Booklet TE3.pdf

8/10/2019 Booklet TE3.pdf

1/88

TECHNICAL ENGLISH 3 2011 USAC

RevolucionUnattende

Technical English 3


2/88


2


3/88


3

Estudiantes de la Facultad de Ingeniera

Conscientes del vertiginoso avance de la globalizacin nos damos cuenta de lanecesidad de mantener una comunicacin adecuada en el comercio, industria y

mercadotecnia dentro de nuestra sociedad y considerando el desarrollo de

competencias adecuado, se ha construido un novedoso programa para contribuir a

que la Gloriosa Tricentenaria Universidad de San Carlos de Guatemala se

mantenga con ese alto nivel que la ha distinguido durante aos.

Este proyecto naci a principios del ao 2008 con el afn de lograr que todo

estudiante egresado de la Facultad de Ingeniera tenga conocimiento de Ingls

Tcnico para poder aplicarlo tanto en sus estudios como en su desempeo

profesional.

Demostrando que hoy y siempre SOMOS LOS LIDERES de la ingeniera y pioneros

en el cumplimiento de las necesidades de formacin de nuestros profesionales,

dedicamos este trabajo a todos aquellos estudiantes a quienes les interese mejorar

competentemente la aplicacin de los procedimientos de ingeniera y tengan el

deseo de aprender nuevas tcnicas desarrollando habilidades que constantemente

expanden la efectividad y campos de aplicacin de Ingeniera. Esta primera edicin

de este folleto fue creado para cumplir y llenar los requisitos del programa cuyo

objetivo es contribuir a la preparacin integral para llenar de los perfiles de los

profesionales de hoy.

Logrando el cambio propuesto.

ING.MURPHY OLIMPO PAIZ RECINOS

DECANO


4/88


4


5/88


5

Students of Engineering School

Conscious of the vertiginous advance of the globalization we realize the necessity to

maintain an adapted communication in commerce, industry and marketingresearch within our society and considering the development of appropriated

competences, we have developed a novel program to contribute that the Glorious

Tricentennial University of San Carlos of Guatemala stays with that high level that

has distinguished it during years.

This project started the first semester 2008 with the eagerness to obtain that all

withdrawn students of the Faculty of Engineering have knowledge of Technical

English, becoming it a necessity that the students apply this knowledge in their

studies as in their professional performance.

Demonstrating that today and always WE ARE LEADERS of engineering, pioneers

in the fulfilment of the necessities of formation of our professionals, we present to

all students who, by their competent application of engineering procedures and

their readiness to learn new techniques and to develop skills that constantly

expand the effectiveness and fields of application of engineering. The First Edition

of this booklet was created to carry out and to fill the requirements of the program

which objective is to contribute to the integral preparation of the students in order

to fill the profiles of nowadays professionals.

Reaching goals through change

ENGR.MURPHY OLIMPO PAIZ RECINOS

DEAN


6/88


6


7/88


7

Awareness / Acknowledgment

Information contained in this work has been obtained by gathering

information from sources believed to be reliable. However, neither

the sites or the authors guarantees the accuracy or completeness of

any information published herein and neither the Technical

Language Area not its assistants shall be responsible for any errors,

omissions, or damages arising out of use of this information. This

work is gathered with the understanding that the topics are

supplying information but are not attempting to render engineering

or other professional services. If such services are required, the

assistance of an appropriate professional should be sought.


8/88


8


9/88


9


10/88


10

Contenido

LEAN MANUFACTURING ................................................................................................................................. 12

INTRODUCTION ................................................................................................................................................... 12

LEAN MANUFACTURING GOALS.............................................................................................................................. 13

STEPS TO ACHIEVE LEAN SYSTEMS ........................................................................................................................... 14

DESIGN A SIMPLE MANUFACTURING SYSTEM ............................................................................................................. 14

THERE IS ALWAYS ROOM FOR IMPROVEMENT............................................................................................................ 14

CONTINUOUSLY IMPROVE ..................................................................................................................................... 15

MEASURE .......................................................................................................................................................... 15

HOMEWORK: ...................................................................................................................................................... 16

PROCESS DIAGRAMS ....................................................................................................................................... 17

INTRODUCTION ................................................................................................................................................... 17

OPERATIONS DIAGRAM ........................................................................................................................................ 18

IMPORTANT CONSIDERATIONS................................................................................................................................. 19

PROCESS FLOW DIAGRAM ..................................................................................................................................... 19


PROCESS TRAVEL DIAGRAM ................................................................................................................................... 20


HOMEWORK ....................................................................................................................................................... 22

QUALITY CONTROL .......................................................................................................................................... 25

INTRODUCTION ................................................................................................................................................... 25

QUALITY CONTROL CONCEPTS ................................................................................................................................ 25

QUALITY ASSURANCE ............................................................................................................................................ 25

MEASURING THE QUALITY ..................................................................................................................................... 26

2.1 EVALUATING THE QUALITY ............................................................................................................................ 26INTRODUCING LEAN PROCESSES ............................................................................................................................. 27

LEAN TECHNIQUES ............................................................................................................................................... 27

VALUE STREAM MAPPING...................................................................................................................................... 27

THE 5SMETHOD .................................................................................................................................................. 28

RAPID IMPROVEMENT EVENTS................................................................................................................................. 28

LEAN MATERIALS AND KANBAN ............................................................................................................................... 29

HOMEWORK ....................................................................................................................................................... 29

ALTERNATIVE ENERGY..................................................................................................................................... 32

INTRODUCTION ................................................................................................................................................... 32

TODAYS ENERGY SOURCES =FOSSIL FUELS................................................................................................................ 32THE PROBLEMS OF THE USE OF THE FOSSIL FUELS......................................................................................................... 33

THE SOLUTIONS ................................................................................................................................................... 34

SOLAR ENERGY ................................................................................................................................................ 34

SOLAR HEAT ....................................................................................................................................................... 35

PHOTOVOLTAIC,OR SOLAR,CELLS .......................................................................................................................... 35

HOW SOLAR CELL ENERGY WORKS ........................................................................................................................... 36


11/88


11

HOW SOLAR THERMAL ENERGY WORKS .................................................................................................................... 39

WIND ENERGY ................................................................................................................................................. 41

HOW WIND POWER WORKS ................................................................................................................................... 42

TYPES OF WIND TURBINES .................................................................................................................................... 43

HORIZONTAL AXIS WIND TURBINES (HAWT) ........................................................................................................... 44

VERTICAL AXIS .................................................................................................................................................... 45

GEOTHERMAL ENERGY .................................................................................................................................... 47

HOMEWORK ....................................................................................................................................................... 48

BIOETHANOL PRODUCTION ............................................................................................................................ 49

WHAT IS BIOETHANOL? ........................................................................................................................................ 50

BENEFITS ........................................................................................................................................................... 50

BIOETHANOL PRODUCTION.................................................................................................................................... 51

BIOETHANOL USAGE ............................................................................................................................................ 53

NEGATIVE SIDES OF BIOETHANOL............................................................................................................................ 55

ACTIVITIES ......................................................................................................................................................... 56

REFERENCES ....................................................................................................................................................... 58

GEARS ............................................................................................................................................................. 59

BEARINGS ........................................................................................................................................................ 62

ENGINES AND MOTORS................................................................................................................................... 65

INTERNAL COMBUSTION ENGINES ........................................................................................................................... 65

BASIC ENGINE PARTS ........................................................................................................................................... 67

ENGINE PROBLEMS .............................................................................................................................................. 68

ELECTRIC MOTOR ............................................................................................................................................ 70

