Click on the catagories below to view the available turorials
Basic Hydraulics - Centrifugal Pumps
Click on a topic below for a brief description of its contents.
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This
waterhammer tutorial looks at the subject from a different perspective
than does my earlier one. Part 1 covers what? & why? while
Part 2 looks the the causes and variables.
When Bubbles Don't Burst - Why Cavitation is Damaging
This
tutorial takes a look at cavitation from a different perspective.
It expands upon my original turoral "Cavitation - A Largely
Misunderstood Phenomenon.
Preservation of Efficiency
- Affinity Revisited
In
"Centrifugal Farce & Affinity" we took a look at the affinity laws
and showed how the predict pump performance when its speed changes or
its impeller is trimmed. This tutorial goes a step further and
describes the effect of these changes on pump efficiency.
Net Positive Suction Head
- NPSHa & NPSHr
This
tutorial provides a simple yet detailed explaination of the components
of NPSH. It also discusses their relationship to cavitation in a
centrifugal pump.
Specific Gravity &
Viscosity - Parts 1 & 2
Specific
gravity and liquid viscosity affect centrifugal pump operation in very
different ways. This two part tutorial discusses the impact of
each. Part 1 covers SG while Part 2 looks at Viscosity.
Liquid Friction - The
Tarantino Effect
The
physics of liquid friction is still pretty sketchy. Unlike solid
friction, velocity and surface area are major considerations.
This tutorial compares these two forms of friction and goes into some
detail
about each.
Centrifugal
force is a farce! It is all about the velocity added by a pump's
impeller. This tutorial dispells this myth and explains the
relationship of velocity to the three affinity laws.
Wire To Water Energy Calculator
This
Excel based calculator allows you to compare the energy consumption of
two different pumps based upon hydraulic and motor efficiency. It
computes annual operating costs for both and the payback period for the
more efficient system.
Basic Hydraulics - Displacement Pumps
Click on a topic below for a brief description of its contents.
Positive Displacement Pumps - Part 1 Reciprocating Pumps
Positive Displacement Pumps - Part 2 Rotary Pumps
Viking Pump Company - PD Pump White Papers
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Other Pump Topics
Click on a topic below for a brief description of its contents.
Constant Pressure Booster Systems
The Self Priming Pump
How Curve Shape Can Influence Pump Selection
Siphons & the Siphon Effect - That Sucking Sound
Pascal's Principle - Paradox Lost
Parallel Pumping - Parts 1 & 2
Two Steps to Longer Pump Life - Parts 1 & 2
Centrifugal Pump Operation at Off Design Conditions - Igor Karassik
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Centrifugal Pump Operation at Off Design Conditions - Parts 1 - 3
In the mid eighties, Igor Karassik wrote a three part series that described the problems associated with off BEP operation. Part 1 explores radial thrust and temperature rise while Part 2 looks at internal recirculation and air binding. Part 3 discharge recirculation and discharge bypass's. All are written in a very understandable manner which is the goal of Pump Ed 101. These are scanned files and are approximately 5 meg each.
Download Part 1
Download Part 2
Download Part 3
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Two Steps to Longer Pump Life - Parts 1 & 2
This tutorial explores the two most important preventive maintenance steps that influence pump and motor life. Part 1 looks at off BEP operation and outlines how to determine the "as built" operating point. Part 2 investigates current unbalance and the corrective measures that should be taken.
Download Part 1
Download Part 2
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Parallel Pumping - Parts 1 & 2
Sometimes the flow and head of two pumps operating in paralle is not what we expect it to be. This tutorial takes a look at the performance of identical and dissimilar pumps and the effect of the system curve. Part 1 compares the pumps and Part 2 factors in the system curve.
Download Part 1
Download Part 2
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Pascal's Principle - Paradox Lost
The pressure exerted by a colum of water depends upon its density and hight - - it has absolutely nothing to do with the its volume. In this tutorial we take a close look at this paradox and provide various examples that support Pascal's Principle.
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Siphons & The Siphon Effect - That Sucking Sound
In this turorial we explain how a pipeline siphon works and provide several examples of how they can affect pump performance.
Download
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How Curve Shape Can Influence Pump Selection
Some pump curves are very steep while others are pretty flat. And, ofcourse there many inbetween. This turorial looks at how the shape of a performance curve can influence a pump's performance in a particular application.
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Sewage & Wastewater
Click on a topic below for a brief description of its contents.
Air vs Oil Filled Sewage Pump Motors
Sewage Pump Impeller Selection
Vortex Action - How Lower Efficiency Can Reduce Cost
Lower Flow Nonclogs - Solids Handling Options
Pressure Sewer Systems
Lift Station Maintenance
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Lower Flow Nonclogs - Solids Handling Options
There are times when pumps installed in lower flow applications need the ability to pass a full 3" spherical solid. Should you install a 4" pump and run to the left of the performance curve? Probably not. This tutoral provides several options that will enhance pump life.
