Zero-discharge treatment system for circulating cooling water

Abstract

The utility model discloses a zero-discharge treatment system for circulating cooling water. The zero-discharge treatment system comprises a hardness removal device, a first silicon removal device, a second silicon removal device, a microfiltration device, a reverse osmosis device and an evaporation device, the first silicon removal device is connected with the hardness removal device; the microfiltration device and the reverse osmosis device are sequentially connected with the first silicon removal device; the second silicon removal device is connected with the reverse osmosis device and is used for receiving reverse osmosis concentrated water and carrying out deep silicon removal treatment; and the evaporation device is connected with the second silicon removal device. According to the circulating cooling water zero-discharge treatment system disclosed by the utility model, circulating cooling water is treated through the hardness removal device, the first silicon removal device, the microfiltration device, the reverse osmosis device, the second silicon removal device and the evaporation device, so that pollutants such as calcium, magnesium, silicon, COD (Chemical Oxygen Demand) and phosphate in the circulating cooling water are removed to the maximum extent; and high-quality fresh water is recycled through a concentration, evaporation and crystallization technology, so that zero discharge of circulating cooling water is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a circulating cooling water zero-discharge treatment system. Background Art

[0002] For power plant circulating cooling water, environmental protection requirements are becoming increasingly stringent, with lower water intake quotas, less external discharge, and higher wastewater quality standards. For gas-fired power plants without desulfurization systems and secondary reuse points that can fully absorb circulating wastewater, it is particularly important to reuse circulating cooling water. Traditional chemical softening-filtration treatment can only remove calcium, magnesium, silicon and some COD in circulating cooling water, but cannot remove anions (such as Cl - and SO4 2 - ). Since it is impossible to further reduce the inorganic salts in the circulating cooling water, it is difficult to fully reuse the circulating cooling wastewater treated by traditional methods without discharging it, so there is an upper limit to the concentration ratio. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a circulating cooling water zero-discharge treatment system which can meet the zero-discharge requirement of circulating cooling water in power plants.

[0004] The utility model solves the technical problem by adopting the following technical solution: providing a circulating cooling water zero-discharge treatment system, including a hardness removal device, a first silicon removal device, a second silicon removal device, a microfiltration device, a reverse osmosis device and an evaporation device;

[0005] The first desiliconization device is connected to the hardness removal device to receive the cooling water after hardness removal from the hardness removal device; the microfiltration device and the reverse osmosis device are connected to the first desiliconization device in sequence to perform microfiltration treatment and reverse osmosis treatment on the cooling water after desiliconization;

[0006] The second desiliconization device is connected to the reverse osmosis device, receives the reverse osmosis concentrated water and performs deep desiliconization treatment; the evaporation device is connected to the second desiliconization device, and performs evaporation treatment on the reverse osmosis concentrated water after deep desiliconization.

[0007] In some embodiments, the hardness removal device comprises a hardness removal reaction tank, a hardness removal flocculation tank and a hardness removal sedimentation tank which are sequentially connected to each other;

[0008] The hardness removal reaction pool comprises a first hardness removal pool for adding a hardness removal agent therein and a second hardness removal pool for adding a flocculant therein; the first hardness removal pool and the second hardness removal pool are connected.

[0009] In some embodiments, the first desiliconization device comprises a desiliconization reaction tank, a desiliconization flocculation tank and a desiliconization sedimentation tank which are sequentially connected to each other;

[0010] The desiliconization reaction pool comprises a first desiliconization pool for adding a desiliconizer and a second desiliconization pool for adding a flocculant; the first desiliconization pool and the second desiliconization pool are connected.

[0011] In some embodiments, the second desiliconization device comprises a deep desiliconization reaction tank, a deep desiliconization flocculation tank and a deep desiliconization sedimentation tank which are sequentially connected to each other;

[0012] The deep desiliconization reaction pool comprises a first deep desiliconization pool for adding a desiliconizer therein and a second deep desiliconization pool for adding a flocculant therein; the first deep desiliconization pool and the second deep desiliconization pool are connected.

[0013] In some embodiments, the circulating cooling water zero-discharge treatment system further includes mud discharge pipelines respectively connected to the hardness removal device, the first silicon removal device, and the second silicon removal device.

[0014] In some embodiments, the hardness removal device, the first silicon removal device and the second silicon removal device are respectively integrated devices.