TERMINOLOGY .................................................................................................................................................... 70

DCMOTOR ........................................................................................................................................................ 71

ACMOTOR......................................................................................................................................................... 71

PARTS OF AN ELECTRIC MOTOR .............................................................................................................................. 71

DIGITAL ELECTRONICS ..................................................................................................................................... 72

ADVANTAGES ..................................................................................................................................................... 72

DISADVANTAGES ................................................................................................................................................. 72

CONSTRUCTION ................................................................................................................................................... 73

LOGIC FAMILIES ................................................................................................................................................... 73

RECENT DEVELOPMENTS ....................................................................................................................................... 74

LOGIC GATE ........................................................................................................................................................ 74

KARNAUGH MAP ................................................................................................................................................. 76

PRINCIPLES OF TELECOMMUNICATIONS ......................................................................................................... 79

BASIC ELEMENTS ................................................................................................................................................. 79

TELECOMMUNICATION NETWORKS.......................................................................................................................... 80

COMMUNICATION CHANNELS................................................................................................................................. 80

MODULATION ..................................................................................................................................................... 80


12/88


12

LEAN MANUFACTURING

Introduction

Lean manufacturingor lean

production, which is often known simply as

Lean, is a production practice that considers

the expenditure of resources for any goal other

than the creation of value for the end customer

to be wasteful, and thus a target for

elimination. Working from the perspective of

the customer who consumes a product or

service, value is defined as any action or

process that a customer would be willing to

pay for.

Basically, lean is centered around

creating more value with less work. Lean

manufacturing is a generic process

management philosophy derived mostly

from theToyota Production System (TPS)

(hence the term Toyotism is also prevalent)

and identified as Leanonly in the 1990s.It is

renowned for its focus on reduction of the

original Toyotaseven wastes in order to

improve overall customer value, but there

are varying perspectives on how this is best

achieved.

Lean manufacturing is a variation on the theme ofefficiencybased on optimizing flow; it is a

present-day instance of the recurring theme in human history toward increasing efficiency,

decreasing waste, and using empirical methods to decide what matters, rather than uncritically

accepting pre-existing ideas.
http://en.wikipedia.org/wiki/Toyota_Production_Systemhttp://en.wikipedia.org/wiki/Muda_(Japanese_term)http://en.wikipedia.org/wiki/Economic_efficiencyhttp://en.wikipedia.org/wiki/Economic_efficiencyhttp://en.wikipedia.org/wiki/Economic_efficiencyhttp://en.wikipedia.org/wiki/Economic_efficiencyhttp://en.wikipedia.org/wiki/Muda_(Japanese_term)http://en.wikipedia.org/wiki/Toyota_Production_System


13/88


13

The elimination of waste is the goal of Lean, and Toyota defined three broad types of waste:

Muda

Mura

Muri

Muda: is a traditional general Japanese term for an activity that is wasteful and doesn't add value or is

unproductive and it is also a key concept in theToyota Production System (TPS).

The original seven mudaare:

Transportation(moving products that is not actually required to perform the processing)

Inventory(all components,work in process and finished product not being processed)

Motion (people or equipment moving or walking more than is required to perform the

processing)

Waiting(waiting for the next production step) Overproduction(production ahead of demand)

Over Processing(due to poor tool or product design creating activity)

Defects(the effort involved in inspecting for and fixing defects)

Mura: is traditional general Japanese term for unevenness, inconsistency in physical matter or human

spiritual condition.

Muri: is a Japanese term for overburden, unreasonableness or absurdity, which has become

popularized in the West by its use as a key concept in theToyota Production System.

Lean Manufacturing Goals

The four goals of Lean manufacturing systems are to:

Improve quality: In order to stay

competitive in todays marketplace, a

company must understand its customers'

wants and needs and design processes to

meet their expectations and

requirements.

Eliminate waste:Waste is any activity that

consumes time, resources, or space but

does not add any value to the product or

service. There are seven types of waste.
http://en.wikipedia.org/wiki/Muda_(Japanese_term)http://en.wikipedia.org/wiki/Muri_(Japanese_term)http://en.wikipedia.org/wiki/Mura_(Japanese_term)http://en.wikipedia.org/wiki/Toyota_Production_Systemhttp://en.wikipedia.org/wiki/Work_in_processhttp://en.wikipedia.org/wiki/Toyota_Production_Systemhttp://en.wikipedia.org/wiki/Toyota_Production_Systemhttp://en.wikipedia.org/wiki/Work_in_processhttp://en.wikipedia.org/wiki/Toyota_Production_Systemhttp://en.wikipedia.org/wiki/Mura_(Japanese_term)http://en.wikipedia.org/wiki/Muri_(Japanese_term)http://en.wikipedia.org/wiki/Muda_(Japanese_term)


14/88


14

Reduce time:Reducing the time it takes to finish an activity from start to finish is one of

the most effective ways to eliminate waste and lower costs.

Reduce total costs:To minimize cost, a company must produce only to customer demand.

Overproduction increases a companys inventory costs due to storage needs.

Steps to achieve lean systems

The following steps should be implemented in order to create the ideal lean

manufacturingsystem:

1. Design a simple manufacturing system

2. Recognize that there is always room for improvement

3. Continuously improve the lean manufacturing system design

4. Measure

Design a simple manufacturing system

A fundamental principle of lean

manufacturing is demand-based flow

manufacturing. In this type of production

setting, inventory is only pulled through each

production center when it is needed to meet

a customers order. The benefits of this goal

include:

Decreased cycle time

Less inventory

Increased productivity

Increased capital equipment utilization

There is always room for improvement

The coreof lean is founded on the concept of continuous product and process improvement and

the elimination of non-value added activities. The Value adding activities are simply only those things

the customer is willing to pay for, everything else is waste, and should be eliminated, simplified,

reduced, or integrated(Rizzardo, 2003). Improving the flow of material through new ideal system

layouts at the customer's required rate would reduce waste in material movement and inventory.


15/88


15

Continuously improve

A continuous improvement mindset is essential to reach a company's goals. The term "continuous

improvement" means incremental improvement of products, processes, or services over time, with

the goal of reducing waste to improve workplace functionality, customer service, or productperformance (Suzaki, 1987).

Measure

A set of performance metrics which is considered to fit well in a Lean environment is overall

equipment effectiveness,or OEE, which is a hierarchy of metrics which focus on how effectively a

manufacturing operation is utilized.

To keep things really simple, lean manufacturing has a base premise and overall goal to get

more done with lessand this is effectively done, by:

Minimizing inventory at and through all stages of production

Eliminating waste

Reducing wait times, queues

Shortening product cycle times from raw materials to finished goods

Lean manufacturing involves some real positive, productive changes in businesses that willhave a measurable impact in the bottom line. Benefits of lean production could include:

Reduced lead time, wait time and cycle time

Liberated capital

Increased profit margins

Increased productivity

Improved product quality

Just in time, affordable, streamlined, cost-efficient processes, products and services

Improved on-time shipments Customer satisfaction and loyalty

Employee retention
http://en.wikipedia.org/wiki/Overall_equipment_effectivenesshttp://en.wikipedia.org/wiki/Overall_equipment_effectivenesshttp://en.wikipedia.org/wiki/Overall_equipment_effectivenesshttp://en.wikipedia.org/wiki/Overall_equipment_effectiveness


16/88


16

Homework:

Investigate the following terms related to lean manufacturing and give their definition:

Just in time Kanban Kaizen Poka Yoke

Suggested videos:

http://www.youtube.com/watch?v=c0Q-xaYior0&feature=related

http://www.youtube.com/watch?v=SU01D-jTZcE&feature=related

http://www.youtube.com/watch?v=Q89qAbAAR3Q&feature=related

http://www.youtube.com/watch?v=ZdHGTCXcJQU&feature=related

http://www.youtube.com/watch?v=mKb84GafalI

Activities

Complete the next chart with the next definitions:

Lean manufacturing

Reduce Time

Continuously Improve

TPS

Improve quality
http://www.youtube.com/watch?v=c0Q-xaYior0&feature=relatedhttp://www.youtube.com/watch?v=SU01D-jTZcE&feature=relatedhttp://www.youtube.com/watch?v=Q89qAbAAR3Q&feature=relatedhttp://www.youtube.com/watch?v=ZdHGTCXcJQU&feature=relatedhttp://www.youtube.com/watch?v=mKb84GafalIhttp://www.youtube.com/watch?v=mKb84GafalIhttp://www.youtube.com/watch?v=ZdHGTCXcJQU&feature=relatedhttp://www.youtube.com/watch?v=Q89qAbAAR3Q&feature=relatedhttp://www.youtube.com/watch?v=SU01D-jTZcE&feature=relatedhttp://www.youtube.com/watch?v=c0Q-xaYior0&feature=related


17/88


17

PROCESS DIAGRAMS

Introduction

The process diagrams are very important in the manufacturing industry because they give us a

clear perspective of the processes with every step, including materials, time, distance and others. This

helps the engineers to interpret and analyze the manufacturing process and make decisions that will

improve the process without being there to watch how everything works.

The diagrams are composed by three parts:

Header

Body

Summary

In the header you will include all the relevant information such as: company name, analyst,

date, process, area, page number, type of diagram, etc.

In the body, you will draw the diagram that is required according the specifications of each

type and of the process.

And in the summary you will write all the steps that the process has, including time. Time is

the most important factor because we use it to calculate the process efficiency and productivity.

Example:

Header

Body

Summary


18/88


18

Operations Diagram

This diagram is a graphic representation of the operations and inspections in a production

process. In this diagram well include the following symbols:

Description Symbol

Operation: is when the process has materials transformation, or

involves any action or activity for the creation of products.

Inspection:is when we check how the process is going and also

the quality of the product during the manufacturing process.

Combined:this is an operation-inspection step and is used when

in the process you have to check the products during an

operation.

Company name: Johns house Analyst: John Hamilton Date: Nov. 20th

, 2010

Process: making of hot chocolate Area: kitchen Type of diagram: operations

Page1 of1

0.7 min

In a pot put 1 liter of water, in a stove

With high fire, let it boil

1 min

Take the 0.30 pounds of chocolate

out of the bag and put it into the pot

0.5 min 7 min

Get some marshmallows Stir frequently and let the

chocolate melt and get the

desired consistency

0.5 min

Check if the chocolate is ready

0.8 min

Get a cup and serve

0.5 minAdd the marshmallows

0.4 min

Check if its not too hot, Enjoy!

1

2

43

1

5

1

6


19/88


19

Summary

Description Symbol # of steps Time

Operation 6 10.5

Inspection 1 0.4

Combined 1 0.5

Totals 8 11.4

Important considerations

Note that the time is given in minutes; this is a standard for all the diagrams.

The diagram always is going to be drawn from right to left, even if it has simultaneous

processes or not. The time is placed in the upper-left corner of the symbol.

A brief description of every step of the process is written at the right side of the symbol.

When numbering the process remember that you have to do it according to its function in the

diagram, and when you have a simultaneous process you have to write the number on the left

first and then in the right, as shown in the example.

Process Flow Diagram

The process flow diagram is a graphic representation of the steps that follows a chronologic

sequence of activities in a process or procedure, identifying them with symbols according to its

nature, and also includes all the considered important information that is needed for analysis. This

information could be distance, time, quantity, etc. This helps us discover and eliminate waste and

delays, making the process more efficient and increase the productivity in the manufacturing

industry.

In this diagram we include the storage, operation, inspection, combined, delays and

transportation symbols.

Description Symbol

Operation:is when the process has materials transformation,

or involves any action or activity for the creation of products.


20/88


20

Inspection: is when we check how the process is going and also the

qualityof the product during the manufacturing process.

Combined: this is an operation-inspection step and is used when in the

process you have to check the products during an operation.

Delay: this is used when nothing is being done in the process, It could be

the wait for other paralell process to finish before adding the product to

the asemblyline.

Transportation: is when the product is moved more than 1.5

meters to the next step. This is because the human body Can move

something from one side to other between 0 and 1.5 m and its

irrelevant according to standars.

Storage: this is used at the beginning of the process when the

materials are taken from the raw materials storage and at the end

of it in the finished product storage.

As the operations diagram,it has the same parts: header, body and summary, and its

important to include in the summary the time and distance that you have in the diagram.


Time is given in minutes; this is a standardfor all the diagrams.

The diagram always is going to be drawn from right to left, even if it has simultaneous processes or not.

The time is placed in the upper-left corner of the symbol.

The distance is written meters and in the lower-left corner of the symbol. A brief description of every step of the process is written at the right side of the symbol.

When numbering the process remember that you have to do it according to its function in the diagram,

and when you have a simultaneous process you have to write the number on the left first and then in

the right, as shown in the example.

Process Travel Diagram

This diagram uses the same symbolismas the process flow and also the same structure, the only

difference is that we draw the diagram in a plan view of the manufacturing plant.

Remember to always draw the symbols in a 1 cm2

area. This is a standard for all the diagramsthat

youre going to draw.


21/88


21


Time is given in minutes; this is a standard for all the diagrams.

The diagram is drawn in a plan view of the manufacturing plant.

The time is placed in the upper-left corner of the symbol.

The distance is written in meters and the lower-left corner of the symbol.

A brief description of every step of the process is written at the right side of the symbol.

When numbering the process remember that you have to do it according to its function in the

diagram and the sequence in the process.

Example: (For space reasons, this diagram doesnt include the time and distance)

Company name: Industry S.A. Analyst: John Hamilton Date: Nov 20th

, 2010

Process: production of ketchup Area: manufacturing plant Type of diagram: process travel

Page 1of 1


22/88


23/88


23

Activities:

According to the picture below, determine what symbol each operation needs:


24/88


24

Complete the summary table for the diagram below:

Description Symbol No. of steps Time Description 2 Symbol No. of steps2 Time2

Tables storage

Sawing and Comprobation

Sawdust 6%

Waiting to be processed

Transfer to the pendulum

(forklift)



Transfer to the pendulum

(forklift)



Cut and Comprobation

Sawdust 0.32%

Waiting to be transported



Transfer to the assembly area

(forklift)

Transfer to the assembly area(forklift)

Cross storage

Sawdust 0.38%

Sawdust

Cut and Comprobation

Devastation and Comprobation

Assembly and Comprobation

Sawdust and Tables.

Transfer to the Store (forklift)

Storage


25/88


25

QUALITY CONTROL

Introduction

Quality control is a critical concept in every industry and profession.

As globalizationcontinues and the world become smaller, making it possiblefor consumers to pick and choose from the best products worldwide, the

survival of your job and of your company depends on your ability to produce

a quality product or service. In this chapter, we define the term quality,

and we introduce some important quality control concepts and methods.

For most people, quality is associated with the idea of a product or

service that is well done, looks good and does its job well. We think of a quality product as one that

lasts, holds up well under use, and doesnt require constant repair. A quality product or service should

meet a high standard in many areas, such as form, features, fit and finish, reliability and usability.

Quality control concepts

Costumer based: Quality is meet customer expectations.

