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NeSSI™– An Alternative Viewpoint. Questions, notes and comments compiled by Rob Dubois Dow Chemical CPAC/NeSSI Workshop May 11, 2006. Technical/Design Comments. It is not real clear which way the flow path goes on some of the modular products.
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NeSSI™– An Alternative Viewpoint Questions, notes and comments compiled by Rob Dubois Dow Chemical CPAC/NeSSI Workshop May 11, 2006
Technical/Design Comments • It is not real clear which way the flow path goes on some of the modular products. • True and especially with intense packaging arrangements • A local “hard copy” flow graphics schematic is always advised • Gen II defines a graphical user interface (GUI). This is expected to simplify or eliminate this issue. At least one GC manufacturer has a GUI embedded in their smart GC. • Add tagging/flow direction on the block and/or substrate. • Position indicators/buttons/lights on valves are helpful • Local indicators – flow, pressure, etc. are useful • No mandated marking standard. Add to SP76 revised list. • Some modular designs/architectures are more visual than others
Technical/Design • Components may be inadvertently misaligned on the substrate since no positioning mechanism is included in the SP76 standard. • True, there is no definitive alignment method. SP76 committee did not include an alignment pin in initial standard. • One vendor says he is ready to adopt the alignment pin – but recommendation is to adopt the standard location via SP76 committee revisit of issue • Blank hole cover can be used on one vendor's product • Strong recommendation to reconvene SP76 committee for minor items/improvements (Dan Podkulski to advise) • include an O-ring standard size • provide a standard alignment pin location • Standardize markings on the substrate • Propose dimensions for a high flow iteration (1.5 X?) • Determine if any changes are needed to accommodate a plastic block/non-metallic version of SP76. • Standardize on the location of an optional weep/sniff hole
Technical/Design • Lots of o-rings may present more opportunities for leaks. What history do we have on performance and leak immunity? • No systematic history of problems. There have been some examples of out of the box component failure. • No end users had complaints had outstanding complaints after 2-3 years of service. Dozens of installations now in the field. (~200-300 installs?) • Incorrect installations are always an issue –can be put on backwards. • UOP claims more compact, rigid design causes less leaks than individual plumbed discrete components. A compact substrate is stiffer with less inherent flex.
Technical/Design • Are there standards for the O-ring materials? • No, they differ between the major substrate mfgs. since the o-ring not defined by SP76. e.g. Parker -007, CIRCOR -006, Swagelok -006. (very close however) • Vendors will do interoperability study and report on findings. (Steve Doe, Bob Sherman, Dave Simko). By when?
Technical/Design Details • Small flow paths can be a concern for "dirty" applications in both vapour and liquid applications. Are there any guidelines where to employ this technology? (e.g. particle size limits, pressure drop vs. number of components, viscosity for liquids?) • 90% of 300-400 applications on a new major project will employ NeSSI . Applications include olefins, aromatics, polyethylene, etc. • Lots of experience on fluids like water, diesel fuel • Viscosity up to xxxxx cP and what xx C? Diesel applications are in wide use • Recommendations for filtration? ie. filter to x microns – is this different than conventional? • The smallest ID factor typically are the sample inject valve ports. • Refer to Swagelok CFD data – the components are the limiting factor. Lowest cV is the constraint. Reference needed. • Swagelok plans to follow-up with data on viscosity limitation based on temperature. • May be useful to include a link on the CPAC web – outlining rules of thumb…for viscosity/temp., filtration recommendations, etc.
Comparison of Internal Diameters (Tubing vs. Modular) • Valco valve used for GC sampling 0.010” port ID’s • 1/16” OD tubing 0.030” ID • 1/8” OD x .028” wall tubing 0.069” ID • Swagelok Surface Mount component 0.090” ID • Swagelok substrate 0.100” ID • CIRCOR substrate 0.110”, transfer tubes 0.120” and surface mount component min. 0.110” • Parker substrate and SM component ~ 0.115” ID • ¼” OD x .065” wall tubing 0.120” ID • ¼” OD x .049” wall tubing 0.152” ID • ¼” OD x .035” wall tubing 0.180” ID • Take-away – many of the miniature, modular products are equivalent to heavy wall ¼” OD tubing in passageways. Typical GC sampling valves are MUCH smaller in size (order of magnitude) and they are used commonly in vapour systems.
