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Believe your instruments, unless…

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…

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Specifying Elastomer Seals for Plastic Piping

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…

Moving Air In Pneumatic Conveying Systems

Dilute-phase conveying systems generally use centrifugal fans and positive displacement blowers for supplying conveying air to the conveying system. However, for some conveying systems, compressed air from a central compressor station is also used. The two important criteria required for…

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Reboiler Condensate Drums: Silencing Hydraulic Hammer

Condensate pots are commonly used on the condensing sides of some reboilers, such as those that are heated by steam or refrigerant vapor. These pots provide a liquid seal that prevents uncondensed vapor from blowing out of the reboiler into…

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Reduce Costs with ‘Step-down’ Filtration

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…

Tank Vapors: Optimize Ejector Sizing for Better Control

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…

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Calculate Liquid Volumes in Tanks with Dished Heads

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…

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Sterilization Approaches

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…

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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…

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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…