CN117088541A - System for reverse osmosis dense water adjusts circulating water quality and reduces corrosion rate - Google Patents

Abstract

A reverse osmosis concentrated water system for regulating circulating water quality and reducing corrosion rate, including a pretreatment system, a primary reverse osmosis system, a secondary reverse osmosis system, and an EDI system. The present invention is a reverse osmosis concentrated water system for regulating circulating water quality and reducing system corrosion rate. The high alkalinity and high hardness reverse osmosis concentrated water produced in the system is discharged into the circulating water system through the circulating water pipe in the factory area and replenished into the circulating water tower pool through the conveying pipe. , replacing the traditional dosing method of adding large amounts of sodium carbonate and calcium chloride to solve system corrosion problems caused by insufficient alkalinity and hardness of circulating water, reducing wastewater treatment costs, while reducing the dosage of chemicals and the intensity of personnel dosing, effectively improving economic benefits. , realizing the resource utilization of reverse osmosis concentrated water.

Description

A system for reverse osmosis concentrated water to regulate circulating water quality and reduce corrosion rate

Technical field

The invention relates to the technical field of water treatment, and specifically to a system for regulating the quality of circulating water and reducing the corrosion rate of reverse osmosis concentrated water.

Background technique

In the modern coal chemical production process, a large amount of recycled water is used as the water supply source for the indirect open cooling tower. The recycled water has low alkalinity and low hardness. When used as industrial circulating water supply water, it is highly corrosive. Therefore, alkali addition and calcium supplementation, that is, adding large amounts of sodium carbonate and calcium chloride, are often used to increase the alkalinity and hardness of the system and solve the corrosion problems in the system. Although this method can effectively utilize low alkalinity and low hardness water quality to increase the concentration ratio of the circulating water system and reduce the amount of supplementary water, thereby improving the economic benefits brought by it, when the heat load of the system is insufficient or the evaporation volume decreases when the temperature drops in winter, the circulating cooling Water often fails to reach the predetermined concentration ratio, and the system operates at a low concentration ratio. In some systems with low alkalinity or low hardness, the heat exchange equipment is more prone to corrosion, thus bringing safety to the stable operation of the heat exchange equipment in the production system. Hidden danger.

Contents of the invention

In order to solve the existing defects of low circulating water quality and high system corrosion rate of cooling towers, the purpose of the present invention is to provide a system for regulating the quality of circulating water with reverse osmosis concentrated water and reducing the system corrosion rate.

In order to achieve the above purpose, the present invention adopts the following technical solution: a system for reverse osmosis concentrated water to regulate the quality of circulating water and reduce the corrosion rate of the system, including a pretreatment system 1, a primary reverse osmosis system 2, a secondary reverse osmosis system 3, and an EDI System 4.

The pretreatment system 1 includes a raw water tank 11, a raw water pump 12, a heat exchanger 13, a self-cleaning filter 14, an ultrafilter 15, and an ultrafiltration water tank 16. The raw water tank 11 collects production water or secondary water from the pipe network. The water is reused and sodium hypochlorite is added to the original water tank 11 for sterilization. The water in the original water tank 11 is pressurized by the original water pump 12 and heated through the heat exchanger 13. The heated water enters the self-cleaning filter 14 to remove large suspended solids in the water. , finally enters the ultrafilter 15 to remove most of the colloids, suspended solids and some organic matter in the water, and then the ultrafiltration produced water flows into the ultrafiltration water tank 16.

The first-level reverse osmosis system 2 includes a first-level reverse osmosis booster pump 21, a first-level security filter 22, a high-pressure water pump I 23, a first-level reverse osmosis device 24, a carbon remover 25, a first-level reverse osmosis water production tank 26, a concentrated Water tank 27, desalinator 28, factory circulating water pipe 29, ultrafiltration produced water is pressurized by the first-level reverse osmosis booster pump 21 and added with reducing agent and anti-scaling agent, and then passes through the first-level security filter 22 is filtered, and then further boosted by the high-pressure water pump I23 and sent to the first-level reverse osmosis device 24 to remove most of the dissolved salts, and then the carbon dioxide in the water is removed by the carbon remover 25, and the reverse osmosis produced water flows into the first-level reverse osmosis device 24. The first-level reverse osmosis water production tank 26, the reverse osmosis concentrated water flows into the concentrated water tank 27, the reverse osmosis concentrated water undergoes reverse osmosis desalination treatment of concentrated water through the desalter 28, and the produced water is merged into the first-level reverse osmosis main pipe and enters the first-level reverse osmosis main pipe The reverse osmosis water production tank 26 and the reverse osmosis concentrated water are discharged into the circulating water system through the factory circulating water pipe 29 as circulating water replenishment.

