparatus used in this experiment. Lab equipment is more expensive but will allow more efficient containment of the water vapor and negligible loss of distilled water. You can achieve a simpler setup using common household items like a teapot or saucepan, a metal mixing bowl as the condensation surface, and a bowl or kitchen container for water collection. Laboratory clamps will, however, be very useful regardless of which type of apparatus you use.
The basic process this experiment tries to achieve is to bring salt water to the boiling point, let it evaporate, then bring the water vapor into contact with a cold surface that will cause it to condense and drip into a collection container. To use lab equipment, connect a condenser to the downward-pointing arm of a distillation flask. Place a collection beaker beneath the condenser and attach hoses to the condenser and a faucet so that tap water runs through in and drains back into the sink. Put salt water in the distillation flask and bring it to a low boil over a Bunsen burner.
Using home equipment may lead to loss of water vapor but will still visibly demonstrate the desalination process. Heat salt water in a pan or kettle on the stove. Set up a chilled metal bowl upside down over the point where steam will rise from the boiling salt water, with the bowl angled so that the water that condenses on its inner surface will drip down to one point on the edge for collection. Placing a bag of ice on top of the bowl will keep it chilled.
This experiment involves fire and boiling liquids, which can pose a hazard especially with household setups. Before turning on the heat, test every part of your setup to make sure that it is stable and secure. If any part is tippy or loose, adjust the clamps or the placement of the apparatus before proceeding. If using a bag of ice to chill the bowl, bear in mind that the ice will melt during the experiment, and this may cause a shift in weight. When in doubt, tape it into position with duct tape.