Water purifying system

Abstract

The present invention relates to a water purification system, wherein the water purification system comprises a raw water area for receiving raw water, a purified water area for receiving purified water generated by filtering at least a portion of the raw water in the raw water area, a filter unit configured to separate and discharge the raw water into wastewater and the purified water, respectively, and a flushing tank configured to receive and store the purified water in the purified water area and supply the stored purified water to the raw water area, and wherein at least a portion of the purified water supplied from the flushing tank to the raw water area after flowing from the purified water area to the flushing tank may be re-filtered and then discharged from the purified water area and re-flow into the flushing tank.

Description

Technology Field

[0001] The present invention relates to a water purification system. Background Technology

[0002] A water purifier is a device that removes contaminants, ions, odors, turbidity, etc. from water and supplies it to the user.

[0003] In cases where water is supplied to users after removing impurities through a filtration method, the water purifier includes a water filter to filter the water. One example of such a water filter is a reverse osmosis filter equipped with a reverse osmosis membrane. The reverse osmosis filter filters the water by passing it through the reverse osmosis membrane at a predetermined pressure during the water inflow process. Additionally, ions that do not pass through the reverse osmosis membrane are discharged into the wastewater line along with the water that has passed through.

[0004] Therefore, in a reverse osmosis filter, water with a high TDS (Total Dissolved Solids) concentration—that is, water containing unfiltered ions—exists on one side centered around the reverse osmosis membrane, while water with a low TDS concentration—that is, filtered water from which ions have been removed—exists on the other side.

[0005] Meanwhile, while water is not being filtered through the reverse osmosis filter, water on the filtering side moves to the non-filtering side due to osmotic pressure. Consequently, the TDS concentration of the water on the filtering side increases and becomes similar to that of the water on the non-filtering side.

[0006] Under these conditions, when water filtration resumes through the reverse osmosis filter, water with a high TDS concentration initially present on the filtration side of the filter is supplied to the user, and this phenomenon is called creep.

[0007] In the case of general water purifiers, to reduce creep, the volume of the wastewater side is minimized, the wastewater side is removed, or a flushing method is used. If the volume of the wastewater side is minimized, the assembly is structurally inefficient. In the case of the method of removing the wastewater side, there is a problem where the recovery rate and TDS fluctuate because the flow rate of purified water is unstable during the initial operation.

[0008] Finally, in the case of the flushing method, a method was used in which flushing water is introduced and discharged into the wastewater side while the outlet side is closed. In this case, there is a limit to the capacity of the flushing water, and when the flushing water is completely used, raw water must be introduced to lower the TDS in the wastewater side; therefore, although the width can be reduced, the existence of a concentration difference is inevitable. Consequently, there are limitations in minimizing the phenomenon of initial TDS increase during extraction after stagnation.

[0009] Therefore, if you intend to use a flushing method, there is a need for technology that can minimize the difference in TDS between purified water and wastewater. The problem to be solved

[0010] The objective of the present invention is to provide a water purification system capable of minimizing the difference in TDS between purified water and wastewater during flushing. means of solving the problem

[0011] In one example, the water purification system includes a raw water area for receiving raw water, a water purification area for receiving purified water generated by filtering at least a portion of the raw water in the raw water area, a filter unit configured to separate and discharge the raw water into wastewater and the purified water, and a flushing tank configured to receive and store the purified water in the water purification area and supply the stored purified water to the raw water area, and after flowing from the water purification area to the flushing tank, at least a portion of the purified water supplied from the flushing tank to the raw water area may be re-filtered and then discharged from the water purification area and re-flowed into the flushing tank.

[0012] In another example, the water purification system further includes a wastewater line for discharging the wastewater from the raw water area to the outside and a wastewater valve disposed in the wastewater line and configured to regulate the flow rate of the wastewater discharged through the wastewater line according to the degree of opening and closing of the wastewater valve, and the recovery rate, which is the ratio of the discharge of the purified water and the wastewater, may be adjustable according to the degree of opening and closing of the wastewater valve.

[0013] In another example, the water purification system may further include an inlet line for supplying raw water from a water source to the raw water area, a drainage line for discharging the purified water from the water purification area to a demand place, a flushing tank inlet line branched from the drainage line for discharging the purified water to the flushing tank, and a flushing tank discharge line for discharging the stored purified water from the flushing tank to the raw water area.

