KR102477972B1 - Reverse osmosis apparatus having automatic cleaning system and operating method thereof - Google Patents

Abstract

The present invention relates to a reverse osmosis facility having an automatic cleaning system and a method of operating the same, and more specifically, to a reverse osmosis facility including a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit and an automatic cleaning method using the reverse osmosis membrane module cleaning unit. Calculate the water temperature-corrected reverse osmosis membrane production quantity with the measured values of the water temperature sensor of the water to be treated and the reverse osmosis membrane production water flow rate sensor, and perform maintenance cleaning if it is measured at 85% or less of the initial value, i) the maintenance cleaning It is performed twice or more a day, or ii) the water temperature corrected reverse osmosis membrane production volume is reduced to 85% or less of the initial value, the electrical conductivity removal rate of the reverse osmosis membrane product water is reduced to 85% or less of the initial value, and the reverse osmosis membrane module inlet line pressure and concentrated water Reverse osmosis equipment characterized in that recovery cleaning is performed when the difference in discharge line pressure increases by 15% or more from the initial value and an automatic cleaning method thereof.

Description

Reverse osmosis apparatus having automatic cleaning system and operating method thereof}

The present invention relates to a reverse osmosis facility equipped with an automatic cleaning system and a method for operating the same.

More specifically, in a reverse osmosis facility including a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit, and an automatic cleaning method using the same, the reverse osmosis membrane module cleaning unit corrects the water temperature with the measured values of the water temperature sensor of the water to be treated and the flow rate sensor of the reverse osmosis membrane product water If the reverse osmosis membrane production volume is calculated and measured to be 85% or less of the initial value, maintenance cleaning is performed, i) the maintenance cleaning is performed twice or more a day, or ii) the water temperature corrected reverse osmosis membrane production volume is less than the initial value decreased to 85% or less, the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate decreased to 85% or less of the initial value, and the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure increased to 15% or more from the initial value It relates to a reverse osmosis facility and an automatic cleaning method thereof, characterized in that it performs recovery cleaning in the case of

In general, there seems to be no disagreement that the most difficult thing in the operation of a reverse osmosis membrane facility is the manager's accurate recognition of membrane contamination and proper cleaning of the membrane. In addition, there seems to be no disagreement that appropriate cleaning management of the reverse osmosis membrane is the most important facility maintenance technology, and is also related to the extension of the life of the reverse osmosis membrane.

Most of the prior art, including Korean Patent Registration Nos. 10-1928203 and 10-1813159 related to cleaning and automation of reverse osmosis membrane facilities, mainly focuses on the type of cleaning chemicals and the hardware configuration method for automation of the facility. From the point of view of operation managers lacking specialized knowledge, it is judged that these contents do not provide sufficient information for proper operation due to membrane fouling of reverse osmosis membrane facilities. This is because the most important membrane contamination state in automatic chemical cleaning of the reverse osmosis membrane is not sufficiently reflected, and a suitable cleaning method is not provided. For example, the automatic cleaning time is performed at 10% rather early without waiting until the 15% increase compared to the initial pressure, which is the general CIP time point, and it is easy to measure the pressure. I think. In addition, even if the reverse osmosis membrane is not contaminated, there can be a difference of 15% in pressure and production volume even with a difference of only 5 degrees due to the water temperature. can't

As the most effective improvement measure for this, it is to select the appropriate chemical cleaning method according to the situation by classifying the concentration and the type of chemical used under the condition accompanied by economic feasibility, and to apply the setting indicator that reflects the automatic cleaning time to the raw water temperature. It is expected to be useful for practical management aspects.

Accordingly, the present invention provides an automatic reverse osmosis membrane cleaning management program for recognizing membrane contamination of a reverse osmosis membrane in which water temperature is reflected more accurately as a method of automating a management program for a manager lacking professional knowledge and determining this as a cleaning time point. In addition, two cleaning methods divided into maintenance cleaning, which is frequently performed with low chemical concentration, and recovery cleaning, which is a general CIP cleaning method, are combined with automatic programmability to achieve economical conditions. Provided is a method for controlling excessive membrane fouling of an existing reverse osmosis membrane under By implementing this, it is possible to reduce the possibility of product water quality deterioration, which is a phenomenon of reduced production quantity and reduced performance of the separation membrane due to excessive contamination of the reverse osmosis membrane of the facility, by providing an automated program even by a manager lacking professional knowledge. In addition, irreversible contamination can be reduced by application of maintenance cleaning before excessive contamination of the reverse osmosis membrane, which greatly increases the cleaning efficiency during recovery cleaning. can significantly increase life expectancy.

Korean Patent Publication No. 10-2009-0043842 Korean Registered Patent Publication No. 10-1928203 Korean Registered Patent Publication No. 10-1928212 Korean Patent Registration No. 10-1813159

The present invention was developed to solve the above problems, and provides a more economical and more effective cleaning time for both equipment manufacturing cost and operating cost to managers who lack expertise in the operation and management of reverse osmosis facilities for various waters to be treated. It is an object of the present invention to provide an automated cleaning system for a reverse osmosis membrane that determines and proceeds automatically.

In addition, the present invention is intended to provide an economical and effective automatic cleaning method for reverse osmosis equipment including a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit.

In order to solve the above problems, in the present invention, in the reverse osmosis facility having a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit and an automatic cleaning method using the same, the reverse osmosis membrane module cleaning unit comprises a water temperature sensor of the water to be treated and a flow rate sensor of the reverse osmosis membrane product water Calculate the water temperature-corrected reverse osmosis membrane production volume with the measured value and perform maintenance cleaning if it is measured at 85% or less of the initial value, i) the maintenance cleaning is performed twice or more a day, or ii) the water temperature-corrected reverse osmosis membrane The production volume is reduced to 85% or less of the initial value, the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate is reduced to 85% or less of the initial value, and the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure is greater than the initial value. If it increases to 15% or more, recovery cleaning can be performed.

