Chemical Engineering Practice

AIChE Equipment Testing Procedure - Particle Size Classifiers, 2nd Edition

June, 1993
This procedure offers complete methodologies for sampling and measuring particle streams and summarizes methods of particle size analysis. It also lists operating variables to be considered and measured. Although the procedure is intended specifically for particle classification equipment, many of...

Reduce Unplanned Shutdowns

September
2003
Instrumentation
Cindy Scott
Today's intelligent devices are equipped with modern alarm technology that enables speedy delivery of critical information to key personnel, thus enhancing efficiency and minimizing downtime.

Optimize Energy Use in Distillation

March
2012
Reactions and Separations
Douglas C. White
Nonlinearities in the response of a column to changes in operating conditions and in common economic valuation functions can have significant impacts on the economic optimum energy consumption for the column. Here’s a way to account for such...

The Case for Double Mechanical Seals

June
2009
Back To Basics
Jack Berg
Using double mechanical seals as part of thermoplastic pumps can prevent costly downtime and environmental damage.

The Chemical Industry Phoenix

June
2012
Process Automation Corner
Terry McMahon
Seven years ago, I wrote a column for another publica­ tion entitled “The U.S. Chemical Industry: R.I.P.” This pillar of American economic strength, which a few years earlier was the leading exporter among U.S. manufac­turing sectors (with net exports of $15–20 billion annually), was shriveling due in large part to policy blunders and regula­tory mistakes.

Harness Electricity to Operate Valves

June
2012
Back To Basics
Justin Ledger
Actuators automate valves by converting an input signal into motion. This article explains the basics of electric actuator design and explores the different types of electric actuators.

Physical and Chemical Equilibrium for Chemical Engineers

April, 2012
This book concentrates on the topic of physical and chemical equilibrium. Using the simplest mathematics along with numerous numerical examples it accurately and rigorously covers physical and chemical equilibrium in depth and detail. It continues to cover the topics found in the first edition...

Applying Bus Technologies in Process Control

December
2002
Instrumentation
Ed Smigo
Fieldbus technologies have become increasingly popular in process control applications. This article highlights the practical applications and economics of various buses, so that an engineer can choose the best one for his or her process.

Designing Experiments for the Modern Micro Industries

February
2006
Computational Methods
Phillip H. Williams
Although the sparsity of effects principle is still good advice, we need to be careful of emphasizing it too much -- to the point that it becomes an assumed practice, rather than a useful rule of thumb.

Find Mixing Success Through Failures - Part 2

December
2008
Fluids and Solids Handling
David S. Dickey
Understanding when and why mixing fails in the laboratory is often the only way of avoiding a similar failure in a production-scale reactor. Here we examine mixing in stirred-tank reactors and provide guidance on scale-up.

Understand the Real World of Mixing

March
2010
Back To Basics
Thomas Post
Most chemical engineering curricula do not adequately address mixing as it is commonly practiced in the chemical process industries. This article attempts to fill in the gaps by explaining flow patterns, mixing techniques, and the turbulent,...

Squeeze More Out of Complex Columns

July
2002
Reactions and Separations
Piyush Shah
These distillation setups can cut capital and operating costs by up to 30%, and increase separation efficiency. Here is a straightforward method for evaluation.

Understand Temperature Change in Process Stream Mixing

September
2006
Heat Transfer
Dharmendra Tiwary
The isobaric and adiabatic mixing of process streams can yield an outlet stream temperature that is either in between, higher than, or lower than the inlet stream temperatures. This article uses simulation to explore temperature-change scenarios in...

Use Spreadsheets to Estimate Modeling Parameters

February
2008
Computational Methods
Tomas B. Co
Dynamic process modeling based on non-uniformly sampled data and multiple sampling runs, even for nonlinear systems, can be performed using spreadsheet implementations of the weighted-least-squares (WLSQ) and Runge-Kutta WLSQ methods.

Understand the Fundamentals of Centrifugal Pumps

October
2010
Back To Basics
J. Howard Kelly, P.E.
Efficient and reliable pumps can significantly improve a plant’s bottom line. This article reviews important concepts that a chemical engineer must understand and the factors that need to be considered when selecting radial-flow centrifugal pumps.

Understand Thermodynamics to Improve Process Simulations

December
2011
Computational Methods
David Hill
Selecting a thermodynamic model is an important step in process simulation — one that many engineers overlook. This overview of applied thermodynamics can help you choose the right model for your process.

