Manufacturing and Energy

Positive Displacement Vs Centrifugal Pumps - How to Select

technologist — Sun, 23 Mar 2008 21:10:16 -0700

When to use a centrifugal or a Positive Displacement pump (PD) is not always a clear choice. To make a good choice between these pump types it is important to understand that the two types of pumps behave very differently. By looking at the performance chart below you can see just how different they are. The centrifugal has varying flow depending on pressure or head, whereas the PD pump has more or less constant flow regardless of pressure

Read It Here....

Can hot water freeze faster than cold water?

technologist — Fri, 22 Feb 2008 04:37:47 -0700

Hot water can in fact freeze faster than cold water for a wide range of experimental conditions. This phenomenon is extremely counter- intuitive, and surprising even to most scientists, but it is in fact real. It has been seen and studied in numerous experiments. While this phenomenon has been known for centuries, and was described by Aristotle, Bacon, and Descartes, it was not introduced to the modern scientific community until 1969, by a Tanzanian high school student named Mpemba.

Read More.......

Cooling Tower: Performance calculation - I

technologist — Thu, 24 Jan 2008 21:48:03 -0700

I am invariably finding many hits on cooling tower capacity & performance calculation and related queries. Therefore, I have decided to include the detailed calculation procedure in order to enable many students & process engineers who are interested in improving cooling towers performance by following these simple steps. If you have any query, kindly post them in the comments section. I�ll try my level best to answer those queries as soon as possible. First you should collect all the data as given below. Be sure that the data collected for these temperatures is most accurate because of lower absolute level of generally ~40�C average temperatures, an error of 0.5�C due to manual data collection & judgment will cause more than 1.2% error in the result at one calculation. Repeating such errors may result in cumulative errors of more than 10% in totality giving you totally absurd results. So the basic point is that collect the data on regular basis, keep a watch to have a feel of real values & then proceed

Read More.....

How to Calculate Viscosity of Liquid Mixture?

technologist — Tue, 04 Dec 2007 21:13:48 -0700

Have you ever faced a problem of calculating the Viscosity of a Muixture?
Most of us feel that there is no approx formula for calculating Viscosity of mixture of liquids.

Now here is a useful co-relation. Thanks to Milt, It is his effort which can be very useful for many of us.

Read More...

Understanding Compressor Curves

technologist — Mon, 26 Nov 2007 03:50:30 -0700

Compressor Curves are generally misunderstood in day-today working of process engineers and many confusions arises out of discussion among cross functional teams. This becomes more confusing in case of Recycle loop systems for example in Ammonia synthesis loop OR Ethylene oxide Synthesis Loop.

Read More....

Process Engineers - Real Challenges Or Mistakes

technologist — Thu, 01 Nov 2007 21:51:59 -0700

Many forums or dicussion board / Blogs will tell you about the role of process engineers in the chemical manufacturing industry. But you may rarely find out the real technical challenges faced by a process engineer. Recently I faced some of them & then thought to write on this issue.

The most important out of several ones is the availability of CORRECT DATA.

Read More.....

HydroPower - Is it clean or not?

technologist — Fri, 12 Oct 2007 23:54:27 -0700

Opponents of dams have long argued against putting barriers in the natural flow of a river. Dams, they point out, prevent endangered fish from migrating, alter ecosystems, and threaten the livelihoods of local communities.

Native Americans, fishing communities, and environmentalists have made these arguments in their quest to decommission four dams on Klamath River, which runs from southwest Oregon to the coast of California. But with California requiring a 25 percent reduction in the state's carbon dioxide emissions by 2020, clean energy has suddenly entered the Klamath dam debate.

Read More....

Acetic Acid Exchanger Failure - Part II

technologist — Fri, 12 Oct 2007 23:49:31 -0700

This is with reference to my earlier post on the topic.

After analysis, we found that the selection of worng type of pipe is causing typical failure problem.

Read More