Real Lime Application of Heat

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Real Lime Application of Heat Mass Transfer

• P M V Subbarao
• Associate Professor
• Mechanical Engineering Department
• IIT Delhi

Understand Philosophy Through Experience
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The Bare Pentium 4 Processor
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Heat Sinks for Pentium 4
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Pentium 4 While Performing
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Heat Transfer An Engineering Science

• The first law of thermodynamics establishes a
  relationship between heat and work (Energy
  Interactions).
• The second law of thermodynamics states that the
  spontaneous energy interactions are
  unidirectional.
• Thermodynamics is totally silent on the question
  the rate at which heat travels.
• How to control the rate of heat transfer?
• Heat Transfer is an Engineering science to design
  thermal infrastructure.
• It evolved over 200 years.

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Applications of Mass Transfer
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Mass Transfer

• Mass transfer The transfer of mass into or out
  of a substance
• The transfer of a chemical compound from one
  phase to another
• Examples
• Evaporation liquid gas
• Diffusion high concentration low
  concentration

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Various Mass Transfer Phenomenon
Evaporation Drying Concentration Baking Frying Bo
iling
Diffusion Salt through cheese curd Smoke through
meat Marinade or curing solution through meat Lye
in tomato peeling
Not mass transfer Moving a fluid from one place
to another
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Osmosis

• Osmosis is the net movement of water across a
  partially permeable membrane from a region of
  high solvent potential to an area of low solvent
  potential, up a solute concentration gradient.
• Osmosis is responsible for the ability of plant
  roots to suck up water from the soil.
• Since there are many fine roots, they have a
  large surface area, water enters the roots by
  osmosis, and generates the pressure required for
  the water to travel up the plant.
• Osmosis can also be seen very effectively when
  potato slices are added to a high concentration
  of salt solution.
• The water from inside the potato moves to the
  salt solution, causing the potato to shrink and
  to lose its 'turgor pressure'.
• The more concentrated the salt solution, the
  bigger the difference in size and weight of the
  potato slice.
• For example, freshwater and saltwater aquarium
  fish placed in water of a different salinity than
  that they are adapted to will die quickly, and in
  the case of saltwater fish, rather dramatically.

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DIFFUSION OF 02 AND C02 ACROSS THE
ALVEOLAR-CAPILLARY MEMBRANE

• All gas movement in the lung occurs as a result
  of passive diffusion, i.e., gas moves from one
  region to another only when the partial pressure
  of gas is greater in one region than another.
• The transfer of gas from the alveolus to the
  blood occurs by simple diffusion.
• The rate of transfer depends on what?

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Desert Cooler
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Evaporative Cooling

• Cooling through the evaporation of water is an
  ancient and effective method of lowering
  temperature.  
• Both plants and animals use this method to lower
  their temperatures.  
• Trees, through the process of evapotranspiration,
  for example, remain cooler than their
  environment. 
• People accomplish the same thing when they
  perspire. 
• For both trees and people the underlying
  scientific principle is the same when water
  evaporates, that is, changesfrom a liquid to a
  gas, it takes heat energy from the surrounding
  environment, thus leaving its environment cooler.

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Primitive Products

• Finally, some of us may have discovered that
  water kept in a canvas bag, porous clay
  container, or in a canteen with a water-soaked
  cloth cover, is much cooler, especially on a hot
  day, than water kept in plain metal or plastic
  containers.  
• As the water evaporates from the surfaces of
  these containers it draws heat away from the
  containers and the water they hold, as well as
  fromthe air around them, thus leaving the water
  cooler.

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Syllabus

• Introduction 3 Lecture
• Introduction to Heat Transfer Relationship to
  thermodynamics Heat Transfer as an engineering
  science Practical relevance Mechanisms of Heat
  transfer conduction, convection and radiation
  related parameters.
• Conduction Heat Transfer 8 Lectures
• Heat Conduction equation and its approximations
  steady and unsteady, single and multidimensional,
  constant and variable properties, with and
  without heat generation. Steady state conduction
  thermal resistance networks in planar,
  cylindrical and spherical systems critical
  radius of insulation extended surface heat
  transfer fin effectiveness and efficiency
  thermal insulation. Transient conduction in
  semi-infinite and finite media lumped
  capacitance method. Introduction to numerical
  solution of heat conduction equations.

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• Diffusion Mass Transfer 3 Lectures
• Constitutive equations and definitions for
  composition of binary mixtures Fick's law of
  diffusion and binary diffusion coefficient
  conservation equation for species steady and
  transient diffusion analogy to conduction heat
  transfer.
• Convection Heat Transfer 11 Lectures
• Mechanism of convection analogy of heat,
  momentum and mass transport in moving fluids th
  concept of transport in a boundary layer
  similarity, scaling laws and analogy between
  momentum, heat and mass transfer turbulence.
• External flows flat plate in parallel flow
  cylinder in cross flow applications. Internal
  flows concepts of mean velocity and mixing cup
  temperature hydrodynamically and thermally fully
  developed and developing flows energy balance
  circular tubes -- laminar and

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• turbulent flows. Free convection governing
  parameters external and internal flows mixed
  convection.
• Boiling and Condensation 3 Lectures
• Basic phenomena boiling modes and boiling curve
  regimes in pool boiling forced convection
  boiling regimes of flow for forced convection
  boiling in a tube condensation film and
  drop-wise condensation applications.
• Heat Exchangers 4 Lectures
• Heat exchanger types definition of overall heat
  transfer coefficient heat exchanger analysis
  rating and sizing of heat exchangers Log mean
  temperature difference method Number of Transfer
  Units effectiveness method compact heat
  exchangers.

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• Radiation Heat Transfer 10 Lectures
• Basic concepts and definitions Intensity,
  emissive power, irradiationand radiosity black
  body radiation and spectral dependence of
  emissive power emissivity absorptivity and
  reflectivity Kirchhoff's law gray and diffuse
  surfaces Radiative Exchange view factor black
  body radiation exchange exchange between gray,
  diffuse surfaces gas radiation radiation
  combined with conduction and convection.

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BOOKS

• Fundamentals of Heat and Mass Transfer (Fifth
  edition) Incropera F.P. and De Witt, D.P.
• Heat Transfer -- a practical approach Cengel Y.
• Heat Transfer (Ninth edition) Holman J.P.
• Fundamentals of Heat Mass Transfer M.
  Thirumaleshwar.
• Heat Transfer Kreith F. and Bohn

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What is Heat Transfer?

• Thermal energy is related to the temperature of
  matter.
• For a given material and mass, the higher the
  temperature, the greater its thermal energy.
• Heat transfer is a study of the exchange of
  thermal energy through a body or between bodies
  which occurs when there is a temperature
  difference.
• When two bodies are at different temperatures,
  thermal energy transfers from the one with higher
  temperature to the one with lower temperature.
• Heat always transfers from hot to cold.
• Heat is typically given the symbol Q, and is
  expressed in joules (J) in SI units.
• The rate of heat transfer is measured in watts
  (W), equal to joules per second, and is denoted
  by q.
• The heat flux, or the rate of heat transfer per
  unit area, is measured in watts per area (W/m2),
  and uses q" for the symbol.