The water temperature corrected reverse osmosis membrane production volume according to the present invention is the following equations (1) and Equation (2), the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate is the following equation (3), the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge The difference in line pressure is calculated according to the following equation (4), and provides a reverse osmosis facility having an automatic cleaning system and an automatic cleaning method using the same.

(Equation 1)

[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193

(Equation 2)

Water temperature corrected reverse osmosis membrane production = normal production × [flow rate correction factor]

(Equation 3)

Water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate (%) = 100 - {(produced water electrical conductivity value)/(raw water electrical conductivity value)} × {(produced water flow rate value)/(produced water flow rate initial value)} × ( flow correction factor) × 100

(Equation 4)

Difference between water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure = {(RO inlet electronic pressure gauge value) - (RO concentrated electronic pressure gauge value)} × {(RO production volume initial value + concentrated water initial value)/ (RO production quantity measured value + concentrated water quantity measured value)}

The present invention provides an optimal cleaning method for a separation membrane, which is most important in operating a reverse osmosis membrane, by clicking an automatic operation button provided on a control program screen, which is economical for both equipment manufacturing price and operating cost, even for managers lacking expertise in the operation and management of reverse osmosis equipment. It provides optimal operation and convenience, including the function of automatically performing the

In addition, it is possible to prevent excessive contamination of the reverse osmosis membrane module in advance by automated maintenance cleaning, which is frequently performed compared to the strong recovery cleaning method, which is a conventional general cleaning method. In addition, it is possible to increase recovery cleaning performance and increase the life of the reverse osmosis membrane module, thereby reducing maintenance costs.

In addition, high-pressure operation due to excessive contamination of the reverse osmosis membrane, which is a major factor in deterioration of reverse osmosis membrane production water, can be avoided as much as possible by automated maintenance cleaning, so that relatively stable salt rejection performance of the reverse osmosis membrane can be maintained for a long time.

In addition, by configuring the CIP tank and the cleaning solution supply pump of the reverse osmosis membrane module cleaning unit as a single unit and using two or more types of cleaning chemical stock solution supply units, cleaning of two or more different types of chemicals can be performed with the single unit CIP tank and cleaning solution supply pump. It can reduce equipment cost and scale down.

Due to this effect, the automatic cleaning system can be simplified to reduce the size and price of cleaning facilities, and the low-pressure operation of the reverse osmosis membrane due to automatic cleaning management can reduce power costs and costs due to an increase in the replacement cycle of the reverse osmosis membrane. In addition, by introducing a method for determining maintenance and recovery cleaning reflecting the water temperature of the water to be treated, the reverse osmosis membrane contamination, which excludes the variable of water temperature change as much as possible, is more accurately recognized and applied to the automatic cleaning program, thereby further optimizing the operation and management cost of the reverse osmosis membrane facility. can

1 schematically shows a reverse osmosis facility equipped with an automatic cleaning system according to an embodiment of the present invention.
Figure 2 shows a correction formula for calculating the water temperature corrected reverse osmosis membrane production volume according to an embodiment of the present invention and the result.
3 shows the flow rate of produced water of a temperature-corrected sewage reuse reverse osmosis membrane facility operated for about 4,000 hours according to an embodiment of the present invention.
4 shows the pressure difference before and after maintenance cleaning of a sewage recycling reverse osmosis membrane facility operated for about 4,000 hours according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail. The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

The term "CIP (clean in place)" used throughout this specification is generally performed for regeneration of contaminated water treatment membranes, and cleaning of contaminated membranes during filtration operation of general water treatment membrane facilities is performed on pipes, It refers to a method of using chemicals in an assembled water-passing interior without disassembling equipment components such as vessels, filters, and fittings.

In addition, in the present invention, “recovery cleaning” is the most powerful level of cleaning that can be normally applied to a separation membrane that has been contaminated to a generally acceptable level (usually suggested by a separation membrane manufacturer) to recover the maximum filtration performance of the separation membrane. means how to do it.

A representative recovery cleaning method for a reverse osmosis membrane according to an embodiment of the present invention is as follows.

(Step 1: Acid washing) ① Preparation of hydrochloric acid (HCl) 0.3% by mass cleaning stock solution in CIP tank (22 in Fig. 1) - ② (10 in Fig. 1) Chemical solution prepared by CIP pump 23 -> 15 -> 7 -> 4 -> Circulating cleaning of RO and CIP facilities in the order of 22 (approximately 1 to 3 hours) - ③ Chemical immersion cleaning by stopping the CIP pump (approximately 1 to 3 hours) - ④ Drainage of chemical solution inside RO and CIP facilities (flushing with raw water)

(Step 2: Alkaline cleaning) Again ① Preparation of sodium hydroxide (NaOH) 0.15% by mass cleaning stock solution in the CIP tank (22 in FIG. 1) - The following ② to ④ procedures are the same as acid cleaning

(Step 3: Flushing inside the final pipe and proceeding with normal operation) Automatically enters normal operation after CIP is finished. However, since the initial product water is contaminated by the cleaning liquid inside the pipe (19 in FIG. When the electrical conductivity of the produced water is high, the produced water is automatically discarded, and over time, when the electrical conductivity of the produced water is lower than the value set in the produced water electrical conductivity sensor, the produced water valve is automatically opened to produce produced water.

