Silica Scaling Under Controlled Hydrodynamic Conditions

Abstract

Silica scaling has been previously shown to be affected by hydrodynamic conditions. A pilot plant incorporating a water tunnel was built to investigate the effect of hydrodynamic conditions and silica colloid particle size on the rate of and style of silica scaling. In the water tunnel, fluid flow and silica colloid particle size can be controlled. Development and design of the test rig is described. Tests using vertical flat plates and vertical cylinders have been conducted. We believe that flat plate results are affected by bacterial deposition, but the vertical cylinder experiments show a definite hydrodynamic and particle size effect. Ultimately, the aim of this work is to characterise the link between fluid flow characteristics, silica colloid particle size and the scaling process, and to thereby understand the fundamental processes involved in silica scaling in geothermal systems.