Statistical based:The less variation you have, the higher the quality of

your product or service.

After an organization decides on a definition of quality, you needstandards against which to measure your quality. The reason is because

many standards are driven by the desire to safeguard and well-being of

the people who use the products or services companies provide. Quality

standards are also critical in support of international trade.

Quality Assurance

Quality assurance focuses on the ability of a process to produce or deliver a quality product or

service. This method differs from quality control in that it looks at the entire process, not just the final

product. Quality control is designed to detect problems with a product or service; quality assurance

attempts to head off problems at the pass by tweaking a production process until it can produce a

quality product.


26/88


26

Measuring the quality

The old manager saying: You cant manage what

you can measure rings especially true in quality control.

A good measurement system helps you to know whereyouve been and where you are going. Costumers

typically require that you measure certain attributes of

your product or service against their specifications. So,

working in quality control means that you have to

determine what to measure, how to measure it and when

to measure it.

Employee training is critical to ensure that everyone involved in your process measures the

same specifications in the same way. You also need to collect data in a usable format so that you cananalyze it to determine the effectiveness of your quality process. The effectiveness of your quality

process is directly related to the quality of your data collection and analysis process. If you dont have

a good data, you cant make good decisions.

2.1 Evaluating the quality

The most common way to analyze the data you collect is to use

statistics. Statistics serve many purposes within quality control:

Statistics helps you to determine which processes or parts of processes

are causing your company the most problems (by using the 80/20 rule

80 percent of your problems are caused by 20 percent of what you do).

You can use statistics for sampling so that you dont have to test 100

percent of the items you make.

Statistics can help you spot relationships between the values you

measureeven if the relationships arent obvious. They also allow you to

identify small variations in your process that can lead to big problems if

you dont correct them.

Although, much of statistics allows you to look back only at was happened in the past.

Statistical Process Control (SPC) allows you to identify problems before they can negatively impact the

quality of your product or service. The basic idea behind SPC is that if you can spot a change in a

process before it gets to the point of making bad products, you can fix the process before bad

products hits the shelves.


27/88


27

Introducing Lean Processes

Lean processes are the latest diet craze in the world of quality control. Leanis a quality control

technique you can use to identify and eliminate the flab in your companys processes. The flab is all

the dead weight carried by a process without adding any value.

Most company processes are wastefulin terms of time and materials, which often results in

poorer quality to the costumer a concern of all businesses. Lean focuses in customer satisfaction

and cost reduction. Proponents of the technique believe that every step in a process is an opportunity

to make a mistake to create a quality problem, in other words. The fewer steps you have in a

process, the fewer chances for error you create and the better the quality in your final product or

service.

You can apply the lean techniques in the following sections to all types of processes andenvironments ranging from offices, to hospitals, to factories. In most cases applying lean concepts

doesnt require an increase in capital costs it simply reassigns people to more productive purposes

and of course, lean processes are cheaper to operate.

Lean Techniques

Value Stream Mapping

People think in images, notin words, so giving them a picture of

how something is done is often

better than telling them about a

process. After all, the quote is

Show me the money! not Tell me

about the money!

Value Stream Mapping

visually describes a production

process in order to help workers

locate waste within it. Waste is any

activity that doesnt add value for the customer. Typically, eliminating waste involves reducing the

amount of inventory sitting around and shortening the time it takes to deliver a product or service to

the customer upon its order.


28/88


29/88


29

Lean materials and Kanban

A companys materials are essential for the organization to work well, but they also tied up a

large part of a companys capital. And while the company does its business year in and year out, its

materials are, stolen, damaged, rotting, corroding, and losing value in many other ways.

A key part of the lean approach is to minimize the amount of materials (both incoming and finished

goods) you have sitting around in your facility. Excess materials hide problems with purchasing, work

scheduling, scrap rates, and so on. Eliminating this excess materials provides an immediate financial

benefit to your companyif you eliminate correctly.

You dont want to eliminate so thoroughly that you cause shortages. One method you can use

to fix the problem of excess materials without causing shortages is Kanban. Kanban is a materials

system controlled by the customer. When the customer buys an item, action cascades back up the

production line to make one more of that item.

Homework

Investigate and make a summary of the following topics:

Total Quality Management (TQM)

Six Sigma

Toyota Production System (TPS)

Suggested videos

http://www.youtube.com/watch?v=U7Z33tljMTQ

http://www.youtube.com/watch?v=LdhC4ziAhgY
http://www.youtube.com/watch?v=U7Z33tljMTQhttp://www.youtube.com/watch?v=LdhC4ziAhgYhttp://www.youtube.com/watch?v=LdhC4ziAhgYhttp://www.youtube.com/watch?v=U7Z33tljMTQ


30/88


30

Activities:

Write in each screw a different description about Quality Control:

Complete with the description of each lean technique:

Value stream Mapping

Rapid improvement events

Lean material and Kanban


31/88


31

Complete the chart with the 5s technique:


32/88


32

ALTERNATIVE ENERGY

Introduction

You need energy to start your day. Your breakfast is the fuel your body needs to work. What

would you do if you ran out ofyour favorite cereal? You could buy another box. But what if the store

was all out, too? What if it wasnt getting any more deliveries? What would you do then? The answer

seems simple; youd have to find another food for breakfast. The world faces a similar problem; our

fuel resources are running low and could run out in your lifetime.

Most everything in the world needs energy to work. Think about the energy you use each day:

the lights you turn on, the bus or car you take to school, the computer you use for homework, the

television you watch before bed. Even while you sleep, energy runs your furnace heating your houseand the refrigerator keeping food from spoiling. It even runs the alarm clock that wakes you up in the

morning. Now think about how many people live on the Earth. With a population of more than 6

billion, the world uses a lot of energy.

Todays energy sources = fossil fuels

1. Coal

People mine for coal, a hard, black, rock,

throughout the world. Power plants use coal to generate

electricity by grindingit into a powder that is burned. The

burned powder heats water to create steam. The power of

the steam turns turbines. The spinning motion of the

turbines generates electricity. A network of wires called power grid, bring this electricity to houses

and other buildings.

2. Oil

Companies drillfor oil on land or in the ocean and store it

in large barrels or underground tanks. People turn oil into

many products, including plastics. Your ballpoint pen, your


33/88


33

nylon backpack, and even your fleecejacket are all made from oil. Some homes burn oil for heat and

some power plants burn oil too. In many countries, however, oils main use is for transportation. Oil is

made into gasoline for cars, diesel fuel for trucks, and jet fuel for airplanes.

3. Natural gas

Companies drill for natural gas the same way they do for oil. Natural gas is highly flammable.

Gas stoves cook food with a lower flame. In the United States, and probably other countries, the

houses heating system and water heater may use natural gas. Natural gas is also used in power

plants to create electricity.

The problems of the use of the fossil fuels

Fossil fuels have been a useful source of energy, but we need to rethink how much we depend

on them. We need to consider three main facts. First, fossilfuel supplies are low. We use so much

energy that someday well use up all of Earths fossil fuels. At the rate we use now fossil fuels,

scientists estimate that the worlds reserve will last 40 to 70 more years. What will happen after all of

the oil, coal, and natural gas have run out? How will

we travel from place to place? How will we light our

homes? How will we communicate with each other?

The second fact is that the fossil fuels cost a

lot of money. Countries buy fossil fuels from each

other. Because the supply is low, they can raise their

prices. If countries go to war or have a disagreement,

they may not want to buy fuel from each other. No

one will get what they need.

Finally, burning fossil fuels harms Earth. Coal, oil, and natural gas create a lot of air pollution.

