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Engineering Practice: Get More From Vertical Thermosiphon Reboilers

A very common heat exchanger in the chemical process industries (CPI) is the vertical thermosiphon reboiler (VTR; Figure 1). Due to size and fluid-flow restrictions, however, its heat transfer rate is often quite low. The subcooled region formed at the…

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Facts at Your Fingertips: Biodiesel Production

Biodiesel can be produced from vegetable oils by three types of reactions: base catalyzed transesterification of the oil; direct acid-catalyzed transesterification of the oil; and conversion of the oil to its fatty acids, and then to biodiesel. Biodiesel is typically…

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Facts at Your Fingertips: Heat Transfer System Design  

Pumps Centrifugal pumps with cast or forged steel casings are typically appropriate for systems with large flowrates Positive displacement pumps frequently can handle smaller flowrates of less than 100 gal/min Sealless pumps (canned motor or magnetic drive) avoid the installation…

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Feature Report: Part 1: Using Installed Gain to Improve Valve Selection

  The perfect valve to control your process has been selected. The valve will pass your maximum flow. Everything is great, right? In some cases digging a little deeper might help. The control valve usually should not be the most…

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Valves and Specialty Metal Materials

The role of valves in a process is far from insignificant. These components enable engineers to control the vitals of a process: temperature, pressure, concentration, and flow. In some cases, the failure of a valve could be catastrophic and in…

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Feature Report: Spray Technology Fundamentals & Applications: Game Winning Strategies

Spray technology is a powerful tool used to achieve higher levels of overall process performance. Strategic decisions in selecting and employing spray technology can yield dramatic wins. Understanding sprays, drop size, and the strengths and characteristics of nozzle types and…

Engineering Practice: Discharge Coefficients and Flow Resistance Factors

This article presents the fundamental concepts of the discharge coefficient, KD, of a relief valve or a safety relief valve, and flow resistance factor, KR, of a rupture disk, and their proper use in sizing an emergency relief system. When…

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Strategies to Minimize Wastewater Discharge

As regulatory issues, environmental sensitivity, and longterm water supply concerns increase, the chemical process industries (CPI) are considering ways to reduce their water discharges. In fact, more and more companies are evaluating the viability of zero-liquid-discharge (ZLD) processes. This usually…

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 The Path to the Perfect Plant

Process engineers understand how to harness the power of closed-loop multi-variable control in their plants. The evolution of digital control in the chemical process industries (CPI) has provided that power. Yet digital control represents just one facet of optimization and…

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Feature Report: Water Reuse and Conservation in the CPI

The need to conserve water is becoming a common concern throughout the world. Whether this is due to the cost of water, availability of water, or environmental concerns, water conservation is becoming a major focal point, both in the public…