Electrode boilers

Claim 3

A method as defined in claim 1, wherein said step of feeding additional water consists of effecting a single uninterrupted feeding of water terminating when the magnitude of said current reaches said second value.

Claim 4

A method as defined in claim 1, wherein said step of withdrawing water consists of effecting a single uninterrupted withdrawal of water.

Claim 5

An arrangement comprising an electrode steam boiler of the type comprising electrodes supported in the interior of the boiler and maintained at least partly immersed in water contained in said boiler for heating such water and extending into the water in said boiler in direction transverse to the plane of the water level in said boiler; monitoring means for monitoring the magnitude of the current flowing through at least one of said electrodes while said electrodes are partly immersed in the water in said boiler to indirectly monitor the lowering of the water level in said boiler resulting from the conversion of the water in said boiler into steam; feeding means operatively associated with said monitoring means and operative for feeding additional water into said boiler beginning at a time after the magnitude of said current has fallen to a predetermined first value as a result of the fall of the water level to a predetermined first level due to the conversion of the water in said boiler into steam and operative for effecting such feeding of additional water only until the magnitude of said current rises to a predetermined second value indicative of a rise of the water level in said boiler to a predetermined second level higher than said first level; and withdrawing means operatively associated with said monitoring means and operative for withdrawing water from said boiler beginning at a time after the magnitude of said current has fallen to said first value and only until a time before the magnitude of said current again falls to said predetermined first value.

Claim 6

An arrangement comprising an electrode steam boiler of the type comprising electrodes supported in the interior of the boiler and maintained at least partly immersed in water contained in said boiler for heating such water and extending into the water in said boiler in direction transverse to the plane of the water level in said boiler; monitoring means for monitoring the magnitude of the current flowing through at least one of said electrodes while said electrodes are partly immersed in the water in said boiler to indirectly monitor the lowering of the water level in said boiler resulting from the conversion of the water in said boiler into steam; feeding means operatively associated with said monitoring means and operative for feeding additional water into said boiler beginning at a time after the magnitude of said current has fallen to a predetermined first value as a result of the fall of the water level to a predetermined first level due to the conversion of the water in said boiler into steam and operative for effecting such feeding of additional water only until the magnitude of said current rises to a predetermined second value indicative of a rise of the water level in said boiler to a predetermined second level higher than said first level; and withdrawing means operatively associated with said monitoring means and operative for withdrawing water from said boiler beginning at a time after the magnitude of said current has fallen to said first value and only until a time before the magnitude of said current again falls to said predetermined first value.

Claim 7

An electrode steam boiler comprising a water-receiving shell, water-heating electrodes supported in said shell, means for supplying current to said electrodes, a pump for supplying feed water to said shell, means for monitoring the current supplied to at least one of said electrodes, means controlled by said monitoring means for starting said pump during a period commencing after said current falls below a first predetermined value and for subsequently stopping the pump when the current subseQuently rises to a second and higher predetermined value, and further means controlled by said monitoring means for withdrawing water from the shell in a period following the fall of the current to said first predetermined value during which the feed water pump is inoperative.

Claim 8

An electrode steam boiler comprising a water-receiving shell, water-heating electrodes supported in said shell, means for supplying current to said electrodes, a pump for supplying feed water to said shell, means for monitoring the current supplied to at least one of said electrodes, means controlled by said monitoring means for starting said pump during a period commencing after said current falls below a first predetermined value and for subsequently stopping the pump when the current subseQuently rises to a second and higher predetermined value, and further means controlled by said monitoring means for withdrawing water from the shell in a period following the fall of the current to said first predetermined value during which the feed water pump is inoperative.

Claim 11

The method claimed in claim 6, in which each period of water withdrawal from the boiler ends immediately before the commencement of an interval of feed water supply, so that water withdrawal occurs when the concentration of salts in the boiler water is highest.

Claim 12

The method claimed in claim 6, in which the quantity of water withdrawn during each withdrawal period is set to a predetermined value, which value is adjustable.

Claim 13

The method claimed in claim 6, in which the water is withdrawn from a region in the boiler adjacent to the lower ends of the electrodes.

Claim 14

A boiler as claimed in claim 5, in which the means for withdrawing water from said shell is a pipe connected to said shell and valve means controlling the flow of water through said pipe.

Claim 15

A boiler as claimed in claim 5, in which the means for withdrawing water from said shell is a pipe passing through the shell wall into the interior of said shell and valve means controlling the flow of water through said pipe.

Claim 16

A boiler as claimed in claim 10, in which said valve means is electrically operated, opening and closing of said valve means being effected in timed relationship with the intermittent operation of said feed water pump.

Claim 17

A boiler as claimed in claim 12, in which said monitoring means comprises an adjustable electric timer arranged to open said valve means for a pre-set period prior to each period of operation of said feed water pump, and to close said valve means prior to initiating operation of said feed water pump.

Claim 18

A boiler as claimed in claim 11, in which said valve means is electrically operated, opening and closing of said valve means being effected in timed relationship with the intermittent operation of said feed water pump.

Claim 19

A boiler as defined in claim 14, in which said monitoring means comprises an adjustable electric timer arranged to open said valve means for a pre-set period prior to each period of operation of said feed water pump, and to close said valve means prior to initiating an operation of said feed water pump.