Technical/Design Comments . • What are the current and pending miniature analyzers or sensors available for the NeSSI platform? • UV, VIS, Raman, NDIR, oxygen, moisture, pH, RI, ORP, DO • Pending: vapochromic O2, LC, GC (SLS, others) • Honeywell PHASED GC currently in beta with UOP and Air Products • What are the target (analytical) applications? • optical, oxygen, chromatography, pH, various component specific sensors, moisture • What new technologies (analytical and non-analytical) are coming available for the NeSSI platform? • smart heaters, miniature flow devies, Intrinsically safe NeSSI- bus structure (I2C, CiA CAN), microPumps
Technical/Design Comments • If area classification for on-board monitoring devices is Class 1, Division 1 (Zone 1), is this adding more cost to the design of the systems? Why not Division 2? • intrinsically safe is a globally acceptable certification – ideal for companies involved in multiple geographical installations and who are always dealing with various certifications • Hybrid systems (Div 1 & 2) will be available – end user can pick and choose according to their needs. • Probably biggest reason for an Intrinsically Safe solution is that is eliminates costly and cumbersome wiring/conduit etc. and allows plug and play connectors • Div 2 not acceptable for all enclosed systems handling hydrocarbons without added cost associated with additional methods of protection • No data that designing an out of the box Div/Zone 1 IS system from scratch is any more expensive.
Technical/Design Comments • Rotameters can pose problems when used with a modular system (i.e. orientation and real estate issues). Is there an alternative or better way to measure flow? • d/p cell with capillary or orifice • Coriolis • Thermal • Vapour pressure/pressure monitors in lieu of flow • Other? • Some brands of modular systems are less flexible with respect to making design changes after construction • Your choose as End User • All suppliers say their product is quite flexible
Commercial/Upfront Cost Comments • The cost appears to be too high when compared to a conventional system. • One vendor says a 5-20 block can be twice the price of a conventional system • The same vendor says at a 25-60 block count price becomes equal • LTCO (Long Term cost of Ownership) is a driver for End Users. How measure? • Standardization is important • Reliability - how do you put a savings on this? • What is the purchasing channel? Through an integrator? • Is there a commercial agreement in place at your company? • How do we make the price comparison? The price comparison is made to what yardstick? Do we need a neutral buyer to check? • One vendor has said in the past that his product is 10-20% more expensive • Noted that surface mounted (down mount) components are more expensive than conventional equivalents.
Commercial/Upfront Cost Comments • The cost of spare parts required appears high. • see comments on pricing previous page • The technical advantages may not justify the initial upfront expense. (i.e. delta vs. conventional) • We have seen cases where a $12K conventional system might cost $20K as NeSSI. • We have also seen examples of systems that are less expensive than a conventional systems. Was preferred pricing extended? • Pricing of early systems has been an issue. Will volume production produce cost savings?
Costs • What is the actual LTCO comparison of NeSSI vs. a traditional SS for a typical system? (i.e. CEMS, multi stream GC, photometer, etc.). It would be valuable to obtain validated historical data, not projections. • Dan Podkulsi has agreed to talk with their maintenance technicians and collect data by years end. • Collect costs spent to maintain, etc. • We would like to see an actual NPV calculation for implementation of NeSSI vs. traditional sample system. • End Users need to do more in this area. • Dow has did an internal NPV evaluation. (not public)
Implementation and Integration Comments • Lack of knowledge and experience by the end user community limits willingness to implement the systems. What can be done to improve this knowledge and experience base? • Let’s collectively publish the list of known applications… • It would be good to a get a number count but some vendors feel they may lose competitive advantage. • Substrate manufacturers (Steve Doe, Bob Sherman, Dave Simko) please send a list of applications they have sold into. • Send anonymous and generic list send c/o of Dave Veltkamp. Specify application and analysis method at minimum. No need to specify numbers sold. This information will be added to this document. • e.g. Impurities in ethylene using GC.