The advantage of the recovery cleaning according to one embodiment of the present invention is that the separation membrane performance is most excellent because the separation membrane is washed most strongly in a conventional method, and the disadvantage is that it takes a long time compared to ① maintenance cleaning (maintenance cleaning Within 1 hour, recovery cleaning 2~6 hours), ② Since the concentration of the chemical is high, the time for [automatic discarding of produced water if the electrical conductivity of produced water is higher than the value set in the electrical conductivity sensor of produced water] after cleaning and the amount of produced water to be discarded There are very many (hours).

In addition, in the present invention, “maintenance cleaning” is similar to recovery cleaning, but is simple and low-intensity cleaning. (Pump energy is saved), ② Due to frequent management of membrane contamination, RO is relatively less exposed to high pressure, and the degree of contamination of RO is low.

A representative method for maintaining a reverse osmosis membrane according to an embodiment of the present invention is completed with the following one-step cleaning.

(Step 1: Acid washing) ① Preparation of hydrochloric acid (HCl) 0.045% by mass cleaning stock solution in CIP tank (22 in Fig. 1) - ② (10 in Fig. 1) Chemical solution prepared by CIP pump 23 -> 15 -> 7 -> 4 -> Circulation cleaning of RO and CIP facilities in the order of 22 (approx. 25 minutes) - ③ Chemical immersion cleaning by stopping the CIP pump (approx. 25 minutes) - ④ Drainage of chemical solution inside RO and CIP facilities (flushing with raw water)

The advantages of recovery cleaning according to an embodiment of the present invention are that weak cleaning is performed frequently, ① effective RO membrane contamination management is possible (pump energy is saved), and ② membrane contamination is frequently managed, so the time for exposure to high pressure RO is relatively small. The degree of stubborn contamination of RO is low, so the recovery effect of separator cleaning is great during recovery cleaning in the future. If the facility does not have a stand-by, production water is often stopped, and because there is flushing using raw water after washing, the amount of raw water that is wasted increases.

Until now, there is almost no concept of dividing and managing chemical cleaning of reverse osmosis membrane (RO) facilities into [maintenance cleaning] and [recovery cleaning], and it is known that only recovery cleaning is performed repeatedly.

The present invention can alleviate the deterioration in production water quality, which is the phenomenon of decrease in production quantity due to membrane fouling and degradation of membrane performance due to accumulation of membrane fouling, which are the biggest disadvantages of general reverse osmosis membrane facilities, by an automatic cleaning method that systematically combines maintenance cleaning and recovery cleaning methods. It relates to an automatic cleaning method and system for reverse osmosis membrane equipment that can be used.

According to the implementation of the present invention, it is possible to significantly improve the reduction in production quantity and deterioration in the quality of production water of the reverse osmosis membrane facility by applying a chemical cleaning method by an automated program, and greatly extend the life of the reverse osmosis membrane module. In addition, many facility managers do not properly recognize the serious level of membrane contamination of the reverse osmosis membrane module due to the accumulated filtration amount, which is the biggest disadvantage of general reverse osmosis membrane facilities, and the appropriate time for chemical cleaning is exceeded, resulting in a large recovery rate due to chemical cleaning. It can be degraded or even irreversible. However, with the implementation of the present invention, the manual membrane cleaning method, which is most difficult for system administrators, is automatically programmed, so that a good filtration environment for the reverse osmosis membrane module can be provided at all times even by managers without professional knowledge. there is.

The present invention is specifically a pretreatment device mainly composed of filter media from raw water; A product water line in which the pretreated water passes through a reverse osmosis membrane module through a high-pressure pump and the product water is discharged through a product water pipe; A concentrated water line in which pretreated water does not pass through the reverse osmosis membrane module through the high-pressure pump, and the discharged water is discarded through the concentrated water pipe or circulated and reused as the inflow of the reverse osmosis membrane module; The raw water and production water of the reverse osmosis membrane facility are taken into the CIP tank, and the cleaning chemical solution is injected into the CIP tank by the chemical pump from the reverse osmosis membrane cleaning chemical stock solution tank as much as the programmed amount to prepare the cleaning chemical solution in the CIP tank. A CIP line that circulates the cleaning chemical solution between the reverse osmosis membrane facility and the CIP tank by supplying it through the inlet of the reverse osmosis membrane module with the CIP pump to recover the cleaning chemical solution that has passed through the inside and outside of the reverse osmosis membrane module back to the CIP tank; Automatic cleaning device for reverse osmosis equipment in which maintenance cleaning and recovery cleaning are automatically performed by a program composed of an automatic valve and a control device/program capable of automatically changing the liquid flowing through the device and the line according to the use and purpose, and its use it's about how

In the present invention, in order to solve the above problems, a reverse osmosis production unit including a water-to-be-treated inlet line, a product water line, a concentrated water discharge line, and a reverse osmosis membrane module, and producing product water using the reverse osmosis membrane module; a reverse osmosis membrane module washing unit branched off from the concentrated water discharge line of the reverse osmosis production unit; And a water temperature sensor for the water to be treated, a reverse osmosis membrane product water flow rate sensor, a reverse osmosis membrane product water electrical conductivity sensor, a reverse osmosis membrane module inlet line pressure sensor, and a reverse osmosis facility having sensors including a concentrated water outlet line pressure sensor,

The reverse osmosis membrane module cleaning unit calculates the water temperature-corrected reverse osmosis membrane production volume with the measured values of the water temperature sensor of the water to be treated and the reverse osmosis membrane product flow rate sensor, and performs maintenance cleaning when the water temperature is measured at 85% or less of the initial value,

i) the maintenance cleaning is performed twice or more a day, or

ii) The water temperature corrected reverse osmosis membrane production volume is reduced to 85% or less of the initial value, the reverse osmosis membrane product water electrical conductivity removal rate is reduced to 85% or less of the initial value, and the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure Provided is a reverse osmosis facility equipped with an automatic cleaning system, characterized in that performing recovery cleaning (recovery cleaning) when increases by 15% or more from the initial value.

