K-Patents Process Refractometer measures PAG solutions in heat treating quench systems

There is a growing interest amongst the leading aircraft and automotive manufacturers to install K-Patents Process Refractometer PR-23 in the Drop Bottom Quench furnace systems that are used for aluminum heat treating. Polymer quenchants are used to control distortion and to prevent cracking of steel during the hardening process.

For many years, water-in-oil emulsions were used, but these fluids were susceptible to biological attack. Subsequently, polymer quenchants were developed and the class of polymers that has gained widest acceptance in the industry are poly(alkylene glycols) - or PAG's as they are commonly known.

Traditionally, handheld or laboratory Brix refractometers indicating sucrose content on a Brix scale, have been used for monitoring PAG quenchant concentrations. K-Patents Process Refractometer PR-23 can provide the same measurement capability real-time in-line. The measurement signal can be sent to a PLC or recorder using digital or analogue outputs for continuous monitoring purposes.

The Brix reading can be converted into the quenchant concentration using a specific conversion factor for the quenchant being measured. The factor is typically from 2 to 2.5 for new PAG solutions and is typically provided by the manufacturer of the quenchant.

Read more: Technical Note 7.01.01 Application specifics: Recommended Practice for the calibration of PR-23 Refractometer for PAG quenchants (pdf)