Guided Wave pioneered in-line fiber optic sample interfaces more than twenty-five years ago, with the introduction of the SST (Single Sided Transmission) Probe. This probe permits precise spectroscopic analysis of products directly in the process line without the need for sample systems and their associated investment and installation costs, lag times, failures, and constant maintenance requirements. In refineries, there are various operations that make the use of the SST probe ideal. For example, in para-xylene and petrol/gasoline plants where the sample is very clean (free from particulates and moisture), a direct in-situ SST probe is the best choice. It allows direct process measurement with simple installation in a pressurized line.
However, for diesel/gas oil applications it is highly recommended to use a heated MultiPurpose Flow cell (MPFC) with a heated incoming line to dissolve the trace levels of water in the sample. While direct insertion probes eliminate sample loops and sample systems and their associated problems, sometimes it is necessary to install sample loops for safety, service, and/or sample conditioning reasons. The MPFC is a convenient, compact, rugged sample interface that is easy to install and even easier to service. The cell’s sapphire windows can be cleaned by simply removing a clean-out plug (a Guided Wave innovation) for direct access to the windows without disconnecting process lines or fiber optic cables.
How to Choose the Right Probe or Flow Cell for Refinery Measurements
Guided Wave probes and flow cells offer high throughput, collimated optical beams through the sample, yielding lower noise and more accurate transmission values free of sample index of refraction effects. For faster maintenance and cleaning of insertion probes, Guided Wave’s Extractor Mechanism can be used. The controlled extraction of an in-line probe from pressurized process streams or reactors can be accomplished without shutting down the process, allowing continued use of the analyzer to verify process quality. Coupled with a gate or ball valve, these extractors have proven safe and effective in a variety of refinery installations such as Reformer, Gasoline Blending, Blender and Feed Streams saving downtime. James Low, Guided Wave’s Director of Sales and Support states, “The SST insertion probe extractor assembly is worth every penny when you consider the time saved on insertion probe maintenance.” He continue “I’ve been with Guided Wave almost since its beginning and the SST probe and the multipurpose flow cell are extremely durable and reliable. Our probes and flow cells are compatible with nearly every brand of analyzer and in normal refinery use they function virtually forever”.