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Product Viscosity Versus Shear

Feb 11 2013 06:50 PM | Steve Hall in Fluid Flow

Many products are known to be “shear thinning,” which is a term given to materials that exhibit a decrease in viscosity when force is exerted. The viscosity of pseudoplastic fluids decreases with shear, and recovers quickly when the shear is removed. Examples include paper pulp in water, latex paint, molasses, and pharmaceutical suspensions (such as certain cough syrups).

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Centrifugal Pumps: Understanding Cavitation

Nov 08 2010 01:30 PM | Mukesh Sahdev in Fluid Flow

Operating a pump under the condition of cavitation for even a short period of time can have damaging consequences for both the equipment and the process. Operating a pump at low flow conditions for an extended duration may also have damaging consequenc...

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Valve Sizing and Selection

Dec 05 2011 03:20 PM | Chris Haslego in Fluid Flow

Sizing flow valves is a science with many rules of thumb that few people agree on. In this article I'll try to define a more standard procedure for sizing a valve as well as helping to select the appropriate type of valve. **Please note that the corr...

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Falling Film Evaporators in the Food Industry

Nov 08 2010 01:40 PM | Chris Haslego in Heat Transfer

That orange juice that you had this morning sure tasted good didn't it?  Did you ever wonder how they get it concentrated into that little can?  Chances are the manufacturers used a falling film evaporator.  Falling film evaporators are especially p...

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Basics of Polystyrene Production

Nov 08 2010 01:40 PM | Chris Haslego in Process and Reactions

Polystyrene is a widely used polymer.  After production of the monomer, from one of a few processes, the monomer proceeds to further processing to form polystyrene. Styrene Monomer ProductionThe energy needed for the reaction is supplied by superheate...

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Flow Through Orifice Plates in Compressible Flu...

Nov 08 2010 01:40 PM | dkirk in Safety and Pressure Relief

The calculation of compressible flow through orifice plates at high dP (critical flow) appears to be carried out incorrectly in most instances. This flow condition is often encountered on gas plants, compressor stations and pipelines where orifice plat...

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Heat Exchanger Effectiveness

Nov 08 2010 01:40 PM | Chris Haslego in Heat Transfer

Calculating heat exchanger effectiveness allows engineers to predict how a given heat exchanger will perform a new job. Essentially, it helps engineers predict the stream outlet temperatures without a trial-and-error solution that would otherwise be ne...

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Extractive Distillation: An In-Depth Look

Nov 08 2010 01:40 PM | Chris Haslego in Separation Technology

Distillation is the most widely used separation technique in the chemical and petroleum industry. However, not all liquid mixture are amenable to ordinary fractional distillation. When the components of the system have low relative volatilities (1.00...

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Plate Heat Exchangers: Preliminary Design

Nov 08 2010 12:50 PM | Chris Haslego in Heat Transfer

Numerous articles have been published regarding the advantages of compact heat exchangers. Briefly, their higher heat transfer coefficients, compact size, ease of service, cost effectiveness, and their unique ability to handle fouling fluids make compa...

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Statistical Process Control: Process and Qualit...

Jul 14 2012 06:50 PM | Chris Haslego in Process and Reactions

Statistical Process Control (SPC) provides a way to monitor chemical and other processes. We'll focus on continuous chemical processes and how the process and quality control departments utilize SPC. Process control engineers use SPC to monitor a process's stability, consistency and overall performance. Quality control engineers use SPC to see if the process is functioning within quality standards. In industry, these two departments work together to monitor a chemical process.

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Water Chemistry and Treatment

Jun 03 2012 06:50 PM | Chris Haslego in Utilities

Water is a natural solvent. Rain water is acidic due to carbon dioxide picked up in the atmosphere. Water and CO2 make carbonic acid (acid rain). Water hardness is primarily calcium and magnesium. Calcium is limestone - common throughout Midwest. Acid water dissolves limestone, iron, and other minerals in soil.

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Estimating Heat Capacities for Solutions with D...

Nov 08 2010 01:40 PM | Chris Haslego in Calculations and Tips

Often times it is necessary to find the heat capacity for solutions with dissolved solids. A quick estimation method was proposed by Dimoplon in 1972. The proposed expression is:Cp(soln) = W1 Cp(solid) + W2 Cp(water)Eq. (1)where:Cp(soln) = Heat capacit...

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Why Become a Chemical Engineer?

