Electrically insulated air-conducting water heater

Abstract

Electric shock to a user has been a major concern for a conventional electric water heater installed in or near a bathroom. An electrically insulated air-conducting water heater utilizes electrically insulating hot air to indirectly heat water to avoid electric hazard to a user of an electric water heater. The present invention comprises an air pump unit, a heating and temperature control unit, and an air venting unit having a plurality of tiny air nozzles immersed in a water pool. Ambient air is collected by the air pump unit, heated in the heating and temperature control unit, and injected into a water pool through the air venting unit as a form of zillions of small hot bubbles to heat the water. Apart from serving as an electrically safe water heater, the present invention also functions as a hot-bubble sauna machine, bathroom body dryer, and air conditioner.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a water heater, particularly to a water heater using electrically insulating air as a heat conducting medium to increase water temperature.BACKGROUND OF THE INVENTION[0002]In general, there are two types of water heaters, one burning natural gas and the other consuming electricity to raise the temperature of water. The latter is often adopted as a replacement for the former to avoid the danger of carbon-monoxide poisoning. However, a conventional electrical water heater employs an electric heating element or coil in direct contact with water through a heat conducting metallic material. In practice, only pure water is a good insulator. A user of an electric water heater could be constantly exposed to electric hazard when, for instance, taking a bath. The present invention overcomes this difficulty by adopting air, a much better electrically insulating medium, to conduct heat from an electric heating element to water. The pr...

AI Technical Summary

Benefits of technology

[0006]The air venting unit has a plurality of tiny air nozzles, through which hot air is injected into water in the form of a great number of micro hot air bubbles. Since a micro air bubble has a smaller buoyant force compared with that of a large air bubble, a micro-bubble can be kept in water for a longer time to heat the water. Furthermore, the overall heating area of a great number of micro-bubbles can be significantly larger than that of a single large air bubble of the same volume Therefore, the heat stored in the air can be efficiently conducted to water. The following theory provides a concrete proof to the concept.

[0008]As mentioned above, a smaller hot bubble has smaller buoyant force and can stay in water over a longer time. According to the Archimedean principle, a body immersed in a fluid gets a buoyant force FB equal to the weight of the fluid it displaces. In other words, a bubble experiences a buoyant force equal to the weight of the water having the same volume as the bubble:FB=ρVg   (9)where V is the volume of a bubble, p is the density of a fluid, and g is the gravitational acceleration. It is evident from Equation (9) that the buoyant force FB and thus the upward acceleration of the bubble in water are proportional to its own volume. In other words, a smaller hot bubble can stay in water longer than a larger one. This increased heating time allows the smaller hot air bubbles to transfer more heat to water.

[0009]Thus, the disclosure of using a large amount of hot micro-bubbles to heat water is a key technical advancement of the present invention. The small bubble size not only increases the heat transfer area between air and water but also increases the heating time of air to water. This technical advancement effectively increases the heat transfer efficiency from hot air to water.

[0012]According to the aforementioned concepts, the present invention employs electrically insulating hot air as a heating medium for a water heater. Electric energy is first transferred to heat energy stored in air, which is then transferred to water through a thermal conductive structure, or a large number of hot air bubbles in water, or both. This water heating process ensures electric insulation between the electricity and a user in water. The high speed air bubbles ejected from the tiny air nozzles in the air venting unit can at the same time generate ultrasound to massage or clean a user in the water pool, dry the body of a person or a pet animal, and warm up a cold bathroom.

Problems solved by technology

A user of an electric water heater could be constantly exposed to electric hazard when, for instance, taking a bath.

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