Determinationof

calorific valueby

bomb calorimeter

Calorific Value

Calorific Value may be defined as the amount of heat liberated in calories by the complete combustion of unit weight materials with oxygen and the condensation of produce to desiredtemperature.The calorific value of a fuel may be defined as the amount of heat generated by burning one kg of fuel completely.

Calorimeter

It is a device used to calculatethe Calorific Value of Solid , Liquid & Gaseous Fuels.

Bomb Calorimeter

A bomb calorimeter is a type of constant-volume calorimeter used in measuring the heat of combustion of a particular reaction.Used to measure enthalpy changes of combustion reactions at a constant volume.

Overview

Basically, a bomb calorimeter consists of aSmall cup to contain thesampleOxygenA stainless steel bombWaterAstirrerAthermometerThe dewar (to prevent heat flow from the calorimeter to the surroundings)Ignition circuit connected to the bomb.

Figure - BOMB CALORIMETER

Determination of C.V By bombcalorimeter(con.)• The vessel is fitted with a tight screwcap.

Tight screwcap

Determination of C.V By bombcalorimeter(con.)• Two electrod are connected each other through platinumwire.• The wire remain in a platinum dipped cap just belowit.• A small amount of substance under investigation is taken inplatinum cap.

Electrod

CapPlatinum wireSubstance

Determination of C.V By bombcalorimeter(con.)• The vassel is then filled with excess of oxygen at a pressure of about

20-25 atm and is subsequently scaled.

𝑂2 in

Determination of C.V By bombcalorimeter(con.)

• It is now dipped in a insulated water bath• which is also have mechanical stirrer and athermometer

Water bath

Mechanical stirrer

Thermometer

Determination of C.V By bombcalorimeter(con.)

• The initial temperature of water is noted

• Combustion is started by passing electric current through the platinium wire.Thats raise the temperature of water,it is recorded from the temperature

• By knowing the heat capacity of thermometer and also raise in temperature.the heat envolved can be calculated

Video Of Bomb Calorometer