[0014] In another example, the water purification system may further include an inlet valve positioned in the inlet line, positioned upstream of a first connection point where the inlet line is connected to the flushing tank discharge line, to selectively block the inflow of raw water; a drain valve positioned in the drain line, positioned downstream of a second connection point where the flushing tank inlet line branches off from the drain line, to selectively block the discharge of the purified water to a demand source; a flushing valve positioned in the flushing tank discharge line, to selectively open and close the flushing tank discharge line as it opens and closes; and a pump positioned in the inlet line, positioned downstream of the first connection point, to pump water within the inlet line toward the raw water area.

[0015] In another example, when the water supply mode is used to supply water within the water purification area to the user, the inlet valve and the drain valve are opened, the flushing valve is closed, the pump is initiated to pump water within the inlet line to the raw water area, and the wastewater valve may be opened to the extent that the recovery rate corresponds to a predetermined first recovery rate.

[0016] In another example, if the above water supply mode is maintained for longer than a predetermined first reference time, the wastewater valve may be opened to an extent corresponding to a second recovery rate, which is a recovery rate in which the discharge ratio of the wastewater is higher than the first recovery rate.

[0017] In another example, when the above water supply mode is terminated after the above first reference time has elapsed and then enters a first drain mode for discharging the wastewater through the wastewater line, the inlet valve, the drain valve, and the flushing valve are closed, the pump operation is terminated, and the wastewater valve may be opened to an extent that the recovery rate corresponds to the above second recovery rate.

[0018] In another example, after the first drain mode, when entering a storage mode to store purified water in the flushing tank, the inlet valve is opened and the pump can be started to operate.

[0019] In another example, when the storage of purified water in the flushing tank is completed and the flushing mode is entered to send the stored purified water to the filter unit, the inlet valve is closed and the flushing valve is opened, and the wastewater valve may be opened to an extent corresponding to a third recovery rate, which is a recovery rate in which the discharge rate of the wastewater is higher than the first recovery rate and the discharge rate of the wastewater is lower than the second recovery rate.

[0020] In another example, when entering the first water purification resupply mode in which purified water must be supplied externally in the first drain mode, the storage mode, or the flushing mode, the inlet valve and the drain valve are opened, the flushing valve is closed, the pump is started to operate to pump water in the inlet line to the filter section, and the wastewater valve may be opened to an extent that the recovery rate corresponds to the second recovery rate.

[0021] In another example, when the flushing mode is maintained for a predetermined second reference time and then enters a standby mode, the flushing valve is closed, the pump operation is terminated, and the wastewater valve can be opened to the extent that the recovery rate corresponds to the first recovery rate.

[0022] In another example, if the above standby mode is maintained for a predetermined third reference time, it may be arranged to re-enter the above storage mode.

[0023] In another example, when the above water supply mode is terminated before the above first reference time elapses and then enters a second drain mode for discharging wastewater through the wastewater line, the inlet valve, the drain valve, and the flushing valve are closed, the pump operation is terminated, and the wastewater valve can be opened to an extent that the recovery rate corresponds to a predetermined first recovery rate.

[0024] In another example, after the second drain mode, when entering the second water supply re-supply mode, which requires supplying water to the outside within a predetermined third standard time, and entering the storage mode for storing water in the flushing tank, the inlet valve is opened, the pump is started to operate, and the wastewater valve can be opened to an extent corresponding to the second recovery rate, which is a recovery rate in which the discharge rate of the wastewater is higher than the first recovery rate.

[0025] In another example, when the storage of purified water in the flushing tank is completed and the flushing mode is entered to send the stored purified water to the filter unit, the inlet valve and the flushing valve are opened, and the wastewater valve may be opened to an extent corresponding to a second recovery rate, which is a recovery rate in which the discharge rate of the wastewater is higher than the first recovery rate.

[0026] In another example, after the second drain mode, when entering the second purified water resupply mode in which purified water must be supplied externally within a predetermined third reference time, the inlet valve and the drain valve are opened, and the pump may be started to operate.

[0027] In another example, the flushing tank may include an outer tank having a space formed inside, and an inner tank inserted into the outer tank and connected to the flushing tank inlet line and the flushing tank discharge line, the volume of which can change according to the amount of water introduced from the flushing tank inlet line and the amount of water discharged through the flushing tank discharge line.

[0028] In another example, the flushing tank may further include a pressure sensor attached to the inner wall of the outer tank and configured to detect changes in applied pressure.

[0029] In another example, it may further include an inlet valve positioned in the inlet line, positioned upstream of a first connection point where the inlet line is connected to the flushing tank discharge line, thereby selectively blocking the inflow of raw water; a flushing valve positioned in the flushing tank discharge line, thereby selectively opening and closing the flushing tank discharge line as it opens and closes; a wastewater valve positioned in the wastewater line, configured to regulate the flow rate of wastewater discharged through the wastewater line according to the degree of opening and closing; and a control unit configured to control the opening and closing of the inlet valve, the flushing valve, and the wastewater valve based on a pressure value acquired by the pressure sensor.

