Abstract:
A fluid heating apparatus has a fluid flow path from an inlet to an outlet, with multiple heating sections positioned along the flow path. Each heating section is at least one pair of electrodes between which an electric current is passed through the fluid to resistively heat the fluid during its passage along the flow path. At least one of the heating sections has a segmented electrode made up of a plurality of electrically separable segments. This allows an effective active area of the segmented electrode to be controlled by selectively activating the segments. A controller determines a required voltage and current to be delivered to the fluid by each heating section, and allows for input conductivity as well as variations in fluid conductivity with temperature. The controller activates selected segments of the segmented electrode to effect delivery of desired current and voltage by the segmented electrode to the fluid.
Abstract:
An electric fluid heater includes a body having a fluid inlet and a fluid outlet and defines a fluid passage between the fluid inlet and the fluid outlet. At least two heating assemblies are disposed in the body and arranged in parallel, each heating assembly including at least two electrodes configured to heat fluid by passing alternating electric current through the fluid; wherein the at least two heating assemblies are arranged in the body so that fluid flowing through the fluid passage flows simultaneously through the at least two heating assemblies. Corresponding heating methods and heating systems employing such heaters and methods are also disclosed.
Abstract:
An apparatus for heating fluid, includes a preheat reservoir having at least one pair of reservoir electrodes between which an electric current can be passed through fluid in the preheat reservoir, to heat fluid in the reservoir to a preheat temperature, the preheat temperature being less than a desired output fluid temperature of the apparatus; and an outflow temperature boost passage through which fluid from the preheat reservoir flows to an outlet of the apparatus, the outflow temperature boost passage having at least one pair of outflow electrodes between which an electric current can be passed through fluid in the outflow temperature boost passage, to heat fluid dynamically in the outflow temperature boost passage to the desired output fluid temperature.