Sometimes an idea makes so much sense that its hard to understand why it took so long to surface. Thats what I thought when I first heard about the New Sampling/Sensor Initiative or NeSSI. After all, the concept of replacing the maze of tubing, fittings and other hardware in a sampling system with miniature modular components promised to save space, ease design and reconfiguration and provide long-term savings.
Despite those attractions, the success of such a modular platform clearly depends upon its implementation. For good reason users resist when a single vendor tries to make its design the de facto standard. Worse yet is when several vendors or even organizations battle over standards, leaving users to choose sides and ultimately to deal with incompatibilities.
Luckily, representatives from operating companies, hardware vendors and academia early on saw the need for cooperative efforts to develop such an approach to sampling. The result was the launch in 2000 of NeSSI, under the aegis of the Center for Process Analytical Chemistry (CPAC) at the University of Washington, Seattle. This has led to standards for the modular building blocks, so any NeSSI-compliant surface-mount component will attach to any NeSSI substrate. Industry is starting to use such modules to build so-called Generation I systems (CP, September 2005, Smaller, smarter systems streamline sampling).
However, large-scale installations remain relatively rare. Not only does the concept differ from what plants are used to, but the individual components are more expensive than conventional tubing, fittings, valves, etc., and systems havent been in the field enough time to document the long-term savings possible with Generation I.
So, it was appropriate that a significant portion of the program for the first Swagelok Technology Summit, held in mid-November in Houston, focused on NeSSI.
Generation I systems offer a number of benefits, noted John Wawrowski of Swagelok. Configuration software cuts design time to minutes from hours. Putting a system together only requires a hex-head screwdriver, with individual components or even the entire system easily removed for maintenance in fact, a spare system could be stocked to lessen downtime. The modular approach reduces sample transport lines and the size of enclosures. And NeSSI can be used with many liquids as well as gases, he added.
Moreover, Wawrowski stressed, Generation I systems are forward-compatible with next generation technology. The first major deployment of a Generation II system may soon take place in Singapore (CP, September 2006, Process analysis gains greater online role).
Dave Simko of Swagelok provided a preview of what Generations II and III promise. In Generation II, data inputs and outputs will move to the NeSSI field devices, with bi-directional communication via a digital bus that is standard for all components. Each wire will handle many devices and each device will be able to send data on many variables. This will enable smart systems that self-adjust to maintain optimal performance as process conditions change. And systems will be intrinsically safe.
Generation III will extend the power of the systems by putting micro-analytical devices right at the substrates, thus reducing sample volume needed and sampling lags. Brian Marquardt of CPAC highlighted a wide variety of sensor technologies now commercial or under development for NeSSI systems.
For NeSSI to truly take hold, it must address a completely integrated analyzer and sample-system solution, bluntly stated Dave Novak of Siemens Energy & Automation. It certainly looks like NeSSI is poised to do just that.
