US 5,492,602 AGranted

Water purifier having a multi-level boiler tray

AssigneeEmerson Electric Co.

InventorsJonathan C. Vogelman, William F. Strutz

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Abstract

A distiller for producing potable water employs a metal boiler tray having a cover member in which there is an inlet for raw water and which together form a steam chamber having an outlet for steam. The boiler tray bottom has a plurality of steps including a highest, an intermediate and a lowest level step which are all covered with water at the beginning of a distillation cycle. The temperature of the highest level step is monitored with a sensor. A rise in the temperature of the highest level step by a predetermined amount above the boiling temperature of water indicates that the highest and intermediate level steps have become dry. This results in a signal to a controller to open a valve and admit replenishment raw water whose amount is dependent on valve open time. Steam evolved from the boiler tray is conducted through a first check valve in the cover member to demister chamber when the mist or carryover water in the steam impinges on a baffle and is separated from the steam as condensate. A feedback tube having a check valve interconnects the demister chamber with the steam chamber so that negative pressure in the steam chamber that accompanies infeed of cool raw water causes the condensate to be withdrawn from the demister chamber and returned to the boiler chamber.

Claims35

Dependent claims

A water distiller including a steam generating chamber, a condenser, means defining a passageway for conducting steam from the chamber to the condenser,

the steam generating chamber comprising a boiler tray for containing water, the boiler tray having a bottom including a succession of highest, intermediate and lowest level steps such that the water may vary in depth from the least depth above the highest level step to the greatest depth above the lowest level step,
an electric heater element for heating the boiler tray,
a cover member for covering the boiler tray to define the chamber and to contain steam generated by heating water in the boiler tray,
a raw water infeed valve controllable to initiate and terminate the infeed of water to the boiler tray, said infeed valve having an inlet for connecting to a source of raw water and an outlet, the steam chamber having an inlet for raw water to which said outlet of said infeed valve is coupled,
a temperature sensor for sensing the temperature of the boiler tray,
a controller operatively connected to said infeed valve, to said temperature sensor and to said heater element,
said controller responding to occurrence of a boiler tray temperature sensed by said sensor indicative of the water above the highest and intermediate steps of the tray bottom having been evaporated and water still boiling on the lowest level step of the boiler tray bottom by controlling said infeed valve to open for water to flow from said outlet of the infeed valve to said inlet of said chamber for a predetermined time interval sufficient to cover all steps of the boiler tray bottom and then terminate infeed of water.

4 more elements

A water distiller comprising:

a boiler tray for containing water having an interior bottom surface and an exterior bottom surface, the interior bottom surface having a highest level step and at least one lowest level step such that water in the tray can vary in depth from the least depth above the highest level step to the greatest depth above the lowest level step,
an electric heater element arranged in heat transfer relationship with said exterior bottom surface of the boiler tray,
a cover member for closing the boiler tray to define a chamber for containing steam resulting from the heater element boiling water covering the steps in the interior bottom of the boiler tray, the chamber having an inlet for raw water,
a condenser and means providing a passageway for conducting the steam from said chamber to said condenser,
a valve having an inlet for connecting to a source of raw water and an outlet, and, means for connecting the outlet to said inlet for raw water in said chamber said valve being controllable to open to initiate infeed of water to the boiler tray and to close for terminating infeed of water,
a temperature sensor arranged out of contact with any water in the tray and in contact with the tray for sensing the temperature of the boiler tray in the vicinity of the highest level step in the boiler tray,
a controller operatively connected to said infeed valve, to said temperature sensor and to said heater element,
said controller responding to said sensor sensing a temperature above the boiling point of water in said vicinity of said highest level step indicative of the water formerly covering said highest level step having been evaporated while there is still water boiling on the lowest level step by said controller causing said valve to open for raw water to be conducted from said outlet of said valve of said inlet of said chamber for raw to be received in the boiler tray at a step in the bottom of the boiler tray at a level above said lowest level step, the infeed of water being terminated by said controller controlling said valves to close when a predetermined depth of water above the highest level step in the tray bottom attained.

5 more elements

Dependencies are inferred from the claim text.