The burning of fossil fuels releases harmfulemissionsthat cause asthma and other health problems.This pollution also leads to acid rain and snow. Many scientist and citizens are concerned about the

carbon dioxidereleased by burning fossil fuels. Carbon dioxide belongs to a group of gases known as

greenhouse gases.As these gases collect in the atmosphere, they act like the glass wallsof a

greenhouse, trappingwarm air close to Earths surface. This warmingis natural, and long ago it made

the planets environmentmildenough to support life. However, when human activities pump larger-

than-normal amounts of carbon dioxide into the atmosphere, more heat is trapped, and


34/88


34

temperatures can grow unnaturally high. As a result, there can be major effects on weather that may

be devastating to the environment and all the people on Earth.

The solutions

What can we do about our energy problems? Instead of relying on fossil fuels, we need to

examine our green alternatives. Green energy is renewable it is constantly being replaced and

wont run out. Natural forces, such aswind, water, and sunlight are green energy sources. Its not

easy to switchto green energy; however, we rely on fossil fuels every day. People would need to

spend huge amounts of money to change from one kind of fuel to another. We need to take action,

but first, we need to understand our energy alternatives, then we can make the best energy choices

to preserve our planet.

Solar energy

Put on sunglasses, rub in sunscreen, and hit the beach. Its

time to soak up some rays! The sun can give you a great tan or make

you sweatplaying Frisbee. The suns light and heat can also help us

solve our energy problems. You have probably noticed wires

running from your home to poles on the street. These wires connect

you to the power grid of your community. Homes that use solarpower, dont need as much energy from the grid. There are two

types of solar power: solar cell energy and solar thermal energy.

Solar Energy, the energy generated by the sun. This energy is in the form of electromagnetic

radiation and travels to the earth in waves of various lengths. Some of the radiation becomes evident

as heat, some as visible light. All life on earth depends ultimately on the sun's radiation. It warms the

earth and provides the energy that green plants use to make their food. (Without plants, there would

be no animals, since all animals must feed on plants or on plant-eating organisms.)

Since ancient times attempts have been madewith varying successto put the energy from

the sun to practical use. In the third century B.C., the Greek mathematician and physicist Archimedes

is said to have used the sun's rays reflected from mirrors to set fire to an invading Roman fleet. In the

19th century, John Ericsson, designer of the ironclad warship Monitor, built an engine that was

powered by the sun's energy.


35/88


36/88


36

To a very limited extent solar batteries have been used to supply electric power to businesses

and residences. However, photovoltaic cells are relatively costly to manufacture and are thus not

practical for generating large amounts of electricity commercially. Research in the use of photovoltaic

cells for solar energy is directed toward finding ways of increasing the efficiency of the cells and of

reducing their cost.

How solar cell energy works

The solar cells that you see on calculators andsatellites are also called photovoltaic (PV) cells,

which as the name implies (photo meaning "light" and voltaic meaning "electricity"), convert sunlight

directly into electricity. A module is a group of cells connected electrically and packaged into a frame

(more commonly known as a solar panel), which can then be grouped into larger solar arrays, like the

one operating at Nellis Air Force Base in Nevada.

Photovoltaic cells are made of special materials called

semiconductors such as silicon, which is currently used most

commonly. Basically, when light strikes the cell, a certain portion of it

is absorbed within the semiconductor material. This means that the

energy of the absorbed light is transferred to the semiconductor. The

energy knocks electrons loose, allowing them to flow freely.

PV cells also all have one or more electric field that acts to force electrons freed by light

absorption to flow in a certain direction. This flow of electrons is a current, and by placing metal

contacts on the top and bottom of the PV cell, we can draw that current off for external use, say, to

power a calculator. This current, together with the cell's voltage (which is a result of its built-in

electric field or fields), defines the power (or wattage) that the solar cell can produce.

That's the basic process, but there's really much more to it. On the next page, let's take a

deeper look into one example of a PV cell: the single-crystal silicon cell.

Silicon has some special chemical properties, especially in its crystalline form. Anatom of sili-con has 14 electrons, arranged in three different shells. The first two shells -- which hold two and

eight electrons respectively -- are completely full. The outer shell, however, is only half full with just

four electrons. A silicon atom will always look for ways to fill up its last shell, and to do this, it will

share electrons with four nearby atoms. It's like each atom holds hands with its neighbors, except that
http://science.howstuffworks.com/satellite.htmhttp://science.howstuffworks.com/electricity.htmhttp://science.howstuffworks.com/atom.htmhttp://science.howstuffworks.com/atom.htmhttp://science.howstuffworks.com/electricity.htmhttp://science.howstuffworks.com/satellite.htm


37/88


37

in this case, each atom has four hands joined to four neighbors. That's what forms the crystalline

structure, and that structure turns out to be important to this type of PV cell.

The only problem is that pure crystalline silicon is a poor conductor of electricity because none

of its electrons are free to move about, unlike the electrons in more optimum conductors like copper.To address this issue, the silicon in a solar cell has impurities -- other atoms purposefully mixed in with

the silicon atoms -- which changes the way things work a bit. We usually think of impurities as

something undesirable, but in this case, our cell wouldn't work without them. Consider silicon with an

atom of phosphorous here and there, maybe one for every million silicon atoms. Phosphorous has

five electrons in its outer shell, not four. It still bonds with its silicon neighbor atoms, but in a sense,

the phosphorous has one electron that doesn't have anyone to hold hands with. It doesn't form part

of a bond, but there is a positive proton in the phosphorous nucleus holding it in place.

Whenenergy is added to pure silicon, in the form of heat for example, it can cause a few

electrons to break free of their bonds and leave their atoms. A hole is left behind in each case. These

electrons, called free carriers, then wander randomly around the crystalline lattice looking for another

hole to fall into and carrying an electrical current. However, there are so few of them in pure silicon,

that they aren't very useful.

But our impure silicon with phosphorous atoms mixed in is a different story. It takes a lot less

energy to knock loose one of our "extra" phosphorous electrons because they aren't tied up in a bond

with any neighboring atoms. As a result, most of these electrons do break free, and we have a lot

more free carriers than we would have in pure silicon. The process of adding impurities on purpose is

called doping, and when doped with phosphorous, the resulting silicon is called N-type ("n" for

negative) because of the prevalence of free electrons. N-type doped silicon is a much better

conductor than pure silicon.

The other part of a typical solar cell is doped with the element boron, which has only three

electrons in its outer shell instead of four, to become P-type silicon. Instead of having free

electrons, P-type ("p" for positive) has free openings and carries the opposite (positive) charge.

Before now, our two separate pieces of silicon were electrically neutral; the interesting part

begins when you put them together. That's because without an electric field, the cell wouldn't work;

the field forms when the N-type and P-type silicon come into contact. Suddenly, the free electrons on

the N side see all the openings on the P side, and there's a mad rush to fill them. Do all the free

electrons fill all the free holes? No. If they did, then the whole arrangement wouldn't be very useful.

However, right at the junction, they do mix and form something of a barrier, making it harder and
http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/fpte.htmhttp://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/fpte.htm


38/88


38

harder for electrons on the N side to cross over to the P side. Eventually, equilibrium is reached, and

we have an electric field separating the two sides.

This electric field acts as a diode, allowing (and even pushing) electrons to flow from the P side

to the N side, but not the other way around. It's like a hill -- electrons can easily go down the hill (to

the N side), but can't climb it (to the P side).