The secondary reverse osmosis system 3 includes a secondary reverse osmosis water supply pump 31, a secondary security filter 32, a high-pressure water pump II 33, a secondary reverse osmosis device 34, and an intermediate water tank 35. The water produced by the primary reverse osmosis passes through the secondary The reverse osmosis water pump 31 pressurizes and adds alkali solution to adjust the pH value of the water to above 7, and then filters it through the secondary security filter 32. After filtering, the high-pressure water pump II 33 further increases the pressure and sends it to the secondary reverse osmosis water pump 31. The permeator 34 further performs desalination treatment, and the produced water enters the intermediate water tank 35 .

The EDI system 4 includes an EDI water supply pump 41, an EDI security filter 42, EDI 43, a desalted water tank 44, a low-pressure desalted water pump 45, and a high-pressure desalted water pump 46. The secondary reverse osmosis produced water is pressurized by the EDI water supply pump 41 , is filtered by the EDI security filter 42 and enters the EDI 43 for fine desalination treatment. The produced water enters the desalted water tank 44 and is pressurized by the low-pressure desalted water pump 45 and sent to the gasification deaeration station and other users. The high-pressure desalted water pump 46 is sent to the boiler deaeration station. .

Compared with existing cooling towers that use recycled water to add chemicals for circulating water replenishment and water quality adjustment, the present invention has the following beneficial effects.

The present invention is a reverse osmosis concentrated water system for regulating circulating water quality and reducing system corrosion rate. The high alkalinity and high hardness reverse osmosis concentrated water produced in the system is discharged into the circulating water system through the circulating water pipe 29 in the factory area and fed into the circulating water tower through the conveying pipe. pool, replacing the traditional dosing method of adding large amounts of sodium carbonate and calcium chloride to solve system corrosion problems caused by insufficient alkalinity and hardness of circulating water, reducing wastewater treatment costs, while reducing the dosage of chemicals and personnel dosing intensity, effectively improving the economy Benefit, realizing the resource utilization of reverse osmosis concentrated water.

Description of the drawings

Figure 1 is a schematic diagram of a system according to the present invention for reverse osmosis concentrated water to regulate the quality of circulating water and reduce the corrosion rate of the system.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on The embodiments of the present invention and all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "top", "bottom", "one side", "other side", "front", "back", "middle part", "inner", " The orientation or positional relationship indicated by "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have Specific orientations, construction and operation in specific orientations, therefore cannot be understood as limitations of the invention; the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative Importance; In addition, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

The present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, the present invention provides a system for reverse osmosis concentrated water to regulate circulating water quality and reduce system corrosion rate, including a pretreatment system 1, a primary reverse osmosis system 2, a secondary reverse osmosis system 3, and an EDI system 4.

The pretreatment system 1 includes a raw water tank 11, a raw water pump 12, a heat exchanger 13, a self-cleaning filter 14, an ultrafilter 15, and an ultrafiltration water tank 16. The raw water tank 11 collects production water or secondary water from the pipe network. The water is reused and sodium hypochlorite is added to the original water tank 11 for sterilization. The water in the original water tank 11 is pressurized by the original water pump 12 and heated to 25±2°C through the heat exchanger 13. The heated water enters the self-cleaning filter 14 for removal. Large particles of suspended solids in the water finally enter the ultrafilter 15 to remove most of the colloids, suspended solids and some organic matter in the water, and then the ultrafiltrated water flows into the ultrafiltration water tank 16 .