Implementation and Integration Comments • Lack of integration experience has been evident among product suppliers. Are there ways to improve the delivery channel and integration model? • Competition prevents some substrate manufacturers from sourcing components from a competitor. • Traditional integrators may resist modular since it may be considered as a threat • Component/substrate mfgs. May not have the suite of skills needed to do integration properly • Analyzer suppliers – perhaps an opportunity? • Component/substrate mfgs. may try centralized geographical and/or regional integration.
Implementation and Integration Comments • Some integrators will provide a performance guarantee on their systems. Will a modular system provider do so? (even if components are used which are not their own.) • Siemens will provide a guarantee on a modular system to the same extent we will provide on a conventional system • Parker will a supply a performance guarantee based ona performance spec • Circor will provide a performance guarantee based on a performance spec. • Swagelok (Dave Simko) to check • Other manufacturers comments?
Maintenance Support Comments • It is not real clear which way the flow path goes on some brands of modular systems. Consequently there appears to be no real easy way to trouble shoot a system. How can troubleshooting be made easier? • See Technical/Design Comment on flow paths
Maintenance Support Comments • There remains confusion about how we would troubleshoot a panel. For example, we have heard that it is necessary to have a spare panel to replace a faulty system as an entity. This seems cost prohibitive, so if this is not the case field troubleshooting appears difficult. • No need to do this. However, multiple, identical panels may justify a hot spare. • To aid troubleshooting, make sure jigs are supplied by the particular vendor you buy from – these should be included as spare parts – e.g. and blank-off blocks to isolate problems on a substrate. • Write a pressure check and flow path check into your factory acceptance test. Having people familiar with the product has been very useful and overcomes lots of issues. (Chevron used an example of two of their sites.)
Miscellaneous Comments • For some modular systems, there doesn't appear to be any space savings advantages when compared to conventional systems when placed in "real life" situations. (e.g. the use of hybrid systems with external filtration components, off substrate flow devices, space consumed by conventional tubing and fittings, etc.) • Previously some components were missing e.g. flow devices, coalescing filters slowly these are coming available in substrate mount format • Some folks like lots of spacing and spread out on purpose • Rotameters can be a bit of design bottleneck for modular • Need an off substrate bypass flow for ½” tube equivalent • 3 GPM of diesel for external filter (Patrick Lowery to check) • need better ideas on how to more tightly integrate a system • Flat, convection heater enables the use of more intensive designs. • Dan P. will send Rob D. additional photos of compact Sarnia installs • Dow has an example of a compact 4 stream system
Miscellaneous Comments • More detail is needed on the cost of the next generation (Gen II) systems. The next generation appears to allow for more "on board" monitoring devices. Has anyone determined whether the added up front cost of these devices along with their added maintenance costs are justified by the information they are supposed to provide? • Needs to be compared against a traditional system with the same kind of systems • Still defining the bus structure so at this moment we do not now – suspect cheaper than 4-20 mA since infrastructure is reduced
Miscellaneous Comments • Wiring and infrastructure associated with 4-20 mA and discrete systems is costly and wiring intensive in electrically hazardous areas. • a digital Intrinsically Safe bus is eminent • SAM (sensor actuator manager) is emerging which should lower costs – signal concentrator • the idea of a smart system is to increase reliability and lower maintenance costs • A Gen 1½ system using a PLC and traditional wiring is costly. Need to go to Gen II. (Chevron comment) • NeSSI is an enabler for driving change in Process Analytical • already new heaters, new flow devices, a new bus structure's in progress, common substrate architecture, etc. • enables miniaturization and system intensification