In the reverse osmosis facility having an automatic cleaning system according to one embodiment of the present invention, the reverse osmosis production unit includes a raw water inlet line through which water to be treated is supplied; a pretreatment device connected to the raw water inlet line and provided before the reverse osmosis membrane module to remove impurities in order to reduce the amount of particulate matter and improve turbidity and hardness; a high-pressure pump supplying water to be treated pre-treated by removing impurities in the pre-treatment device to a reverse osmosis membrane module; a reverse osmosis membrane module for producing demineralized filtered water from the treated water supplied from the high-pressure pump; a reverse osmosis membrane product line through which the desalinated filtered water is discharged to a pipe; and a concentrated water discharge line through which pretreated water to be treated is not filtered through the reverse osmosis membrane module and excluded substances are concentrated and discharged.

In the reverse osmosis facility having an automatic cleaning system according to an embodiment of the present invention, the reverse osmosis membrane module washing unit is branched by the concentrated water discharge line and the CIP facility inlet conversion valve to circulate water to the CIP facility. incoming CIP facility inlet line; A CIP tank for preparing a reverse osmosis membrane cleaning solution by supplying a first cleaning agent stock solution or a second cleaning agent stock solution to a tank storing fresh water; And a CIP facility discharge line for supplying the reverse osmosis membrane cleaning liquid prepared in the CIP tank to the contaminated reverse osmosis membrane module,

In the CIP tank, the first cleaning chemical stock solution supply unit composed of the first cleaning chemical stock solution storage tank and the chemical pump and the second cleaning chemical stock solution supply unit composed of the second cleaning chemical stock solution storage tank and the chemical pump are provided with fresh water by a programmed method. A reverse osmosis membrane cleaning solution is prepared by supplying a first cleaning chemical stock solution or a second cleaning chemical stock solution to the stored CIP tank,

The prepared reverse osmosis membrane cleaning solution is filtered by the reverse osmosis membrane cleaning solution filter by the cleaning solution supply pump and then supplied to the contaminated reverse osmosis membrane module through the CIP facility discharge line,

After cleaning the contaminated reverse osmosis membrane module, the cleaning solution can be circulated to the CIP equipment inlet line and the CIP tank.

In the reverse osmosis facility having an automatic cleaning system according to one embodiment of the present invention, the reverse osmosis facility includes a raw water inlet valve installed before the pretreatment device; a reverse osmosis membrane produced water/produced water waste conversion valve connected to the reverse osmosis membrane module; and a concentrated water discharge/inlet switching valve for the CIP facility, a reverse osmosis membrane cleaning solution supply valve, and a CIP tank drain valve 16 provided between the reverse osmosis membrane module and the reverse osmosis membrane module cleaning unit.

In the reverse osmosis facility equipped with an automatic cleaning system according to an embodiment of the present invention, the temperature-corrected reverse osmosis membrane production quantity is the following formula (1), the water temperature-corrected reverse osmosis membrane production water electrical conductivity removal rate is Equation (3), the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure can be calculated according to the following equation (4).

(Equation 1)

[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193

(Equation 2)

Water temperature corrected reverse osmosis membrane production = normal production × [flow rate correction factor]

(Equation 3)

Water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate (%) = 100 - {(produced water electrical conductivity value)/(raw water electrical conductivity value)} × {(produced water flow rate value)/(produced water flow rate initial value)} × ( flow correction factor) × 100

(Equation 4)

Difference between water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure = {(RO inlet electronic pressure gauge value) - (RO concentrated electronic pressure gauge value)} × {(RO production volume initial value + concentrated water initial value)/ (RO production quantity measured value + concentrated water quantity measured value)}

In the reverse osmosis facility equipped with an automatic cleaning system according to an embodiment of the present invention, the maintenance cleaning includes acid cleaning in which the facility is circulated and cleaned with 0.03 to 0.05% by mass hydrochloric acid cleaning stock solution. can

In the reverse osmosis facility equipped with an automatic cleaning system according to an embodiment of the present invention, the recovery cleaning is performed by pickling with 0.2 to 0.4% by mass of hydrochloric acid cleaning solution and 0.1 to 0.2% by mass of sodium hydroxide. It may include alkali cleaning with a cleaning stock solution and flushing of the inside of the facility.

In addition, in the present invention, in the automatic cleaning method of reverse osmosis equipment having a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit,

The reverse osmosis membrane module cleaning unit calculates the water temperature-corrected reverse osmosis membrane production volume with the measured values of the water temperature sensor of the water to be treated and the flow rate sensor of the reverse osmosis membrane product water, and performs maintenance cleaning when the measured value is less than 85% of the initial value,

i) the maintenance cleaning is performed twice or more a day, or

ii) The water temperature corrected reverse osmosis membrane production volume is reduced to 85% or less of the initial value, the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate is reduced to 85% or less of the initial value, and the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line Provided is an automatic cleaning method for reverse osmosis equipment comprising performing recovery cleaning when the difference in pressure increases by 15% or more from an initial value.

The initial value is the water temperature-corrected initial index performance generated during the test process of the facility's official production flow rate and recovery rate conditions at the time of shipment from the manufacturing plant, and the arithmetic average value of each of the flow rate, pressure, and water quality data is stored in the control program. In addition, the initial value is automatically updated immediately after recovery cleaning, and the arithmetic average value of each of the water temperature, flow rate, pressure, and water quality data generated during normal operation stored for one day after recovery cleaning is converted to a new initial value. In case the reverse osmosis membrane is replaced with a new product in the future, the initial performance index at the time of shipment from the factory will be applied again.

