KR102639627B1 - Energy recovery and reuse of CCRO system using concentrate water pressure - Google Patents

Abstract

The present invention relates to an energy recovery and reuse CCRO system using concentrated water pressure and a control method thereof, and more specifically, to a CCRO system comprising at least one RO module into which raw water flows through a raw water inflow line equipped with a high-pressure pump, and wherein the RO RO (Reverse Osmosis) process unit that separates and discharges concentrated water and treated water produced by the reverse osmosis process of the module into a concentrated water discharge line and a treated water discharge line, respectively; It includes a circulation line that connects the raw water inflow line and the concentrated water discharge line and is provided with a concentrated water circulation pump, and allows the concentrated water discharged through the concentrated water discharge line to reflow into the RO module and reach a preset concentration. A CCRO (Closed Circuit Reverse Osmosis) process unit that circulates the concentrated water until it is discharged to the outside; And a device that is connected to the concentrated water discharge line and recovers and stores high-pressure discharge pressure from the concentrated water discharged to the outside after the circulation process of the CCRO process unit in the form of pneumatic pressure, and supplies the stored air pressure to be used as an operating means of the selected pneumatic valve. It is characterized by including a pneumatic recovery unit.

Description

Energy recovery and reuse of CCRO system using concentrate water pressure and its control method {Energy recovery and reuse of CCRO system using concentrate water pressure}

The present invention can achieve a high recovery rate of treated water produced in the RO (Reverse Osmosis) process through the CCRO process (Closed Circuit Reverse Osmosis), which performs the formation of a closed circuit and the circulation process of concentrated water, especially the discarded concentrated water. The pressure is recovered and stored as pneumatic pressure, and the stored air pressure is discharged according to the ON/OFF of the valve that is repeatedly operated in the concentrated water discharge section of the CCRO process. This relates to an energy recovery and reuse CCRO system using concentrated water pressure that can save energy by storing concentrated water pressure as pneumatic pressure and reusing it for valve operation, and its control method.

In general, the Reverse Osmosis (RO) method is mainly used as a method of treating and reusing high-concentration TDS raw water, including seawater.

In the reverse osmosis method, ionic substances dissolved in water are almost excluded, and various types of ionic substances dissolved in water are removed by a semipermeable membrane through which pure water passes.

In order to separate ionic substances and pure water from such raw water, a pressure higher than osmotic pressure is required. This pressure is called reverse osmosis, and in the case of seawater desalination, a high pressure of approximately 40 to 70 bar is required.

Therefore, in order to provide reverse osmosis pressure, a water treatment device using reverse osmosis is installed with a raw water supply means (high pressure pump, etc.) that pressurizes raw water.

In this desalination process using reverse osmosis, when compressed against a semi-permeable membrane at a pressure higher than the osmotic pressure of the incoming water, ions that did not pass through the semi-permeable membrane are concentrated to a high concentration and discharged to the outside, and the solution that passed through the membrane is treated as treated water from which salts have been removed. This is how it is obtained.

At this time, the concentrated water that fails to pass through the semi-permeable membrane and is discharged to the outside retains almost the same pressure as the inflow water, and from an energy perspective, has a high energy loss.

In order to improve this problem, in Patent No. 10-1309870, Patent No. 10-1560698, and Patent No. 10-1853281, the energy contained in the concentrated water discharged to the outside with most of the reverse osmosis pressure is recovered. Technologies have been presented.

However, in the case of the above-mentioned conventional technologies, most of them are methods of supplementing the pressure of the influent water added to the semipermeable membrane inlet to overcome osmotic pressure, and a number of recovery devices or control valves that require separate power are added for this, and high concentration Concentrated water is configured to rejoin the inflow water, so if the concentration of organic matter is high, contamination of the separation membrane can accelerate, and there is a problem that it is difficult to expect a high recovery rate of treated water with a general reverse osmosis process alone.

In addition, in the case of recovered concentrated water, the high pressure required for reverse osmosis is maintained by a high-pressure pump, so expansion pressure is constantly applied to various pipes, etc., and this expansion pressure is repeated in the long term by repeatedly turning on/off the valve. When switched to OFF, there is a problem in that it causes continuous damage to pipes and equipment load, which acts as a factor in reducing durability.

In particular, water treatment facilities for reverse osmosis processes, even if concentrated water energy recovery technology is applied, are equipped with not only high-pressure pumps that require high power, but also various valves to control the movement and blocking of fluid. Separate opening and closing operations of these valves are required. Driving power is required, and as processing capacity increases, pneumatic valves are applied to drive valves and ensure system stability. In this case, an air compressor that consumes additional power must be installed, resulting in power use and operating costs. There is a problem that is increasing.

