Introduction to Engineering Calculations Chapter 1 Introduction to Engineering Calculations

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.

CHEMICAL PROCESS RAW MATERIALS INTERMEDIATE PRODUCT REACTION PROCESS SEPARATION PROCESS REACTION PROCESS RAW MATERIALS INTERMEDIATE PRODUCT FINAL PRODUCT

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 36 mg 1 g = 0.036 g 1000 mg 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 36 mg 1 g = 0.036 g   1000 mg 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 1 cm s2 h2 day2 m km (3600 x 24 x 365) 2 km = 9.95 x 109 km/ yr 2 100 x 1000 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

Base Units Base Units Quantity SI Symbol American CGS Length meter m foot ft centimeter cm Mass kilogram kg pound mass lbm gram g Moles gram-mole mole pound mole lbmole Time second s Temperature Kelvin K Rankine R

Multiple Unit Preferences Multiple SI Units Multiple Unit Preferences tera (T) = 10 12 centi (c) = 10 -2 giga (G) = 10 9 milli (m) = 10 -3 mega (M) = 10 6 micro (μ) = 10 -6 kilo (k) = 10 3 nano (n) = 10 -9

Derivatives SI Units Derived SI Units Quantity Unit Symbol Equivalent to the Base Unit Volume Liter L 0.001m3 = 1000 cm3 Force Newton (SI) Dyne (CGS) N 1 kg.m/s2 1 g.cm/s2 Pressure Pascal Pa 1 N/m2 Energy/ Work Joule Calorie J cal 1 N.m = 1 kg.m2/s2 4.184 J =4.184 kg.m2/2 Power Watt W 1 J/s = 1 kg.m2/s3

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. gc = 1 kg.m/s2 32.174 lbm.ft/s2 1N 1 lbf

ANY QUESTION?