Patent Application
20080023400
With initial reference to
The pre-filter 12 in the primary flow branch 18 includes a first container 30 having an inlet 32 adjacent an outer wall and a centrally located pre-filter outlet 34. Within the container 30 is a pre-filter cartridge 36 with a conventional filter medium, such as a tubular body of a spun fiber material through which the water flows to trap relatively large particles. If the source water is relatively free of large particles, the pre-filter 12 may be eliminated. The water to be treated enters the inlet 32 flows through the pre-filter cartridge 36 to a central bore which communicates with the pre-filter outlet 34. The pre-filter outlet 34 is connected by a conduit 40 to an inlet 42 of the ion separation module 14.
The ion separation module 14 has a standard ion separation membrane 46, such as a reverse osmosis membrane or a nano-filtration membrane, within a second container 44, thereby defining an outer chamber 48 and an inner chamber 50 that are separated by the membrane 46. Alternatively, the ion separation module 14 may comprise an electrodialysis device, an electrodialysis reversal device, a distillation unit, or a capacitive deionization device. The inlet 42 for the ion separation module 14 opens into one end of the outer chamber 48. A drain outlet 52 is located at the opposite end of the outer chamber 48 and is significantly smaller than the inlet 42. The size differential between the inlet 42 and the outlet 52 creates a pressure differential between the outer and inner chambers 48 and 50, which forces some of the water through the ion separation membrane 46 into the inner chamber 50 in a well known manner as in standard reverse osmosis systems. The drain outlet 52 is connected to a drain line 54 that either leads to a sewer system or may be recycled via a pump (not shown) to the water inlet port 26 of the treatment system, as is done in previous reverse osmosis water treatment systems for water conservation.
The ion separation module 14 has a treated water outlet 56, which is connected to an inlet 58 of the post-filter 16. The post-filter 16 has a third container 60 within which a conventional tubular-shaped filter medium 62 is located. The filter medium 62 for the post-filter 16 can be similar to that used in the pre-filter 12 but able to trap smaller particles, or it may be another type, such as a sediment filtration medium or activated charcoal. The treated water from the ion separation module 14 flows through the post-filter medium 62 exiting that filter via an outlet 64, which is connected to the water outlet port 28 of the first water treatment system 10. Thus, highly purified water passes from the primary flow branch 18 to the water outlet port 28.
As noted previously, such highly purified water is devoid of minerals, which are beneficial to a person's health, and is relatively tasteless. As a result, the bypass flow branch 20 provides a fluid path parallel to the primary flow branch 18 so that some minerals in the source water reach the water outlet port 28, thereby providing improved taste and beneficial minerals to the treated water. In particular, the water inlet port 26 for the first water treatment system 10 also is connected to an inlet 66 of a bypass filter 22. The bypass filter contains a filter medium similar to that used in the pre-filter 12. The bypass filter 22 has an outlet 70, which is connected by the orifice 24 to the water outlet port 28 of the first water treatment system 10. The size of the bypass orifice 24 is selected to determine the portion of the total water flow through the first water treatment system 10, which passes through the bypass flow branch 20. For example, when used where the feed water contains approximately twice the level of minerals that would be deemed to be healthy, the orifice would be set to allow about half of the feed water to enter the by-pass.
A bypass flow branch 124 is connected in parallel with that primary flow branch 111. The bypass flow branch 124 includes a conduit 126 that couples the outlet 106 of the pre-filter 104 to a variable orifice 128, such as provided by an adjustable valve. The variable orifice 128 allows a user to adjust the portion of the total flow through the second water treatment system 100 which passes through the bypass flow branch 124. This controls the amount of minerals which are allowed to bypass the primary flow branch 111 for health and taste reasons. The terminus of the bypass flow branch 124 is connected to a conduit 119 coupled to the treated water outlet 117 of the ion separation module 110 thereby combining the water flows from the primary and bypass flow branches 111 and 124.
That combined water flow is applied to a sterilization module 118, which may either treat the water flowing there through with light from an ultraviolet source or pass that water through a membrane that is capable of retaining pathogens. The sterilization module 118 eliminates pathogens from the water flow. The outlet 120 of the sterilization module 118 is coupled to the water outlet port 122 of the second water treatment system 100. Alternatively, a post filter, similar to the post-filter 16, may be inserted between the treated water outlet 117 of the ion separation module 110 and the inlet of the sterilization module 118.
It should be noted that the variable orifice 128 of
The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.
