The design and performance of novel on-line electrostatic charge-density monitors, injectors and neutralisers for use in fuel systems

The theoretical derivation of the performance of a relaxation-type charge-density monitor is discussed. Practical devices of this type produced are described and the performance on diesel fuel related to the theory. Problems of apparent variations in conductivity of the fuel lead to a system of charge-density measurements independent of fuel conductivity. The use of an electrostatic charge injector in a feedback loop with a charge-density monitor acting as a null detector is shown to produce a practical system for charge elimination from fuel flowing down pipelines. The system has been tested on a full-scale flow rig.