The present invention relates generally to fluid treatment systems such as water treatment systems, and more particularly to a reverse osmosis filtration system.
Untreated water includes dissolved minerals, salts, metals and other substances that affect the quality of the water. The dissolved solids in the water come from a variety of sources including leaves, silt, as well as fertilizers and pesticides used in landscaping and agriculture. The amount of the dissolved solids in the water, known as the total dissolved solids (TDS), affects water quality and taste. As a result, the Environmental Protection Agency (EPA) has set standards regarding the acceptable TDS in drinking water. There are also standards or ranges of allowable TDS that are allowable for other uses of water such as for boilers.
Water filter systems have been developed to reduce the TDS in water to meet the EPA's standards and to improve the quality of a water supply. One type of water filtration system is a reverse osmosis filter system that reduces the TDS by 90-99%. Reverse osmosis systems typically include a manual bypass valve that blends or mixes feed water (i.e., incoming water), such as potable water, with product water, treated water or filtered water (i.e., outgoing water) to achieve a desired TDS level in the water. The manual bypass valves are typically manually set to a fixed valve position, where the valve position includes any valve position including a fully closed position, a fully open position and any position therebetween, based on the TDS level in the feed water entering the system. However, the TDS level in feed water varies, and the filter/membrane in the reverse osmosis system degrades or scales over time, resulting in fluctuating feed water TDS concentration levels and product TDS concentration levels that are outside designated water quality standards. To account for such fluctuations in the TDS concentration levels in conventional reverse osmosis systems, the TDS concentration levels in the water must be manually monitored and the bypass valve must be manually adjusted based on the monitored levels to maintain the TDS concentration levels in the product water within desired levels and standards.
Accordingly, there is a need for a water filter system that automatically monitors TDS concentration levels in the water and automatically adjusts the bypass valve to account for variations in treated water TDS levels.