Technical & Practical
Variable Frequency Drives: An Algorithm for Selecting VFDs for Centrifugal Pumps
This article describes an algorithm that end users can use to develop a program on a personal computer to assess the technical and economic feasibility of installing a variable frequency drive (VFD) on centrifugal pumps. This simple algorithm serves a…
Kettle Troubleshooting
A survey of tower failures [ 1 ] ranks kettle reboilers as the most troublesome reboiler type in the chemical process industries (CPI). Excessive pressure drop in kettle reboiler circuits is the prominent kettle malfunction, causing liquid to back up…
Doing an Energy Audit
Today’s high costs of energy make an energy audit evaluation of process facilities a must. Most plants were designed and built when energy costs were low by today’s standards. This makes facilities that have not been reviewed for energy efficiency…
The ‘BIST’ In Electronic Valve Actuators
For valves operating in hazardous environments, certification testing is critical to ensure the reliability and safety of the equipment. But this testing process has historically required facilities to shut down and sacrifice valuable production hours to check each valve. Built-in…
Low-Pressure Measurement
Because of the behavior of materials under vacuum, including lowered boiling points, low-pressure operations are useful tools in chemical processing, as well as in research and development and manufacturing. Areas where a vacuum system is necessary or useful include the…
A ‘Sound’ Solution to Material Flow Problems
Particulate buildup and other material flow problems are common hurdles wherever dry materials find application in the chemical process industries (CPI). Since manual intervention is costly in terms of downtime, and can be quite hazardous for the personnel involved, dedicated…
Updating the Rules For Pipe Sizing
Pipe sizing calculations include certain values that are time dependent, such as costs. While some costs rise, others decrease over time. It is the designers task to ensure that the total cost is minimized. For fluid flow calculations, heuristic criteria…
Capital And Production Costs: Improving the Bottom Line
The chemical process industries (CPI) invest large amounts of capital each year and spend even more to produce the goods they sell. In 2007, CPI companies large enough to be in the Fortune 500 list invested more than $100 billion…
Wastewater Treatment: Energy-Conservation Opportunities
Typical wastewater-treatment plants (WWTP) — both industrial and municipal — consume large amounts of energy, which can represent 50% or more of the facility’s variable operating and maintenance costs. Most employ biological processes that rely on energy-intensive aeration systems whose…
Pressure Relief Requirement During External Pool-Fire Contingency
Relief system design is an important engineering activity throughout the chemical process industries (CPI). The main purpose of this task is to design a system that protects process equipment and piping against all possible causes of overpressure. It should relieve…