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INEOS Nitriles implemented a high-volume bypass to reduce maintenance on its reactor off-gas system using Swagelokās MPC NeSSI-compliant substrate and modules.
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Technicians also implemented NeSSI hardware on INEOSā reactor off-gas system (See Figure 1) that previously needed filters changed twice a week because its galvanic cells would foul easily. The techs built a high-volume bypass, which enabled conditioning only of samples going to the analyzer, and lengthened the time between filter replacements to 45 days to 60 days. The bypass also allowed line clearing without risking exposure to staff. Laser technology is used for 30-day calibration. Changing and calibrating filters takes less than 30 minutes. Though MPC was 7% to 10% more costly than traditional sampling components, the new off-gas systemās installationĀ was 50% faster, its footprint shrank by 50% and its required maintenance was reduced.
Next, after an unexpected hard failure of a primary gas analyzer, INEOS used its small, on-site inventory of MPC parts to help install a backup analyzer in just 2.5 hours. Hoffman says installing this many devices in such a short time would have been very difficult with traditional components.
Finally, INEOS also used a NeSSI-based optical flow cell developed by Applied Analytics Inc. to reduce the footprint of an optical measurement system to 1.6 in. x 7.75 in., which means it only requires an external flow controller. The facility also is integrating Horibaās mass flow controllers for liquid and gas and Emerson Process Managementās flow controllers into its NeSSI systems.
āDespite these gains, there are still many people resisting and not wanting to consider NeSSI because they donāt want to expose themselves to the potential that a new sampling system might not work,ā adds Hoffman. āHowever, the benefits outweigh the exposure, and there is no exposure and no problems if implementation is done properly upfront.ā
Analyzer Accuracy = Trust
Because butyl rubber manufacturing is a sensitive process and because traditional sample handling systems (SHSs) have accuracy problems, engineers are skeptical of the data they get from on-line moisture analyzers via distributed control systems (DCS), says Jamie Canton, analyzer specialist at Lanxess Inc..
For example, moisture analysis systems at Lanxessā butyl plant in Sarnia, Ontario, previously needed high flow rates and fast loops to deliver representative process parts per million (PPM) moisture conditions to the analyzer, but these rates also increased sample delivery lag times. This happened because high steam-trace energy was needed to prevent moisture absorption on the sample transport pipe wall, which caused subsequent steam-related failures and SHS and analyzer downtime. In addition, because operators could view the moisture analyzerās data via the DCS, but were blind to the SHS, they typically ordered manual inspections for both, which could take as long as six hours. āThese time lags were extremely costly sometimes because moisture levels exceeded specification, resulting in poor product quality and extended plant downtime,ā explains Canton.
Then, while improving nine gas chromatographs (GCs) at the Sarnia plant, its engineers began seeking way to increase trust in their moisture analyzerās data and their confidence in acting on it. Lanxessā engineers subsequently selected NeSSI-based components, including Parker Hannifinās IntraFlow and R-Max air-actuated (DBB) stream switching system, which enabled remote validation and multi-stream analysis of one analyzer.
Canton adds that the plantās butyl moisture sampling system now includes two membrane separators to protect the analyzer from costly flooding due to heat-trace failures. Nitrogen reference gas is dried in an on-board desiccant drier, and is used for calibration and verification. A normally closed (NC) R-Max switch direct sample flow to the analyzer, while a normally open (NO) R-Max directs the standard reference to it. In addition, bypass and analyzer flow indication is performed by Honeywell Sensotecās 1 psig differential pressure (dP) sensors that measure pressure drops across restricted orifice plates. The sensorās transmitter sends a 4-20 mA output to the DCS to show flow conditions (See Figure 2).
FIGURE 2: TRUE CONFIDENCE GAME |
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