In the automatic cleaning method for reverse osmosis equipment according to an embodiment of the present invention, the water temperature corrected reverse osmosis membrane production quantity is the following formula (1) and the water temperature corrected reverse osmosis membrane production water electrical conductivity is the following formula (3) ), the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water outlet line pressure can be calculated according to the following equation (4).

(Equation 1)

[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193

(Equation 2)

Water temperature corrected reverse osmosis membrane production = normal production × [flow rate correction factor]

(Equation 3)

Water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate (%) = 100 - {(produced water electrical conductivity value)/(raw water electrical conductivity value)} × {(produced water flow rate value)/(produced water flow rate initial value)} × ( flow correction factor) × 100

(Equation 4)

Difference between water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure = {(RO inlet electronic pressure gauge value) - (RO concentrated electronic pressure gauge value)} × {(RO production volume initial value + concentrated water initial value)/ (RO production quantity measured value + concentrated water quantity measured value)}

In the automatic cleaning method for reverse osmosis equipment according to an embodiment of the present invention, the oil and fat cleaning includes acid cleaning in which the equipment is circulated and cleaned with 0.03 to 0.05% by mass of hydrochloric acid cleaning stock solution,

The recovery cleaning may include acid cleaning with 0.2 to 0.4% by mass of hydrochloric acid cleaning stock solution, alkali cleaning with 0.1 to 0.2% by mass of sodium hydroxide stock solution, and flushing of the inside of the equipment.

Hereinafter, implementation examples and embodiments of the present invention will be described in detail so that those with general knowledge in the technical field to which the present application pertains can easily practice, as shown in the accompanying drawings, preferred embodiments of the present invention. In particular, the technical idea of the present invention and its core configuration and operation are not limited by this. In addition, the contents of the present invention can be implemented in various types of equipment, and is not limited to the implementation examples and examples described herein.

1 schematically shows a reverse osmosis facility equipped with an automatic cleaning system according to an embodiment of the present invention.

In order to achieve the above object, the present invention provides a raw water inlet line (1) through which water to be treated is supplied to receive produced water using a reverse osmosis facility; A reverse osmosis membrane module (7) and a pretreatment device (5) for removing turbidity and hardness to improve pre- and filtration performance; Reverse osmosis membrane module (7) High-pressure pump (6) for supplying high-pressure pre-treated water for filtration purposes; a reverse osmosis membrane module (7) supplying water to be treated at high pressure to produce demineralized filtered water; a reverse osmosis membrane production water line (2) in which demineralized filtered water is produced and discharged to a pipe; It includes a reverse osmosis production unit composed of a concentrated water discharge line (3) in which the pretreated water to be treated is not filtered through the reverse osmosis membrane module (7) and the excluded substances are concentrated and discharged, and the concentrated water is discharged from the concentrated water discharge line (3). / CIP facility inlet line (4) branched to the CIP facility inlet switching valve (14) and circulating water flows into the CIP facility; Cleaning chemical stock solution ① Cleaning chemical stock solution consisting of a storage tank and chemical pump ① Supply unit 8 and cleaning chemical stock solution ② Cleaning chemical stock solution consisting of a storage tank and chemical pump ② Supply unit 9 CIP in which fresh water is stored by a programmed method Reverse osmosis membrane cleaning solution is prepared by supplying the cleaning chemical stock solution ① or ② to the tank 22, and the reverse osmosis membrane cleaning solution is filtered through the reverse osmosis membrane cleaning solution filter 11 by the cleaning solution supply pump 10, and then discharged through the CIP facility discharge line 23. a reverse osmosis membrane module cleaning unit in which cleaning solution is supplied to the contaminated reverse osmosis membrane module (7) and circulated to the CIP facility inlet line (4) and the CIP tank (22); Including, a raw water inlet valve 12 that automatically controls the flow of the liquid in a programmed manner, a reverse osmosis membrane produced water / produced water waste conversion valve 13, a concentrated water discharge / CIP facility inlet conversion valve 14, a reverse osmosis membrane Automatic valves composed of a cleaning liquid supply valve 15 and a CIP tank drain valve 16; Including, the water temperature sensor 17 of the treated water, the reverse osmosis membrane product water flow rate sensor 18, the reverse osmosis membrane product water electrical conductivity sensor 19, the reverse osmosis membrane module inlet pressure sensor 20 and the concentration line pressure sensor 21 configured sensors; Including,

The water temperature sensor 17 of the water to be treated and the reverse osmosis membrane product flow rate sensor 18 calculate the water temperature corrected reverse osmosis membrane production volume and automatically perform maintenance cleaning when it is measured at 15% or less of the initial value,

The maintenance cleaning is performed twice or more a day, or the water temperature sensor 17 of the water to be treated and the reverse osmosis membrane produced water flow rate sensor 18 calculate the water temperature corrected reverse osmosis membrane production volume and measure it to 15% or less of the initial value, and the reverse osmosis membrane The product water electrical conductivity sensor (19) is increased by more than 15% than the normal measured value, and the pressure reduction value obtained by subtracting the value of the concentrating line pressure sensor (21) from the value of the inlet pressure sensor (20) of the reverse osmosis membrane module is increased by more than 15% than the normal measured value Provided is an automatic cleaning device and control method for a reverse osmosis facility, characterized by a method including a method of proceeding with recovery cleaning when this occurs at the same time.

