Among the challenges of effective solid-liquid filtration is the accumulation of solids on the filter surface, which creates an increasingly dense mass that process fluid must push through. In many applications in the chemical process industries (CPI), a step-down filtration…
Properly sized ejector stations can save capital costs and reduce downtime Steam-assisted, gravity-drainage (SAGD) operations employ large tanks that vent flammable and sometimes toxic gases. Safety and environmental concerns often require engineers to design vapor-recovery units (VRUs) to collect these…
This article presents equations that allow the user to calculate liquid volume as a function of liquid depth, in both vertically and horizontally oriented tanks with dished heads. The equations accommodate all tank heads that can be described by two…
Maintaining high-purity conditions in the chemical process industries (CPI) depends in large part on the techniques used for sterilization. As a method to inactivate or eliminate potentially harmful microbes, sterilization can be achieved through a number of different approaches, such…
I was having a “wallflower moment” after Ms. Ruth Sands’ excellent troubleshooting presentation at the March AIChE meeting. That presentation was well summarized by Editor in Chief, Rebekkah Marshall in the April issue of CE (p. 5). I wanted to…
The chemical process industries (CPI), like many others, increasingly employ non-metallic piping systems for fluid transfer — including polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC) and fiberglass-reinforced plastic (FRP) — instead of exotic metal piping. While non-metallic piping systems have…
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 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?…
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…
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…