Validate Your Engineering Software!

July
2001
Instrumentation
Michael  Tanzio
You really can't guarantee that applications work correctly unless you take specific steps to validate the software.

Don't Get Burned Picking Dry-Type Flame Arresters

October
2002
Fluids and Solids Handling
Stanley G. Grossel
These commonly used devices rely on an internal medium to extinguish flame fronts and take the punch out of shock waves, protecting piping, equipment and personnel. Selecting such equipment involves considering the probable type of combustion,...

Safely Handle Powdered Solids

December
2005
Fluids and Solids Handling
Robert Zalosh
Understand some of the accident scenarios that result in dust explosions, and follow these suggestions for preventing them.

Improving Heat Exchanger Designs

April
2007
Heat Transfer
Christopher A. Bennett
This article defines and explains the factors that affect heat exchanger design margins. With the proper application of design margins, capital costs can be lowered and plant operations improved.

Screw Feeders: A Guide to Selection and Use

February
2003
Fluids and Solids Handling
Timothy Bell
Gain insight as to what screw feeder is best for your application. Plus, learn how to size, specify and test screw feeders.

Succeed at Catalyst Scale-Up

June
2006
Reactions and Separations
Uday T. Turaga
Follow these principles to reduce the time required for scale-up and commercialization to improve the resource effectiveness of the effort.

Determine the Right Eye Protection

September
2011
Safety
Harry J. Elston
Wearing the appropriate protective eyewear begins with a thorough safety assessment. These guidelines clarify how to identify hazards and select protective equipment to avoid eye injuries.

Take Another Look at Steam Traps

June
2001
Fluids and Solids Handling
S. Raghavi  Chari
Think twice before installing a steam trap. In the case of superheated lines, steam traps may prove to be a waste of time, effort, and money

Troubleshooting Tangential Flow Filtration

June
2003
Reactions and Separations
Kent Iverson
Tangential flow filtration (TFF) is commonly used to concentrate and dialyze solutes. It generally involves the circulation of the feed solution over a filter surface. This article presents a brief overview of the principles governing TFF, and...

Efficient Technology Evaluation

February
2007
Critical Issues
Reuel Shinnar
To stay competitive in today's economic climate, rapid and effective assessments of new technologies is a must. Requiring a minimal amount of data, this powerful method can effectively evaluate new ideas and research programs at an early stage...

Choose the Right Elastomer

June
2008
Materials
William M. Stahl
Match a material's performance to process conditions to reduce leaks, improve safety and extend the mean time between failures (MTBF).

Improve Flange Joint Reliability

January
2011
Back To Basics
Thomas Sandbrook
Proper design, installation, and maintenance of flanged connection systems can prevent loss of containment and process interruptions. Follow this seven-step approach to ensure reliability of this critical process equipment.

Inhibiting and Monitoring Corrosion

March
2012
Heat Transfer
Gary Geiger
Understand corrosion and ways to control it, and implement these monitoring techniques to improve cooling water system efficiency and reliability and reduce energy consumption.

Evaluating Dryers for New Services

December
2003
Heat Transfer
Charles G. Moyers
Continuous dryers are accurately and easily evaluated using laboratory-scale simulators combined with the specific drying rate approach.

Effectively Manage the Lifecycle of a Product

July
2007
Information Technology
Baha Korkmaz
By incorporating the batch standards S88 and S95 into the entire product lifecycle, companies can optimize their processes and project management. This enables them to rapidly get their products to market — a critical factor in staying competitive.

Minimize Scale-Up Risk

March
2010
SBE Special Section
J. Brad Cort
Proven commercial-scale equipment already exists for many operations involved in producing biofuels from lignocellulosic feedstocks.

Reduce Piloting Time and Cost

July
2011
Process Development
David A. Berg
Pilot-scale experimentation is essential to establish a sound foundation for a new chemical processing unit. These best practices can reduce the time and cost involved in process development.

Uncovering the Realities of Simulation

May
2001
Computational Methods
Marco S. Satyr
Running sophisticated process simulations does not guarantee correct results. You need to understand the thermodynamic assumptions underlying the program and how to ensure proper applications.

Size Letdown Lines for Pressure Surges

November
2001
Fluids and Solids Handling
Gianni  Anci
A high-pressure gas flow in a letdown circuit can cause damage to piping and equipment. Here is how to design a system to avoid damage should a pressurized gas flow occur GianniAnci-

Implementing an EHS Management Information System

May
2004
Information Technology
Jill Barson Gilbert
Information technology issues are just as important as business and environmental, health and safety considerations. Follow these ten tips to deply an effective EMIS with a positive return on investment.

