Evenly Dispersed Energy. Ensured.
The water circulation system is an integral component to the ET-DSP™ method. Without this system the electrode temperatures would rise and the surrounding soil would desiccate and become more resistive. The increase in soil resistivity increases the amperage draw on the PDS and can ultimately result in a main fuse, electrode or transformer failure. This can occur even at relatively low currents.
The most important function of the water circulation system is the heat transfer mechanism associated with convection. Physics dictates the vast majority of the electrode’s energy is concentrated at the ends. By purposely injecting at the ends, the water is heated to steam temperatures and is transported throughout the targeted volume. These both greatly enhance the heating process and allows ET-DSP™ to dynamically strip more SVOC’s and other non-volatile contaminants such as creosote.
The water is distributed down the inside plumbing of the electrode, exiting the electrode through slots near the base and then washes over the outer surface of the metal. Some of the water is transported out into the subsurface soil to maintain the current pathway. The rest re-enters the electrode through upper slots and is then re-circulated back to the water holding tank.
The amount of water that is directed into the formation is dependent on the permeability of the subsurface soil. In cases where soil of high permeability require heating, design changes to the electrodes are necessary in order to reduce the amount of leakage into the formation. Typical injection rates into the formation are usually on the order of 0.1 to 0.2 gpm per electrode. In most operations, this type of cooling operation is sufficient to maintain control on the maximum electrode temperature.