When light, in the form ofphotons,hits our solar cell, its energy breaks apart electron-hole

pairs. Each photon with enough energy will normally free exactly one electron, resulting in a free hole

as well. If this happens close enough to the electric field, or if free electron and free hole happen to

wander into its range of influence, the field will send the electron to the N side and the hole to the P

side. This causes further disruption of electrical neutrality, and if we provide an external current path,

electrons will flow through the path to the P side to unite with holes that the electric field sent there,

doing work for us along the way. The electron flow provides the current, and the cell's electric field

causes a voltage. With both current and voltage, we have power, which is the product of the two.

There are a few more components left before we can really use our cell. Silicon happens to be

a very shiny material, which can send photons bouncing away before they've done their job, so

an antireflective coating is applied to reduce those losses. The final step is to install something that

will protect the cell from the elements -- often a glass cover plate. PV modules are generally made by

connecting several individual cells together to achieve useful levels of voltage and current, and

putting them in a sturdy frame complete with positive and negative terminals.

How much sunlight energy does our PV cell absorb? Unfortunately, probably not an awful lot.

In 2006, for example, most solar panels only reached efficiency levels of about 12 to 18 percent. The

most cutting-edge solar panel system that year finally muscled its way over the industry's long-
http://science.howstuffworks.com/light3.htmhttp://science.howstuffworks.com/light3.htm


39/88


39

standing 40 percent barrier in solar efficiency -- achieving 40.7 percent [source:U.S. Department of

Energy]. So why is it such a challenge to make the most of a sunny day?

The sun radiates approximately 1000W per square meter, so a 10 x 10 cm solar cell is exposed

to nearly 10 watts of radiated power. Depending on the quality of the cell, it can produce an electrical

output of 1 - 1.5 watts. To increase the output, several cells are combined and connected to a PV

module. The connection of several PV modules is also referred to as a PV array.

How solar thermal energy works

Solar thermal energy uses heat instead of light. People can

place thermal panels on their roofs to absorb the suns heat. Tubing

filled with water runs under the panels. The sun warms the water.

This water can then be used to make a cup of cocoa, fill a swimmingpool, or run through a homes heating system.

Thermal energy can also create electricity. In a solar power plant, the sun heats a liquid until it

boils. Then the steam created from this boiling liquid runs a turbine to generate electricity. In order

for the liquids to boil, these power plants use mirror to focus the suns heat and increase its strength.

Some mirrors are curved and shaped like a saucer. Others are shaped like a trough or placed in a line.

Some new solar energy plants have a power tower. Thousands of mirrors surround the tower and

focus the suns heat to the top.
http://www.energy.gov/print/4503.htmhttp://www.energy.gov/print/4503.htmhttp://www.energy.gov/print/4503.htmhttp://www.energy.gov/print/4503.htm


40/88


40

The solar collectors absorb the sunsrays, convert them to heat and transfer the heat to a

heat-transfer fluid. (The heat-transfer fluid is typically a glycol and water mixture in regions where

seasonal freezing in a concern.) The heat-transfer fluid is then pumped into a heat exchanger located

inside the water storage tank where it heats the water.

After releasing its heat via the heat exchanger, the heat-transfer fluid flows back to the

collectors to be reheated. The controller keeps the heat-transfer fluid circulating whenever there is

heat available in the solar collectors. In the winter, a boiler serves as an alternate heat source. Solar

thermal systems can be integrated into existing hot water systems with relative ease.

A solar thermal system consists primarily of the following components:

The collector, which is normally installed on the rooftop, represents the key component of a solar

thermal system. It consists of specially coated tubing that is used to absorb the solar radiation and to

convert it into heat. To minimize thermal losses, this tubing is embedded in a heat-insulated container

equipped with a transparent cover. A heat-transfer fluid (usually a mixture of water and ecologically-

safe anti-freeze) flows inside the tubing and circulates between the collector and hot water tank.

The Solar Controller. Solar thermal systems are operated by a solar controller. Once the temperature

at the collector rises several degrees above the temperature in the storage tank, the solar controller

switches on the circulation pump and the heat-transfer fluid transports the heat accumulated in the

collector to the hot water tank.

The Hot Water Tank. There are two basic kinds of tanks. Drinking water storage tanks are used for

heating drinking water and consist of steel tanks that are filled with drinking water and equipped with

two heat exchangers.

Combination storage tanks are used for both drinking water and supplying heating systems. They have

two internal tanks to keep the water separated. The solar thermal circuit is connected to the lower

heat exchanger. The boiler connects to the upper heat exchanger.

In most cases, solar thermal energy systems are designed to meet 100% of a households

energy demands for water heating during the summer months from May to September. During the

winter months, the boiler will likely be used for space heating and can also heat water during that

time. In this way, solar energy accounts for approximately 60% of the energy used to heat water

throughout the year.


41/88


41

Generally speaking, the size of your solar thermal system will vary depending on the climate and

overall water usage. The following guidelines can be used to estimate your system requirements:

Collector surface area

m2

flat-plate collector surface per person 1 m2evacuated tube collector surface per person

As you can see, evacuated tube type collectors are more efficient given the same area. This

may be something to consider if your rooftop is not very large.

Storage tank volumes

20-30 gallons per person

Since household hot water requirements remain relatively consistent throughout the year, the

use of solar energy for hot water generation can be extremely cost-effective. The solar thermal

system can easily be designed to meet a specific households energy demands for hot water usage.

With a properly sized system, 50% to 65% of the annual hot water requirements would be provided

by solar energyand during the summer, 100% could be achieved, allowing the conventional heating

system to be completely off during that time.

Wind Energy

Wind is moving air. The motion is caused by changes in air temperature. Warm air is light, and

cold air is heavy. When the land beats up during the day, it warms the air above it. This warm air rises

higher in the sky; while cold air moves down to fill the space left by the warm air. This movement of

air creates wind.

Wind can be powerful, as with a destructive hurricane, but its

power can also be used for good. Sailors use the wind to keep their

sailboats moving. Throughout history people have used windmills to

harness the winds energy for grinding grain or pumping well water. Today

people use wind turbines to generate electricity.


42/88


42

How wind power works

A wind turbine has what looks like an airplane

propeller mounted very high in a tower. The blades of the

turbine catch the wind and spin. The blades spin a shaftthat is connected to an electrical generator. Wires connect

the generator to the power grid to bring electricity to

buildings in the area.

To increase the amount of power, turbines are

often grouped in wind farms. Most wind farms arent

owned by electric power companies. They are owned by

wind

farmerswho sell the

electricity to

power companies. Wind turbines work best where wind

blows strongest. Wind is usually stronger the higher you

go. Thats why turbines are often mounted on tall

towers or placed on the top of hills. Some towers stand

between 100 and 250 feet (30 and 76 meters) high.

Shorelines and wide-open prairies are also good places

for towers. Turbines dont work well in location of toomany mountains, forests, or buildings, which block the

winds flow. Some people place small turbines on their roofs and position them in a way to catch the

most wind.

The process of converting the wind into mechanical energy starts with the wind turbine blades. There

are two different types of blade designs, lift type and drag type:

Lift Type: This is a common type of the modern horizontal axis wind turbine blade that you see at all

the big wind farms. This type of blade has a similar design of an airplane wing. As the air blows on both

side of the blade, it takes the air long to travel across the leading edge creating a lower air pressure and

higher air pressure on the tailing edge. This pressure difference pulls and pushes the blade around.

Lift type blades have much higher rotational speeds than drag type, which make them well suited for

generating electricity.

Drag TypeThe first type of wind turbines created used a drag design. This type of wind turbine uses

the force of the wind to push the blade. A savonius is a perfect example of this design type, the wind is

resisted by blade and the winds force on it pushes it around. This design normally creates a slower


43/88


43

rotational speed with a higher torque than a lift type design. This design has been used for centuries

for milling, sawing, pumping, but rarely used for energy generation on large scale.