[0015] In some embodiments, the circulating cooling water zero-discharge treatment system further includes a circulating cooling tower, and the circulating cooling tower is connected to the hardness removal device via a drainage pipe; a sewage pump is provided on the drainage pipe.

[0016] In some embodiments, the circulating cooling water zero-discharge treatment system further includes a cooling tower forebay, wherein the cooling tower forebay is connected to the circulating cooling tower via a circulating pipeline to form a circulating loop with the circulating cooling tower;

[0017] In some embodiments, the circulating cooling water zero-discharge treatment system further includes a first return pipe connected between the evaporation device and the cooling tower forebay for transporting the evaporated condensed water to the cooling tower forebay.

[0018] In some embodiments, the circulating cooling water zero-discharge treatment system further comprises a second return pipe connected between the reverse osmosis device and the cooling tower forebay, through which the reverse osmosis produced water is transported to the cooling tower forebay.

[0019] The circulating cooling water zero-discharge treatment system of the utility model treats the circulating cooling water through a hardness removal device, a first silicon removal device, a microfiltration device, a reverse osmosis device, a second silicon removal device and an evaporation device, removes pollutants such as calcium, magnesium, silicon, COD and phosphate in the circulating cooling water to the maximum extent, and recovers high-quality fresh water through concentrated evaporation and crystallization technology, thereby achieving zero discharge of circulating cooling water. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0021] Figure 1 It is a structural schematic diagram of a circulating cooling water zero-discharge treatment system according to an embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0023] like Figure 1 As shown, a zero-discharge treatment system for circulating cooling water according to an embodiment of the utility model comprises a hardness removal device 10, a first silicon removal device 20, a microfiltration device 30, a reverse osmosis device 40, a second silicon removal device 50 and an evaporation device 60 connected in sequence.

[0024] The above-mentioned devices sequentially perform hardness removal, silicon removal, microfiltration, reverse osmosis, deep silicon removal and evaporation treatment on the circulating cooling water discharged from the circulating cooling system, removing pollutants such as calcium, magnesium, silicon, total phosphorus, COD, and soluble inorganic salts in the circulating cooling water. The recycled water produced by the reverse osmosis device 40 and the evaporation device 60 is high-quality fresh water, which can be used as feed water for the circulating cooling system or the boiler feed water system. The chemical sludge and crystallized mixed salt produced in each treatment can be discharged from the system as solid waste.

[0025] The hardness removal device 10 serves as the processing front end of the circulating cooling water zero-discharge treatment system, is connected to the circulating cooling tower 70, receives the circulating cooling water discharged from the circulating cooling tower 70, and performs hardness removal treatment on the circulating cooling water.

[0026] Preferably, the hardness removal device 10 is an integrated device.

[0027] Furthermore, the hardness removal device 10 may include a hardness removal reaction tank 11, a hardness removal flocculation tank 12 and a hardness removal sedimentation tank 13 which are connected in sequence. The hardness removal reaction tank 11, the hardness removal flocculation tank 12 and the hardness removal sedimentation tank 13 may be separated and formed in an integral tank body, and the three are arranged according to the water flow direction.

[0028] The de-hardening reaction tank 11 may further include a first de-hardening tank 111 and a second de-hardening tank 112 connected to each other, wherein a stirrer is provided in each of the first de-hardening tank 111 and the second de-hardening tank 112. The first de-hardening tank 111 is used for putting a de-hardening agent into the first de-hardening tank 111, and the de-hardening agent is mixed with circulating cooling water in the first de-hardening tank 111 to remove calcium and magnesium ions in the water. The second de-hardening tank 112 can be separated and connected to the first de-hardening tank 111 by at least two first partitions 14 staggered up and down, and the cooling water in the first de-hardening tank 111 can pass from below one first partition 14 along the first partition 14, and then flow upward along another first partition 14 into the second de-hardening tank 112. The second de-hardening tank 112 is used for putting a flocculant into the second de-hardening tank 112, and the flocculant is mixed with circulating cooling water in the second de-hardening tank 112 to remove heavy metals, phosphates and COD in the water. The cooling water in the second hardness removal tank 112 then enters the hardness removal flocculation tank 12, and a coagulant is added to the hardness removal flocculation tank 12 to accelerate the formation of alum flocs. The hardness removal flocculation tank 12 is equipped with a stirrer for stirring. The flocculated water enters the hardness removal sedimentation tank 13 for solid-liquid separation, and the supernatant overflows into the first desiliconization device 20.