The first-level reverse osmosis system 2 includes a first-level reverse osmosis booster pump 21, a first-level security filter 22, a high-pressure water pump I 23, a first-level reverse osmosis device 24, a carbon remover 25, a first-level reverse osmosis water production tank 26, a concentrated Water tank 27, desalinator 28, factory circulating water pipe 29, ultrafiltration produced water is pressurized by the first-level reverse osmosis booster pump 21 and added with reducing agent and anti-scaling agent, and then passes through the first-level security filter 22 is filtered, and then further boosted by the high-pressure water pump I23 and sent to the first-level reverse osmosis device 24 to remove most of the dissolved salts, and then the carbon dioxide in the water is removed by the carbon remover 25, and the reverse osmosis produced water flows into the first-level reverse osmosis device 24. The first-level reverse osmosis water production tank 26, the reverse osmosis concentrated water flows into the concentrated water tank 27, the reverse osmosis concentrated water undergoes reverse osmosis desalination treatment of concentrated water through the desalter 28, and the produced water is merged into the first-level reverse osmosis main pipe and enters the first-level reverse osmosis main pipe The reverse osmosis water production tank 26 and the reverse osmosis concentrated water are discharged into the circulating water system through the factory circulating water pipe 29 as circulating water replenishment.

The secondary reverse osmosis system 3 includes a secondary reverse osmosis water supply pump 31, a secondary security filter 32, a high-pressure water pump II 33, a secondary reverse osmosis device 34, and an intermediate water tank 35. The water produced by the primary reverse osmosis passes through the secondary The reverse osmosis water pump 31 pressurizes and adds alkali solution to adjust the pH value of the water to above 7, and then filters it through the secondary security filter 32. After filtering, the high-pressure water pump II 33 further increases the pressure and sends it to the secondary reverse osmosis water pump 31. The permeator 34 further performs desalination treatment, and the produced water enters the intermediate water tank 35 .

The EDI system 4 includes an EDI water supply pump 41, an EDI security filter 42, EDI 43, a desalted water tank 44, a low-pressure desalted water pump 45, and a high-pressure desalted water pump 46. The secondary reverse osmosis produced water is pressurized by the EDI water supply pump 41 , is filtered by the EDI security filter 42 and enters the EDI 43 for fine desalination treatment. The produced water enters the desalted water tank 44 and is pressurized by the low-pressure desalted water pump 45 and sent to the gasification deaeration station and other users. The high-pressure desalted water pump 46 is sent to the boiler deaeration station. .

The water supply and drainage workshop introduces reverse osmosis concentrated water into aromatic hydrocarbon purification circulating water, gasification circulating water, mixed refrigeration circulating water, and air separation thermoelectric circulating water. After the reverse osmosis concentrated water is replenished into the system, the water quality is significantly optimized, reaching the water quality prediction index, and reducing The dosage of chemicals is reduced, the film formation speed of the system is accelerated, and the corrosion rate of the system is greatly reduced.

Table 1 Reverse osmosis concentrated water quality

project unit maximum smallest average PH — 7.98 7.70 7.80 CD us/cm 1684.00 1466.00 1560.00 total phosphorus mg/L 1.22 1.00 1.13 calcium hard mg/L 472.40 357.70 403.00 Alkalinity mg/L 535.40 470.30 499.00 Cl- mg/L 209.20 152.40 184.77

Table 2 Circulating water quality control indicators

serial number project unit Control indicators 1 PH — 7.8-902 2 CD us/cm ≤3000 3 total phosphorus mg/L 3-6 4 calcium hard mg/L ≤650 5 Alkalinity mg/L ≤450 6 Cl- mg/L ≤700

Table 3 Monthly usage of chemicals before and after reverse osmosis concentrated water is replenished

serial number project unit Dosage amount before transformation (monthly) Dosage amount after transformation (monthly) 1 Sodium carbonate Ton 2 0 2 calcium chloride Ton 2 0

Table 4: Circulating water quality before and after reverse osmosis concentrated water is replenished (concentration factor N=4 times)

serial number project unit Circulating water quality indicators before transformation Water quality index of circulating water after transformation 1 CD us/cm 816.01 1128.0 2 calcium hard mg/l 142.83 201.84 3 Alkalinity mg/l 165.06 243.23 4 Cl- mg/l 103.59 114.13