Download
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Vortex Action - How Lower Efficiency Can Reduce Cost
Vortex pumps have a bad reputation in the engineering community because of their low hydraulic efficiency. It turns out that their lower maintenance will often substantially reduce overall operating costs even though electrical costs may be slightly higher. This tutorial explains vortex action and provides several examples that show why this type of pump may be a better choice.
Download
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Variable Speed Pumping Systems
Click on a topic below for a brief description of its contents.
Variable Speed Pump Selection - Parts 1 - 3
This tutorial takes a different approach to pump selection for VFD operation. Part 1 addresses constant pressure / variable flow while Part 2 addresses variable pressure / variable flow. Part 3 adds an elevation or constant pressure component to variable pressure / variable flow.
Download Part 1
Download Part 2
Download Part 3
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Lift Station Level Control - Almost Utopia
Back in the old days level control had nothing to do with saving energy. In fact it was often a necessary evil. With the advent of the VFD you may be able to achieve relatively constant flows and reduce the energy required. This tutorial investigates the possibilities.
Download
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Comparing Energy Consumption - To VFD or Not to VFD
If the goal of your VFD application is to reduce energy consumption, you have to do a careful comparison between VFD and constant speed operation. This tutorial uses a constant pressure application to show you the proper way to do that comparison.
Download
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Variable Frequency Control - Other Advantages
VFD's can reduce energy consumption by allowing a pump to run at the duty point required by the system and it can change that duty point in real time. But they offer several other advantages that can often justify their use even if pump speed is not varied. This tutorial explores those other advantages.
Download
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Balancing Voltage & Frequency - Fluxuating Flux
We all know that a VFD varies the frequency seen by an electric motor. That is how it varies the motor speed. But, did you know that it must also vary the voltage? If it did not, the magnetic field produced by the stator would become saturated and torque would become unreliable. This tutorial explains the volts / hertz relationship that must be maintained by the VFD.
Download
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Resonant Frequency & Critical Speed
The vibration that occurs in a pumping system due to resonance is not a good thing. Resonance arrises when a variable speed pump reaches a critical speed. It turns out that the first or lowest critical speed can be easily calculated from simple data provided by the manufacturer. This tutorial explores resonant frequency and shows how to calculate the speed that causes it.
Download
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Pump Sizing & Selection Tools
Click on a topic below for a brief description of its contents.
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Confusing Units of Measure - Work, Power, & Torque
This tutorial could be located under other categories because it applies to all rotating machinery. It compares the units of measure, used in a rotational environment, with their linear cousins. Hopefully it makes them a little more understandable.
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Inertia - Confusing Units Revisited
Rotational inertia is quite different than its linear cousin but there are times when we need to understand its relationship with torque. This tutorial investigates rotational inertia, compares it with linear inertia, and uses some simple examples to show the effects of its contributors.
Download
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Process Control - Parts 1 & 2
This two part tutorial attempts to make process control understandable. Part 1 takes a look at very simple control algorithms while Part 2 investigates the more complex PID control used in VFD applications. Also see "PID Control" under the Variable Speed section for another approach.
Download Part 1
Download Part 2
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Power Factor - Parts 1 & 2
This tutorial takes a detailed look at the cause and effects of PF. Part 1 (Electricity Behaving Badly) explains PF and it causes. Part 2 (Electricity Behaving Better) investigates potential fixes and shows their effect.
Download Part 1
Download Part 2
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VAST (Various And Sundry Things)
Click on a topic below for a brief description of its contents.
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The tutorials and topics presented here
were developed over the past fifteen years. Several were written
for
my own employees in an effort to further their understanding of the
equipment and applications that were our life's blood. Others
were written specifically for specifying engineers so that they could
gain an unbiased understanding of different options. But, most
were developed to provide information for the overall pump
community. So far, they have been well received and I have shared
them via one web site or another
since 1997. Many emails from around the world have offered
compliments, corrections, and suggestions. Please keep them
coming.
Some are short and simple --
"The Self Priming Pump", for example, gives a brief overview of self
priming pumps and the applications for which they are intended.
These will usually reference another tutorial for more detailed
study. Others, like "AC Power", are far more detailed and present
a thorough overview from generation to consumption. "Hertz" and
"HPSA", on the other hand, are designed to be interactive learning
and sizing tools. "Centrifugal Pump Dynamics" is html based and
uses animations to get its points across. My "Pumps &
Systems" magazine articles offer a short review of a broad range of
pump,
motor and control topics. Some of the "two part" articles, such
as "Power Factor" provide an in depth review.
The "Puzzler" is a totally different
animal. It uses the findings of simple Physics to help explain
some of the every day and, even more complex phenomena that we
encounter in pumping applications. I developed the Puzzler
as the basis for my weekly "lunch & learn" seminars that I
presented to my employees. The beauty of the
"Puzzler" is that it promotes learning rather than memorization.
For example, why memorize a fact such as -- the head produced by
a centrifugal pump changes as the square of a change in speed -- when
the "falling body" equation shows you why?
If you have questions or suggestions,
please drop me an email.