Registered Patent No. 10-1309870 Registered Patent No. 10-1560698 Registered Patent No. 10-1853281

Therefore, the purpose of the present invention is to not only achieve a high recovery rate of treated water produced in the RO (Reverse Osmosis) process, but also to recover the pressure of the discarded concentrated water and store it as pneumatic pressure, and to use the stored air pressure in the RO process or CCRO process. Energy recovery and reuse CCRO system using concentrated water pressure that can achieve energy savings while reducing the shock load on internal pipes and devices due to high pressure concentrated water pressure by utilizing it for the operation of various pneumatic valves required in It provides a control method.

As a means to solve the above-mentioned problems, the energy recovery and reuse CCRO system utilizing the pressure of concentrated water of the present invention (hereinafter referred to as the "system of the present invention") is an energy recovery and reuse CCRO system in which raw water flows in through a raw water inflow line equipped with a high-pressure pump. An RO (Reverse Osmosis) process unit that includes one or more RO modules and separates and discharges concentrated water and treated water produced by the reverse osmosis process of the RO modules into a concentrated water discharge line and a treated water discharge line, respectively; It includes a circulation line that connects the raw water inflow line and the concentrated water discharge line and is provided with a concentrated water circulation pump, and allows the concentrated water discharged through the concentrated water discharge line to reflow into the RO module and reach a preset concentration. A CCRO (Closed Circuit Reverse Osmosis) process unit that circulates the concentrated water until it is discharged to the outside; And a device that is connected to the concentrated water discharge line and recovers and stores high-pressure discharge pressure from the concentrated water discharged to the outside after the circulation process of the CCRO process unit in the form of pneumatic pressure, and supplies the stored air pressure to be used as an operating means of the selected pneumatic valve. It includes a pneumatic recovery unit, wherein the pneumatic recovery unit includes an inflow pipe branched from the concentrated water discharge line, an inflow valve mounted on the inflow pipe and selectively opened and closed, and connected to the inflow pipe and having a constant volume therein. An expansion tank divided into an air chamber and a water chamber in which high-pressure concentrated water moving through the concentrated water discharge line flows in and expands, and the compressed air that communicates with the air chamber of the expansion tank and is discharged according to compression of the air chamber flows in and out. It is characterized by including a pressure tank in which it is stored.

As an example, the CCRO process unit is equipped with a control valve that is mounted on the circulation line to be located at the rear end of the concentrated water circulation pump and operates to open and close selectively, and is branched from the circulation line to operate between the front end and the rear end of the control valve. It is characterized by further comprising a second circulation line connecting the second circulation line and an adsorption filter that is mounted on the second circulation line and allows organic matter in the concentrated water circulating to the second circulation line to be adsorbed when the control valve is closed.

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As an example, the pneumatic recovery unit includes a first operating pipe connected to the air chamber of the expansion tank and equipped with a check valve to supply outside air to the air chamber in one direction, and a first operating pipe between the air chamber of the expansion tank and the pressure tank. It is characterized by including a second operating pipe that connects and is equipped with a second check valve to allow compressed air discharged from the air chamber to flow into the pressure tank in one direction.

As an example, chemicals for cleaning the RO module are stored, and the treated water or concentrated water discharged from the RO module is connected to the treated water discharge line or concentrated water discharge line of the RO process unit, and the treated water or concentrated water discharged from the RO module is introduced through the cleaning line. CIP chemical tank connected to the front of the RO module; And a cleaning pump mounted on the cleaning line and selectively operated to supply treated water or concentrated water mixed with chemicals stored in the CIP chemical tank to the RO module as cleaning water.

As an example, the air mixer is provided between the CIP chemical tank and the cleaning pump and supplies and mixes compressed air with the cleaning water that moves according to the operation of the cleaning pump.

As an example, the cleaning pump is characterized as a multi-stage pump in which a plurality of impellers are installed in a multi-stage manner to generate fine bubbles in cleaning water mixed with compressed air.

