Title

Membrane Separation of Polymer Quenchants

Authorship

HOWARD, R.D.; TOTTEN, G.E.

HOWARD, R.D.

I am this author

TOTTEN, G.E.

I am this author

DOI

10.5151/2594-5327-49v8-255-266

Downloads

Abstract

Aqueous polymer quenchants based on poly(alkylene glycol), PAG, copolymers are being used increasingly as replacements for both oil and water in ferrous and non-ferrous quenching operations. The performance of all polymer quenchants, including those based on PAG, are dependent on polymer concentration. The optimal concentration varies with the alloy, cross-section size and the degree of agitation. Therefore, it would be ideal if the polymer quenchant could be readily varied with respect to the quenching requirement. One method which provides quenchant concentration control is membrane separation technology. Membrane separation techniques, such as ultrafiltration and reverse osmosis, permit the separation and concentration of the polymer which can be subsequently rediluted to the desired concentration. These separation methods may also be used to remove residual polymer from rinse water streams, or even from waste water before emission from the heat treating plant. This would substantially reduce the potential ecological impact of the polymer quenchant. Membrane separation technologies have been reported for use in polymer quenching systems. However, until recently, these technologies have not been sufficiently developed where they could be readily used with trouble-free operation. This paper will discuss the importance of polymer concentration control, provide a basic review of membrane separation principles and discuss the successful use of various membrane separation systems in use today.

Keywords

polymer quenchants, membrane separation, PAG, ultrafiltration, reverse osmosis, heat treatment, environmental impact