JPS58223476A - Water purifying device - Google Patents

Abstract

PURPOSE:To prevent deterioration of function of a separating membrane and to improve a desalting performance, by forming the separating membrane of a separator with cellulose acetate semipermeable membrane, and providing a valve on the passage of clear water from the separator to a water tank or a clear water discharge port. CONSTITUTION:When concentration of impurities in clear water is discriminated to be below specified value by a sensor 55 and a water quality discriminating circuit 57, a three-way valve 59 connects the line between a separator 39 and a water tank 51. Discriminated clear water is sent to the water tank 51. When concentration of impurities in clear water is above specified value, the valve 59 connects the line between the separator 59 and a clear water discharge port 53. When discriminated clear water flows to the clear water discharge port 53, and a water purifying device 33 is in suspension, the three-way valve 59 closes the passage between the separator 39 and water tank 51 to prevent mixing of water in the water tank 51 with undiscriminated water, and connects the line to the clear water discharge port 53.

Description

[Detailed description of the invention] This invention relates to improvements in water purification devices.

Some water purification devices use cellulose acetate-based semipermeable membranes as separation membranes. When this semipermeable membrane dries, it deteriorates and its desalting ability decreases.

By the way, in recent water purification devices, a device (hereinafter referred to as a clean water discriminating device) is used that detects the electrical conductivity of fresh water, determines whether it is good or bad, and either guides the fresh water to a water storage tank or discharges it. It is being

The valve of this device is a three-way valve.If a cellulose acetate-based semipermeable membrane is used as a separation membrane in a water purification device using this device, the following problems may occur.

That is, as shown in FIG. 1, the sensor 55 determines whether the quality of fresh water is good or bad. The fresh water that has detected this sensor 55 is discharged to the water storage tank 51 or the fresh water outlet 53 by a three-way valve.
sent to. That is, good quality fresh water is sent to the water storage tank 51, and poor quality fresh water is sent to the fresh water outlet 53.

On the other hand, the fresh water located between the separator 39 and the sensor 55 (hereinafter referred to as unclassified fresh water) is not classified by the vermilion sensor 55. Therefore, while the water purification device is stopped, it is necessary to distinguish between the fresh water 1 in the water storage tank 51 and the unclassified fresh water. Therefore, while the water purification device is stopped, the three-way valve 59 is
The line between a 39 and the water storage tank 51 is closed, and the separator 39 and fresh water outlet 53 are opened. Therefore, if the water purifier 21 is not used for a long period of time, the water in the separator 39 will flow out or evaporate from the fresh water outlet 53. As a result, the cellulose acetate-based semipermeable membrane in the separator dries out and deteriorates.

The purpose of this invention is to produce cellulose acetate-based semipermeable membranes
It is an object of the present invention to provide a water purification device having a lf membrane with a clean water discrimination device while preventing performance deterioration of the separation membrane.

Hereinafter, a first embodiment of the present invention will be described based on the drawings.

In Fig. 2, 31 is a water intake port, and the raw water is supplied to the water purification device 3.
It flows into 3. 35 is a filter, and the water intake port 31
Remove dust, sand, etc. from the raw water that has flowed in. Reference numeral 37 denotes a pump that causes the raw water filtered by the filter 33 to flow into the separator 39.

This pump 37 is driven by a five motor 41.

The separator 39 uses a cellulose acetate semipermeable membrane as a separation membrane. This separation membrane separates raw water into fresh water and concentrated water. 45 is a concentrated water outlet, which discharges the concentrated water separated by the separator 39. 43 is a pressure regulating valve, which is provided between the divider 39 and the concentrated water outlet 45. This pressure regulating valve 43 regulates the pressure within the separator 39. 47 is a check valve, which is provided between the pressure regulating valve 43 and the concentrated water outlet 45. This check valve 47 is closed except when draining water. Therefore, the concentrated water between the dispenser 39 and the check valve 47 does not run out, and the semipermeable membrane is therefore less likely to dry out. By providing this check valve 47, the effect of the present invention, which aims to prevent the cellulose acetate semipermeable membrane from drying out and maintain raw water separation ability over a long period of time, is further enhanced.