In the automatic cleaning apparatus and method of a reverse osmosis facility in which maintenance cleaning and recovery cleaning are automatically performed by a program according to an embodiment of the present invention, the CIP tank 22 and the cleaning liquid supply pump 10 of the reverse osmosis membrane module cleaning unit The CIP unit composed of is characterized in that it is configured as one set and uses two or more kinds of cleaning chemical stock solution supply units to enable cleaning of two or more different chemicals with a single CIP unit. The above effect can perform cleaning of two or more different chemicals with one set of CIP units composed of a single unit of the CIP tank 22 and the cleaning liquid supply pump 10, thereby reducing equipment cost and reducing scale.

In general, when two or more chemicals with completely different chemical functions are needed during chemical cleaning of the reverse osmosis membrane, the process is performed sequentially by chemical type. Using this feature, the first chemical stock solution is mixed with fresh water filled in the CIP tank to prepare the first cleaning solution, and after completion of the recovery cleaning, the waste liquid remaining in the reverse osmosis production unit and the reverse osmosis membrane module cleaning unit is used as the raw material to be treated. First discharge to the drain through flushing and opening of the automatic valve. Thereafter, the raw water to be treated is filled in the CIP tank, and similar to chemical cleaning, the cleaning liquid supply pump 10 circulates the fresh water between the reverse osmosis production unit and the reverse osmosis membrane module cleaning unit to wash the inside of the pipe and discharge it to the drain. Residual first cleaning chemicals in the reverse osmosis production unit and the reverse osmosis membrane module cleaning unit are washed with water. Thereafter, the second chemical stock solution cleaning procedure, which is the second chemical cleaning step, is performed in the same manner as the first chemical stock solution cleaning procedure.

An automatic cleaning device and method for a reverse osmosis facility in which maintenance cleaning and recovery cleaning are automatically performed by a program according to an embodiment of the present invention are characterized in that automated maintenance cleaning is applied. The above effect can prevent excessive contamination of the reverse osmosis membrane module in advance, enabling low-pressure stable filtration during most of the operating period, saving energy for the high-pressure pump, and reducing maintenance costs by increasing recovery cleaning performance and increasing the lifespan of the reverse osmosis membrane module. can do.

In addition, high-pressure operation due to excessive contamination of the reverse osmosis membrane, which is a major factor in deterioration of reverse osmosis membrane production water, can be avoided as much as possible by automated maintenance cleaning, so that relatively stable salt rejection performance of the reverse osmosis membrane can be maintained for a long time.

For example, on the basis that the proportion of organic contamination is higher than that of inorganic contamination in the characteristics of reverse osmosis membrane contamination, when the first cleaning agent and the second cleaning agent are used as organic contamination and inorganic contamination cleaning agents, respectively, one type of organic contamination first cleaning agent is used. A method of applying a method of applying the maintenance cleaning and sequentially step-by-step application of the first cleaning agent and the second cleaning agent to the recovery cleaning may be effective. At this time, it is preferable that the maintenance cleaning has a low chemical concentration of 1/5 to 1/10 of that of the restorative cleaning, and the cleaning time is also completed within a relatively short time of 1 to 1.5 hours.

In the automatic cleaning device and method of a reverse osmosis facility in which maintenance cleaning and recovery cleaning are automatically performed by a program according to an embodiment of the present invention, a water temperature sensor for treated water (17) and a reverse osmosis membrane product water flow rate sensor (18) Using the data of the reverse osmosis membrane product water electrical conductivity sensor 19, reverse osmosis membrane module inlet pressure sensor 20, and concentration line pressure sensor 21, selective automatic maintenance and recovery cleaning of the reverse osmosis membrane module 7 is programmed. characterized by

The maintenance cleaning is performed by calculating the water temperature-corrected reverse osmosis membrane production volume with the measured values of the water temperature sensor 17 of the water to be treated and the flow rate sensor 18 of the reverse osmosis membrane production water, and automatically proceeding with maintenance cleaning when it is measured at 15% or less of the initial value. The purpose is to remove the variable of the reverse osmosis membrane production quantity due to the temperature change of the water to be treated, which is not a factor caused by membrane fouling, by applying . In addition, adopting the change in the production quantity of the reverse osmosis membrane for the automation of maintenance and cleaning is because the reduction in production quantity occurs first among the phenomena caused by membrane contamination when the inlet pump for the reverse osmosis membrane is operated at a constant speed. It is effective to apply by washing.

2 and Table 1 show a correction formula for calculating the water temperature corrected reverse osmosis membrane production volume according to an embodiment of the present invention and the result thereof.

More specifically, one RO module BW-1812-75 of US DOW company is used as raw water, and the raw water inflow is 1.35L/min, the production is 12L/hr, the concentrated water is 1.15L/min, and the recovery rate is 15% based on the water temperature of 25℃. After stabilization, all facilities were maintained, and the raw water was sequentially lowered with a cooler, and the results of measuring the change in production in the raw water temperature range of 4 to 25 ° C are summarized in FIG. 2 and Table 1.

Raw water temperature (℃) Production quantity (L/hr) flow correction factor 4 4.0 0.33 10 6.0 0.5 16 8.5 0.7 21 10.5 0.87 25 12.0 1.0

In the corresponding water temperature range, the production volume was very accurately proportional, and the flow rate correction coefficient and the water temperature corrected reverse osmosis membrane production volume were able to derive the relationship of the following equations (1) and (2) from the results of FIG. 2.

(Equation 1)

[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193

(Equation 2)

Water temperature corrected reverse osmosis membrane production quantity = normal production × [flow rate correction factor]

By calculating the flow rate correction coefficient derived from Equations (1) and Equation (2) and the water temperature-corrected reverse osmosis membrane production quantity accordingly, it is possible to determine the decrease in production volume of the reverse osmosis facility, which determines whether maintenance cleaning is entered.

