Noram G/W Drainage Retention Tester

Lorentzen & Wettre

Abstract

Practical experience has shown that existing method of drainage determination, such as Freeness, can result in poor correlation with forming section performance. The G/W Drainage-Retention Tester is an instrument intended to monitor the entire drainage pattern to better predict furnish behavior on a paper machine.
The studies were conducted to evaluate the GWDRT and results showed that the GWDRT can be used to study the entire drainage profile of a furnish. Data collected can be used to determine and compare pulp characteristics in terms of free drainage, overall drainage, retention, solids levels, and formation. Rather than evaluate and report drainage with a single number, the GWDRT has the ability to provide data which distinguishes between free drainage and overall drainage. Experience has also shown that GWDRT can detect differences in the drainage characteristics of different pulps that conventional CSF Freeness Testers were unable to detect. These features make the GWDRT an invaluable tool for both mill control and research purposes.