The rotating blades are connected to a shaft which is connected to a generator. Some micro

wind turbines are designed to be direct drive, where the blades connect directly to a low RPM

generator, usually around 500+ RPM. The larger wind turbines make the use of gears to increase a

slow blade turn, sometimes as slow as 9 RPM, into 1800+ RPM that can be used to drive a generator.

These gears lose energy and cause additional cost, maintenance, and downtime. Many recent

advances and ingenuity has gone into improving the design.

How is the electricity created?

The generator uses the turning

motion to spin a magnetic rotor inside

the generator housing that is

surrounded by loops of copper wire

(often wrapped around iron cores). As

the rotor spins around the inside of the

core it excites "electromagnetic

induction" through the wire that

generates an electrical current.

Where does the wind come from?

The suns energy fuels our wind. As solar rays come

down hit Earth they heat it up. Wind is created by the Earth

unevenly heating. The irregularities of the Earth cause the

suns rays to heat differently from one area to the next. This

creates areas with different pressures; nature will balance

these differences by moving higher pressure air toward the

lower pressure air which is wind.

Types of Wind Turbines

Wind turbines can be separated into two basic types

determined by which way the turbine spins. Wind turbines

that rotate around a horizontal axis are more common (like a

wind mill), while vertical axis wind turbines are less frequently

used (Savonius and Darrieus are the most common in the group).


44/88


44

Horizontal Axis Wind Turbines (HAWT)

Horizontal axis wind turbines, also shortened to HAWT,

are the common style that most of us think of when we think of

a wind turbine. A HAWT has a similar design to a windmill, it has

blades that look like a propeller that spin on the horizontal axis.

Horizontal axis wind turbines have the main rotor shaft

and electrical generator at the top of a tower, and they must be

pointed into the wind. Small turbines are pointed by a simple

wind vane placed square with the rotor (blades), while large

turbines generally use a wind sensor coupled with a servo motor

to turn the turbine into the wind. Most large wind turbines have

a gearbox, which turns the slow rotation of the rotor into a faster

rotation that is more suitable to drive an electrical generator.

Since a tower produces turbulence behind it, the turbine

is usually pointed upwind of the tower. Wind turbine blades are

made stiff to prevent the blades from being pushed into the

tower by high winds. Additionally, the blades are placed a

considerable distance in front of the tower and are sometimes

tilted up a small amount.

Downwind machines have been built, despite the problem of turbulence, because they don't

need an additional mechanism for keeping them in line with the wind. Additionally, in high winds the

blades can be allowed to bend which reduces their swept area and thus their wind resistance. Since

turbulence leads to fatigue failures, and reliability is so important, most HAWTs are upwind machines.

HAWT advantages

The tall tower base allows access to stronger wind in sites with wind shear. In some wind shear sites,

every ten meters up the wind speed can increase by 20% and the power output by 34%.

High efficiency, since the blades always move perpendicularly to the wind, receiving power through the

whole rotation. In contrast, all vertical axis wind turbines, and most proposed airborne wind turbine

designs, involve various types of reciprocating actions, requiring airfoil surfaces to backtrack against

the wind for part of the cycle. Backtracking against the wind leads to inherently lower efficiency.


45/88


45

HAWT disadvantages

Massive tower construction is required to support the heavy blades, gearbox, and generator.

Components of a horizontal axis wind turbine (gearbox, rotor shaft and brake assembly) being lifted

into position.

Their height makes them obtrusively visible across large areas, disrupting the appearance of the

landscape and sometimes creating local opposition.

Downwind variants suffer from fatigue and structural failure caused by turbulence when a blade passes

through the tower's wind shadow (for this reason, the majority of HAWTs use an upwind design, with

the rotor facing the wind in front of the tower).

HAWTs require an additional yaw control mechanism to turn the blades toward the wind.

HAWTs generally require a braking or yawing device in high winds to stop the turbine from spinning

and destroying or damaging itself.

Cyclic stresses and vibration

When the turbine turns to face the wind, the rotating blades act like a gyroscope. As it pivots,

gyroscopic precession tries to twist the turbine into a forward or backward somersault. For each blade

on a wind generator's turbine, force is at a minimum when the blade is horizontal and at a maximum

when the blade is vertical. This cyclic twisting can quickly fatigue

and crack the blade roots, hub and axle of the turbines.

Vertical axis

Vertical axis wind turbines, as shortened to VAWTs, have

the main rotor shaft arranged vertically. The main advantage of

this arrangement is that the wind turbine does not need to be

pointed into the wind. This is an advantage on sites where the

wind direction is highly variable or has turbulent winds.

With a vertical axis, the generator and other primary

components can be placed near the ground, so the tower does not

need to support it, also makes maintenance easier. The main

drawback of a VAWT generally create drag when rotating into the

wind.

It is difficult to mount vertical-axis turbines on towers, meaning they are often installed nearer

to the base on which they rest, such as the ground or a building rooftop. The wind speed is slower at a

lower altitude, so less wind energy is available for a given size turbine. Air flow near the ground and


46/88


46

other objects can create turbulent flow, which can introduce issues of vibration, including noise and

bearing wear which may increase the maintenance or shorten its service life. However, when a

turbine is mounted on a rooftop, the building generally redirects wind over the roof and this can

double the wind speed at the turbine. If the height of the rooftop mounted turbine tower is

approximately 50% of the building height, this is near the optimum for maximum wind energy andminimum wind turbulence.

VAWT subtypes

Darrieus wind turbine

Darrieus wind turbines are commonly called "Eggbeater" turbines, because they look like a

giant eggbeater. They have good efficiency, but produce large torque ripple and cyclic stress on the

tower, which contributes to poor reliability. Also, they generally require some external power source,

or an additional Savonius rotor, to start turning, because the starting torque is very low. The torqueripple is reduced by using three or more blades which results in a higher solidity for the rotor. Solidity

is measured by blade area over the rotor area. Newer Darrieus type turbines are not held up by guy-

wires but have an external superstructure connected to the top bearing.

Savonius wind turbine

A Savonius is a drag type turbine, they are commonly used in cases of high reliability in many

things such as ventilation and anemometers. Because they are a drag type turbine they are less

efficient than the common HAWT. Savonius are excellent in areas of turbulent wind and self starting.

VAWT advantages

No yaw mechanisms is needed.

A VAWT can be located nearer the ground, making it easier to maintain the moving parts.

VAWTs have lower wind startup speeds than the typical the HAWTs.

VAWTs may be built at locations where taller structures are prohibited.

VAWTs situated close to the ground can take advantage of locations where rooftops, mesas,

hilltops, ridgelines, and passes funnel the wind and increase wind velocity.

VAWT disadvantages

Most VAWTs have a average decreased efficiency from a common HAWT, mainly because of the

additional drag that they have as their blades rotate into the wind. Versions that reduce drag produce

more energy, especially those that funnel wind into the collector area.


47/88


47

Having rotors located close to the ground where wind speeds are lower and do not take advantage of

higher wind speeds above.

Because VAWTs are not commonly deployed due mainly to the serious disadvantages mentioned

above, they appear novel to those not familiar with the wind industry. This has often made them the

subject of wild claims and investment scams over the last 50 years.

Geothermal energy

Old faithful, Yellowstone National Parks most

famous geyser,erupts with thousands of gallons of water

and steam every hour to hour and a half. This popularWyoming tourist spot is the home to more than 60

percent of the worlds geysers. In just one square mile

(2.6 square kilometers), you can see more than a 150 of

them.

