Flow-through test methodology

Technically, the best method to ensure precise exposure and water quality is the use of a flow-through test methodology. A continuous-flow methodology usually involves the application of peristaltic pumps, flow meters, and mixing chambers to ensure an accurate concentration. Continuous flow methods are rarely used. The usual method is an intermittent flow using a proportional diluter (Figure 3.10) to mix the stock solution with diluent to obtain the desired test solutions. 

The horizontal LAD testing methodology is depicted in Figure 9.8. To measure the frictional and dynamic pressure drops, the channel is mounted inside a test tank and flow is routed through the screen and out through a port at the end of the channel. Pressure drop as a function of mass flow rate down the LAD is measured at multiple locations to quantify performance. 

Tests are conducted at atmospheric pressure. The partial pressures of liquids are determined by the thermostatic baths (temperature control) and volumetric flow rates passing through saturators. The methodology of these calculations is described in detail in Patat and Kirchner (1975). 

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