The reverse osmosis concentrated water is used to replenish circulating water at 70 cubic meters/hour to adjust the quality of the circulating water. It is no longer discharged to subsequent devices for treatment. The hardness and alkalinity have reached the predicted indicators, and the system corrosion rate has dropped significantly. Sodium carbonate and calcium chloride When the addition of chemicals is stopped, the monthly savings are 2 tons of sodium carbonate * 1,800 yuan / ton = 3,600 yuan, and 2 tons of calcium chloride * 1,600 yuan / ton = 3,200 yuan. The monthly cost of pharmaceuticals is saved at 81,600 yuan / year, and subsequent water consumption is reduced. The processing cost is 70 cubic meters per hour * 4.91 yuan per cubic meter = 392.8 yuan per hour * 4,000 hours (from November to April of the following year) = 1.3748 million yuan, with a total cost saving of 1.4564 million yuan.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

In addition, it should be understood that although this specification is described in terms of implementations, not each implementation only contains an independent technical solution. This description of the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole. , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (1)

1. A system for reverse osmosis concentrated water to regulate circulating water quality and reduce system corrosion rate, including a pretreatment system (1), a primary reverse osmosis system (2), a secondary reverse osmosis system (3), and an EDI system (4) ; The pretreatment system (1) includes a raw water tank (11), a raw water pump (12), a heat exchanger (13), a self-cleaning filter (14), an ultrafiltration filter (15), and an ultrafiltration water tank (16). The raw water tank (11) collects production water or reclaimed water from the pipe network and adds sodium hypochlorite to the raw water tank (11) for sterilization. The water in the raw water tank (11) is pressurized by the raw water pump (12) and passes through The heat exchanger (13) heats up, and the heated water enters the self-cleaning filter (14) to remove large suspended solids in the water, and finally enters the ultrafilter (15) to remove most of the colloids, suspended solids and some organic matter in the water before ultrafiltration. The produced water flows into the ultrafiltration water tank (16); The first-level reverse osmosis system (2) includes a first-level reverse osmosis booster pump (21), a first-level security filter (22), a high-pressure water pump I (23), a first-level reverse osmosis device (24), and a carbon remover (25), a first-level reverse osmosis water production tank (26), a concentrated water tank (27), a desalinator (28), a factory circulating water pipe (29), and the ultrafiltration produced water passes through the first-level reverse osmosis booster pump (21) After pressurizing and adding reducing agent and scale inhibitor, it is filtered by the first-level security filter (22), and then further boosted by the high-pressure water pump I (23) and sent to the first-level reverse osmosis device. (24) Remove most of the dissolved salt, and then remove carbon dioxide from the water through the carbon remover (25). The reverse osmosis water flows into the first-level reverse osmosis water production tank (26), and the reverse osmosis concentrated water flows into the In the concentrated water tank (27), the reverse osmosis concentrated water undergoes reverse osmosis desalination treatment through the desalination device (28). The produced water is merged into the primary reverse osmosis main pipe and enters the primary reverse osmosis water production tank (26). The reverse osmosis concentrated water The circulating water in the factory area is discharged into the circulating water system through the water pipe (29) as circulating water replenishment; The secondary reverse osmosis system (3) includes a secondary reverse osmosis water supply pump (31), a secondary security filter (32), a high-pressure water pump II (33), a secondary reverse osmosis device (34), and an intermediate water tank (35 ), the primary reverse osmosis produced water is pressurized by the secondary reverse osmosis water supply pump (31) and added with alkali solution to adjust the pH value of the water to above 7, and then filtered by the secondary security filter (32). Then, the high-pressure water pump II (33) further increases the pressure and sends it to the secondary reverse osmosis device (34) for further desalination treatment, and the produced water enters the intermediate water tank (35); The EDI system (4) includes an EDI water supply pump (41), an EDI security filter (42), an EDI (43), a desalted water tank (44), a low-pressure desalted water pump (45), and a high-pressure desalted water pump (46). , after the secondary reverse osmosis water is pressurized by the EDI water supply pump (41), it is filtered by the EDI security filter (42) and enters the EDI (43) for fine desalination treatment. The produced water enters the desalted water tank (44) and is desalted by low pressure. The brine pump (45) pressurizes the gasification deaeration station and other users, and the high-pressure desalination pump (46) sends the boiler deaeration station.