Joe Evans
Have you ever wondered why the pressure of a fluid flowing in a pipe decreases as its velocity increases? Could it have something to do with why airplane's fly? Why does 115 volts plus 115 volts equal 230 volts in some cases, but only 208 volts in others? Doesn't the pressure that a liquid exerts have anything to do with its volume? When is a watt not a volt-amp? Is centrifugal force really a farce? How come liquid friction, but not solid friction, is affected by velocity and surface area?
If you find these and other questions relating to pumps, motors, and electricity especially titillating, you are going to love the Puzzler. The Puzzler poses a pointed question, but that question is just the tip of the iceberg! The discussion that follows explores not only the question but also the physics surrounding it.
The current Puzzler Series consists of
more than forty brain teasers designed to expand your knowledge of
mechanics, hydraulics, and electricity. The dowload button is
below the titles.
|
Basic Puzzlers The Restricted Pipe Puzzler (Bernoulli Principle) The Water Column Puzzler (Hydrostatic Paradox) The Sinking Float Puzzler (Buoyancy) The Barrel Burst Puzzler (Pascal’s Experiment) The False Force Puzzler (Centrifugal Force) The My Shaft’s Bigger Than Yours Puzzler (Torque) The WK2 Puzzler (Inertia) The Belt Tightening Puzzler (Mechanical Friction) The Warranty Puzzler (Time Dilatation) The Water Supply Puzzler (Exponential Function) Hydraulic Puzzlers The
Affinity Puzzler (The Affinity Laws) |
The Worn Pump Puzzler ( Axial & Radial Thrust) The Differing Pressure Puzzler (Eductors) The Corrupted Curve Puzzler (Positive Displacement Pumps I & II) The Leaking Pump Puzzler (Hydraulic Ram) The Air Lock Puzzler (Siphon) The Drawdown Puzzler (Hydropneumatic Tanks) The Priming Puzzler (Centrifugal Pump Priming) The Suction Air Puzzler (Pipeline & System Air) Electrical Puzzlers The Mumbo-Jumbo Puzzler (Motor Insulation) The Right Motor Puzzler (Service Factor) The Kill A Watt Puzzler (Reactance) The Starting Puzzler (Motor Starting Techniques) The Changing Voltage Puzzler (Three Phase Connections) The Distorted Wave Puzzler (Harmonics) The Syntax Puzzler (Boolean Logic) The Grounded Pump Puzzler (Corrosion Protection) The Country Boy Puzzler (Phase Generator) The 4” Motor Puzzler (Tesla Meets Newton) |
Download The Complete Puzzler Series (918 K Acrobat Document)
A BRIEF
INTRODUCTION TO CENTRIFUGAL PUMPS -
Joe Evans, Ph.D
Download ( 1001 K Acrobat Document)
CONSTANT PRESSURE BOOSTER SYSTEMS - Joe Evans, Ph.D
This
tutorial will allow you to enter the realm of constant pressure and the
booster systems that support
it. It starts with a brief overview of the differential pressure
booster and then takes a look at PRV controlled simplex, duplex, and
triplex constant pressure systems. From there it moves on to VFD
control and the advantages it can offer. Topics covered include
tank vs tankless systems, sequencing, pressure vs flow control, and
pump selection. If you are unfamiliar with the VFD, download
"Variable Frequency 101" as you will need an understanding of
their operation for the second half of this discussion.
Download
( 263 K Acrobat Document)
This brief overview discusses the advantages and limitations of self priming centrifugal pumps. It also references a "Puzzler" for a more detailed understanding of centrifugal pump priming.
Download ( 108 K Acrobat Document)
THE AC
INDUCTION MOTOR - Joe Evans, Ph.D
This introduction is intended for those with little or no background in electric motors. It begins with the very basics including magnetism, direct current, and the operation of a simple DC motor. From there it moves on to alternating current, induction, and the operation of a simple AC motor. It concludes with a discussion of work, torque, and horsepower. It is an excellent primer for some of the electrical "Puzzlers".
Download ( 422 K Acrobat Document)
THE SINGLE
PHASE INDUCTION MOTOR - Joe Evans, Ph.D
The major difference in single and three phase motors is that the single phase motor requires some sort of starting mechanism to get it rotating. This overview looks at four of the most popular starting (and two running) techniques and the pros and cons of each. It also includes a discussion of single and three phase rotational fields. It is aimed at the pump professional who works with single phase submersible wastewater pumps, well pumps, and small centrifugals.
Download ( 547 K Acrobat Document)
Why is AC power the
standard in the US? What is the
difference between single phase and three phase sine waves? Why
does a voltmeter read 115V, 230V, or 460V when the actual voltage is
quite a bit higher? How does a transformer work? What is the
difference between Wye & Delta versions? Do resistive and
inductive circuits behave differently?
What is power factor and what does it have to do with reactance?
How can capacitive reactance be
used to correct the problems caused by inductive reactance? This short
course is designed for the pump professional who
wants to gain a basic understanding of AC power and its application to
electric motors.
