Probes

The inline Raman probe and flow cell is used to monitor a slip stream sample line.  The Raman probe is protected from the sample stream by a 1 mm thick sapphire window that is rated up to 550 psi.  Typical flow rates are 20 to 50 cc/min.  The sample cell has minimal dead space and can be easily cleaned if necessary.  Conventional stainless steel compression fittings allow quick connection with a conventional refinery sampling stream.  Just like the immersion Raman probes the inline unit is intrinsically safe with no electrical connections and can be used with fiber optic cables that are up to 300 meters (1,000 ft) in length.  The inline probe is encased in a NEMA 12 or NEMA 4x enclosure that protects it from the outside environment.

This design is similar to the inline Raman probe and flow cell shown above, but has some additional features integrated into the enclosure that are useful for certain applications.  On the cover of the enclosure is a sample button that is pushed whenever a process grab sample is obtained.  The most recent spectrum from that stream is then saved in a specific location, so it is easily accessible when updating chemometric models.  Inside the enclosure there are: a needle valve for flow control, a visual flow meter and electronic flow sensor, two pressure gauges, two bleed lines, a nitrogen purge line, and an interface board for connecting the low voltage outputs of the button/electronic flow sensor. 

The inline Process Raman probe and flow cell is used to monitor a slip stream sample line.  The Process Raman probe is protected from the sample stream by a sapphire ball lens that is rated up to 350 C and 3000 psi.  Typical flow rates are 20 to 50 cc/min.  The sample cell has minimal dead space and can be easily cleaned if necessary.  Conventional stainless steel compression fittings allow quick connection with a conventional refinery sampling stream.  Just like the immersion Raman probes the inline unit is intrinsically safe with no electrical connections and can be used with fiber optic cables that are up to 300 meters (1,000 ft) in length.  The inline probe is encased in a NEMA 12 or NEMA 4x enclosure that protects it from the outside environment.

The online immersion Raman probe interfaces directly into the process stream allowing one to monitor directly at the process conditions.  The probe is intrinsically safe since it does not require any electrical connections, and only light is transmitted via fiber optic cables to and from the probe.  Since our instrument works in the NIR region, the fiber optic cables can be up to 300 meters (1,000 ft) in length for sampling streams located at a remote location in the refinery.  For comparison MID IR instruments are limited to fibers that can only be a few meters in length.  The probes can be manufactured from a variety of materials including 316-SS, carbon steel, alloy-20, hastelloy, etc.  The probes are also designed to be retractable for easy access and cleaning in low pressure applications (<200 psi).  High pressure applications require a welded ANSI flange seal and are rated up to 3,000 psi.  Sample excitation and collection are conducted through a sapphire window located on the immersed end of the probe.  The probes are rated up to 250 ^OC.