Meanwhile, the control method of the energy recovery and reuse CCRO system utilizing concentrated water pressure of the present invention (hereinafter referred to as the 'control method of the present invention') is a method of controlling the above-described system, which includes: a) operating the high pressure pump to RO stage in which raw water flows into the RO module and treated water and concentrated water are separately discharged through the reverse osmosis process of the RO module; b) a CCRO step of operating a concentrated water circulation pump to re-introduce and circulate the concentrated water discharged from the RO step into the one or more RO modules through a circulation line; c) a stop step of measuring the TDS concentration of the concentrated water discharged from the RO module and stopping the circulation of the concentrated water by the concentrated water circulation pump when the measured TDS concentration is higher than a preset standard TDS concentration; d) a discharge step of discharging the concentrated water produced in the RO module to the outside through a concentrated water discharge line; and e) a pneumatic recovery step of recovering and storing high-pressure discharge pressure from the concentrated water discharged in the discharge step in the form of pneumatic pressure.

As one example, the CCRO step is characterized by including a step of allowing the circulating concentrated water to pass through an adsorption filter to adsorb and remove organic substances contained in the concentrated water.

As described above, according to the system and control method of the present invention, the pressure of concentrated water produced in the RO (Reverse Osmosis) process is increased through the CCRO process (Closed Circuit Reverse Osmosis), which performs the formation of a closed circuit and the circulation process of concentrated water. It is recovered and reused to drive the RO device valve, and at the same time, it has the effect of achieving a high recovery rate of treated water while alleviating pipe shock caused by repeated opening and closing of the concentrated water discharge valve.

In addition, through the repetitive movement of the expansion tank using the pressure of the high-pressure concentrated water that is discarded, compressed air can be filled in the pressure tank without using additional energy, and the filled compressed air can be used to operate various pneumatic valves required for system operation. Since the valve is supplied in such a way that power or an air compressor is not required to drive the valve, there is an effect of saving energy and operating costs.

In addition, the durability of the system can be improved by reducing the expansion shock and load on piping and other facilities due to the instantaneous high pressure of concentrated water due to valve ON/OFF during the initial operation of the high pressure pump or repeated operation of the concentrated water discharge valve in the RO process. There is an effect that makes it possible.

In addition, during the CIP cleaning process due to the performance degradation of the RO module, air is supplied using compressed air recovered from the pressure tank, and fine bubbles generated by a multi-stage pump with multiple impellers are supplied to perform chemical cleaning. There is an effect of further increasing the cleaning ability by performing physical cleaning using fine bubbles in parallel.

1 is a schematic diagram showing the system of the present invention.
Figure 2 is an operating state diagram of the second circulation line of the CCRO process unit according to an embodiment of the present invention.
3A to 3B are diagrams showing the operating state of the pneumatic recovery unit according to an embodiment of the present invention.
Figure 4 is a schematic diagram showing a cleaning configuration according to an embodiment of the present invention.

In describing the present invention, the terms and words used in the specification and claims are based on the principle that the inventor can appropriately define the concept of the term in order to explain the invention in the best way. It must be interpreted with meaning and concepts consistent with the technical ideas of.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the system of the present invention includes an RO (Reverse Osmosis) process unit 40 that desalinizes incoming raw water through a reverse osmosis process, and a reverse osmosis process of the RO process unit 40. The CCRO (Closed Circuit Reverse Osmosis) process unit 50, which repeatedly circulates the concentrated water produced in the concentrated water to a set concentration and then discharges it, and the high-pressure discharge pressure used in the reverse osmosis process of the RO process unit is in the form of pneumatic pressure. It may include a pneumatic recovery unit 60 for recovery and storage.

The RO process unit 40 may include one or more RO modules 420 through which raw water flows in through the raw water inflow line 410, and filters the incoming raw water through a reverse osmosis process to produce concentrated water and treated water, respectively. can be produced

The RO module 420 can be applied by selecting an appropriate one among various known filtration membranes for physical filtration of raw water, and two or more RO modules 420 can be connected in parallel to selectively control the treatment flow rate of raw water. there is.

The treated water produced in the RO module 420 can be used as industrial or agricultural water through post-treatment such as pH adjustment. In the case of concentrated water, it can be discharged in a more concentrated state after circulation in the CCRO process unit 50, which will be described below, and can be transferred to a separate abatement facility and then post-treated.

The RO module 420 can receive raw water that has been primarily filtered through a pretreatment process.

As an example, raw water delivered from a sewage treatment plant, etc. may be transferred by the inlet pump 20 after staying in the raw water tank 10 for a certain period of time, and after passing through the pre-treatment filter 30 and undergoing physical filtration, the raw water inlet line ( It can flow into the RO module 420 through 410).

Whether or not this pretreatment process is performed can be determined by considering the degree of contamination of the raw water and the filtration treatment conditions of the RO module 420. At this time, the purification facilities applied in the pretreatment process are not limited to the above-mentioned pretreatment filter 30, and it is natural that various physical or chemical facilities can be additionally applied.

