Abstract: Apparatus for treating a fluid in a conduit by the application thereto of radio-frequency electro-magnetic signals, includes a core element of magnetically-permeable material extending around the conduit, and one or more primary coils through which the core element extends and is energized with radio-frequency electrical signals by at least one signal generator; wherein at least one of the primary coils has an extent and/or disposition circumferentially of the core element and the conduit such as to establish an effective magnetic field throughout the core element.

Abstract: An apparatus establishes electrodes in a region of an electrically conductive liquid flowing along a pipe. The apparatus includes a core of magnetically conductive material surrounding the pipe, an energizable primary coil that creates an electric field within the liquid, a secondary passage connected at the region, and a flow restriction for restricting the flow of the liquid in the secondary passage to create an electrical resistance along which an electrical current flows through the liquid.

Abstract: Electrodes are established in a region of an electrically conductive liquid flowing along a pipe, by surrounding the pipe containing the liquid with a core of magnetically conductive material which passes through a primary coil energized by an electrical signal to create an electric field within the liquid, by connecting a secondary passage at the region for the liquid to flow between opposite sides of the core, and by restricting the flow of the liquid in the secondary passage to create an electrical resistance along which an electrical current flows through the liquid.