Technical & Practical
Heat transfer system cleaning
A well designed and operated heat-transfer-fluid system is a key feature of a safe, reliable and cost-effective heating design. However, problems can arise if the heat-transfer fluid becomes heavily degraded or the system is allowed to accumulate solids and other…
How long does it take to reach steady state?
How long does it take a six-tray, 4-ft dia. deisobutanizer to achieve steady state? That depends on your definition of “steady state”. Some control experts regard 95% of “ultimate value” as a good definition, but how useful is that definition?…
Preventing Self-Heating and Ignition in Drying Operations
Many solid materials can exhibit self-heating, which — if unchecked — can progress to a fire or even explosion. And even if the situation does not get that far, it is likely to affect the output of the process, in…
Todays Process Automation Worlds
Modern industrial-automation systems rely entirely on digital technology, that is, computers. And as is typical of digital products, suppliers love to add features — data collection, alarm management, and so on — that are very useful for process operations but…
Evaluating Capital Cost Estimation Programs
Capital cost assessment is an integral part of process design when building or expanding a chemical process plant. It is required to provide project analysis and evaluation, to select among alternative designs, to plan the appropriation of funds and to…
When troubleshooting the extractor
I have an ongoing dispute with a longtime colleague, Bob Miller. I said he ruined my new safety boots. He said he didn’t. Bob was a young, fearless distillation engineer at a time when our extraction engineer refused to take…
Heat Exchangers for Hot Acids: Material Selection
To make the modern materials we use every day, such as plastics, metals, electronics, pharmaceuticals, fuels and so on, strong acids are used to convert the earth’s raw materials into modern materials. In fact, so many tons of acid are…
Gas-Liquid Mixing: Physical Considerations
Gas-liquid reactors in the chemical process industries (CPI) have increasingly been designed to handle larger manufacturing scales. Since gas-liquid reactors can represent substantial capital and operating costs for the user, optimizing mixing and maximizing productivity are critical. The need for…
A Clearer View Of Crystallizers
Improved understanding of crystallizer equipment and operation can aid purification efforts in the CPI Crystallization is a key purification technique for various sectors of the chemical process industries (CPI). Several approaches for industrial crystallization have evolved over time, and highly…
Liquid-Gas Coalescers: Demystifying Performance Ratings
Engineers working in the chemical process industries (CPI) sometimes have to deal with aerosol contamination issues in which liquid-gas coalescers are routinely employed. For example, liquid-gas coalescers are used to protect compressors, liquid-gas contactors, turbines, low-NOx burners, metering and instrumentation…