Eliminate Iteration from Flow Problems

March
2008
Fluids and Solids Handling
John D. Barry
This article introduces a novel approach to solving flow and pipe-sizing problems based on two new dimensionless quantities that are independent of line size and flow.

Predicting Emissivities of Combustion Gases

June
2009
Heat Transfer
Alireza Bahadori
Use this new correlation, which employs easy-to-solve algebraic equations to estimate gas emissivities, to simplify the design and optimization of boilers, furnaces and other combustion equipment.

Learn to Effectively Operate and Maintain Pumps

December
2011
Back To Basics
Daniel Kernan
Centrifugal pumps play a central role in chemical processing. Proper pump operation and maintenance can improve a facility's productivity, reduce downtime, and trim costs.

Optimize Mixing by Selecting the Proper Baffles

February
2002
Fluids and Solids Handling
Kevin J. Myers
It is common knowledge that baffles promote better flow in an agitated vessel, but how to apply them and what kind to use take some ingenuity.

Improve Solids Handling During Thermal Drying

November
2004
Fluids and Solids Handling
Herman Purutyan
Follow these guidelines for ensuring the proper flow of slurries, pastes and wet powders to achieve a dried product with the desired characteristics.

Selecting and Using Bolted Head Closures

April
2007
Fluids and Solids Handling
John C. Birkmire, P.E.
Proper design, fabrication, assembly and operation of a pressure vessel closure are essential to ensuring product containment, integrity and quality.

Solving Phase Equilibrium Problems

September
2008
Reactions and Separations
James R. Reinhardt
Use this optimization-based approach to analyze multi-component, multi-phase Equilibria.

Visualizing the McCabe-Thiele Diagram

December
2009
Reactions and Separations
Paul M. Mathias
Use this spreadsheet-based visualization and interactive analysis of the McCabe-Theile diagram to understand the foundations of distillation engineering. <br><br>

Identifying Corrosion and Its Causes

April
2011
Fluids and Solids Handling
Mel J. Esmacher, P.E.
An important first step in maintaining equipment reliability and efficiency is understanding the various types of corrosion damage that can occur.

Realize Greater Benefits from CFD

March
2001
Fluids and Solids Handling
Ahmad H. Haidari
Computational fluid dynamics has moved from mainframes to PCs and laptops. Newer and better software lets you conduct analyses not possible before, and regular engineers, not just experts, can now carry out CFD.

Air Heater Cleaning Simplified

October
2001
Heat Transfer
Brad Buecker
This high-pressure water washing technique can be used to clean Ljungstrom-type air heaters.

Reduce Costs with Dividing-Wall Columns

May
2002
Reactions and Separations
Michael A. Schultz
These distillation columns can significantly reduce capital and energy expenses vs. conventional multicolumn arrangements.

Production Modeling for Multimodal Operations

February
2004
Information Technology
Jeffrey D. Kelly
Two new views for production modeling are introduced - production flow networks and production flow maps - that focus on unit operations and feedstocks, respectively.

Pipeline Pressure Drop: A New Design Correlation

June
2006
Fluids and Solids Handling
Roger Gilmont
A linear equation has been derived to accurately calculate the flowrate of fluids in the laminar and turbulent regions, and to derive an equation for use in the transitional regions.

Selecting Entrainers for Azeotropic Distillation

March
2009
Reactions and Separations
Vivek Julka
This systematic methodology uses residue curve maps to identify and evaluate substances that can facilitate distillation by breaking an azeotrope.

Uncovering the Realities of Simulation, Part 2

June
2001
Computational Methods
Marco S. Satyro
Simulation software is a commonly used design tool, thanks mainly to its availability on the desktop. However, one has to understand thermodynamic basics before accepting the desktop's final answer.

Real World Modeling of Distillation

July
2003
Reactions and Separations
Ross Taylor
Previously, simulations based on nonequilibrium, or rate-based, models were considered impractical due to their complexity. However, with ever-increasing computing power, these simulations are not only feasible, but in some circumstances they should...

Clarifying Centrifuge Operation and Selection

August
2004
Fluids and Solids Handling
Victor Norton
Before selecting a centrifuge for your application, understand its principles of operation and investigate the key process variables.
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