May 30 2012 06:50 PM | Chris Haslego in For Students

How about a career where the opportunities are endless? Trying not to sound like an advertisement, I'd like to describe some of the more common careers pursued with a Chemical Engineering degree. Firstly, if you're considering studying Chemical Engineering, but you're a little timid because of the horror stories that you hear, you actually may want to think about it some more!

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Tank Blanketing Basics Covered

Nov 08 2010 01:40 PM | proinwv in Safety and Pressure Relief

Tank blanketing, or padding, refers to applying a cover of gas over the surface of a stores commodity; usually a liquid. Its purpose is either to protect or contain the stored product or prevent it from harming personnel, equipment, or the environment....

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Understanding Compressible Flow

Nov 08 2010 01:40 PM | rxnarang in Fluid Flow

Understanding the flow of compressible fluids in pipes is necessary for a robust design of process plants. The main difference between incompressible fluid, like water, and compressible fluid, vapor, is the greater change in pressure and density. This...

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Steam Tracing with MS Excel

May 24 2012 06:50 PM | adelange in Heat Transfer

Heat tracing is used to prevent heat loss from process fluids being transported in process fluid pipes, when there is risk of damage to piping, or interference with operation such as fouling or blockage, caused by the congealing, increase in viscosity, or separation of components, in the fluid below certain temperatures, or when there is risk of formation of corrosive substances or water due to condensation in corrosive services.

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Pinch Technology: Basics for Beginners

Nov 08 2010 01:30 PM | Mukesh Sahdev in Heat Transfer

While oil prices continue to climb, energy conservation remains the prime concern for many process industries. The challenge every process engineer is faced with is to seek answers to questions related to their process energy patterns. A few of the fre...

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Factors Affecting the Quality of Quicklime

Nov 08 2010 01:30 PM | Chris Haslego in Archived Articles

Archived article in PDF format This is a legacy article shown in Adobe Acrobat format embedded into the page below. If you cannot see the article below, please download Acrobat Reader.

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Centrifugal Pumps: Basic Concepts of Operation,...

Nov 08 2010 11:30 AM | Mukesh Sahdev in Fluid Flow

The operating manual of any centrifugal pump often starts with a general statement, "Your centrifugal pump will give you completely trouble free and satisfactory service only on the condition that it is installed and operated with due care and is prope...

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Using Equivalent Lengths of Valves and Fittings

Nov 08 2010 01:20 PM | pleckner in Fluid Flow

One of the most basic calculations performed by any process engineer, whether in design or in the plant, is line sizing and pipeline pressure loss. Typically known are the flow rate, temperature and corresponding viscosity and specific gravity of the f...

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Deaerators for Boilers

May 22 2012 09:54 AM | Chris Haslego in Utilities

Removing dissolved oxygen from boiler feed water is absolutely necessary to protect your boiler equipment from severe corrosion. But the make-up water necessary in any boiler system inevitably contains dissolved oxygen. Oxygen can sometimes enter condensate systems as well. A good deaerator is essential to trouble-free boiler operation.

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Hollow Fiber Membranes

Nov 08 2010 01:20 PM | Chris Haslego in Separation Technology

Membrane separation processes has become one of the emerging technology which undergo a rapid growth during the past few decades. It has drawn the world attention especially in the separation technology field, one of the chemical engineers' specialty w...

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Fume Control and Scrubbing on Hydrochloric Acid...

Nov 08 2010 01:20 PM | Chris Haslego in Process and Reactions

New standards for hydrochloric acid emissions are expected to be proposed by the EPA soon, and these will affect the design of scrubbers for pickle line fume exhaust systems. This paper discusses hydrochloric acid fume scrubbing, with particular refere...

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Ammonia: The Next Step

Nov 08 2010 01:20 PM | Guest in Process and Reactions

Steam reforming of hydrocarbons for ammonia production was introduced in 1930. Since then, the technology has experienced revolutionary changes in its energy consumption patterns. Ranging from an early level of 20 Gcal/tonne (79.4 MBtu/tonne) to about...

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Making Decisions with Insulation

Nov 08 2010 12:30 PM | Chris Haslego in Heat Transfer

Many people overlook the importance of insulation in the chemical industry. Some estimates have predicted that insulation in U.S. industry alone saves approximately 200 million barrels of oil every year. While placing insulation onto a pipe is fairly...

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