The invention relates generally to water delivery systems. More specifically, the invention relates to a water delivery system comprising a sink, faucet, and pumping devices that continuously circulates clean water and diverts dirty water that has touched a user's hands. By diverting only contaminated water and recirculating clean water, the water delivery system has the ability to improve water conservation.
Several prior art systems have been designed in an attempt to conserve water. For example, in public restrooms, some systems rely on sensors that automatically turn on the flow of water when a user's hands are placed below the faucet. To conserve water, the flow is terminated when the user's hands are removed. These widely used systems are often referred to as automatic faucets. Automatic faucets have two key parts: a sensor, such as an infrared sensor, that senses the proximity of the user's hands and an electrically switched valve that opens the water flow.
Theses automatic faucets suffer from problems associated with both the sensor and the switched valve. For example, the sensor is not always accurate and may start the water flow too early or keep it running after the user moves his hands away from the faucet. In addition to wasting water, the lack of accurate responsiveness of those sensors results in inconvenience to the user.
The main disadvantage with these types of systems is the added cost. In addition, automatic faucets require batteries, which deplete and run out over time, or require a dedicated power source. These components are vulnerable to failure. In fact, the fundamental disadvantage of the automatic faucets' water conservation methodology is that it relies on sensing and switching, both of which are carried out by extra components that require power, maintenance, and can fail.
Other water conserving systems include self-closing faucets, such as those used in airplanes and other public restrooms. With these systems, the user depresses a knob on the faucet to begin the flow of water. The knob slowly returns to the off position, at which time the water flow ceases. Users find these faucets inconvenient because the time period the faucet stays open is fixed and is normally too short for a particular user and she has to re-press the knob several times while using the faucet. If the faucet remains open too long, water is being wasted. Theses faucets are prone to failure of the mechanical timing mechanism that results in the time period becoming even shorter, leading to inconvenience, or longer and leading to water waste. Another disadvantage of self-closing faucets is the need to touch them with unclean hands, which is a hygiene hazard in public bathrooms and health facilities. It would therefore be advantageous to develop a water conservation system that does not suffer the drawbacks associated with the prior art.