Technical & Practical
Level-Measurement Device Selection
Effective level measurement in the chemical process industries (CPI) helps maintain material inventory at economic quantities, improves product quality and maximizes plant output by avoiding spills and process upsets. When they are incorrectly matched to their application, level-measurement devices can…
Mass Transfer in Fermentation Scaleup
How big can a fermenter get? And what would the biggest fermenter look like? The answers to these questions depend upon how the requirements of heat transfer, mass transfer (gas-to-liquid), and momentum transfer (mixing) are met. In an earlier article…
Dilute-phase Pneumatic Conveying: Instrumentation and Conveying Velocity
Dilute-phase pneumatic conveying systems must be operated in a certain sequence and have sufficient instrumentation and operating controls to assure reliable operation and prevent problems. This article discusses two subjects that are important for successful dilute-phase conveying. Discussed below are…
FDA Form 483: Minimizing FDA Inspection Citations
As an owner or manager of a company whose product is regulated by the U.S. Food and Drug Administration (FDA), you will, at some point, be subjected to an FDA inspection. And once an inspection is underway in your facility,…
Methanol-to-Olefins Process
Ethylene and propylene are the most important intermediates in the petrochemical industry. Globally, they are produced mainly by steam cracking of hydrocarbons, such as naphtha, propane and ethane. The methanol-to-olefins (MTO) process is an alternative approach to producing these light…
Polypropylene Production via Gas-Phase Process: Stirred-bed reactor
Since 1956, polypropylene has been commercially produced using catalysts and technology that were developed from independent research by Karl Ziegler and Giulio Natta. Their namesake catalysts have enabled the widespread use of this polymer in the decades since. Polypropylene has…
Compressible Fluid Flow Calculation Methods
Compressible gas flow with significant variation in density along pipes is commonplace in the chemical processing industries (CPI). In designing these pipes for compressible flow, it is important to calculate the pressure loss or maximum gas-handling capacity for safety and…
Quick Pipe and Duct Flow Calculations
Would you like to make a quick mental calculation to determine approximate flowrate, velocity, or pipe and duct sizes for many common situations? This article presents two methods for estimating flow characteristics without the aid of charts, tables, calculators or…
Chemical Protective Clothing
Workers in the chemical process industries (CPI) can wear chemical protective clothing to protect themselves from exposure to potentially hazardous chemicals in the form of vapor, liquid and solid particles. While chemical protective clothing has not been regulated to the…
Small-matrix, Model-less Multivariable Control
Beginning with the early days of automated multivariable control in the 1980s, the trend has always been toward the use of larger matrices and more models. Today’s multivariable controllers commonly comprise dozens of variables and hundreds of models. But the…