Getting the Best from Your Investment

As the use of vacuum-based equipment in industrial applications continues to grow, vacuum pump system life cycle costs are increasingly scrutinised. Andrew Chew of Edwards, outlines the factors that are key to optimising vacuum system specification

In the drive to optimise their processes, leading manufacturers and processors investing in new industrial vacuum equipment and those running existing systems, need to consider the following issues to ensure they get the best from their investment: performance, running costs and contamination. Those that are analysing these issues seriously are making significant gains in quality and efficiency. Recognising the critical performance factors and understanding how they impact on the process is key to optimising the vacuum system specification. For example, in a chemical processing application, it may be health and safety legislative issues which determine the choice of pump. Many processors whose equipment has traditionally been specified to the T4 temperature rating of 135Ã C have had to make compromises in vacuum pump speed and efficiency in order to meet ATEX regulations. In fact, T4 is an over-specification for most multipurpose chemical processing applications and users may find that other temperature classifications specified under the new rules will allow them to meet the regulations with more efficient vacuum pumps. In other applications, the critical factors may be accuracy of the vacuum pressure, the way the system is controlled or integrated into other control equipment, or it may be environmental factors such as noise or heat generated by the system. The traditional solution is not always the best one. When Edwards supplied equipment for the world's largest mechanically pumped vacuum degassing facility at the ORI Martin steelworks in Brescia, Italy, it was not traditional steam ejector technology that they recommended, but a 'dry' pumping system. This solution uses less energy than the traditional alternative, avoiding the issues of disposal of contaminated waste water and oil, and, crucially in this built up area, offered quieter operation.The issue of running costs is increasingly being taken into account by manufacturers and processors making capital purchases. The key factors affecting the running costs of a vacuum system include energy consumption and maintenance. Modern vacuum pumps are either oil-lubricated or 'dry', that is they have no oil in the swept volume. Choice of pumpsMany vacuum pumps in laboratory, processing and manufacturing applications, are oil-sealed pumps. Manufacturers of these pumps ensure their products achieve maximum throughput with low base pressures, but for the user to achieve optimum performance, the choice and use of lubricating oil â a vital and yet often overlooked component â must be carefully considered.