[0030] In another example, the control unit may control the inlet valve to close the inlet valve that was open when the pressure acquired by the pressure sensor is greater than or equal to a predetermined reference pressure, control the flushing valve to open the flushing valve that was closed, and control the degree to which the wastewater valve is opened or closed so that the flow rate of wastewater discharged through the wastewater line is reduced. Effects of the invention

[0031] According to the present invention, since a portion of the flushing water can be filtered again and fed back into the filter, the TDS of the water flowing into the filter can be kept low, thereby minimizing creep phenomena. Brief explanation of the drawing

[0032] FIG. 1 is a water piping diagram of a water purification system according to one embodiment of the present invention. FIG. 2 is a flowchart illustrating the operation sequence of a water purification system according to one embodiment of the present invention. Figure 3 is a diagram illustrating the water supply mode. Figure 4 is a diagram illustrating the case where the water supply mode is maintained for longer than the first reference time. Figure 5 is a diagram illustrating the first drain mode. Figure 6 illustrates the storage mode. Figure 7 is a diagram illustrating the flushing mode. Figure 8 is a diagram illustrating the standby mode. Figures 9 and 10 are enlarged drawings of a flushing tank. Specific details for implementing the invention

[0033] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0034] Meanwhile, in the present invention, the expressions upstream and downstream may be based on the direction of fluid flow. For example, if the fluid flows from left to right, the left side may correspond to upstream and the right side to downstream.

[0035] As illustrated in FIG. 1, a water purification system according to one embodiment of the present invention may include a filter unit (10) and a flushing tank (20). The filter unit (10) may be a reverse osmosis filter capable of removing ionic substances from raw water by reverse osmosis. The filter unit (10) may separate the raw water into wastewater and purified water and discharge them, respectively.

[0036] The filter unit (10) may include a raw water area (11) and a purified water area (12). Raw water delivered from a water source may be supplied to the raw water area (11). Purified water may be received in the purified water area (12). Purified water may be produced by filtering at least a portion of the raw water in the raw water area (11).

[0037] The flushing tank (20) may be configured to receive and store purified water from the purified water area (12) and to supply the stored purified water to the raw water area (11).

[0038] A water purification system according to one embodiment of the present invention is characterized by the technical feature that, after flowing from a water purification area (12) into a flushing tank (20), at least a portion of the purified water supplied from the flushing tank (20) to the raw water area (11) can be re-filtered and then discharged from the water purification area (12) and re-flow into the flushing tank (20). According to the present invention, since at least a portion of the purified water supplied from the flushing tank (20) to the raw water area (11) is re-filtered and re-flowed into the flushing tank (20), the TDS of the purified water supplied from the flushing tank (20) to the raw water area (11) can be lowered. Below, the remaining structures that enable this are described in detail.

[0039] A water purification system according to one embodiment of the present invention may further include a wastewater line (30) and a wastewater valve (31). The wastewater line (30) may be a line for discharging wastewater from a raw water area (11) to the outside. The wastewater valve (31) may be positioned in the wastewater line (30) and configured to regulate the flow rate of wastewater discharged through the wastewater line (30) according to the degree of opening and closing.

[0040] A water purification system according to one embodiment of the present invention may be able to adjust the recovery rate, which is the ratio of purified water to wastewater discharged according to the degree of opening and closing of the wastewater valve (31). A high recovery rate means a high discharge ratio of purified water. For example, when the wastewater valve (31) is opened to the maximum, the discharge ratio of wastewater increases, and the recovery rate may be minimized.

[0041] A water purification system according to one embodiment of the present invention may include an inlet line (40), a drainage line (50), a flushing tank inlet line (60), and a flushing tank discharge line (70).

[0042] The inlet line (40) may be a line for supplying raw water from a water source to a raw water area (11). The drain line (50) may be a line for discharging purified water from a purified water area (12) to a demand source. The inlet line (40) and the drain line (50) may be connected to a filter unit (10). The flushing tank inlet line (60) may be a line branched from the drain line (50) to discharge purified water to a flushing tank (20). The flushing tank discharge line (70) may be a line for discharging the purified water stored in the flushing tank (20) to the raw water area (11).

[0043] A water purification system according to one embodiment of the present invention may include an inlet valve (41), a drain valve (51), a flushing valve (71), and a pump (80).

