510 likes | 1.43k Views
Introduction to Engineering Calculations. Chapter 1. What’s in this chapter?. Bioprocess Engineering Profession Units and Dimension Conversions of Unit Systems of Units Force, Weight and Mass. Introduction.
E N D
Introduction to Engineering Calculations Chapter 1
What’s in this chapter? • Bioprocess Engineering Profession • Units and Dimension • Conversions of Unit • Systems of Units • Force, Weight and Mass
Introduction • Describe the basic techniques for the handling of units and dimensions in calculations. • Describe the basic techniques for expressing the values of process variables and for setting up and solving equations that relate these variables. • Develop an ability to analyze and work engineering problems by practice.
Bioprocess Engineering Profession BIOCHEMIST VS BIOPROCESS ENGINEER
Role of Bioprocess Engineering • exploit advances in biology to create new products • design biochemical processes & operate plants • develop energy resources, • protect the environment. • Develop new, environmentally benign, and safer processes to make the biochemical products that people depend on. • Work in research and development laboratories, creating polymeric materials with improved performance and durability. • Work in manufacturing, making vaccines and antibiotics. • Invent new ways to keep our food and water supplies safe.
RAW MATERIALS SEPARATION PROCESS INTERMEDIATE PRODUCT REACTION PROCESS INTERMEDIATE PRODUCT SEPARATION PROCESS FINAL PRODUCT CHEMICAL PROCESS
Bioprocess Engineer’s Task You need to: • Minimize production of unwanted byproducts • Separate the good (product) from the bad (byproducts) • Recover the unused reactants • Maximize profit, minimize energy consumption, minimize impact on the environment
OPPORTUNITIES FOR BIOPROCESS ENGINEERS • pharmaceuticals • polymers • energy • food • consumer products • biotechnology • electronic and optical materials.
Units and Dimensions Objectives: • Convert one set of units in a function or equation into another equivalent set for mass, length, area, volume, time, energy and force • Specify the basic and derived units in the SI and American engineering system for mass, length, volume, density, time, and their equivalence. • Explain the difference between weight and mass • Apply the concepts of dimensional consistency to determine the units of any term in a function
Units and Dimensions • Dimensions are: • properties that can be measured such as length, time, mass, temperature, • properties that can be calculated by multiplying or dividing other dimensions, such as velocity (length/time), volume, density • Units are used for expressing the dimensions such as feet or meter for length, hours/seconds for time. • Every valid equation must be dimensionally homogeneous: that is, all additive terms on both sides of the equation must have the same unit
Conversion of Units • A measured quantity can be expressed in terms of any units having the appropriate dimension • To convert a quantity expressed in terms of one unit to equivalent in terms of another unit, multiply the given quantity by the conversion factor • Conversion factor – a ratio of equivalent values of a quantity expressed in different units • Let’s say to convert 36 mg to gram Conversion factor
Dimensional Equation • Write the given quantity and units on the left • Write the units of conversion factors that cancel the old unit and replace them with the desired unit • Fill the value of the conversion factors • Carry out the arithmetic value
Dimensional Equation • Convert 1 cm/s2 to km/yr2
Systems of Units • Components of a system of units: • Base units - units for the dimensions of mass, length, time, temperature, electrical current, and light intensity. • Multiple units- multiple or fractions of base unit • E.g.: for time can be hours, millisecond, year, etc. • Derived units - units that are obtained in one or two ways; • By multiplying and dividing base units; also referred to as compound units • Example: ft/min (velocity), cm2(area), kg.m/s2 (force) • As defined equivalent of compound unit (Newton = 1 kg.m/s2)
Systems of Units • 3 systems of unit: a) SI system b) American engineering system c) CGS system
Force and Weight • Force is proportional to product of mass and acceleration • Usually defined using derived units ; 1 Newton (N) = 1 kg.m/s2 1 dyne = 1 g.cm/s2 1 Ibf = 32.174 Ibm.ft/s2 • Weight of an object is force exerted on the object by gravitational attraction of the earth i.e. force of gravity, g. • Value of gravitational acceleration: g = 9.8066 m/s2 = 980.66 cm/s2 = 32.174 ft/s2
Force and Weight • gc is used to denote the conversion factor from a natural force unit to a derived force unit.