Download ( 397K Acrobat Document)
VARIABLE
FREQUENCY 101 - Joe Evans, Ph.D
Why not debunk some of those myths surrounding VFD's and learn how simple they really are. Did you know that they have been around, in one form or another, since the invention of the AC induction motor? This short introduction will help the pump professional gain an understanding of their inner workings, potential problems, and some of the applications for which they are well suited. Topics include: the relationship between frequency and motor windings (poles), Pulse Width Modulation (PWM) output, effective voltage, insulation stress, harmonics, bearing damage, and typical applications in the pumping environment.
Download (368 K Acrobat Document)
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CENTRIFUGAL PUMP MOTOR SELECTION,
INSTALLATION, & START UP - Joe Evans, Ph.D
The vast
majority of failures of new electric motors can be attributed to
improper selection, installation, and start up. Although factory
defects do occur, they are rare and are quite apparent upon tear down
and inspection. This short publication is a guide to the
proper selection, installation, and start up of new and replacement
centrifugal pump motors. (This tutorial was updated on 2/12/06)
Download ( 35 K Acrobat Document)
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RESONANT FREQUENCY
The resonant
frequency of and object is the frequency at which it begins to vibrate
of its own accord. In this demonstration, by the University of
Michigan Physics Laboratory, sound waves are porduced at various
frequencies and projected upon a wine glass. A strobe light
allows us to view its vibrations and eventual shattering.
Download "Variable Frequency 101" for a detailed explaination of
resonant
frequency and its potentially damaging effect upon pumps.
Download ( 3.48M Quick Time Movie)
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AIR VS OIL FILLED
SEWAGE PUMP MOTORS -
Joe Evans, Ph.D
Some manufacturers believe that filling a motor with oil is the only way to go while others think air to be a better solution (pun intended). This paper takes an honest look at these two popular submersible sewage pump motor designs and compares the advantages and disadvantages of each. Topics covered include motor efficiency, heat transfer, bearing lubrication, maintenance, and environmental concerns.
Download (235K Acrobat Document)Return to Titles
SEWAGE PUMP
IMPELLER SELECTION - Joe Evans, Ph.D
This overview discusses the various impeller designs used in raw sewage pumping applications. Designs covered include the major members of the radial vane family, the vortex impeller, and the centrifugal screw. Topics include centrifugal impeller basics, design pros & cons, operational characteristics, and application selection criteria.
Download (339K Acrobat Document)
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PRESSURE SEWER SYSTEMS: CENTRIFUGAL VS POSITIVE
DISPLACEMENT - Joe Evans, Ph.D
During the past thirty years, low pressure grinder pump sewer systems have become a popular alternative to traditional gravity systems. The two basic pump designs, centrifugal and positive displacement, used in these systems are as different as night and day. This short article discusses the operating characteristics of centrifugal and positive displacement grinder pumps when installed in a pressure sewer system. Topics covered include pipeline velocity, unvarying vs dynamic flow, self limiting system pressure, operating power, and impeller / cutter design.
Download
(115K Acrobat Document)
HERTZ: A VARIABLE FREQUENCY / SPEED CALCULATOR
AND PLOTTING TOOL - Joe Evans, Ph.D
Hertz is an Excel program that allows you to illustrate the laws of affinity, perform a design point calculation, and plot centrifugal pump performance curves as a function of frequency or RPM. It is named for the German physicist, Heinrich Hertz, who discovered the very low frequency electromagnetic radiation we now call radio waves. After many decades of cps (cycles per second) we are finally giving him credit.
Directions
for its use can be found at the
bottom of the spread sheet. "Auto Plot" automatically plots the
60, 55, 50, 45, 40, 35 and 30hz performance curves (in feet and
PSI) for the data you entered. You can also enter a system
curve so that you can evaluate your selection. Instructions for
custom plots are also included.
Download
(115K Excel Document)
HERTZ VHS: PUMP SIZING FOR HIGH SPEED DRIVES - Joe Evans, Ph.D
Hertz VHS is similar to Hertz except that it is customized for use with high speed well pump drives. It plots both 30-60hz and 30-80hz performance curves and allows you to properly size a 4" submersible or above ground pump to a constant pressure application.
Directions
for its use and an explanation
of the examples included can be found at the bottom
of the spread sheet. "Auto Plot" automatically plots the 60, 55,
50, 45, 40, 35, and 30hz performance curves
for the 60hz data entered. It also plots the 80, 70, 60, 50, 40,
and 30hz curves for high speed operation. Curves
are plotted in both feet and PSI. You can also enter "pumping
level" (static level + drawdown + elevation) and obtain plots
that show performance at the application point rather than the
pump discharge. An optional, constant pressure
curve allows you to compare a pump's output to the sytem requirements.
