GB2280858A

GB2280858A - Water purifier with different degrees of purification

Info

Publication number: GB2280858A
Application number: GB9414128A
Authority: GB
Inventors: Masafumi Ito; Yoshiaki Yamada; Kazuya Sakamoto; Yasuyoshi Kawabe
Original assignee: Teac Corp; Toyo Roki Mfg Co Ltd
Current assignee: Teac Corp; Roki Co Ltd
Priority date: 1993-07-14
Filing date: 1994-07-13
Publication date: 1995-02-15
Anticipated expiration: 2014-07-13
Also published as: GB9414128D0; KR950002826A; GB2280858B; JPH0724446A; KR0122505B1

Abstract

Water is purified by three successive filters 2, 3, 4, and valves 101, 26 and pump 32 enable water to be delivered to common outlet 7 from the downstream side of any selected filter. Thus water suitable for drinking is filtered by all three filters, while washing water is less purified. Valves and pump are controlled via a control circuit by manual switches. Filter 2 contains a wound fibre element to remove solid particles. Filter 3 contains an active carbon bed followed by a hollow fibre membrane unit. Filter 4 is a reverse osmosis unit which is controlled by a float 30 to maintain downstream storage tank 29 full. Tank 29 may be exposed to ultra-violet light. <IMAGE>

Description

"WATER PURIFIER WITH DIFFERENT DEGREES OF PURIFICATION" The present invention generally relates to water purifiers, and more particularly relates to a water purifier having the function of providing different degrees of purification by cascading different filter mediums.

Water purifiers in the prior art remove impurities from service water by running water through either the wind filter, the activated charcoal filter, or the hollow filter membrane, each of which has a different filtration level. A type of water purifier for a higher degree of purification has been developed which uses the above mentioned filters arranged in a series.

An example of this type of water purifier is the one disclosed in Japanese Patent No. S63-11956.

This water purifier has the water supply portion, the first activated charcoal layer, the second activated charcoal layer, and the cation exchange resin layer in this sequence from the bottom to the top of its cylindrical container, and water provided from the bottom is purified by going through each of the layers.

In the water purifiers of the prior art, the degree of purification cannot be changed by water usage, and the same water filtered at the same filtration level is used, for example, as bath water, washing water, and drinking water. For the use as bath water or washing water, a sufficient degree of water purification can be obtained by using the first activated charcoal layer or an additional second activated charcoal layer, while a higher degree of purification is necessary for drinking water.

Accordingly, water of the highest purification used for drinking is used for all the purposes in the water purifiers of the prior art, because of their inability to change the degree of water purification. This means that the downstream filters, which have higher filtration levels, are wasted by exhaustive use more than necessary.

The water volume decreases as service water goes through each filter, since some of the water is taken out by the filters along with the impurities.

Thus, if highly purified water is used for a purpose which requires water in a large quantity, such as used in a bath or in a sink for washing, a supply of water may not be sufficient.

In recent years, the reverse osmosis membrane has been getting wide attention as a filter medium which can provide a highly purified water. Since it takes time for the reverse osmosis membrane to produce purified water in a large quantity, water purification should be ongoing at any time, and produced water should be kept in a tank prior to use. Obviously, water purifiers using the reverse osmosis membrane can not be used for the purposes which require a large quantity of water.

As described above, water with a different degree of purification is required for a different purpose in a different quantity. Some water purifiers in the prior art can selectively provide either service water or water of a fixed degree of purification, but there are none which meet the demand described above.

Accordingly, there is a need in the field of water purification for a water purifier which can provide water of a different degree of purification for a different purpose in a different quantity.

Accordingly, it is a general object of the present invention to provide a water purifier which can satisfy the need described above.

It is another and more specific object of the present invention to provide a water purifier which can provide water of a different degree of purification for a different purpose in a different quantity.

In order to achieve this object, a water purifier according to the present invention for providing water of different degrees of purification includes a water purification unit for purifying water and having a plurality of cascaded filters having different degrees of purification, a water providing unit for providing water from a point immediately after one of the cascaded filters, and a selecting unit for selecting that one of the cascaded filters.

The water purifier according to the present invention can provide water from a point immediately after a filter selected from the cascaded filters, and, thus, can provide water of a selected degree of purification.

In preferred embodiment of the present invention, the water purifier further includes a water saving unit for saving water filtered by the last one of the cascaded filters, wherein the last one of the cascaded filters is a reverse osmosis membrane filter.

In the water purifier according to the preferred embodiment of the present invention, the reverse osmosis membrane can provide water of a high degree of purification, which is not produced in a large quantity in a short time, but the lack of its quantity is alleviated by the water saving unit which saves the highly purified water. Furthermore, water of different degrees of purification can be provided for different purposes of water use, and, thus, demand for a large quantity of water can be met by providing less purified water than the most highly purified water.

Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.

Figs.l, 2, and 3 are a diagonal view, a plane view, and a front view, respectively, of a water purifier according to the present invention; Fig.4 is a diagram showing the structure for water flow and electrical control of the water purifier according to the present invention; Fig.5 is a illustrative drawing showing the structure of a reverse osmosis membrane filter used in the water purifier in Fig.4; Fig.6 is a diagram showing the inside of the casing in Fig.l; Fig.7 is a cross sectional view which is taken along a vertical plane perpendicular to the front face of the water purifier in Fig.l, and which superimposes some of the elements not on the plane; Fig.8 is an alternate water purifier according to a second preferred embodiment of the present invention; and Fig.9 is an alternate water purifier according to a third preferred embodiment of the present invention.

Figs.l to 3 show a water purifier according to a preferred embodiment of the present invention.

In Figs.l to 3, a water purifier comprises a casing 5 which has a bracket 5a for supporting a first, second, and third water purification tanks 2, 3, and 4 in their standing positions, and comprises exit hose 7 which extends from a rotating part 6 provided on an upper surface 5b of the casing 5. The water purification tanks 2, 3, and 4 are provided in parallel to each other on a front face Sc of the casing 5, and are connected in a sequence by pipes which will be described later. The exit hose 7 is flexible so as to allow free movement of the water exit end, and can be revolved around by rotating the rotating part 6.

The water purification tanks 2, 3, and 4 have containers 8, 9, and 10 which contain different filter mediums of different filtration levels, and those filter mediums can be easily replaced or cleaned after removing lids 8a, 9a, and 10a.

A lever switch 11 is provided between the water purification tanks 2 and 3, and a lever switch 12 between the water purification tanks 3 and 4. The first lever switch 11 is operated for the water purified by the water purification tanks 2 and 3 to come out from the exit hose 7, and the second lever switch 12 for the water purified by the water purification tanks 3 and 4.

Fig.4 shows pipes in the water purifier 1.

The container 8 of the water purification tank 2 contains a wind filter 2A which is comprised of notwist fiber wrapped around a tube and removes from service water the impurities of diameters ore than 30 to 40 pm.

The container 9 of the water purification tank 3 is divided by a dividing plate 13 into a bottom room 9b and an upper room 9c, wherein the bottom room contains an activated charcoal filter 3A and the upper room contains a hollow fiber membrane filter 3B. The activated charcoal filter 3A removes the free chlorine compounds and the like from the water purified by the water purification tank 2. Accordingly, the water coming out of the water purification tank 3 does not destroy vitamins and other nutrition included in food when it is used for washing or cooking food. There is a hole 13a made on the dividing plate 13, and the water filtered by the activated charcoal filter 3A flows through the hole 13a into the upper room 9c. The hollow fiber membrane filter 3B removes impurities of diameters more than 0.04 pm from the water filtered by the wind filter 2A and the activated charcoal filter 3A successively.

The container 10 of the water purification tank 4 contains a reverse osmosis membrane filter 4A.

The reverse osmosis membrane filter 4A removes impurities such as heavy metals of diameters more than 0.0001 Sm from the water filtered by the wind filter 2A, the activated charcoal filter 3A, and the hollow fiber membrane filter 3B successively. Accordingly, the water coming out of the water purification tank 4 is highly purified water from which trihalomethane and heavy metals included in service water are removed, and is as innocuous as drinking water.

As shown in Fig.5, the reverse osmosis membrane filter 4A is comprised of reverse osmosis membranes 15 wrapped around a pipe 14 having a number of holes, and meshes 16a are inserted and make spaces between the reverse osmosis membranes 15. The water coming from the water purification tank 3 flows into the spaces through an entrance opening 17, passes through the reverse osmosis membranes 15, and enters the pipe 14 through its holes after running through the meshes 16b which are denser mesh than the meshes 16a.

The water coming into the water purification tank 4 has been filtered by the wind filter 2A, the activated charcoal filter 3A, and the hollow fiber membrane filter 3B in the water purification tanks 2 and 3, and, thus, impurities of diameters more than 0.04 tm have been removed from the water. This means that the quantity of impurities removed by the reverse osmosis membrane 4A can be maintained as little as possible so that its capacity of water purification can be enhanced. The diluted solution, i.e., the water filtered by the reverse osmosis membranes 15, goes out through the pipe 14, and the concentrated solution, i.e., the water removed by the reverse osmosis membranes 15, is removed through the exit opening 18.

The reverse osmosis membrane 15 is comprised of two layers. One is a dense layer having no holes by a visual inspection, and the other is a porous layer which overlays and supports the dense layer. The mechanism of the reverse osmosis by the reverse osmosis membrane 15 is as follows. With an osmosis membrane separating a diluted solution and a concentrated solution, the solution tries to pass through the osmosis membrane from the side of the diluted solution to the side of the concentrated solution in order to reach equilibrium, in which there exists what is called osmotic pressure between the two sides. When pressure bigger than the osmotic pressure is applied on the side of the concentrated solution, however, the solution can move from the side of the concentrated solution to the side of the diluted solution, and, thus, impurities remaining on the side of the concentrated solution can be separated from the solution.

