Corrections: From the October 2012 Letters page: This original article, which appeared in the print edition of Chemical Engineering (September 2012), had two errors: Equation (19) should read D = log (TH)-0.4, and Table 2 was missing decimal points in…
This article is the first in a two-part series, in which the types of process vacuum equipment (steam ejector systems and mechanical vacuum pumps) are discussed.1 Emphasis is given on how they are constructed and operate, and how to design…
There are two main reasons why compressor capacity regulation is used. The most prevalent reason is to adjust the suction flow to match the process demand. The second reason is to save energy. As a rule, capacity control is determined…
The main function of the expansion tank in a heat-transfer system is to allow space for the heat-transfer fluid to expand as it is heated. A properly designed, installed and maintained expansion tank will support longer fluid and equipment life,…
There is a temptation that steam design engineers find difficult to resist — to put condensate from high-pressure (HP) steam mains directly into the low-pressure (LP), pumped condensate-return (CR) mains. After all, the CR main is so convenient — it…
Globe-style control valves are in virtually every chemical processing line where pressure and flow must be controlled. And for the most part, they perform as required, day in and day out, requiring little to no thought or attention. In short,…
The earliest application of the fundamental concepts of fluidization dates back to 16th century when a German scientist (Georgius Agricola) described a process to upgrade ores. However, it was not until the 1930s, with the development of the Winkler coal-gasification…
Corrosion is a large and complex issue that is critical to the chemical process industries (CPI) as well as other industry sectors. Corrosion not only affects personal property like cars and homes but also affects commercial assets such as storage…
Automated systems for batch weighing can improve overall product quality by raising the accuracy and consistency of the mixture compared to what can be achieved with the manual addition of pre-weighed bags. Automated batch-weighing systems integrate load cells with connections,…
Among all the engineers who will be involved in the purchase of a mixer or blender next year, roughly half will welcome a change in their production method. The other half will be determined to prevent it. Searching for the…