초록 ▼

An electric water heater has a vertically disposed tank with a cold water inlet, a hot water outlet and at least one horizontally disposed elongated immersion heating element extending into the region of the tank between an upper region and a lower region. Each heating element is surrounded by an el

An electric water heater has a vertically disposed tank with a cold water inlet, a hot water outlet and at least one horizontally disposed elongated immersion heating element extending into the region of the tank between an upper region and a lower region. Each heating element is surrounded by an elongated closed end tubular sleeve having a plurality of lower openings distributed along the length of the sleeve below the heating element therein and a plurality of upper opening distributed along the length of the sleeve above the heating element. The total area of the upper openings is greater than the area of the lower openings to generate upon operation of the heating element an upwardly directed transverse flow of water in a direction from the lower openings to the upper openings along the entire length of the sleeve. A thermosiphon bypass check valve connected between the cold water inlet and the hot water outlet having a bypass conduit with one or more constrictions and a closure member. The operation of the bypass check valve along with the sleeve surrounding each element generates a thermosiphon effect which improves heat transfer to the water in the tank and thus the heat recovery rate.

대표청구항 ▼

1. In a water heater having an elongated vertically disposed water tank adapted to be normally filled with water, a cold water inlet conduit for delivering cold water to a lower region of the tank, a hot water outlet conduit for removing heated water from an upper region of the tank, and at least on

1. In a water heater having an elongated vertically disposed water tank adapted to be normally filled with water, a cold water inlet conduit for delivering cold water to a lower region of the tank, a hot water outlet conduit for removing heated water from an upper region of the tank, and at least one elongated heating element positioned in the tank so as to be immersed in the water between the upper and lower regions, the at least one heating element extending generally horizontally into the tank from an inner sidewall of the tank to heat water in the tank, the improvement comprising a thermosiphonic apparatus for improving the efficiency of the water heater, the apparatus comprising:an elongated tubular sleeve having a closed end and surrounding each of the at least one heating element, each sleeve having a first plurality of upper openings for providing waterflow communication between the sleeve's inside and outside, the first plurality of openings being distributed along substantially the entire length of the sleeve and being normally positioned above the heating element within the sleeve, and a second plurality of lower openings for providing waterflow communication between the sleeve's inside and outside, the second plurality of openings being distributed along substantially the entire length of the sleeve and being normally positioned below the heating element, the total area of the upper openings being greater than the total area of the lower openings, whereby upon operation of the at least one heating element, the sleeve generates along substantially the entire length thereof an upwardly directed transverse waterflow through the sleeve and in a direction from the second plurality of openings to the first plurality of openings; a bypass conduit positioned externally of the tank and positioned to cause delivery of heated water from the hot water outlet conduit to the cold water inlet conduit, the bypass conduit having an upper end connected to the cold water inlet conduit and a lower end connected to the hot water outlet conduit, said bypass conduit extending upwardly from its connection with the hot water outlet conduit to its connection with the cold water inlet conduit, so that hot water will rise in the bypass conduit, from the hot water outlet conduit to the cold water inlet conduit; and a flow control valve in the bypass conduit having an open position and a closed position, such that in the open position hot water flows from the hot water outlet conduit to the cold water inlet conduit and in the closed position waterflow is obstructed from flowing from the hot water outlet conduit to the cold water inlet conduit; wherein the cold water inlet conduit is substantially immersed within the tank and comprises sidewalls and an open lower end, said sidewalls extending generally vertically downwardly within the tank from an upper wall of the tank to the lower region of the tank, whereby the operation of the bypass conduit cooperatively with the at least one heating element surrounded with the sleeve causes heated water to be circulated by thermosiphonic action in the tank through the bypass conduit from the upper region to the lower region.