http://www.che.com Chemical Engineering en-us 2010 Thu, 18 Mar 2010 4:46:08 EDT The massive buildup of new petrochemical capacity in the Middle East and Asia has been well documented, and its effect on future supply-demand much discussed. But a look at the average ages of... http://www.che.com/processing_and_handling/operations_and_maintenance/5447.html Mon, 1 Feb 2010 0:00:00 EST Most chemical engineers involved with operating large chemical process facilities have encountered the following challenge: Several large engineering contractors built the facility in multiple... http://www.che.com/processing_and_handling/operations_and_maintenance/5326.html Tue, 1 Dec 2009 0:00:00 EST Cooling water systems that rely on cooling towers are a critical component at chemical process industries (CPI) facilities. However, during operation, these open recirculating systems concentrate the contaminants in the makeup water, and as a result, scale formation and biological fouling can occur. To manage this problem, all cooling water systems require proper chemistry control and monitoring. Unless prevented, corrosion and the build up of scale and microbial fouling can impact cooling efficiency and in extreme cases even lead to unit shutdown. This article examines some of the fundamental concepts and treatment options that should be considered to keep open, recirculating cooling systems clean.... http://www.che.com/processing_and_handling/operations_and_maintenance/5005.html Sat, 1 Aug 2009 0:00:00 EDT The heat transfer sufaces of coal-fired process heaters and boilers often undergo severe fouling. If left intact, such deposits, consisting of slag from mineral matter contained in the coal, can reduce heat-transfer-surface availability, reduce thermal efficiency and cause corrosion. If the deposits are adherent and cannot be removed by conventional steam soot-blowers, shutdown and more rigorous cleaning is required. Maintenance personnel have been known to use shot cleaning as a means of removing stubborn deposits. This article proposes the installation of permanent, on-stream shot-blasting equipment for adherent deposit removal... http://www.che.com/processing_and_handling/operations_and_maintenance/4925.html Wed, 1 Jul 2009 0:00:00 EDT Organic-based thermal fluids provide relatively trouble-free service for significant periods of time. However, there comes a time when any fluid (either aromatic- or aliphatic-based) needs to be replaced. Since aromatic-based fluids generally cost more and are complicated to dispose of, they receive far more attention than aliphatic-based fluids when the time comes for replacement. Aliphatic-based fluids (manufactured with mineral oil, petroleum or poly alpha-olefins) are viewed less critically, since they are historically less expensive to purchase and are more easily handled as waste. As a result, these fluids are replaced more frequently than may be required. However, the recently rising costs of petroleum feedstocks have made these relatively low-cost hot oils more expensive to replace. To minimize the waste of good product, this article provides guidance on when to replace thermal fluids and how to achieve this using the most cost-effective method. (Part 1 of this report, p. 34, describes important considerations for avoiding overheating.)... http://www.che.com/processing_and_handling/operations_and_maintenance/4385.html Mon, 1 Dec 2008 0:00:00 EST 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 condition monitoring program, carried out by skilled and determined personnel, using appropriate tools and technology.... http://www.che.com/processing_and_handling/operations_and_maintenance/4320.html Sat, 1 Nov 2008 0:00:00 EDT Improvements in performance can be achieved with the application of heat-transfer-enhancement devices — such as wire matrix inserts, twisted-tape inserts and helically coiled inserts — in the subcooled zone of a vertical thermosiphon reboiler. These enhancement devices reduce the required heat-transfer surface area, subcooled zone length and maximum temperature of the reboiler tube wall, while increasing the overall heat-transfer coefficient, subcooled-zone overall heat-transfer coefficient and average heat flux rate. All together, these benefits translate into a reduction in the size of the exchanger, the area of installation and the initial investment.... http://www.che.com/processing_and_handling/operations_and_maintenance/4321.html Sat, 1 Nov 2008 0:00:00 EDT Click here for full pdf version of this article - includes all graphs, charts, tables, and author information As fuel prices continue to rise, energy management is everyone’s business... http://www.che.com/processing_and_handling/operations_and_maintenance/4090.html Fri, 15 Aug 2008 0:00:00 EDT Corrosion is a cannibalistic force that usually attacks chemical process equipment from the inside out.... http://www.che.com/processing_and_handling/operations_and_maintenance/4100.html Fri, 15 Aug 2008 0:00:00 EDT Water hammer — a high-pressure surge or wave created by the kinetic energy of the moving liquid — is not only a system issue, but primarily a safety concern. Understanding the nature and severity of water hammer in a steam-and-condensate system will allow prevention of its destructive forces. A better understanding will also help with the introduction of preventative measures into system designs, steam system startups, maintenance and installations, which can contribute to personnel safety, reduce maintenance costs, and reduce system downtime.... http://www.che.com/processing_and_handling/operations_and_maintenance/3796.html Tue, 15 Apr 2008 0:00:00 EDT