[0044] An inlet valve (41) is positioned in the inlet line (40), but may be positioned upstream of the first connection point (42) where the inlet line (40) is connected to the flushing tank discharge line (70). The inlet valve (41) can selectively block the inflow of raw water. A TDS sensor is positioned in the inlet line (40) to detect the TDS of the raw water flowing in through the inlet line.

[0045] A drain valve (51) is positioned in the drain line (50), but may be positioned downstream of the second connection point (52) where the flushing tank inlet line (60) branches off from the drain line (50). The drain valve (51) can selectively block the discharge of purified water to the demand source.

[0046] A flushing valve (71) is positioned in the flushing tank discharge line (70) and can selectively open and close the flushing tank discharge line (70) as it is opened and closed. When the flushing valve (71) is opened, water inside the flushing tank (20) can be discharged through the flushing tank discharge line (70) and flow into the filter section (10).

[0047] The pump (80) is positioned in the inlet line (40) and may be positioned downstream of the first connection point (42). The pump (80) can pump water within the inlet line (40) toward the raw water area (11).

[0048] A water purification system according to one embodiment of the present invention may include a control unit (P). The control unit (P) may be configured to control the opening and closing of an inlet valve (41), a drain valve (51), a flushing valve (71), and a wastewater valve (31). Additionally, the control unit (P) may be configured to control the operation of a pump (80).

[0049] The control unit (P) may include a processor and memory. The processor may include a microprocessor such as an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a CPU (Central Processing Unit). The memory may store control instructions that serve as the basis for generating instructions, such as for determining whether to open or close the valve, in the processor. The memory may be a data store such as an HDD (Hard Disk Drive), SSD (Solid State Drive), volatile media, or non-volatile media.

[0050] FIG. 2 is a flowchart illustrating the operation sequence of a water purification system according to an embodiment of the present invention. Hereinafter, the operation of a water purification system according to an embodiment of the present invention will be described in detail based on the above components and FIG. 2.

[0052] Water supply mode

[0053] Inlet valve drain valve Flushing valve pump wastewater valve Open Open Close On 1st recovery rate

[0054] FIG. 3 is a diagram illustrating a water supply mode. The water supply mode may be a mode for supplying water within the water supply area (12) to the user. For example, the water supply mode may refer to a mode entered when the user presses the water supply button of the water purifier to receive water.

[0055] When in the water supply mode, the inlet valve (41) and the drain valve (51) may be opened. Additionally, the flushing valve (71) may be closed. The pump (80) may be initiated to pump water in the inlet line (40) to the raw water area (11). The wastewater valve (31) may be opened to a extent that the recovery rate corresponds to a predetermined first recovery rate. For example, the first recovery rate may be a ratio of purified water to wastewater of 20 to 1. The first recovery rate may be a recovery rate with a relatively low wastewater discharge ratio.

[0056] Meanwhile, if the water purification supply mode is maintained for a long time, the TDS of the raw water area (11) continues to rise, so it may be difficult to maintain a first recovery rate with a low wastewater discharge rate. Below, the case where the water purification supply mode is maintained for a predetermined first standard time or longer is described in detail. The first standard time may be 10 seconds.

[0058] If the water supply mode is maintained for longer than the first reference time,

[0059] Inlet valve drain valve Flushing valve pump wastewater valve Open Open Close On Second recovery rate

[0060] FIG. 4 is a diagram illustrating a case where the water purification supply mode is maintained for longer than a first reference time. When the water purification supply mode is maintained for longer than a predetermined first reference time, the wastewater valve (31) may be opened to an extent corresponding to a second recovery rate. The second recovery rate may be a recovery rate in which the discharge ratio of wastewater is higher than that of the first recovery rate. For example, the second recovery rate may be a ratio of purified water to wastewater of 1 to 1.

[0061] Since the second recovery rate has a higher wastewater discharge rate than the first recovery rate, waste of raw water may occur. However, if the first recovery rate is maintained, the TDS of the raw water area (11) will inevitably continue to increase, so it may be advantageous to change the recovery rate to the second recovery rate after the first reference time.

[0062] Below, the state after the first reference time has elapsed and the water supply mode has ended is described.

[0064] 1st Drain Mode

[0065] Inlet valve drain valve Flushing valve pump wastewater valve Close Close Close Off Second recovery rate

[0066] FIG. 5 is a diagram illustrating a first drain mode. After the water purification supply mode is terminated after a first reference time has elapsed, the water purification system according to one embodiment of the present invention may enter a first drain mode. The first drain mode may be a mode for discharging wastewater through a wastewater line (30).