The RO module 420 uses the principle of pushing back by applying a pressure higher than the osmotic pressure, and has a high ability to remove solid substances, including ionic substances, from incoming raw water.

Accordingly, a high-pressure pump 400 may be provided in the raw water inlet line 410 to allow raw water to move at a high pressure higher than the osmotic pressure and flow into the RO module 420, thereby performing a reverse osmosis process.

In addition, a first pneumatic valve 411 that opens and closes at the rear end of the high-pressure pump 400 may be installed in the raw water inflow line 410 to allow high-pressure raw water to selectively flow into the RO module 420.

This RO process unit 40 further includes a concentrated water discharge line 430 and a treated water discharge line 440 that separate and discharge the concentrated water and treated water produced by the reverse osmosis process of the RO module 420. can do.

A concentrated water flow rate control valve 431 and a treated water flow rate control valve 441 may be installed in the concentrated water discharge line 430 and the treated water discharge line 440 to control the flow rate of the concentrated water or treated water discharged, respectively. .

In addition, the concentrated water discharge line 430 and the treated water discharge line 440 are provided with a third pneumatic valve 432 and a second pneumatic valve 442, respectively, to open and close the pipe in response to the high pressure generated by the high pressure pump 40. can be installed.

Meanwhile, the CCRO process unit 50 forms a closed circuit within the system, and can circulate the concentrated water continuously produced by the reverse osmosis process of the RO process unit 40 so that it re-flows into the RO module 420.

The CCRO process unit 50 may include a circulation line 510 connecting the raw water inflow line 410 and the concentrated water discharge line 430 of the RO process unit 40.

A concentrated water circulation pump 500 is provided in the circulation line 510 to compensate for the loss pressure of the concentrated water discharged through the RO module 420 and moves the concentrated water to the raw water inlet line 410 of the RO module 420. allow inflow.

In addition, a circulation valve 511 is installed in the circulation line 520 to control the circulation of concentrated water moved by the concentrated water circulation pump 500.

At this time, during the circulation of concentrated water by the CCRO process unit 50, the concentrated water flow rate control valve 431 and the third pneumatic valve 432 of the concentrated water discharge line 430 must operate to block to form a closed circuit, The reverse osmosis process of the RO process unit 40 must operate normally so that treated water is continuously discharged during the circulation of concentrated water.

Although not shown in the drawing, the CCRO process unit 50 can detect the TDS concentration of the circulating concentrated water in real time by installing a sensor to measure the TDS concentration of the concentrated water in the concentrated water discharge line 430.

And when the measured TDS concentration of the concentrated water is higher than the preset standard TDS concentration, the CCRO process unit 50 blocks and operates the circulation valve 511 and stops the circulation of the concentrated water by the concentrated water circulation pump 500. In addition, the closed circuit can be opened to discharge the concentrated water to the outside.

Opening of the closed circuit and external discharge of concentrated water can be achieved by opening and operating the concentrated water flow rate control valve 431 and the third pneumatic valve 432 of the concentrated water discharge line 430.

This CCRO process unit 50 maintains the discharge of desalinated treated water without stopping the reverse osmosis process of the RO process unit 40, and supplies the concentrated water to the RO module 420 until the preset concentration concentration is reached. By re-introducing and circulating treated water to achieve a high recovery rate of treated water, the treatment load and treatment process of the post-treatment facility can be reduced.

In addition, the CCRO process unit 50 may further include a component for removing organic substances contained in the concentrated water while the concentrated water is circulated through the circulation line 510.

As shown in FIG. 2, the CCRO process unit 50 is equipped with a control valve 521 that is mounted on the circulation line 510 to be located at the rear of the concentrated water circulation pump 500 and is selectively opened and closed. It may include a second circulation line 520 that branches off from the circulation line 510 and connects the front and rear ends of the control valve 521.

And the CCRO process unit 50 is mounted on the second circulation line 520 and is an adsorption filter that adsorbs organic substances in the concentrated water circulating in the second circulation line 520 according to the closing operation of the control valve 521. It may further include (530).

The concentrated water circulation pump 500 provides compensation pressure for the lost pressure of the concentrated water, by closing the control valve 521 installed at the rear of the concentrated water circulation pump 500 in the circulation line 510. Concentrated water containing organic matter can be circulated along the second circulation line 520 branched from the circulation line 510, and the adsorption filter 530 is used in the process of circulating the concentrated water through the second circulation line 510. As it passes through, organic matter in the concentrated water may be adsorbed and removed. At this time, some of the concentrated water pressure lost during the process of removing organic substances can be compensated for by the concentrated water circulation pump 500.

