Chemical Processing - September 2007 - (Page 33)

ation. Don’t rush into this important step. Good thinking upfront in defining the model will save valuable time on the overall project. It’s important that the boundary conditions of the problem are gathered from a reliable source and that these conditions can be verified through a known solution. If the exact model design isn’t clear, take a “macro” model approach — use a large simplistic model to yield rough solutions to give some idea what the detailed model should look like. After several trial attempts a detailed model then can be developed with reasonable certainty. 6. Use commercial software that has the theory to back it up. Good software developers of commercial code aren’t afraid to publish a theory manual. I’ve invariably found that the quality of the manual correlates with the performance of the software. Commercial codes that have had a poor theory manual or that lacked one have performed poorly. Ignore any hype that the code is so user-friendly that the engineer doesn’t need to have detailed knowledge of the theory. For you P.E.’s (Professional Engineers) out there, “watch it.” You’re responsible for the design or analysis, not the software vendor. Is the bat liable if a baseball player hits a foul ball or strikes out? Don’t ruin your career because you trusted or used a cheap piece of software that’s relatively unproven or isn’t backed by a detailed theory manual. Just because some software is the latest thing on the market and claims to have all the latest “advances” doesn’t make it the best product to use. 7. Perform hand calculations to check the approach. For most problems you can run hand calwww.chemicalprocessing.com by hand to validate your apculations on a test case to check proach. It’s also important to your approach to a problem and run sensitivity studies on govgive you confidence in your soerning parameters to evaluate lution. After completion of the the accuracy needed for these detailed analysis and checking, parameters to get a meaningful see what the governing aspects solution. of the problem are and develop CONVEYOR putnam 6_07.qxd 6/12/2007 10:38 AM Page 1 The last part of simulation almost test cases that can be calculated Sanitary Hygienic Dust-Free The best solution for moving bulk materials is with PIAB Vacuum Conveying. Whether you're feeding material to a form, fill, seal machine or a volumetric feeder or feeding material to a mixer or a blender, PIAB's C-Series vacuum conveying systems make it all happen. Sanitary - 3-A & USDA accepted. Hygienic - quick-change filters prevent cross-contamination of ingredients. Dust-Free - vacuum technology by compressed air prevents product blow-by or leakage. For more information, call (800) 321-7422/(781) 337-7309 or e-mail us at info@piab.com www.piab.com September 2007 • 33 http://www.piab.com http://www.piab.com http://www.chemicalprocessing.com

Table of Contents Feed for the Digital Edition of Chemical Processing - September 2007

Contents From the Editor Field Notes In Process Energy Saver Compliance Advisor Succeed at Simulation Rethink Your Approach to Process Safety Avoid Blending Blunders Get the Right Cartridge or Bag Filter Wireless Proponents Take HART Membrane Boasts Material Benefits Process Puzzler Plant InSites Chem Show Product Preview ISA Product Preview Equipment & Services Product Spotlight/Classifieds Ad Index End Point

Chemical Processing - September 2007

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