As an example of the above results, when the normal production of the reverse osmosis membrane facility is set to 12L/hr under the condition of the raw water temperature of 25°C, if the result of the water temperature of 22°C and the output of 10L/hr is measured after a certain period of time, the normal production under the condition of the water temperature of 22°C is 0.0321 x 22 + 0.193 = 0.8992, i.e. 12L/hr x 0.8992 = 10.79L/hr, so the measured output of 10L/hr is a reduction of 92.7% of the normal output of 10.79L/hr, i.e. 8.3%, the criterion for entering automatic maintenance cleaning Maintenance cleaning does not proceed because it exceeds 85% of the phosphorus normal production (initial value).

3 shows the production water flow rate of the temperature-corrected sewage recycling reverse osmosis membrane facility operated for about 4,000 hours according to one embodiment of the present invention, and FIG. 4 shows the sewage recycling reverse osmosis membrane operated for about 4,000 hours according to one embodiment of the present invention. It shows the pressure difference before and after maintenance and cleaning of equipment.

The outline of operation of the reverse osmosis membrane facility shown in FIGS. 3 and 4 is as follows.

[Overview of RO facility operation]

Flow rate: 6.8 ~ 12.5m3/hr

RO production quantity: 4 ~ 7.5m3/hr

RO module flux: about 18.5LMH (when production quantity is 7m3/hr)

Recovery rate: 60%

RO design: 2 steps ([Step 1] 6 modules/vessel, 4 vessels, [Step 2] 6 modules/vessel, 2 vessels),

Module: CSM RE4040-BE (Toray product)

The results of FIGS. 3 and 4 show the change in production flow rate under conditions in which the pressure difference before and after the RO module is similar, and the production flow rate was maintained at around 7 m ³ /hr through frequent maintenance and cleaning until 2,300 hours of operation, At the end of maintenance cleaning, the production flow rate decreased within a short period of time, and eventually recovery cleaning was performed before reaching 4,000 hours. Of course, since the operation in which maintenance cleaning was stopped was carried out later than the operation in which maintenance cleaning was performed, the RO membrane may be in a relatively more contaminated condition. there was.

Therefore, in addition to the judgment criteria for maintenance cleaning based on the water temperature-corrected reverse osmosis membrane production volume discussed above, in the case of recovery cleaning, i) the maintenance cleaning is performed twice or more a day, or ii) the water temperature-corrected reverse osmosis membrane production volume is 85% of the initial value % or less, the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate decreases to less than 85% of the initial value, and the difference between the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure increases to more than 15% from the initial value In this case, it is possible to maintain stable filtration performance of the RO module by performing recovery cleaning.

1. Raw water intake line
2. Reverse osmosis membrane production line
3. Concentrated water discharge line
4. CIP Facility Inlet Line
5. Pretreatment device
6. High pressure pump
7. Reverse osmosis membrane module
8. First cleaning chemical stock solution supply unit
9. Second cleaning chemical stock solution supply unit
10. Washing liquid supply pump
11. Reverse osmosis membrane washing liquid filtration filter
12. Raw water intake valve
13. Reverse osmosis membrane produced water / produced water waste conversion valve
14. Concentrated water discharge/CIP facility inlet conversion valve
15. Reverse osmosis membrane cleaning solution supply valve
16. CIP tank drain valve
17. Water temperature sensor for water to be treated
18. Reverse osmosis membrane production water flow sensor
19. Reverse osmosis membrane production water electrical conductivity sensor
20. Reverse osmosis membrane module inlet pressure sensor
21. Concentrate line pressure sensor
22. CIP Tank
23. CIP Facility Discharge Line
24. Reverse osmosis membrane raw water electrical conductivity sensor

Claims (10)