The adsorption filter 530 may be one of various known filters for removing organic substances. For example, the adsorption filter 530 may be an activated carbon filter.

Here, when regeneration of the adsorption filter 530 or removal of organic substances in the concentrated water is unnecessary, the concentrated water can be prevented from passing through the second circulation line 520 by opening and operating the control valve 521.

Meanwhile, the pneumatic recovery unit 60 may be connected to the concentrated water discharge line 430, and after stopping the circulation process of the CCRO process unit 50, high pressure The discharge pressure can be recovered and stored in the form of pneumatic pressure.

Although not shown in the drawing, the pneumatic recovery unit 60 can be connected to each pneumatic valve used in system operation through a separate pneumatic pipe, and in the case of stored air pressure, it can be supplied to be used as an operating means for the selected pneumatic valve. .

At this time, the pneumatic valve is a valve that operates by pneumatic pressure, including the first pneumatic valve 411, the second pneumatic valve 332, the third pneumatic valve 432, and the circulation valve 511 mentioned above, as well as the valves described below. It may include an inlet valve 601, a drain valve 611, a fourth pneumatic valve 701, a fifth pneumatic valve 711, and a sixth pneumatic valve 721.

Therefore, according to the system of the present invention, it is possible to recover the discharge pressure discarded in the process of performing the reverse osmosis process of the RO process unit 40 or the circulation process of the CCRO process unit 50 in the form of air pressure, and the recovered air pressure It can be supplied to be used in the operation of various pneumatic valves, etc., and since there is no need for a separate compressed air supply means such as a compressor, not only can energy be saved, but operating costs can also be reduced.

Figures 3a and 3b show the configuration and operating mechanism of a pneumatic recovery unit according to an embodiment of the present invention.

The pneumatic recovery unit 60 according to this embodiment can recover air pressure by the expansion tank 620.

Specifically, the pneumatic recovery unit 60 includes an inlet pipe 600 branching from the concentrated water discharge line 430, an inlet valve 601 mounted on the inlet pipe 600 and selectively opened and closed, and the inlet pipe It may include an expansion tank 620 connected to 600 to recover air pressure, and a pressure tank 630 connected to the expansion tank 620 and filled with recovered air pressure.

The expansion tank 620 forms an air chamber 622 having a constant volume and a space inside the air chamber 622, and an inlet pipe 600 communicates with the space and the concentrated water discharge line 430. A water chamber 621 in which concentrated water moving through flows in and expands may be installed in a compartment.

The pressure tank 630 may be in communication with the air chamber 622 of the expansion tank 620, and compressed air discharged according to the compression action of the air chamber 622 may be introduced and stored.

First, referring to FIG. 3A, when the third pneumatic valve 432 is opened and operated to discharge concentrated water after the circulation of the CCRO process unit 50 is stopped, concentrated water moves and is discharged through the concentrated water discharge line 430. , the concentrated water may flow into the water chamber 621 of the expansion tank 620 through the branched inlet pipe 600.

At this time, the inlet valve 601 of the inlet pipe 600 is also a pneumatic valve and must be maintained in the open state.

As concentrated water discharged at high pressure flows in, the water chamber 621 expands in volume from its original state, and in response, the volume of the air chamber 622 decreases and can be compressed. And as the air chamber 622 is compressed, the compressed air existing in the air chamber 622 can be moved to the connected pressure tank 630 to partially fill the compressed air.

The pneumatic recovery unit 60 may further include a drain pipe 610 branched from the inlet pipe 600, and a drain valve 611 mounted on the drain pipe 610 and selectively opened and closed.

The drain valve 611 of the drain pipe 610 may also be a pneumatic valve, and during the process of filling the pressure tank 630 with compressed air, it must be maintained in a closed state opposite to the inlet valve 601 to prevent outflow of concentrated water.

Here, the pneumatic recovery unit 60 is connected to the air chamber 622 of the expansion tank 620 and is equipped with a check valve 641 to supply outside air to the air chamber 622 in one direction. 640), the air chamber 622 of the expansion tank 620, and the pressure tank 630 are connected and a second check valve 651 is installed so that compressed air discharged from the air chamber 622 flows in one direction. It may further include a second operating pipe 650 that allows air to flow into the pressure tank 630.

That is, in the process of filling the pressure tank 630, the water chamber 611 is expanded by the inflow of concentrated water and the air chamber 622 is compressed accordingly, and at this time, the second check valve 651 is maintained in the open and operated state. Thus, the compressed air in the air chamber 622 can be moved to the pressure tank 630.

