Technical & Practical
Condition-Based Maintenance Management Enhances Reliability
Management is a process of managing risk; maintenance management is a process of managing risk for operational reliability. Since it is hard to manage what cannot be measured, effective maintenance management demands good data on machine health — a comprehensive…
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…
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…
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…
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…
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…
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…
Facts at Your Fingertips: Crystallization
Crystallization is a method of solid-fluid separation in which pure chemical crystals are formed. Crystallization kinetics consists of three major phenomena: nucleation (the birth of a crystal), transfer of the solute from the supersaturated solution to the crystal surface, and…
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…