[0067] In the first drain mode, the inlet valve (41), drain valve (51), and flushing valve (71) can be closed. Also, in the first drain mode, the pump (80) can be deactivated. Additionally, the wastewater valve (31) can be opened to the extent that the recovery rate corresponds to the second recovery rate.

[0068] The first drain mode may be maintained for a predetermined amount of time. For example, the first drain mode may be maintained for 5 minutes. In the first drain mode, the operation of the pump (80) is terminated, and wastewater is slowly discharged through the wastewater line (30) due to residual pressure, so it needs to be maintained for a sufficient amount of time. When the first drain mode ends, it may enter a storage mode for storing purified water in the flushing tank (20).

[0070] Save mode

[0071] Inlet valve drain valve Flushing valve pump wastewater valve Open Close Close ON Second recovery rate

[0072] FIG. 6 illustrates a storage mode. When entering the storage mode, the inlet valve (41) may be opened. Additionally, the pump (80) may be started to operate. During this process, at least some of the raw water introduced through the inlet line (40) becomes purified water and is stored in the flushing tank (20). When the storage of purified water in the flushing tank (20) is completed, the system may enter a flushing mode to send the stored purified water to the filter unit (10).

[0074] Flushing mode

[0075] Inlet valve drain valve Flushing valve pump wastewater valve Close Close Open ON Third recovery rate

[0076] FIG. 7 is a diagram illustrating a flushing mode. When the storage of purified water in the flushing tank (20) is completed and the flushing mode is entered to send the stored purified water to the filter unit (10), the inlet valve (41) may be closed. Additionally, the flushing valve (71) may be opened.

[0077] The wastewater valve (31) can be opened to the extent corresponding to the third recovery rate. The third recovery rate may be a recovery rate in which the wastewater discharge rate is higher than the first recovery rate and the wastewater discharge rate is lower than the second recovery rate. For example, the third recovery rate may be a ratio of purified water to wastewater of 4.8 to 1.

[0078] In flushing mode, purified water stored in the flushing tank (20) can flow into the raw water area (11) of the filter unit (10). Additionally, some of the purified water flowing into the raw water area (11) can be re-filtered and re-flowed back into the flushing tank (20). The re-flowed purified water can be re-flowed back into the raw water area (11) once more. By repeating this circulation process, the TDS of the water flowing into the flushing tank (20) can be continuously lowered.

[0079] The flushing mode may be maintained for a predetermined second reference time. For example, the second reference time may be 60 seconds. After the flushing mode is maintained for the second reference time, it may enter standby mode.

[0081] Standby mode

[0082] Inlet valve drain valve Flushing valve pump wastewater valve Close Close Close Off 1st recovery rate

[0083] FIG. 8 is a diagram illustrating a standby mode. When the flushing mode is maintained for a predetermined second reference time and then enters the standby mode, the flushing valve (71) may be closed. Additionally, the operation of the pump (80) may be terminated. The wastewater valve (31) may be opened to an amount corresponding to the first recovery rate. The standby mode can be understood as a state for entering the purified water supply mode. That is, since the TDS of the raw water area (11) is sufficiently low, the wastewater valve (31) may be opened again to an amount corresponding to the first recovery rate.

[0084] If the standby mode is maintained for a predetermined third reference time, it may be arranged to re-enter the storage mode. For example, the third reference time may be 6 hours. If the standby mode is maintained for a long time, a situation may occur where the TDS of the integer region (12) rises again. Therefore, after a sufficient amount of time has passed, the storage mode and flushing mode may be resumed to lower the TDS of the integer region (12).

[0086] First water purification resupply mode

[0087] Inlet valve drain valve Flushing valve pump wastewater valve Open Open Close On Second recovery rate

[0088] Meanwhile, there may be cases where the first water purification resupply mode is entered while the first drain mode, storage mode, or flushing mode is in progress. The first water purification resupply mode may be a mode in which water purification must be supplied externally while the first drain mode, storage mode, or flushing mode is in progress. For example, one can assume a case where an external user presses the water purification supply button of the water purifier while the first drain mode, storage mode, or flushing mode is in progress.

[0089] In this case, the inlet valve (41) and the drain valve (51) may be opened, and the flushing valve (71) may be closed. Additionally, the pump (80) may be started to pump water in the inlet line (40) to the filter section (10). At this time, the recovery rate of the wastewater valve (31) may correspond to the second recovery rate. This may be the same as the state of FIG. 4.