Some people think of Earth as a solid ball of rock,

but it has many layers. At the center, Earth has a solid

core. Around this core is an area

of hot, liquid rock called magma.

Above the magma is a layer of

solid rock and magma called the

mantle. The temperature of the

mantle can be very high from

2,520 to 5,400 degrees

Fahrenheit (1,382 to 2,982

degrees Celsius) depending on

how deep you go. The surface of

Earth, the crust, sits on the

mantle.

Water sometimes collects

in the rocks underground and

heats up. If there is a vent leading from this deep rock to the surface, superheated water shoots

upward. Earths crust is thicker in some areas than others.


48/88


49/88


49

Bioethanol production

In recent years, largely in response to uncertain fuel supply and efforts to reduce carbon

dioxide emissions, bioethanol (along with biodiesel) has become one of the most promising biofuels

today and is considered as the only feasible short to medium alternative to fossil transport

fuels in Europe and in the wider world.

Bioethanol is seen as a good fuel alternative because the source crops can be grown

renewably and in most climates around the world. In addition the use of bioethanol is generally

CO2 neutral. This is achieved because in the growing phase of the source crop, CO2 is absorbed

by the plant and oxygen is released in the same volume that CO2 is produced in the combustion of

the fuel. This creates an obvious advantage over fossil fuelswhich only emit CO2 as well as other

poisonous emissions. In the 1970s, Brazil and the USA started mass production of bioethanol -grown

from sugarcane and corn respectively. Smaller scale production started more recently in Spain,France and Sweden mostly from wheat and sugar beet.

In recent years the concept of the bio-refinery has emerged, whereby one integrates

biomass conversion processes and technology to produce a variety of products including fuels,

power, chemicals and feed for cattle. In this manner one can take advantage of the natural

differences in the chemical and structural composition of the biomass feed stocks.

The production of bioethanol from traditional means, or 1st

Generation Biofuels is based

upon starch crops like corn and wheat and from sugar crops like sugar cane and sugar beet.However, the cultivation of alternative sugar crops like sweet sorghum opens up new

possibilities in Europe, especially in hotter and drier regions, such as Southern and Eastern

Europe. Sweet sorghumrequires less water or nutrients and has a higher fermentable sugar

content than sugar cane as well as a shorter growing period which means that in some regions

like in Africa you can get 2 harvests a year from the same crop. In addition to this, the

development of lingo-cellulosic technology has meant that not only high energy content starch

and sugar crops can be used but also woody biomass or waste residues from forestry. This

development is seen as the 2nd

Generation of Biofuels.

Depending on the biomass source the steps generally include:

1. Storage

2. Cane crushing and juice extraction

3. Dilution

4. Hydrolysisfor starch and woody biomass

5. Fermentation with yeast and enzymes


50/88


50

6. CO2 storage and ethanol recapture

7. Evaporation

8. Distillation

9. Waste water treatment

10.Fuel Storage

What is Bioethanol?

The principle fuel used as a petrol substitute for road transport vehicles is bioethanol.

Bioethanol fuel is mainly produced by the sugar fermentation process, although it can also be

manufactured by the chemical process of reactingethylenewith steam.

The main sources of sugar required to produce ethanol come from fuel or energy crops. These

crops are grown specifically for energy use and include corn, maize and wheat crops, waste straw,willow and popular trees, sawdust, reed canary grass, cord grasses, jerusalem artichoke,

myscanthus and sorghum plants. There is also ongoing research and development into the use of

municipal solid wastes to produce ethanol fuel.

Ethanol or ethyl alcohol (C2H5OH) is a clear colourless liquid, it is biodegradable, low in toxicity

and causes little environmental pollution if spilt. Ethanol burns to produce carbon dioxide and water,

is a high octane fuel and has replaced lead as an octane enhancer in petrol. By blending ethanol with

gasoline we can also oxygenate the fuel mixture so it burns more completely and reduces polluting

emissions. Ethanol fuel blends are widely sold in the United States. The most common blend is 10%

ethanol and 90% petrol (E10). Vehicle engines require no modifications to run on E10 and vehicle

warranties are unaffected also. Only flexible fuel vehicles can run on up to 85% ethanol and 15%

petrol blends (E85).

Benefits

Bioethanol has a number of advantages over conventional fuels. It comes from a renewable

resource i.e. crops and not from a finite resource and the crops it derives from can grow well (like

cereals, sugar beet and maize). Another benefit over fossil fuels is the greenhouse gas emissions. The

road transport network accounts for 22% of all greenhouse gas emissions and through the use of

bioethanol, some of these emissions will be reduced as the fuel crops absorb the CO2 they emit

through growing. Also, blending bioethanol with petrol will help extend the life of the diminishing oil

supplies and ensure greater fuel security, avoiding heavy reliance on oil producing nations.


51/88


51

By encouraging bioethanols use, the rural economy would also receive a boostfrom growing

the necessary crops. Bioethanol is also biodegradable and far less toxic that fossil fuels. In addition, by

using bioethanol in older engines can help reduce the amount of carbon monoxide produced by the

vehicle thus improving air quality.

Another advantage of bioethanol is the ease with which it can be easily integrated into the

existing road transport fuel system. In quantities up to 5%, bioethanol can be blended with

conventional fuel without the need of engine modifications. Bioethanol is produced using familiar

methods, such as fermentation, and it can be distributed using the same petrol forecourts and

transportation systems as before.

Bioethanol Production

Ethanol can be produced from biomass by the hydrolysis and sugar fermentation processes.

Biomass wastes contain a complex mixture of carbohydrate polymers from the plant cell walls known

as cellulose, hemi cellulose and lignin. In order to produce sugars from the biomass, the biomass is

pre-treated with acids or enzymes in order to reduce the size of the feedstock and to open up the

plant structure. The cellulose and the hemi cellulose portions are broken down (hydrolysed) by


52/88


52

enzymes or dilute acids into sucrose sugarthat is then fermented into ethanol. The lignin which is

also present in the biomass is normally used as a fuel for the ethanol production plants boilers. There

are three principle methods of

extracting sugars from

biomass. These areconcentrated acid hydrolysis,

dilute acid hydrolysis and

enzymatic hydrolysis.

Production Process:

1. Grinding Grain

First, starch should be exposed

from the peel of corn to contact

with water. Also, grinding makescorn small pieces, which can

increase its surface area. Then,

the increase in its surface area

can enhance the contact between

starch and water. Two types of

mills, a roller mill and a hammer

mill, are usually employed. For an

industrial use, a hammer mill is

mostly used because of its

accuracy and its application forlarge amount.

A roller mill has some roll pairs

consisting of two rollers. Corn is

pressed by two rollers and

crushed into small pieces. Around

the rolls there are some trenches

to improve the effectiveness of

the crush. Also, the rotating

speeds of two rollers are different

in order to generate more stresson the corn. Finally, screening is

implemented at the bottom of

the mill. Then, the fine particles

can pass the screen, and the big

particles, which cannot match


53/88


54/88


55/88


55

components). They are, however, regarded as very reliable for the duration of their lifespan and

are often used for emergency power.

Negative sides of BioethanolBioethanol has some deficit. Next figure shows some environmental impacts of ethanol in

gasoline. Although, some of them may be exaggerated, but this approach is very important when we

are considering bioethanol from overall environmental aspects. Corn production causes more soil

erosion and uses more herbicides and insecticides. Also, wastewater from ethanol plant is also

another big problem.

In addition, an increase in the demand of bioethanol may burden on our money. Th

Documents

Booklet TE3.pdf