This air pressure filling process of the pressure tank 630 may be performed for a preset time.

Referring to FIG. 3B, when the air pressure filling process of the pressure tank 630 is completed for a preset time, the inlet valve 601 of the inlet pipe 600 is closed and the drain valve 611 of the drain pipe 610 is opened. It works.

At the same time, the first check valve 641 of the first operation pipe 640 operates to open, and the second check valve 651 of the second operation pipe 650 operates to close.

Therefore, the concentrated water flowing into the water chamber 622 of the expansion tank 620 can be discharged from the water chamber 622 and drained through the drain pipe 610, and the air chamber 621 is opened by opening the first check valve 641. ), the water chamber 622 can be shrunk and the air chamber 621 can be restored to its original volume.

The operating process shown in FIGS. 3A and 3B may be repeated until the pressure tank 630 reaches the set pressure. That is, by repeating the process of allowing concentrated water to flow into the water chamber 622 to compress the air chamber 621 and conversely discharging the concentrated water from the water chamber 622 to restore the air chamber 621, the pressure tank 630 This is to ensure that it is filled up to the preset pressure value.

Although not shown in the drawing, the pressure tank 630 may include a pressure gauge, and the filling state within the pressure tank 630 can be determined according to the measurement results of the pressure gauge.

In addition, the pressure tank 630 can be set to a first pressure value corresponding to buffering and a second pressure value requiring filling, and when the pressure value measured by the pressure gauge reaches the first pressure value, the above-described filling process This can be paused, and when the pressure value measured by the pressure gauge reaches the second pressure value, the above-described repetitive filling process can be resumed.

Meanwhile, the system of the present invention may further include components for cleaning the RO module 420, as shown in FIG. 4.

Referring to FIG. 4, the system of the present invention may further include a CIP chemical tank 70 in which chemicals for cleaning the RO module 420 are stored.

At this time, the chemical can be applied by selecting an appropriate one from among the known chemicals used for cleaning the filtration membrane, and detailed description thereof will be omitted.

The CIP chemical tank 70 is branched from the treated water discharge line 440 of the RO module 420 and has a first branch pipe 700 on which the fourth pneumatic valve 701 is installed, and a concentrated water discharge line 430. It may include a second branch pipe 710 branched from and equipped with a fifth pneumatic valve 711.

Accordingly, the CIP chemical tank 70 can be connected to the treated water discharge line 440 or the concentrated water discharge line 430, and the treated water produced and discharged from the reverse osmosis process of the RO module 420 or the CCRO process unit (50) ), the concentrated water discharged after stopping the circulation operation can be introduced to produce and store washing water mixed with pre-stored chemicals.

In other words, the amount of wastewater generated can be minimized by recycling not only the treated water filtered in the RO module 420 but also the concentrated water used as washing water.

In addition, the CIP chemical tank 70 can be connected to the front end of the RO module 420 through the cleaning line 720, and the cleaning line 720 is equipped with a sixth pneumatic valve 721 to supply cleaning water. It can be controlled.

In addition, the system of the present invention is mounted on the cleaning line 720 and selectively operates with the sixth pneumatic valve 721 to use treated water or concentrated water mixed with chemicals stored in the CIP chemical tank 70 as cleaning water for the RO module. It may further include a cleaning pump 80 that supplies water to 420.

The cleaning process of the RO module 420 using the CIP chemical tank 70 and the cleaning pump 80 can be performed when the performance of the RO module 420 deteriorates.

As an example, although not shown in the drawing, a pressure sensor may be mounted on the RO module 420, and the occurrence of differential pressure can be detected in real time by the pressure value of the RO module 420 measured by the pressure sensor. It is desirable to automatically perform physical cleaning on the RO module 420 when detected.

The cleaning process of the RO module 420 can be performed not only when an increase in differential pressure is detected but also when the amount of water to be treated is insufficient.

Here, during the cleaning process of the RO module 420, all necessary components for the production process of treated water and concentrated water are used, including the first pneumatic valve 411, the second pneumatic valve 442, and the third pneumatic valve 432. The operation of pneumatic valves may be temporarily suspended.

In addition, in the present invention, as shown in FIG. 4, compressed air is provided between the CIP chemical tank 70 and the cleaning pump 80, and is supplied to the cleaning water that moves according to the operation of the cleaning pump 80. And it may further include an air mixer 90 for mixing.

