| 摘要 |
An electrode boiler includes a boiler shell having at least two spaced electrodes arranged about a vertical axis and positioned to be at least partially immersed in a water zone in the shell; the water zone including a relatively cold water zone below the lower edges of the electrodes. A pair of vertically spaced nozzles are provided for introducing water into the shell during operation of the boiler. The vertically higher nozzle is arranged to introduce water into the shell in the water zone directly between the electrodes in substantially horizontal radially-directed jets. The vertically lower nozzle is arranged to introduce water directly into the relatively cold water zone in a stream directed on the base of the boiler shell. Boiler pressure responsive control of a feed water supply system allows water to be supplied to the boiler only through the vertically upper nozzle when the boiler is at or below a normal pre-set boiler steam pressure, and only through the vertically lower nozzle when the pre-set boiler steam pressure is exceeded, thereby minimizing electrical load and water level fluctuations that would occur or be aggravated by introduction of relatively cold water into the water zone between the electrodes while the boiler is overpressure. At fixed time intervals while the boiler is at or below the pre-set pressure, the introduction of water through the upper nozzle is terminated and highly conductive salt laden water is bled therethrough from between the electrodes to waste.
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