Further, 49 is a fresh water discrimination device. This device 49 includes a sensor 55, a water quality determination circuit 57, and a three-way valve 59, and switches the flow direction of the fresh water separated by the separator 39. That is, the fresh water is transferred to the water storage tank 51 or the fresh water outlet 53.
Switch so that it flows smoothly. Sensor 55 detects electrical conductivity in fresh water. Further, the water quality determination circuit 57 is connected to the sensor 51.
Based on this, the three-way valve 59 is operated to switch the communication direction.

This water quality determination circuit 49 operates as follows.

First, when the impurity concentration in the fresh water is determined to be less than a predetermined value by the sensor 55 and the water quality determination circuit 57, the three-way valve 59 connects the line between the separator 39 and the water storage tank 51. The determined fresh water is then sent to the water storage tank 51. On the other hand, similarly, when the impurity concentration in the fresh water is above a predetermined value, the three-way valve 59 connects the line between the separator 39 and the fresh water outlet 57. Then, the determined fresh water flows toward the fresh water outlet 53. In addition, the water purification device 33
When the water storage tank 51 is stopped, the three-way valve 59 closes the separator 39 so that the fresh water in the water storage tank 51 does not mix with unclassified fresh water.
The line between the water tank 51 and the water storage tank 51 is closed, and the line with the fresh water discharge [153] is communicated. That is, in this case, the three-way valve 59 serves as an on-off valve for the fresh water passage leading from the separator 39 to the water storage tank 51. In addition, 61 is a check valve, and the three-way valve 59 and the fresh water outlet 5
It is located between 3. This check valve 61 is an on-off valve for the fresh water passage leading from the separator 39 to the fresh water outlet of the present invention, and is closed except when draining water.

Therefore, even if the three-way valve 59 closes the gap between the separator 39 and the water storage tank 51 and connects the line with the fresh water outlet 53 while the water purification device 33 is stopped, this check valve will prevent the fresh water in the separator 39 from being removed. spillage or evaporation is prevented.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the fresh water discharge passage is merged with the concentrated water discharge passage. Therefore, the concentrated water discharge required in the first embodiment is Exit 45
is not necessary. In this example, if the valve 47 is closed and the valve 48 is opened, the combined water will flow into the separator 39 again by the operation of the pump 37. The combined water flowing into the separator 39 is again separated into fresh water and concentrated water. Therefore, the yield of fresh water from raw water is improved.

In addition, in the second embodiment, the check valve 61 prevents the concentrated water from mixing with the fresh water in the separator 39, in addition to the effect described in the first embodiment. Furthermore, in the first and second embodiments described above, a three-way valve was used as the fresh water discriminating device, but by providing a separate on-off valve for each fresh water passage and interlocking them, the fresh water discriminating device can be configured as fN. m may also be used.

As described above, the present invention provides a water purification device in which on-off valves are installed in each of the fresh water passages from the separator to the water storage tank or the fresh water outlet, and these on-off valves can be closed at the same time. be.

Therefore, even when the water purification apparatus equipped with the fresh water discrimination device is stopped, if this valve is closed, the fresh water in the separator will not flow out from the fresh water outlet or evaporate. For this reason,
The cellulose acetate semipermeable membrane used in the separator is resistant to deterioration even when dried.

As a result, the desalination ability of the semipermeable membrane that separates raw water into fresh water and concentrated water is maintained over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a conventional water purification loading process, FIG. 2 is a flowchart of a first embodiment of the water purification apparatus according to the present invention, and FIG. 3 is a flowchart of a second practical example of the same. 33. Water purification device, 39.-Separator. 51... Water storage tank, 57... Fresh water outlet. 59...Three-way valve, 61...Valve

Claims (1)

[Claims] 1) It has a separator that separates raw water into fresh water and concentrated water, and a fresh water discrimination device that selectively sends this fresh water to a water storage tank or a fresh water outlet depending on the impurity concentration of the fresh water separated by the separator. In the water purification device, the separation membrane of the separator is composed of a cellulose acetate-based semipermeable membrane, and an on-off valve is provided in each of the fresh water passages from the separator to the water storage tank or the fresh water outlet, and these on-off valves are operated at the same time. A water purification device configured to maintain a closed state.