Download
(185K Excel Document)
CPSA: Centrifugal Pump Selection Assistant - Joe Evans, Ph.D
CPSA
is an abbreviated and simpler version of Hertz but, also
has some additional features. It plots a system curve
and the 60 - 30 hz curves (in feet and PSI) for the pump
selected. There is nothing else to muddle the picture and there
is no need to scroll side to side or up and down. It also asks
for the hydraulic efficiencies for each of the flow points and, in
return, prints the HP required as "data lables" on each of the
frequency
curves. This
allows you to quickly determine the power savings for an application
using a given pump.
Download
(121K Excel Document)
VSPA-50: Variable Speed Pump Analyzer 50hz - Joe Evans, Ph.D
VSPA-50
is an international version of PPSA. It plots a system curve
and the 50 - 25 hz performance curves (in any unit of
measure). It can accomodate up to eight H/Q points. If you
enter the power requirement for each of the flow points for the 50hz
curve, it will generate "power data lables" on each of the
frequency
curves. This
allows you to quickly determine the power savings for an application
using a given pump.
Download
(116K Excel Document)
VSPA-60: Variable Speed Pump Analyzer 60hz - Joe Evans, Ph.D
VSPA-60
is an international version of PPSA. It plots a system curve
and the 60 - 30 hz performance curves (in any unit of
measure). It can accomodate up to eight H/Q points. If you
enter the power requirement for each of the flow points for the 60hz
curve, it will generate "power data lables" on each of the
frequency
curves. This
allows you to quickly determine the power savings for an application
using a given pump.
Download
(116K Excel Document)
Radial Thrust Calculator - Joe Evans, Ph.D
The
unbalanced radial thrust that arises in a single volute pump is lowest
at or near BEP depending upon the Pump's Specific Speed (Ns). But
as operation moves away from BEP (especially to the left) the net
radial thrust increses quickly. Unbalanced radial thrust can
cause increased shaft deflection which can lead to increased seal,
bearing, and wear
ring wear. In some cases it can cause the shaft to break.
This calculator allows you to quickly calculate the radial thrust in
PSI at any point
on a pump's H/Q curve.
Download
(58K Excel Document .xlsx)
Download (58K Excel Document .xls)
Return to TitlesSuction Calculators - Joe Evans, Ph.D
Two useful pieces of information that can be used to identify pumps that are prone to cavitation due to suction recirculation are Suction Specific Speed (S) and Suction Energy (SE). This calculator will allow you to calculate both. For more information on S see Terry Henshaw's Oct - Dec 2009 Pumps & Systemsarticles on NPSH and Suction Specific Speed. You can read them at www.pump-zone.com.
Download (2.4M Excel Document .xlsx)
Download (480K Excel Document .xls)
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CONVERT:
A DESKTOP CONVERSION UTILITY
It was eveloped by Josh Madison ( http://www.joshmadison.com/software/convert/ )
Download (156k WinZip file - unzips to a 548k exe file)
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VFD Pump Selection - Constant Pressure - Joe Evans, Ph.D
Download (215K Acrobat Document)
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VFD Pump Selection - Variable Flow / Variable Pressure - Circulation - Joe Evans, Ph.D
Download (183K Acrobat Document)
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VFD Pump Selection - Level Control - Joe Evans, Ph.D
Download (232K Acrobat Document)
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TDH Calculator - Submersible Well Pumps - Joe Evans, Ph.D
Download (54K Acrobat Document)
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Lift Station Maintenance for the Complete Idiot - Steve Cottrell, Enco Southwest Inc.
Don't let the title offend you (Dummies was already taken). Steve's guide is written for that building maintenance guy who wakes up one morning and finds that he now has responsibility for a submersible lift station! It is simple, straight forward and will keep that station up and running. Steve can be reached at: encosw@earthlink.net
Download (1120K Acrobat Document)
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Centrifugal Pump Intro for PP (Part 1 Elementary Mechanics & Hydraulics) - Joe Evans, Ph.D
This Power Point presentation is designed for audiences with a "limited" knowledge of centrifugal pumps. It can be presented in as little as an hour or as a morning or afternoon class if you go into more detail. Use the script to guide you through the slide show. Don't have Power Point on your PC? No problem - - download the pdf version and show it as slides on a PP projector or TV monitor.
As the title implies, this tutorial presents the basic mechanics and hydraulics of centrifugal pump operation. It begins by dispelling the myth of "centrifugal force" and shows that acceleration of a fluid is its sole purpose. It then moves on to a discussion of the pump "curve" and shows examples of series and parallel operation. It touches on specific gravity and why we typically rate pump performance in feet of head. We review the laws of affinity and illustrate them with a pump operating under VFD control. We finish with a discussion of suction conditions and liquid friction.
Download (707K Power Point) DownLoad (177K pdf Version) Download (92K pdf Script)
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HPSA A Variable Frequency Sizing Tool - Level Control - Joe Evans, Ph.D
Download (128K Excel Document)
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Cavitation - A Largely Misunderstood Phenomenon - Joe Evans, Ph.D
Download (519K Acrobat Document)
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About the Author
Download (Resume Acrobat Document)
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The Cowern Papers
Ed Cowern received his BS in Electrical Engineering from MIT and is a district manager for Baldor. His clear and understandable technical papers on electricity and electric motors make them a very useful reference.