A reverse osmosis production unit including a water to be treated inlet line, a product water line, a concentrated water discharge line, and a reverse osmosis membrane module, and producing product water by using the reverse osmosis membrane module;
a reverse osmosis membrane module washing unit branched off from the concentrated water discharge line of the reverse osmosis production unit; and
A reverse osmosis facility having sensors including a water temperature sensor for treated water, a reverse osmosis membrane product water flow rate sensor, a reverse osmosis membrane product water electrical conductivity sensor, a reverse osmosis membrane module inlet line pressure sensor, and a concentrated water outlet line pressure sensor,
The reverse osmosis membrane module cleaning unit calculates the water temperature-corrected reverse osmosis membrane production volume with the measured values of the water temperature sensor of the water to be treated and the reverse osmosis membrane product flow rate sensor, and performs maintenance cleaning when the water temperature is measured at 85% or less of the initial value,
i) the maintenance cleaning is performed twice or more a day, or
ii) The water temperature corrected reverse osmosis membrane production volume is reduced to 85% or less of the initial value, the water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate is reduced to 85% or less of the initial value, and the water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line When the difference in pressure increases to 15% or more from the initial value, recovery cleaning is performed,
The water temperature-corrected reverse osmosis membrane production volume is the following equation (1) and equation (2), the water temperature-corrected reverse osmosis membrane product water electrical conductivity removal rate is the following equation (3), the water temperature-corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure The difference is calculated according to the following equation (4),
(Equation 1)
[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193
(Equation 2)
Water temperature corrected reverse osmosis membrane production = normal production × [flow rate correction factor]
(Equation 3)
Water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate (%) = 100 - {(produced water electrical conductivity value)/(raw water electrical conductivity value)} × {(produced water flow rate value)/(produced water flow rate initial value)} × ( flow correction factor) × 100
(Equation 4)
Difference between water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure = {(RO inlet electronic pressure gauge value) - (RO concentrated electronic pressure gauge value)} × {(RO production volume initial value + concentrated water initial value)/ (RO production quantity measured value + concentrated water quantity measured value)},
The maintenance cleaning includes acid cleaning in which equipment is circulated and cleaned with 0.03 to 0.05% by mass of hydrochloric acid cleaning stock solution,
The recovery cleaning includes acid cleaning with 0.2 to 0.4% by mass of hydrochloric acid cleaning stock solution, alkali cleaning with 0.1 to 0.2% by mass of sodium hydroxide cleaning stock solution, and flushing inside the facility. Equipped with an automatic cleaning system reverse osmosis plant. The method of claim 1,
The reverse osmosis production unit includes a raw water inlet line through which water to be treated is supplied;
a pretreatment device connected to the raw water inlet line and provided before the reverse osmosis membrane module to remove impurities in order to reduce the amount of particulate matter and improve turbidity and hardness;
a high-pressure pump supplying water to be treated pre-treated by removing impurities in the pre-treatment device to a reverse osmosis membrane module;
a reverse osmosis membrane module for producing demineralized filtered water from the treated water supplied from the high-pressure pump;
a reverse osmosis membrane product line through which the desalinated filtered water is discharged to a pipe; and
A reverse osmosis facility equipped with an automatic washing system, characterized in that it includes a concentrated water discharge line in which pretreated water to be treated is not filtered through the reverse osmosis membrane module and excluded substances are concentrated and discharged. The method of claim 1,
The reverse osmosis membrane module washing unit includes a CIP facility inlet line branched by a concentrated water discharge line and a CIP facility inlet conversion valve from the concentrated water discharge line and circulating water flowing into the CIP facility;
A CIP tank for preparing a reverse osmosis membrane cleaning solution by supplying a first cleaning agent stock solution or a second cleaning agent stock solution to a tank storing fresh water; and
Including a CIP facility discharge line for supplying a reverse osmosis membrane cleaning solution prepared in a CIP tank to a contaminated reverse osmosis membrane module,
In the CIP tank, the first cleaning chemical stock solution supply unit composed of the first cleaning chemical stock solution storage tank and the chemical pump and the second cleaning chemical stock solution supply unit composed of the second cleaning chemical stock solution storage tank and the chemical pump are provided with fresh water by a programmed method. A reverse osmosis membrane cleaning solution is prepared by supplying a first cleaning chemical stock solution or a second cleaning chemical stock solution to the stored CIP tank,
The prepared reverse osmosis membrane cleaning solution is filtered by the reverse osmosis membrane cleaning solution filter by the cleaning solution supply pump and then supplied to the contaminated reverse osmosis membrane module through the CIP facility discharge line,
A reverse osmosis facility equipped with an automatic cleaning system, characterized in that after cleaning the contaminated reverse osmosis membrane module, the cleaning solution is circulated to the CIP facility inlet line and the CIP tank. The method of claim 2,
The reverse osmosis facility includes a raw water inlet valve installed before the pretreatment device;
a reverse osmosis membrane produced water/produced water waste conversion valve connected to the reverse osmosis membrane module; and
A reverse osmosis system having an automatic cleaning system, further comprising a concentrated water discharge / CIP facility input conversion valve, a reverse osmosis membrane cleaning solution supply valve, and a CIP tank drain valve 16 provided between the reverse osmosis membrane module and the reverse osmosis membrane module cleaning unit. delete delete delete In the automatic cleaning method of reverse osmosis equipment having a reverse osmosis production unit and a reverse osmosis membrane module cleaning unit,
The reverse osmosis membrane module cleaning unit calculates the water temperature-corrected reverse osmosis membrane production volume with the measured values of the water temperature sensor of the water to be treated and the flow rate sensor of the reverse osmosis membrane product water, and performs maintenance cleaning when the measured value is less than 85% of the initial value,
i) the maintenance cleaning is performed twice or more a day, or
ii) The water temperature-corrected reverse osmosis membrane production volume is reduced to 85% or less of the initial value, the electrical conductivity removal rate of the reverse osmosis membrane product water is reduced to 85% or less of the initial value, and the difference between the reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure is greater than the initial value If it increases to 15% or more, perform recovery cleaning,
The water temperature-corrected reverse osmosis membrane production volume is the following equation (1) and equation (2), the water temperature-corrected reverse osmosis membrane product water electrical conductivity removal rate is the following equation (3), the water temperature-corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure The difference is calculated according to the following equation (4),
(Equation 1)
[Flow rate correction factor] = 0.0321 × raw water temperature (℃) + 0.193
(Equation 2)
Water temperature corrected reverse osmosis membrane production = normal production × [flow rate correction factor]
(Equation 3)
Water temperature corrected reverse osmosis membrane product water electrical conductivity removal rate (%) = 100 - {(produced water electrical conductivity value)/(raw water electrical conductivity value)} × {(produced water flow rate value)/(produced water flow rate initial value)} × ( flow correction factor) × 100
(Equation 4)
Difference between water temperature corrected reverse osmosis membrane module inlet line pressure and concentrated water discharge line pressure = {(RO inlet electronic pressure gauge value) - (RO concentrated electronic pressure gauge value)} × {(RO production volume initial value + concentrated water initial value)/ (RO production quantity measured value + concentrated water quantity measured value)}
The maintenance cleaning includes acid cleaning in which equipment is circulated and cleaned with 0.03 to 0.05% by mass of hydrochloric acid cleaning stock solution,
The recovery cleaning includes acid cleaning with 0.2 to 0.4% by mass of hydrochloric acid cleaning stock solution, alkali cleaning with 0.1 to 0.2% by mass of sodium hydroxide cleaning stock solution, and flushing of the inside of the equipment Automatic cleaning of reverse osmosis equipment, characterized in that method. delete delete

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