theory of boys calorimeter

INTRODUCTION The Boys Gas Calorimeter apparatus was designed by the late Sir Charles Boys F.R.S, to provide a simple but accurate equipment for ascertaining the calorific values of a wide range of gaseous fuels currently in use. The Gas Calorimeter is designed to make sure that the heat from the burner flows up through the calorimeter container and back down again inside the container and back up again before exhausting. This experiment is based on heat transfer from burning the gaseous fuel for heating the water that flows and circulates in a coil heat exchanger. This design ensures maximum heat transfer to the cooling liquid and hence accurate enough for measurement and calculations of calorific value of gas. The amount of heat liberated when a unit mass of fuel is burnt completely is known as the calorific value. Calorific value is the amount of heat that produced by the complete combustion of a fuel or any materials. The higher calorific value or higher heating value means that the water of combustion is completely condensed and the heat contained in the water vapour is recovered while the lower calorific value or lower heating value means that the products of combustions contains water vapour and it is not recovered.

OBJECTIVE 1. To determine the calorific values of natural gas and gas volume factor by Boy’s Gas Calorimeter.

RECOMMENDATION 1. Light the flint gun on the side of the burner so that the flame reaches around the gas and away from you. Wear the glasses for safety. 2. When taking the temperature reading, eyes should be level with the top of the mercury in the thermometer to read it accurately. The reading is not same when look down or up onto the degree lines on the thermometer. Handling the thermometer can affect its reading when touch it, as heat can transfer from hands (warmer to cooler). 3. The air lock can be form in the water supply tube when starting up. Make sure that there are no air locks in this tube. 4. Loose the cork momentarily after the flow of water has been established so that the air trap under the thermometer can be released. 5. Be careful with the hot outlet water. Don’t touch it with bared hand to avoid burns. 6. Any adjustment to the apparatus should be taken 30 minutes earlier before start the experiment. It is because to ensure that the apparatus stabilise enough. 7. All valves should be closed after the experiment is done.