[0090] That is, when entering the purified water re-supply mode while proceeding with the first drain mode, storage mode, or flushing mode, the TDS of the raw water area (11) is not sufficiently low, so the wastewater valve (31) can be opened to the extent that the recovery rate corresponds to the second recovery rate.

[0092] 2nd Drain Mode

[0093] Inlet valve drain valve Flushing valve pump wastewater valve Close Close Close Off 1st recovery rate

[0094] Below, the case where the water purification supply mode is maintained for less than the first reference time is described in detail. When the water purification supply mode is maintained for a relatively short period, it may be possible to maintain a first recovery rate with a low wastewater discharge rate. Therefore, it may not be necessary for the wastewater valve (31) to be opened to the extent that the recovery rate corresponds to the second recovery rate.

[0095] Meanwhile, if the water supply mode is terminated before the first reference time has elapsed, it may enter the second drain mode. The second drain mode may be a mode for discharging wastewater through the wastewater line (30).

[0096] In the second drain mode, the inlet valve (41), drain valve (51), and flushing valve (71) may be closed. Additionally, the pump (80) may be deactivated. The wastewater valve (31) may be opened to the extent that the recovery rate corresponds to a predetermined first recovery rate. This can be understood as the state in FIG. 5 where the second recovery rate is changed to the first recovery rate.

[0097] Meanwhile, if the water purification resupply mode is not entered within the third reference time after the second drain mode, the water purification mode can be entered to store water in the flushing tank (20). Additionally, when the storage mode is completed, the water purification mode can be entered.

[0099] Second resupply mode (same as pure water supply mode)

[0100] Inlet valve drain valve Flushing valve pump wastewater valve Open Open Close On 1st recovery rate

[0101] After the second drain mode, there may be cases where the second water purification mode is entered within the third reference time. The second water purification mode may be a mode in which water purification must be supplied externally within the third reference time after the second drain mode.

[0102] For example, one can assume a case where an external user presses the water supply button of the water purifier within the third reference time after the second drain mode.

[0103] In the second water purification re-supply mode, the inlet valve (41) and the drain valve (51) may be opened. In the second water purification re-supply mode, the flushing valve (71) may be closed. Additionally, in the second water purification re-supply mode, the pump (80) may be started to operate. The wastewater valve (31) may be opened to an extent that the recovery rate corresponds to the first recovery rate. The second water purification re-supply mode can be understood as having the same operating state as the water purification supply mode. That is, it may be the same state as that of FIG. 3.

[0105] <Pre-processing filter (90), Post-processing filter (100)>

[0106] A water purification system according to one embodiment of the present invention may further include a pretreatment filter (90) and a posttreatment filter (100). The pretreatment filter (90) may be placed in the inlet line (40). More specifically, the pretreatment filter (90) may be placed downstream of the first connection point (42) and upstream of the portion of the inlet line (40) connected to the filter section (10).

[0107] The pretreatment filter (90) may be a pre-carbon filter, a sedimentation filter, a high turbidity filter, or a composite filter combining a sedimentation filter and a pre-carbon filter. The pretreatment filter (90) can remove large foreign substances and, at the same time, remove chlorine, organic compounds, odors, and pigments through adsorption.

[0108] A post-treatment filter (100) can be placed in a drainage line (50). More specifically, the post-treatment filter (100) can be placed upstream of the part of the drainage line (50) where the drain valve (51) is placed, and downstream of the second connection point (52).

[0109] The post-treatment filter (100) may be a GAC ​​filter (Granular Activated Carbon filter), a Block carbon filter, a Silver carbon filter, a DI Resin filter (Deionization Resin filter), a TCR filter (Taste Chlorine Reduction filter), etc. The post-treatment filter (100) can improve the taste of water by adsorbing fine substances and removing gas components and odors.

[0111] <Specific structure of the flushing tank (20)>

[0112] FIGS. 9 and 10 are enlarged drawings of a flushing tank. As shown in FIGS. 9 and 10,

[0113] The flushing tank (20) may include an outer tank (21) and an inner tank (22). The outer tank (21) may have a space formed inside. The outer tank (21) may be a sealed tank through which the flushing tank inlet line (60) and the flushing tank discharge line (70) pass.

[0114] The inner tank (22) can be inserted into the interior of the outer tank (21). The inner tank (22) is connected to the flushing tank inlet line (60) and the flushing tank discharge line (70), and its volume may change depending on the amount of water introduced from the flushing tank inlet line (60) and the amount of water discharged through the flushing tank discharge line (70). The inner tank (22) may have an elastically deformable material. FIG. 10 can be understood as illustrating a state in which the volume of the inner tank (22) has increased.

