Air is introduced and retained within a nonpressurized hot water heater tank when water is supplied to the tank and is slowly exhausted after the water supply is shut off to provide space within the tank for expansion of the water when heated. In the embodiment shown, air is aspirated into the water supply and is accumulated within an inverted cup located within the tank. When the water supply stops, air escapes from the cup thereby providing a space within the tank into which the water can expand.
There is provided a heater which includes a vessel in which liquid is contained, and a heater to heat the liquid, the vessel having an inlet by which liquid can be fed into the vessel, and an outlet through which liquid may flow to a point of delivery. The inlet comprises a supply conduit connected to a liquid supply, and liquid flowing along the supply conduit is mixed with a gas. A gas trap is provided to collect gas passing with the liquid from the supply conduit within the vessel, and includes an opening to release collected gas into the vessel, whereby at least when the liquid flow along the supply conduit is stemmed, the released gas provides an expansion space in the vessel into which liquid can expand during subsequent heating, the expansion space being vented from the vessel. An air control valve restricts the amount of gas available for mixing with the liquid as the liquid flow rate through the supply conduit increases, thereby preventing aeration of the liquid.
A water heating and dispensing device includes a tank which forms the main hot water container, a heating device in the tank which is thermostatically controlled in order to maintain the temperature of the water at the desired level, inlet and outlet conduits associated with the tank and a valve associated with the inlet conduit for controlling water flow into the tank and dispensing of water from the outlet conduit. A separate reservoir is connected to the inlet conduit between the valve and the tank through a venturi nozzle which permits water to flow into and out of the reservoir. The reservoir has collapsible wall portions which collapse to provide for a decrease in volume in the reservoir as water is drawn from it through the venturi nozzle during dispensing of water, and which is expandable to an expanded maximum completely filled condition after dispensing has ceased, as a result of water flowing back from the main hot water container through the venturi nozzle. The maximum filled position has a sufficient volume to reduce the water level in the tank and outlet conduit sufficiently to allow for expansion of water in the tank due to heating, without dispensing water from the outlet conduit due to expansion. The reservoir comprises a cylindrical collapsible tube concentric with the inlet conduit and provided at one end with a rigid closure member in which is formed the venturi nozzle.
A volume compensation device for a hot water heater composed of a water tank equipped with a cold water inlet and a hot water outlet, for heating and storing water, the device including: a bellows enclosing a variable volume chamber; a conduit connected for placing the chamber in flow communication with the interior of the tank; and a pressure or temperature controlled lifting mechanism coupled to the bellows for varying the volume of the chamber in response to a temperature related change in the volume of the water in the tank.
A thermal expansion arrester for positioning within the tank of a water heater comprises a rigid tube maintaining a compressible volume of gas between first and second closure members wherein at least one of the closure members comprises a piston that is slidably and sealingly secured within the tube. In a preferred embodiment both closure members comprise pistons held in the tube by crimping its ends. In an uncompressed state the pressure of the gas within the tube is sixty psig.
A device suitable for supplying boiling water, having a thermally insulated compression resistant water reservoir, an electric heating element of such power that the water present in the reservoir is heated to a temperature above its atmospheric boiling point, a temperature control, with which the temperature of the water in the reservoir is adjusted above the boiling temperature under atmospheric pressure, a water inlet circuit which is connected to the water mains and which is suitable for supplying an inlet flow which is at least equal to the delivery flow of the device, as well as a discharge conduit for boiling water joined directly to the reservoir and connected to the top part thereof, the water inlet circuit terminating under or at the underside of the heating element, such a discharge valve is mounted directly on the reservoir or at a point in the discharge conduit as close as possible to the discharge opening in the reservoir.
