Use of a Magnetic Device to Eliminate Hard Calcium Scale Formation, 1997 Pulping Conference Proceedings

Procter and Gamble Paper Products’, Mehoopany, PA., facility produces paper products starting from the raw timber to the finished packaged product. The digesting process in their Pulp Mill utilizes SO2 which is manufactured and recovered in a SO2 scrubber system. Problems were encountered during summer months when the ambient temperature of the cooling water increased due to calcium salt deposits in the scrubber water heat exchanger. This in turn permitted the scrubber operating temperature to exceed design conditions and significantly reduced SO2 recovery from the scrubber. Recently a new magnetic technology, developed by the Hydrodynamics Corporation, utilizing rare earth magnets directly in the fluid flow path was successful in eliminating the hard Calcium scale deposits. This was done by altering the calcium salt crystalline form from the hard calcite to the soft aragonite form. After 10 months of on line time, the hard scale deposits have been eliminated and replaced by a soft plastic residual which was easily removed with water flushing. This device, to date, has been successful in eliminating the need to shutdown and hydroblast the heat exchanger surfaces thus avoiding production losses and potential environmental upsets.