[0115] Since the flushing tank (20) has a double structure including an outer tank (21) and an inner tank (22), contamination can be minimized as a sealed tank, and a separate inflow for water discharge can be eliminated.

[0116] The flushing tank (20) may further include a pressure sensor (23). The pressure sensor (23) may be attached to the inner wall of the outer tank (21) and configured to detect changes in applied pressure. For example, when water flows into the inner tank (22) and the volume of the inner tank (22) increases, the pressure applied to the pressure sensor (23) may increase. At this time, if the pressure obtained by the pressure sensor (23) is greater than or equal to a predetermined reference pressure, it may be determined that the tank is in a full water state.

[0117] The control unit (P) can control the opening and closing of the inlet valve (41), flushing valve (71), and wastewater valve (31) based on the pressure value obtained by the pressure sensor (23).

[0118] More specifically, the control unit (P) can determine that the water level is full when the pressure obtained by the pressure sensor (23) is greater than or equal to a predetermined reference pressure, and can control the water inlet valve (41) to close the water inlet valve (41) that was open for the flushing mode to proceed.

[0119] In addition, the control unit (P) can control the flushing valve (71) to open the flushing valve (71) that was closed.

[0120] Additionally, the control unit (P) can control the degree to which the wastewater valve (31) is opened and closed so that the flow rate of wastewater discharged through the wastewater line (30) is reduced. For example, the control unit (P) can change the degree to which the wastewater valve (31) is opened and closed so that the recovery rate changes from a second recovery rate to a third recovery rate.

[0122] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0123] 10: Filter section 11: Enemy Territory 12: Integer area 20: Flushing tank 21: External tank 22: Internal tank 23: Pressure sensor 30: Wastewater line 31: Wastewater valve 40: Inlet line 41: Inlet valve 42: First connection point 50: Drainage line 51: Drain valve 52: Second connection point 60: Flushing tank inlet line 70: Flushing tank discharge line 71: Flushing valve 80: Pump 90: Preprocessing filter 100: Post-processing filter P: Control unit