Download (1 MB Acrobat Document)
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Web Site Development & Hosting
Pueo Advanced Media
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Why Newton Invented Calclus - Joe Evans, Ph.D
Download (122K Acrobat Document)
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Three Phase Motor Starting Techniques - Joe Evans, Ph.D
Download (282K Acrobat Document)
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Positive Displacement Pumps - Parts 1 & 2 - Joe Evans, Ph.D
Part 1 of this tutorial covers reciprocating designs while Part 2 deals with rotary units.
Download (Part 1 - 187k Acrobat Document) Download (Part 2 - 138k Acrobat Document)
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Viking Pump PD Pump White Papers
In the mid 80's Viking Pump Company published a couple of very useful white papers for positive displacement pump users. AD-19 was all about NPSH while AD-6 covered pressure and vacuum. Both are available below in pdf format.
Download AD-19 5.5mb pdf
Download AD-6 5.7mb pdf
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Sizing Pumps After Sunset - Joe Evans, Ph.D
Download (79k Acrobat Document)
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Background Image - Mt. Hood
The birds eye view of Mt. Hood, that is the background to my title page, shows the winter version of the mountain the American Indians called Wy' East. At 11,235' it is the tallest peak in Oregon and is home to 11 glaciers and 5 ski areas. Mt. Hood is a dormant volcano that last erupted in 1907 and is the second most climbed mountain in the world. It is surrounded by the 1.2 million acre Mt. Hood National Forest which has over 1200 miles of hiking trails. Most importantly, it is in my back yard! The image on the left is the North side as seen from Lost Lake. The one on the right is the Sandy river which originates in
the glaciers and runs through our community.
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Series / Parallel Pumping Analyzer with Autoplot - Joe Evans, Ph.D
Download (130k Excel File Revised 5/20/06)
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Download (55k Acrobat File)
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Centrifugal Pump Efficiency - What, How, Why, When ? - Joe Evans, Ph.D
Download (461k Acrobat File)
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Waterhammer - Its All About Conserving Energy - Joe Evans, Ph.D
Download (233k Acrobat File)
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Educational Seminars & Training
The seminars shown below have been presented to a wide range of audiences over the past twenty years. They are updated continuously and the current Power Point versions include lots of Java based animations that can often clarify many of those, otherwise, subtle points. My audiences include engineering firms, refineries, utilities, AWWA, WEF, MEA, NGWA, RWA, and other pump oriented organizations. Drop me an email if you are interested in an on site seminar or have questions.
Click below to download the pdf that describes the seminars that are approved for CEU credits in Oregon & Washington. Depending upon the acrediting agency, presentations must be a minimum of one or three hours. Half day seminars can be a mix of various one hour presentations.
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Centrifugal Pump Dynamics - Joe Evans, Ph.D
Dynamics Html Version Dynamics Acrobat Version (98k pdf file)
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Anti VFD (Beware of the Nazi's)
As you search the web for more information on variable frequency applications you might get the feeling that we have reentered the era of pre WWII. Some of the sites out there profess that VFD's have no rightful place in our society and that there is no pump application worthy of their use. Most of these opinions come from those who offer competing products and they will show a pump curve or power analysis that proves that their product can always do a better job. I have even read some tax payer sponsored research that goes way over the line. One concluded that magnetic coupling systems offer power savings similar to that of VFD's. This certainly may be true in some instances but, the data used in this particular study was so skewed even Enron would have been concerned !
The same thing can happen on the other side of the aisle - - but it is usually due to a lack of knowledge rather than deceit. Many of the VFD articles in the trade press tend to be written by VFD manufacturers. And, although they have some pretty smart people, most have a limited knowledge of pump applications. Therefore the examples given tend to be more theoretical than practical.
Here is a good rule of thumb: no single application control technique will always be the best choice for a given application. If someone tells you that theirs is always best - - take them off your "favorites" list. In my variable frequency tutorials, I try to use pump curves that are more typical rather than one that is "perfect". This allows you to compare application results in a more realistic light.
PID Control - What, Why, How ? - Joe Evans, Ph.D
The P (proportional) in PID is not too frightening but, what about those other two letters? Are not the integral and derivative parts of that mathematics known as calculus? And, isn't calculus frightening? Well fear no more because this "layman's" discussion of PID control will help you understand what it is, why we use it, and how it works. We start with a discussion of open and closed loop control and give examples of each. We then move on to proportional control and the applications it supports. We end with a discussion of the integral and derivative functions and how they can temper the, sometimes, unruly nature of the proportional controller. Another discussion of this topic can be found in the "Pumps & Systems" section of this site.
