Heat transfer and its application 1
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Heat is a form of energy that can flow into or out of a system via various mechanisms. There are three main mechanisms of heat flow: conduction through direct contact of materials, convection through the mixing and movement of heated portions of a fluid, and radiation through electromagnetic waves. Common applications of heat transfer include evaporation, distillation, drying, crystallization, and sterilization. Heat transfer equipment like tubular heaters, floating head heaters, and heat exchangers facilitate heat exchange between fluids or between fluids and their environments.
Heat transfer and its application 1
- 1. Heat transfer and its application By ā Kiran C.Rodge
- 2. ā¢ Heat is a form of energy, āAny Physical or chemical heat flows into or out of system āSources --- Steam or electric power ā¢ Application ā ļ¼ Evaporation ļ¼Distillation ļ¼Drying ļ¼Crystallization ļ¼Sterilization
- 3. Mechanisms of Heat flow ā¢ Conduction- is achieved by the transfer of the momentum of individual atoms or molecules without mixing.(Rod) ā¢ Convection ā is achieved by actual mixing of warmer portion with cooler portion of same material.(Water) ā¢ Radiation ā by means of electromagnetic waves.(steam)
- 4. Conduction ā¢ Basic law Rate = Driving Force Resistance Fourierās law-the rate of heat flow through a uniform material is proportional to the area and the temperature drop and inversely proportional to the length of the path of flow. q = KmAļt/L Thermal Conductivity- quantity of heat that flows across a unit surface area in unit time when temp. drop constant
- 5. Convection ā¢ Types A) Forced Convection B) Natural Convection Film Coefficients- is the quantity of the heat flowing through unit area of the film for unit drop in temp. ā¢ Principle of heat flow in fluids
- 6. Radiation ā¢ Black body- as a body that radiates maximum possible amount of energy at a given temp. Total amount of radiation emitted by black body q = bAT4 Stefan-Boltzmann law Grey Body- as the body whose absorbing capacity is constant at all wavelengths of radiation at given temp. Total amount of heat transferred by Grey body q = b A(T1 4 āT2 4 ) Stefan Law
- 7. Heat exchange Equipments ā¢ Tubular heater(Shell & tube heater)
- 9. Liquid to liquid heat interchanger
- 10. Double pipe heat interchanger