Claims

Claim 1 A filter unit having a raw water area for receiving raw water and a purified water area for receiving purified water generated by filtering at least a portion of the raw water in the raw water area, and configured to separate and discharge the raw water into wastewater and the purified water, respectively; a flushing tank configured to receive and store the purified water in the purified water area and supply the stored purified water to the raw water area; an inlet line for supplying the raw water from a water source to the raw water area; a drainage line for discharging the purified water in the purified water area to a demand source; a flushing tank inlet line branched from the drainage line to discharge the purified water to the flushing tank; and a flushing tank outlet line for discharging the stored purified water in the flushing tank to the raw water area, wherein at least a portion of the purified water supplied from the flushing tank to the raw water area after flowing in from the purified water area to the flushing tank is re-filtered and then discharged from the purified water area and re-flowed into the flushing tank, and the flushing tank comprises an external tank having a space formed inside; A water purification system comprising an inner tank inserted inside the outer tank, connected to the flushing tank inlet line and the flushing tank discharge line, and having a volume that can be changed by the amount of water introduced from the flushing tank inlet line and the amount of water discharged through the flushing tank discharge line. Claim 2 A water purification system according to claim 1, further comprising: a wastewater line for discharging the wastewater of the raw water area to the outside; and a wastewater valve disposed in the wastewater line and configured to regulate the flow rate of the wastewater discharged through the wastewater line according to the degree of opening and closing, wherein the recovery rate, which is the ratio of the discharged water to the purified water and the wastewater, is adjustable according to the degree of opening and closing of the wastewater valve. Claim 3 delete Claim 4 A water purification system according to claim 2, further comprising: an inlet valve disposed in the inlet line, positioned upstream of a first connection point where the inlet line is connected to the flushing tank discharge line, thereby selectively blocking the inflow of raw water; a drain valve disposed in the drain line, positioned downstream of a second connection point where the flushing tank inlet line branches off from the drain line, thereby selectively blocking the discharge of purified water to a demand source; a flushing valve disposed in the flushing tank discharge line, which selectively opens and closes the flushing tank discharge line as it opens and closes; and a pump disposed in the inlet line, positioned downstream of the first connection point, thereby pressurizing water within the inlet line toward the raw water area. Claim 5 A water purification system according to claim 4, wherein in a water purification supply mode in which purified water within the purified water area is supplied to a user, the inlet valve and the drain valve are opened, the flushing valve is closed, the pump is initiated to pressurize water within the inlet line to the raw water area, and the wastewater valve is opened to an extent that the recovery rate corresponds to a predetermined first recovery rate. Claim 6 A water purification system according to claim 5, wherein when the water purification supply mode is maintained for a predetermined first reference time or longer, the wastewater valve is opened to an extent corresponding to a second recovery rate, which is a recovery rate in which the discharge ratio of the wastewater is higher than the first recovery rate. Claim 7 A water purification system according to claim 6, wherein when the water purification supply mode is terminated after the first reference time has elapsed and the first drain mode for discharging the wastewater through the wastewater line is entered, the inlet valve, the drain valve, and the flushing valve are closed, the pump operation is terminated, and the wastewater valve is opened to an extent that the recovery rate corresponds to the second recovery rate. Claim 8 A water purification system according to claim 7, wherein, after the first drain mode, when entering a storage mode for storing purified water in the flushing tank, the inlet valve is opened and the pump is started to operate. Claim 9 A water purification system according to claim 8, wherein when the storage of purified water in the flushing tank is completed and the system enters a flushing mode to send the stored purified water to the filter unit, the inlet valve is closed and the flushing valve is opened, and the wastewater valve is opened to an extent corresponding to a third recovery rate, which is a recovery rate in which the discharge rate of the wastewater is higher than the first recovery rate and the discharge rate of the wastewater is lower than the second recovery rate. Claim 10 A water purification system according to claim 9, wherein when entering a first water purification resupply mode in which purified water must be supplied externally in the first drain mode, the storage mode, or the flushing mode, the inlet valve and the drain valve are opened, the flushing valve is closed, the pump is started to operate to pump water in the inlet line to the filter section, and the wastewater valve is opened to an extent that the recovery rate corresponds to the second recovery rate. Claim 11 A water purification system according to claim 9, wherein when the flushing mode is maintained for a predetermined second reference time and then enters a standby mode, the flushing valve is closed, the pump operation is terminated, and the wastewater valve is opened to an extent that the recovery rate corresponds to the first recovery rate. Claim 12 A water purification system according to claim 11, wherein if the standby mode is maintained for a predetermined third reference time, the system is configured to re-enter the storage mode. Claim 13 A water purification system according to claim 6, wherein when the water purification supply mode is terminated before the first reference time elapses and then enters a second drain mode for discharging wastewater through the wastewater line, the inlet valve, the drain valve, and the flushing valve are closed, the pump operation is terminated, and the wastewater valve is opened to an extent that the recovery rate corresponds to a predetermined first recovery rate. Claim 14 A water purification system according to claim 13, wherein, after the second drain mode, when entering a second water purification resupply mode in which purified water must be supplied externally within a predetermined third reference time is not entered and a storage mode for storing purified water in the flushing tank is entered, the inlet valve is opened, the pump is started to operate, and the wastewater valve is opened to an amount corresponding to a second recovery rate, which is a recovery rate in which the discharge ratio of the wastewater is higher than the first recovery rate. Claim 15 A water purification system according to claim 14, wherein when the storage of purified water in the flushing tank is completed and the system enters a flushing mode to send the stored purified water to the filter unit, the inlet valve and the flushing valve are opened, and the wastewater valve is opened to an amount corresponding to a second recovery rate, which is a recovery rate in which the discharge rate of the wastewater is higher than the first recovery rate. Claim 16 A water purification system according to claim 13, wherein, when entering a second water purification resupply mode in which purified water must be supplied externally within a predetermined third reference time after the second drain mode, the inlet valve and the drain valve are opened and the pump is started to operate. Claim 17 delete Claim 18 A water purification system according to claim 2, wherein the flushing tank further comprises a pressure sensor attached to the inner wall of the outer tank and configured to detect a change in applied pressure. Claim 19 A water purification system according to claim 18, further comprising: an inlet valve disposed in the inlet line, positioned upstream of a first connection point where the inlet line is connected to the flushing tank discharge line, thereby selectively blocking the inflow of raw water; a flushing valve disposed in the flushing tank discharge line, thereby selectively opening and closing the flushing tank discharge line as it opens and closes; and a control unit configured to control the opening and closing of the inlet valve, the flushing valve, and the wastewater valve based on a pressure value acquired by the pressure sensor. Claim 20 A water purification system according to claim 19, wherein the control unit controls the inlet valve to close the inlet valve that was open when the pressure acquired by the pressure sensor is greater than or equal to a predetermined reference pressure, controls the flushing valve to open the flushing valve that was closed, and controls the degree of opening and closing of the wastewater valve to reduce the flow rate of wastewater discharged through the wastewater line.

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