With reference back to Fig.4, the water supply pipe 19 for bringing service water in is connected to the bottom of the water purification tank 2.

In Fig.4, the first stage purified water which is filtered by the wind filter 2A is supplied through a pipe 22 to the second water purification tank 3 at the bottom. The first stage purified water, then, is filtered by the activated charcoal filter 3A and the hollow fiber membrane filter 3B to become the second stage purified water, which comes out of the second water purification tank 3 to a pipe 24. The second stage purified water, then, is supplied through the pipe 24 to the third water purification tank 4 at the bottom. There is a branch pipe 25 on the pipe 24, and the second stage purified water can go through the branch pipe 25.

The bottom end point of the branch pipe 25 is connected to the exit hose 7, and a first electromagnetic valve 26 is provided on the branch pipe 25. When the first electromagnetic valve 26 is opened, the second stage purified water coming from the second water purification tank 3 goes out of the exit hose 7.

A second electromagnetic valve 27 is provided on the pipe 24 further downstream than the branching point of the branch pipe 25. Thus, the second stage purified water running through the pipe 24 is supplied to the third water purification tank 4 when the electromagnetic valve 27 is open, and, then, is filtered by the reverse osmosis membrane filter 4A.

The third stage purified water which is filtered by the reverse osmosis membrane filter 4A is supplied through a pipe 28 to a water saving tank 29, which is contained in the casing 5.

In the water saving tank 29, there is a water level sensor 30 which monitors the volume of the saved water. When the water in the water saving tank 29 is full, the water level sensor 30 provides an output signal, which makes the electromagnetic valve 27 close.

A pipe 31 is inserted from the top into the bottom of the water saving tank 29, and the other end of it is connected to the exit hose 7. The pipe 31 is provided with a pump 32 and a reverse flow prevention valve 33.

The pump 32 can be switched on by operating the lever switch 12, and takes purified water out of the water saving tank 29 to send it to the exit hose 7.

The reverse flow prevention valve 33 prevents the second stage purified water from flowing into the water saving tank 29.

The reverse osmosis membrane filter 4A can not carry out filtration when the osmotic pressure becomes too high because of the high concentration of impurities in the water purification tank 4. Thus, the remaining water in the water purification tank 4 should drain to keep the concentration of impurities at a constant level. In order to take out the concentrated solution with impurities, the third water purification tank 4 is provided with a first waste pipe 34 which has a relatively small diameter, and with a second waste pipe 35 which has a relatively large diameter.

The concentrated solution drains constantly through the first waste pipe 34. The third electromagnetic valve 36 is opened once in a predetermined period, takes the remaining water out of the water purification tank 4, and cleans the reverse osmosis membrane filter 4A.

As shown in Fig.6, the casing 5 contains the water saving tank 29, the pump 32, a germicidal lamp 37 for germiciding the inside of the casing 5 by ultraviolet light, a valve unit 39 including a base 38 provided with the electromagnetic valves 26, 27, and 36, and a temperature sensor 40 provided on the water supply pipe 19 for measuring the temperature of supplied water. If the temperature sensor detects that the temperature of the supplied water is more than 35 degrees in Celsius, the electromagnetic valves 26 and 27 close in order to prevent the filters from degrading from the heat and to stop the process of water purification.

With reference to Figs.4 and 7, the water purifier 1 has the first, second, and third water purification tanks 2, 3, and 4 on its front face, and the casing 5 behind the water purification tanks 2, 3, and 4 contains the water saving tank 29 and the pipes 22, 24, 25, 28, 31, 34, and 35 which include the first, second, and third electromagnetic valves 26, 27, and 36. The pipes 22, 24, 25, and 28 which are connected to the water purification tanks 2, 3, and 4 are collectively mounted on the casing 5 just behind the water purification tanks 2, 3, and 4. The replacement of the filters can be easily done by taking away the lids 8a, 9a, and 10a in Fig.1.

As shown in Fig.7, the lever switches 11 and 12 between the water purification tanks 2, 3, and 4 are mounted on the bracket 41. Turning the lever switches 11 and 12 to the position A makes end points lla and 12a turn on micro-switches 42 and 43, respectively.

When the lever switches 11 and 12 are in the position B, the micro-switches 42 and 43 are off, respectively.

With reference back to Fig.4, a control circuit 44 opens the electromagnetic valve 26 on the branch pipe 25, when the lever switch 11 is turned to the position A and the micro-switch 42 is on. As a result, the second stage purified water filtered by the water purification tank 2 and 3 goes out from the exit hose 7 through the branch pipe 25. When the lever switch 11 is turned to the position B and the microswitch 42 is off, the electromagnetic valve 26 closes.