At this time, the cleaning pump 80 is preferably a multi-stage pump in which a plurality of impellers are installed in a multi-stage manner to generate fine bubbles in the cleaning water mixed with compressed air. In the cleaning process, the air mixer 90 and the impeller of the multi-stage pump By supplying the generated fine bubbles, chemical cleaning and physical cleaning by fine bubbles can be carried out simultaneously, thereby further increasing the cleaning ability.

In addition, it is desirable to use compressed air recovered and stored in the pneumatic recovery unit 60 as the compressed air supplied from the air mixer 90.

As an example, the air mixer 90 may be connected to the pressure tank 630 of the pneumatic recovery unit 60 through the air inlet line 900, and the seventh pneumatic valve 901 is mounted on the air inlet line 900. Thus, compressed air stored in the pressure tank 630 can be selectively introduced.

In this way, the system of the present invention can fill the pressure tank 630 with compressed air through repeated movement of the expansion tank 620 using the pressure of the high-pressure concentrated water that is discarded, and the filled compressed air can be used to apply various pneumatic pressures necessary for system operation. Since it is supplied to be used in the operation of the valve, power or an air compressor for valve operation is not required, thereby reducing energy and operating costs.

In addition, in general, when the RO process unit 40 is operated, the initial treated water comes out worse than the required water quality, so the initial treated water is discharged as concentrated water or returned to the front, and the treated water is discharged only when the stable required water quality is achieved. Therefore, when returning initially treated water to concentrated water or front end, the valve is switched and a shock load due to high-pressure concentrated water occurs.

However, in the case of the present invention, as described above, the expansion tank 620 not only has the function of recovering the high-pressure concentrated water pressure with air pressure, but also can control the impact force due to the high pressure in the process, and the high-pressure pump 400 Durability of the system by reducing the expansion shock and load on piping and other facilities due to the instantaneous high pressure of concentrated water due to valve ON/OFF during initial operation or repeated operation of the RO process unit (40) and CCRO process unit (50). can be improved.

Meanwhile, the control method of the present invention is a method of controlling the system shown in FIGS. 1 to 4, which operates the high pressure pump 400 to allow raw water to flow into one or more RO modules 420 and reverse osmosis of the RO module 420. Through the process, an RO step can be performed in which treated water and concentrated water are discharged separately.

Then, the CCRO step can be performed by operating the concentrated water circulation pump 500 to re-introduce and circulate the concentrated water discharged from the RO step into the one or more RO modules 420 through the circulation line 510.

In addition, a stop step is performed to measure the TDS concentration of the concentrated water discharged from the RO module 420, and to stop the circulation of the concentrated water by the concentrated water circulation pump 500 when the measured TDS concentration is higher than the preset standard TDS concentration. It can be done.

In the stop step, the circulation of concentrated water is stopped, and a discharge step can be performed in which the concentrated water produced in the RO module 420 is discharged to the outside through the concentrated water discharge line 430.

In particular, the control method of the present invention may further include a pneumatic recovery step of recovering and storing high-pressure discharge pressure from the concentrated water discharged in the discharge step in the form of pneumatic pressure.

The air pressure recovered and stored in the pneumatic recovery step is supplied to be used as an operating means for the selected pneumatic valve in the future, thereby eliminating the need for power or an air compressor to drive the valve, thereby reducing energy and operating costs.

Additionally, in the control method of the present invention, the CCRO step may include a step of allowing the circulating concentrated water to pass through an adsorption filter 530 to adsorb and remove organic substances contained in the concentrated water.

Through the above-described content, those skilled in the art will be able to see that various changes and modifications can be made without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention should not be limited to what is described in the detailed description of the specification, but should be determined by the scope of the patent claims.

10: raw water tank 20: inflow pump
30: Pre-treatment filter 40: RO process unit
50: CCRO process unit 60: Pneumatic recovery unit
70: CIP chemical tank 80: Cleaning pump
90: Air mixer
400: high pressure pump 410: raw water inflow line
411: 1st pneumatic valve 420: RO module
430: Concentrated water discharge line 432: Third pneumatic valve
440: Treated water discharge line 442: Second pneumatic valve
500: Concentrated water circulation pump 510: Circulation line
511: Circulation valve 520: Second circulation line
530: Adsorption filter
600: Inlet pipe 601: Inlet valve
610: drain pipe 611: drain valve
620: Expansion tank 621: Water chamber
622: air chamber 630: pressure tank
640: first operating tube 641: first check valve
650: Second operating pipe 651: Second check valve
700: 1st branch organ 710: 2nd branch organ
730: Cleaning line 900: Air inflow line

Claims (9)