Variable Fixed Speed Control - Float Switch Activation - Joe Evans, Ph.D
So, your waste water application will not lend itself to level control operation. Or, maybe you just prefer float switches over transducers and ultrasonic devices. Whatever the reason, VFS or variable fixed speed control might be a viable alternative to that pump down application. Today you can combine an inexpensive VFD with standard float switch technology and get a multispeed pumping system that can increase application flexibility and efficiency. This short tutorial takes a look at VFS control and how it compares to standard pump down applications.
SDSCA - Simplex / Duplex System Curve Analyzer - Joe Evans, Ph.D
There can be times when we over estimate the flow expected during parallel operation of two non-clogs. SDSCA is an excel spread sheet that allows you to analyze the operation of the same non-clog running under simplex and duplex (parallel) operation. It will generate a system curve based upon the information entered and give you the head required at design flow. You can then enter the curve data for a selected pump and the simplex and duplex operational curves will be plotted against the system curve. Scroll down for detailed instructions. The data used in the example can be found under the "Notes" tab.
Pumps & Systems Magazine Columns - Joe Evans, Ph.D
In September of 2006 I began contributing a monthly educational column to Pumps & Systems Magazine. The unedited versions will be available here in pdf format as they are published. Each of these columns is also listed under the proper category on the home page and includes a short description. If you do not already subscribe to P & S you can do so online at http://www.pump-zone.com/
Nov 2006 - Preservation of Efficiency - Affinity Revisited Dec 2006 - Liquid Friction - The Tarantino Effect
Jan 2007 - When Bubbles Don't Burst - Why Cavitation is Damaging Feb 2007 - Pascal's Principle - Paradox Lost
Mar 2007 - Balancing Voltage & Frequency - Fluxuating Flux Apr 2007 - Comparing Energy Consumption - To VFD or Not to VFD
May 2007 - How Curve Shape Can Influence Pump Selection Jun 2007 - Power Factor Part 1 - Electricity Behaving Badly
July 2007 - Power Factor Part 2 - Electricity Behaving Better Aug 2007 - Vortex Action - How Lower Efficiency Can Reduce Cost
Sept 2007 - Lift Station Level Control - Almost Utopia Oct 2007 - Confusing Units of Measure - Work, Power, & Torque
Nov 2007 - Siphons and the Siphon Effect - That Sucking Sound Dec 2007 - Variable Frequency Control - Other Advantages
Jan 2008 - Process Control Part 1 - Smart and Not So Smart Control Feb 2008 - Process Control Part 2 - Even Smarter Control
Mar 2008 - Parallel Pumping Part 1 - Parallel and Not So Parallel April 2008 - Parallel Pumping Part 2 - Other Considerations
May 2008 - Net Positive Suction Head - NPSHa & NPSHr June 2008 - Two Steps to Longer Pump Life - Part 1
July 2008 - Two Steps to Longer Pump Life - Part 2 Aug 2008 - Waterhammer - Part 1 What & Why
Sept 2008 - Waterhammer - Part 2 Causes & Variables Oct 2008 - Lower Flow Nonclogs - Solids Handling Options
Nov 2008 - Variable Speed Pump Selection - Part 1 Cp-Vf Dec 2008 - Variable Speed Pump Selection - Part 2 Vp-Vf
Jan 2009 - Variable Speed Pump Selection - Part 3 Vp-Vf (+Cp) Feb 2009 - Resonant Frequency & Critical Speed
Mar 2009 - Specific Gravity & Viscosity - Part 1 April 2009 - Specific Gravity & Viscosity - Part 2
May 2009 - Variable Speed Performance Analyzer - 50hz June 2009 - Inertia - Confusing Units Revisited
July 2009 - Why The Left Can Be Dangerous Aug 2009 - Planning for System Growth
Sept 2009 - PD Pump Hydraulics - Part 1 Reciprocating Oct 2009 - PD Pump Hydraulics - Part 2 Rotary
Nov 2009 - Corrosion - A Natural Process Dec 2009 - Magnetic Couplings - Extra Benefits
Jan 2010 - Radial Thrust Calculator Feb 2010 - Suction Calculators
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Other Publications - Joe Evans, Ph.D
The work I did prior to 1986 was quite different than what I do today. I attended grad school (69 - 73) during an interesting era. The advent of the minicomputer in the late 60's and early 70's allowed us to accomplish things that were impossible for those before us. All of a sudden, data generated by scientific instruments (especially the gas chromatograph - mass spectrometer (GC-MS)) that used to take months to analyze provided results within days. Back then the typical minicomputer was the size of a filing cabinet and had 2 - 4 K of memory. Data storage was on paper tape or maybe mag tape if you were lucky. It was still the time of the slide rule and analog recorders and just comparing the area under two plotted curves could take hours. Much of our work on instrument automation was sponsored by NASA and the Robert A Welch Foundation. We were also chosen as one of the few labs to analyze the soil samples gathered by the first NASA Lunar Lander project.
In 1973 I entered the army as captain and chief of the Air Chemistry Branch of the Army Environmental Hygiene Agency. This agency was the army's version of the EPA/NIH and its research was designed to protect our troops and reduce our impact on the environment. One of our major projects at the time was monitoring the detoxification and disposal of our WWII nerve gas stock pile at Rocky Mountain Arsenal (which, by the way, was stored for decades right at the end of the main runway of the old Denver airport). During my stay I continued my work on instrument automation and also the miniaturization of those instruments for use in the field.
