Electrode boiler for hot water - has tapered electrodes to give non-linear control of rate of heating

摘要

An electrode boiler has a set of fixed electrodes in the form of curved fingers on a comb. It has adjustable electrodes in a similar shape which are attached to a shaft through the centre of the boiler. The shaft is turned to bring the adjustable electrodes further in or out of the spaces between the fingers of the fixed electrodes. The fingers on both sets of electrodes are tapered so that as the adjustable electrode moves out of the fixed one the change in current flow per unit movement becomes less. This enables adequate control to be maintained with highly conducting water when there is a very small overlap of the electrodes even for full load.