The control circuit 44 switches the pump 32 on, when the lever switch 12 is turned to the position A and the micro-switch 43 is on. As a result, the third stage purified water saved in the water saving tank 29 is pump out from the exit hose 7 by the pump 32. When the lever switch 12 is turned to the position B and the micro-switch 43 is off, the pump 32 stops pumping.

If the lever switches 11 and 12 are simultaneously set to the position A, a signal from the micro-switch 43 is given priority, and the pump 32 is switched on.

When the water level sensor 30 detects that the water saving tank 29 is not full, the control circuit 44 opens the second electromagnetic valve 27, and the second stage purified water is supplied to the third water purification tank 4. Upon the detection of the fullness of the water saving tank 29 by the water level sensor 30, the second electromagnetic valve 27 closes.

Since the third water purification tank 4 contains the reverse osmosis membrane filter 4A which carries out filtration by applying larger pressure than the osmosis pressure, water is not supplied in a large quantity to the water saving tank 29 through the pipe 28. Since the water saving tank 29 is kept full by opening the electromagnetic valve 27 at any time when it is not full, however, there is no lack of water which is highly purified by the reverse osmosis membrane filter 4A.

As described above, since the branch pipe 25 is connected to the pipe 24, the operation of the lever switches 11 or 12 makes possible that the second stage purified water or the third stage purified water can be selectively used according to the water usage. For example, when water is used as bath water or washing water, the lever switch 11 is operated to use the second stage purified water, and when water is used as drinking water, the lever switch 12 is operated to use the third stage purified water.

Accordingly, there is no lack of water even when water is used for washing or taking bath, and since all the types of purified water are not filtered by the reverse osmosis membrane filter 4A, the reverse osmosis membrane filter 4A gets less dirt than otherwise it would, and thereby the life of the osmosis membrane filter 4A is elongated.

In Fig.8, an alternate water purifier according to a second preferred embodiment of the present invention is shown. An alternate water purifier 1A according to the second preferred embodiment of the present invention in Fig.8 differs from the water purifier 1 of Fig.4 only in an additional branch pipe 100 and an additional electromagnetic valve 101. In Fig.8, the electrical control system shown in Fig.4 is not shown for clarity of the figure. In the alternate water purifier 1A, either one of the first stage purified water coming out of the first water purification tank 2, the second stage purified water coming out of the second water purification tank 3, or the third stage purified water coming out of the third water purification tank 4 can be selected to provide water of a desired degree of purification.

In Fig.9, an alternate water purifier according to a third preferred embodiment of the present invention is shown. An alternate water purifier 1B according to the third preferred embodiment of the present invention in Fig.9 differs from the water purifier 1 of Fig.4 only in a first exit hose 7a and a second exit hose 7b. In an alternate water purifier 1B, the second stage purified water coming out of the second water purification tank 3 and the third stage purified water coming out of the third water purification tank 4 can be obtained from the first exit hose 7a and the second exit hose 7b, respectively.

With this configuration in Fig.9, water for different purposes can be obtained simultaneously.

In the preferred embodiments described above, the configuration of the three water purification tanks 2, 3, and 4 in a series connection has been described as an example, but it is apparent that two or more than three water purification tanks can be used in the present invention.

Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.

Claims

WHAT IS CLAIMED IS

1. A water purifier for providing water of different degrees of purification comprising; water purification means for purifying water and having a plurality of cascaded filters having different degrees of purification; water providing means for providing water from a point immediately after one of said cascaded filters; and selecting means for selecting said one of said cascaded filters.

2. The water purifier as claimed in claim 1, wherein said cascaded filters arranged in a degrees of purification with the filter of highest degree of purification located downstream.

3. The water purifier as claimed in claim 2, wherein said water providing means is a system of pipes.

4. The water purifier as claimed in claim 3, wherein said selecting means is a system of valves.

5. The water purifier as claimed in claim 4, wherein said selecting means further comprises a plurality of switches for operating said valves.

6. The water purifier as claimed in claim 5, wherein said system of pipes comprises a pipe and a plurality of other pipes, each of said other pipes leading water from a point immediately after different one of said cascaded filters to one end of said pipe, the other end of said pipe serving as an exit for water, said different one including a last one of said cascaded filters.

7. The water purifier as claimed in claim 6, further comprising input means for receiving water at a point before a first one of said cascaded filters.

8. The water purifier as claimed in claim 7, further comprising water saving means for saving water filtered by said last one of said cascaded filters, wherein said last one of said cascaded filters is a reverse osmosis membrane filter.

9. A water purifier substantially as hereinbefore described with reference to and as illustrated in any one of Figures 1 through 9.