Steam Generator

A device for heating a conductive liquid comprising:

• (a) a structure defining a plurality of channels extending side-by-side and dielectric walls between each of the plurality of channels, the structure including means for directing the liquid through the channels;
• (b) a set of electrodes within each channel, the set of electrodes within each channel including electrodes disposed at a plurality of locations along the length of the channel;
• (c) an electrical power supply having at least two poles, the power supply being operable to supply different electrical potentials to different ones of the poles;
• (d) a circuit operable to selectively connect the electrodes to the poles and to selectively disconnect electrodes from the poles in a plurality of different connection schemes, each such connection scheme including at least two connected electrodes connected to different poles so that electrical current flows between the connected electrodes along a current path through liquid in at least one of the channels, the circuit also being operable to select isolated electrodes of two different sets which are not connected to a pole of the power supply and connect the selected isolated electrodes to one another so that in at least one connection scheme, the current path extends between the connected electrodes through the isolated electrodes.

A boiler comprising:

• (a) a vessel having a liquid inlet and a vapor outlet;
• (b) a plurality of electrodes disposed within the vessel, the electrodes being disposed in an array extending vertically and extending in at least one horizontal direction so that some of the electrodes are disposed at a higher level than others of the electrodes and some of the electrodes are horizontally offset from others of the electrodes;
• (c) an electrical power supply having at least two poles, the power supply being operable to supply different electrical potentials to different ones of the poles;
• (d) a circuit operable to selectively connect the electrodes to the poles and to selectively disconnect electrodes from the poles in a plurality of different connection schemes, each such connection scheme including at least two connected electrodes connected to different poles so that electrical current flows between the connected electrodes along a current path through liquid in the vessel;
• and
• (e) a control system operative to repeatedly select a connection scheme from the plurality of connection schemes and command the circuit to connect the electrodes in the selected connection scheme, the control system being operative to detect the presence of vapor in current paths associated with various connection schemes and to substantially prevent prolonged operation with those connection schemes having vapor present.

A method of operating a heater comprising the steps of:

• (a) contacting a plurality of electrodes with an electrically conductive liquid;
• (b) selectively connecting electrodes of the plurality of electrodes to establish a conduction path between poles of a power supply through the liquid;
• (c) applying a voltage between the poles to heat the liquid and measuring an actual current flowing through the conduction path;
• (d) comparing the actual current to an expected current for the conductive path;
• and
• (e) repeating steps (b) through (e) with a different selection of electrodes to establish a different conduction path when the comparison performed in step (d) indicates that the actual current is less than the expected current by more than a current tolerance.