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Introduction to Process Technology. Basic Physics. Today’s Agenda. What is Physics? Why is Physics Important to Proc Oper? Properties and Structure of Matter Types of Energy Temperature & Thermal Heat Transfer Physics Laws Flow Rates Force and Pressure Work and Mechanical Efficiencies
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Introduction to Process Technology Basic Physics
Today’s Agenda • What is Physics? • Why is Physics Important to Proc Oper? • Properties and Structure of Matter • Types of Energy • Temperature & Thermal Heat Transfer • Physics Laws • Flow Rates • Force and Pressure • Work and Mechanical Efficiencies • Electricity
What is Physics? Sheldon Teaches Penny Physics From sitcom “The Big Bang Theory”
What is Physics? • Physics is the study of matter and energy • Matter • Energy
Why Physics is Important to Proc Techs & Engineers & Other Technicians • Explains the basic principles of the equipment they use on a day-to-day basis. Examples – • Allows them to understand the processes used to convert raw products to end products • Maintaining safe operations
Why Physics is Important to Proc Techs • Allows them to understand how to troubleshoot the process or to identify a problem and then solve the problem • Allows them to understand how the process affects other processes downstream
Matter and its States • Matter – object that takes up space • Solids – definite shape and volume • Liquids – definite volume, not shape • Gases – no definite volume or shape • Plasma – collection of charge particles that form gas-like clouds or ion beams
Conservation of Matter • Matter cannot be created or destroyed; only changed • Matter is considered to be indestructible
States Changes of Matter • Melting – solid to liquid • Freezing – liquid to solid • Vaporization • Boiling – liquid to gas (heat applied) • Evaporation – liquid to gas (natural) • Condensation – vapor to liquid • Sublimation – solid to vapor • Deposition – vapor to solid
Specific Properties of Matter • Mass – amount of a object • Weight – measure of force of gravity on an object • Volume – amount of space an object takes up
Specific Properties of Matter (Continued) • Density– mass (weight) per unit volume • Specific Gravity – comparison of density to that of water for solids and liquids and to air for gases • Hardness – ability of one substance to scratch/mark another • Odor– smell of substance • Color – optical sensation produced by effect of light waves stiking surface
Specific Properties of Matter (Continued) • Inertia – tendancy of object to move or stay at rest • Force – push or pull on object • Pressure – force exerted on a certain area • Buoyancy – objects’ ability to float • Flow – movement of fluids • Speed – distance object travels in given time. Velocity – speed with direction
Specific Properties of Matter (Continued) • Porosity – measure of small holes in an object • Elasticity – ability of stretched object to regain original shape • Friction resistance of one object sliding on another
Specific Properties of Matter (Continued) • Viscosity – impedance of flow • Tenacity (tensile strength) – strength of material against bends and pulls • Ductility – ability to pull a material • Malleability – ability to mold a material
Specific Properties of Matter (Continued) • Conductivity – ability of material to allow flow of electrons • Adhesion – materials that stick • Cohesive Force – allow materials to resist being separated
Specific Properties of Matter (Continued) • Surface Tension – property of surface of liquid that resists force • Capillary Action – flow of a liquid up a tube without force • Temperature – kinetic energy of molecules
Structure of Matter • Atoms – smallest particle of an element that retains the properties of that element • Protons – positively charged subatomic particle found in the nucleus of an atom • Neutrons – subatomic particle found in the nucleus of an atom that has no charge • Electrons – negatively charged subatomic particle found in orbiting the nucleus of an atom -- Valence Electrons – outermost electrons which provide links for bonding • Molecule – neutral chemically bonded groups of atoms that act as a unit • Isotope – elements with same number of protons, but different number of neutrons
Structure of Matter (Continued) • Atomic Number – the number of protons in the nucleus of an atom of an element • Atomic Mass (Molecular Weight) – weighted average of the masses of the isotopes of an element predominantly from masses of protons & neutrons • Determining Molecular Weight of Compound – Add all masses of each element. Remember to multiply if more than 1 present.