It includes one or more RO modules through which raw water flows in through a raw water inflow line equipped with a high-pressure pump, and the concentrated water and treated water produced by the reverse osmosis process of the RO module are separated into a concentrated water discharge line and a treated water discharge line, respectively. RO (Reverse Osmosis) process unit that discharges emissions;
It includes a circulation line that connects the raw water inflow line and the concentrated water discharge line and is provided with a concentrated water circulation pump, and allows the concentrated water discharged through the concentrated water discharge line to reflow into the RO module and reach a preset concentration. A CCRO (Closed Circuit Reverse Osmosis) process unit that circulates the concentrated water until it is discharged to the outside; and
The high-pressure discharge pressure from the concentrated water that is connected to the concentrated water discharge line and discharged to the outside after the circulation process of the CCRO process is recovered and stored in the form of pneumatic pressure, and the stored air pressure is supplied to be used as an operating means of the selected pneumatic valve. Includes a recovery unit;
The pneumatic recovery unit,
An inflow pipe branching from the concentrated water discharge line, an inflow valve mounted on the inflow pipe and selectively opened and closed, an air chamber connected to the inflow pipe and having a constant volume therein, and high pressure moving through the concentrated water discharge line. Concentrated water comprising an expansion tank in which a water chamber in which concentrated water flows and expands is defined, and a pressure tank in communication with the air chamber of the expansion tank and in which compressed air discharged according to compression of the air chamber is introduced and stored. CCRO system for energy recovery and reuse using pressure.
According to clause 1,
The CCRO process department,
A second circulation line is provided with a control valve that is mounted on the circulation line to be located at the rear end of the concentrated water circulation pump and operates to open and close selectively, and is branched from the circulation line and connects the front end and the rear end of the control valve, and Energy recovery and reuse using the pressure of concentrated water, further comprising an adsorption filter mounted on the second circulation line and allowing organic matter in the concentrated water circulating in the second circulation line to be adsorbed when the control valve is closed. CCRO system.
delete According to clause 1,
The pneumatic recovery unit,
A first operating pipe connected to the air chamber of the expansion tank and equipped with a check valve to supply outside air to the air chamber in one direction, and a second check valve connected between the air chamber of the expansion tank and the pressure tank and equipped with An energy recovery and reuse CCRO system utilizing concentrated water pressure, comprising a second operating pipe that allows compressed air discharged from the air chamber to flow into the pressure tank in one direction.
According to clause 1,
Chemicals for cleaning the RO module are stored, and are connected to the treated water discharge line or concentrated water discharge line of the RO process unit to flow in the treated water or concentrated water discharged from the RO module, and to the front of the RO module through the cleaning line. Connected CIP chemical tank; and
A cleaning pump mounted on the cleaning line and selectively operated to supply treated water or concentrated water mixed with chemicals stored in the CIP chemical tank to the RO module as cleaning water; further comprising a concentrated water pressure. An energy recovery and reuse CCRO system.
According to clause 5,
An air mixer provided between the CIP chemical tank and the cleaning pump and supplying and mixing compressed air with the cleaning water moving according to the operation of the cleaning pump; energy utilizing concentrated water pressure, characterized in that it further comprises a. Recovery and reuse CCRO system.
According to clause 5,
The cleaning pump is,
A CCRO system for energy recovery and reuse using concentrated water pressure, which is a multi-stage pump with a plurality of impellers installed in a multi-stage manner to generate fine bubbles in washing water mixed with compressed air.
A method for controlling the system according to any one of claims 1, 2, 4 to 7, comprising:
a) RO stage in which raw water flows into one or more RO modules by operating a high-pressure pump, and treated water and concentrated water are discharged separately through the reverse osmosis process of the RO module;
b) a CCRO step of operating a concentrated water circulation pump to re-introduce and circulate the concentrated water discharged from the RO step into the one or more RO modules through a circulation line;
c) a stop step of measuring the TDS concentration of the concentrated water discharged from the RO module and stopping the circulation of the concentrated water by the concentrated water circulation pump when the measured TDS concentration is higher than a preset standard TDS concentration;
d) a discharge step of discharging the concentrated water produced in the RO module to the outside through a concentrated water discharge line; and
e) a pneumatic recovery step of recovering and storing high-pressure discharge pressure from the concentrated water discharged in the discharge step in the form of pneumatic pressure; A control method of an energy recovery and reuse CCRO system using concentrated water pressure, comprising a.
According to clause 8,
The CCRO step is,
A control method for an energy recovery and reuse CCRO system using concentrated water pressure, comprising the step of allowing circulating concentrated water to pass through an adsorption filter to adsorb and remove organic substances contained in the concentrated water.

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