After leaving the army in 1975 I joined Finnigan Corporation, a major GC-MS developer and manufacturer of the era. I was in charge of the East Coast applications lab in Washington DC and later moved into the position of product manager. By the mid 70's the minicomputer had advanced substantially and this technology gave us the ability analyze the data provided by a GC-MS in real time - - not days.
In 1977 I made the decision to move to Hawaii and, except for the University of Hawaii, there were no job opportunities that could make use of my past experience. Hawaii is a major union state and unfortunately this spilled over to the university and I doubted that I would fit in well in that environment. So, on a lark, I changed directions and took a position with IBM. Oddly enough, my minicomputer experience paid off and over the next five years I worked in industrial automation as well as distributed processing in the business community. One of our major accomplishments was the implementation of a on line directory assistance system at Hawaiian Telephone. It was a distributed processing system that consisted of three layers of minicomputers and fixed head disk drives that could perform searches as deep as nine levels of indent in seconds. The result was a directory assistance operator reduction of about two thirds which the union, of course, did not see this as a useful technological advance. Although it was nowhere near the speed of Google, it was lightning fast for its day.
In 1983, the Queen's Medical Center (Hawaii's largest healthcare organization) offered me the position of VP of Information Services. I learned early on that accepting this job was a mistake as I was unaware of the politics and in fighting that went on in these "non-profit" organizations. Still, in less than three years we were able to take them to the forefront of the information age. We were the first company in Hawaii to employ personal computers instead of dumb terminals and we had our own "intranet" email system in early '84. Unfortunately continuing confrontations with the CEO (a psychiatrist who was having an affair with the head of nursing who had a striking resembalance to "Miss Piggy") led to my demise in late '85.
In 1986 I accidentally fell into the pump industry. And, as most of you know, once you are in this industry it is hard to escape! Below are several papers that I published or took part in prior to that fall.
Isolation and Partial Characterization of Supernatant and Mitochondrial Shrimp Muscle Malate Dehydrogenases
This paper, published in Comparative Biochemistry & Physiology (Pergamon Press), was a result of the research performed for my masters thesis. It is co-authored by my advisor and two of my associates. The work was sponsored by the National Institutes of Health and the Robert A Welch Foundation.
Program ELAL: An Interactive Minicomputer Based Elemental Analysis of Low & Medium Resolution Mass Spectra
This paper, published in Analytical Chemistry (American Chemical Society), was a result of some of my doctorial research and follow on work done at the U.S. Army Environmental Hygene Agency. The program was the first to computerize the manual elemental analysis methods developed by Dr. Fred McLafferty at Cornell University.
Monitoring Organic Vapors
This paper, published in Environmental Science & Technology (American Chemical Society), was a result of my continuing work at the U.S. Army Environmental Hygene Agency. It discusses the ongoing micro-computerization and miniaturization of environmental monitoring instruments. It was co-authored by Jim Arnold of Varian Associates, a physicist and major contributor to technology advances in mass spectrometry and nuclear magnetic resonance (NMR) spectrometry (now known as magnetic resonance imaging (MRI) due to our ignorance and fear of that other "n" word). The mass spectrometer described in this paper was the predecessor of the one that was aboard the Mars Lander.
User Written Software Extends the Use of GC-MS Data Systems
Published in Finnigan Spectra (Finnigan Corporation), this article revisits the use of Program ELAL and introduces a new program known as FINL (fragment ion and neutral loss analysis). FINL automated another manual elemental analysis methodology that was developed by McLafferty at Cornell University.
INFO
In 1983 I left IBM and assumed the position of VP of Information Services at The Queen's Medical Center in Honolulu. One of the first things that we did was to initiate a news letter to keep the employees of our almost 150 departments up to date on what we were doing. This is the first issue.
The Queen's Medical Center - - A Royal Link to the Past and the Future
In late '83 we entered into an agreement with Management Science America (MSA) to install their GL, AP, and Payroll/Personnel systems and their "Peachpak" interactive PC products. This article highlights our accomplishments over a period of just one year.
OA Reigns Supreme at Queen's Medical Center
In 1985, "Today's Office" (Hearst Business Publications) selected Queen's as one of the nation's leader's in office automation and asked me to write an article outlining what we had done to get there. This was my last non-pump article!
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Education Links
http://www.allaboutcircuits.com/vol_2/index.html
Integrated Publishing - Electrical Engineering Training Series
http://www.tpub.com/content/neets/
Math and Physics Help - Simplifying Math & Physics by Kenny Felder
www.ncsu.edu/felder-public/kenny/home.html
Motion Mountain- Free Physics Text Book
Light & Matter - Free Physics Text Books
Pump School - A Rotary Pump Course
Light My Pump - Lots of Good Pump & Pump System Info
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