States of Energy • Potential – stored energy. Energy of height • Kinetic – energy of motion
Temperature and State Changes • Temperature – kinetic energy of molecules • Heat – transfer of energy as a result of temperature difference • State Changes • Evaporation Boiling • Melting Freezing • Condensing Sublimation • Deposition
Temperature Scales • Fahrenheit • Celsius • Absolute Zero • Kelvin = oC + 273 • Rankine = oF + 460
Temperature Measurement • Fahrenheit • Celsius • Kelvin • Rankine
Temperature (BTU) Transfer • British Thermal Unit (BTU) • Calorie – Metric System • Conduction – heat exchange for objects in direct contact with each other • Convection – heat from circulation of a material • Radiation – heat moving through space
Types of Heat • Specific heat – heat to raise 1 g. by 1 °C • Sensible heat – heat transfer that results in temperature change • Latent heat – heat that causes phase change, but not temp change
Types of Heat • Latent heat of fusion – heat required to change solid to liquid without temp. change • Latent heat of vaporization – heat required to change liquid to vapor without temp. change • Latent heat of condensation – heat given off when vapor is converted to liquid without temperature change
Boiling Point • The temperature of a liquid when its vapor pressure = the surrounding pressure • Increasing the pressure of a system increases boiling point and vice versa… that is why water boils at a lower temperature up in the mountains compared to the coast
Vapor Pressure • Vapor pressure • A measure of a liquid’s volatility and tendency to form a vapor • A function of the physical and chemical properties of the liquid • At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure
Relationship of Boiling Point/vapor pressure/ surrounding pressure • Liquids w/ High VP – Low BP • Liquids w/ Low VP – High BP • As surrounding Pressure increases, then boiling point of liquid increases
Heat Rate Equation • Heat = mass of material x material’s specific heat x change in temperature • Q = mCp∆T • Important for steam production, use • Heat Rate = steam flow x specific heat capacity of steam x change in temperature
Thermal Efficiency • Applied to heat exchanger optimization • Efficiency = (temperature in – temperature out) X 100% temperature in
Physics Laws • Governing Gases – • Boyle’s Law • Charles’ Law • Gay-Lussac’s Law • Avogadro’s Law • Combined Gas Law • Ideal Gas Law • Dalton’s Law • Governing Gases & Liquids - Bernoulli’s Law
General Gas Law • P1V1 = P2V2 n1 T1 n2 T2 Tanker Implodes http://www.break.com/index/tanker-implodes.html
Principles of Liquid Pressure • Liquid pressure is directly proportional to density of liquid • Liquid pressure is proportional to height (amount) of liquid • Liquid pressure is exerted in a perpendicular direction on the walls of vessel
Principles of Liquid Pressure • Liquid pressure is exerted equality in all directions • Liquid pressure at the base of a tank is not affected by the size or shape of tank’ • Liquid pressure transmits applied force equally, without loss, inside an enclosed container or a pipe
Flow Rate • Flowrate = Volume Time Qv = Av volumetric flow rate = area of pipe x velocity of fluid
Bernouli’s Principle • States that in a closed process with a constant flow rate: • Changes in fluid velocity (kinetic energy) decrease or increase pressure • Kinetic-energy and pressure-energy changes correspond to pipe-size changes • Pipe-diameter changes cause velocity changes • Pressure-energy, kinetic-energy (or fluid velocity), and pipe-diameter changes are related
Fluid Flow • Laminar Flow – • When a fluid moves through a system in thin cylindrical sheets with little or no turbulence. Laminar flow allows the existence of static film, which acts as an insulator. • Laminar flow occurs at lower flow rates and in high viscosity fluids.
Fluid Flow • Turbulent Flow – • When a fluid moving through a system moves in a random or irregular pattern (turbulence), the fluid’s particles mix. Turbulent flow allows increased heat transfer to occur. • Turbulent flow decreases the static film. Increased flow rates, low viscosity fluids and bends in pipe and other obstructions cause turbulent flow.
Fluid energy can be in several forms: • Kinetic energy (fluid motion) • System pressure and potential energy • Heat energy (temperature]
Fluid Flow • Laminar Flow – fluid moves in thin sheets with little or no turbulence. • Turbulent Flow – fluid moves in a random or irregular pattern with considerable mixing. Laminar flow Turbulent flow