[0029] The first desiliconization device 20 is connected to the hardness removal device 10, and receives the cooling water after hardness removal from the hardness removal device 10. The first desiliconization device 20 is preferably an integrated device. The first desiliconization device 20 includes a desiliconization reaction tank 21, a desiliconization flocculation tank 22, and a desiliconization sedimentation tank 23 which are sequentially connected and communicated with each other; the desiliconization reaction tank 21, the desiliconization flocculation tank 22, and the desiliconization sedimentation tank 23 can be formed by being separated in an integral tank body, and the three are arranged according to the water flow direction.

[0030] The desiliconization reaction tank 21 may further include a first desiliconization tank 211 for adding a desiliconization agent and a second desiliconization tank 212 for adding a flocculant; the first desiliconization tank 211 and the second desiliconization tank 212 may be separated and connected by at least two second partitions 24 staggered up and down. Agitators are respectively provided in the first desiliconization tank 211 and the second desiliconization tank 212. In the first desiliconization tank 211, the desiliconization agent is mixed with cooling water to remove silicon in the water, and then the cooling water can pass through the second partition 24 from under a second partition 24, and then flow upward along another second partition 24 into the second desiliconization tank 212. In the second desiliconization tank 212, the added flocculant is mixed with the cooling water to further remove heavy metals, phosphates and COD in the water, and the cooling water then enters the desiliconization flocculation tank 22. A coagulant is added to the desiliconization flocculation tank 22 to accelerate the formation of alum flocs. The desiliconization flocculation tank 22 is provided with a stirrer for stirring. The cooling water after flocculation enters the desiliconization sedimentation tank 23 for solid-liquid separation, and the supernatant overflows into the microfiltration device 30.

[0031] The microfiltration device 30 is connected to the first desiliconization device 20 to perform microfiltration treatment on the cooling water after desiliconization. In order to improve the water flow power, a booster pump can be set on the pipeline between the top of the desiliconization sedimentation tank 23 and the microfiltration device 30, and the effluent of the first desiliconization device 20 is transported into the microfiltration device 30 via the booster pump. In the microfiltration device 30, the microfiltration membrane is used to intercept fine particles. The microfiltration device 30 also serves as a pretreatment unit of the reverse osmosis device 40, and its effluent directly enters the reverse osmosis device 40.

[0032] The reverse osmosis device 40 is connected to the microfiltration device 30 to perform reverse osmosis treatment on the cooling water from the microfiltration device 30. The reverse osmosis device 40 can be connected to the second desiliconization device 50 through a concentrated water pipeline to send the reverse osmosis concentrated water to the second desiliconization device 50 for deep desiliconization treatment.

[0033] The second desiliconization device 50 is preferably an integrated device. The second desiliconization device 50 comprises a deep desiliconization reaction tank 51, a deep desiliconization flocculation tank 52 and a deep desiliconization sedimentation tank 53 which are sequentially connected; the deep desiliconization reaction tank 51, the deep desiliconization flocculation tank 52 and the deep desiliconization sedimentation tank 53 can be separated and formed in an integral tank body, and the three are arranged according to the water flow direction.

[0034] The deep desiliconization reaction tank 51 may further include a first deep desiliconization tank 511 for adding desiliconizer and a second deep desiliconization tank 512 for adding flocculant. Agitators may be provided inside the first deep desiliconization tank 511 and the second deep desiliconization tank 512 respectively. The first deep desiliconization tank 511 and the second deep desiliconization tank 512 may be separated and connected by at least two third partitions 54 staggered up and down.

[0035] In the first deep desiliconization tank 511, the desiliconizer is mixed with the cooling water to remove silicon from the water, and then the cooling water can pass through the third baffle 54 from below a third baffle 54, and then flow upward along another third baffle 54 into the second deep desiliconization tank 512. In the second deep desiliconization tank 512, the added flocculant is mixed with the cooling water to further remove heavy metals, phosphates and COD in the water, and the cooling water then enters the deep desiliconization flocculation tank 52. A coagulant is added to the deep desiliconization flocculation tank 52 to accelerate the formation of alum flocs. The deep desiliconization flocculation tank 52 is provided with a stirrer for stirring. The flocculated cooling water enters the deep desiliconization sedimentation tank 53 for solid-liquid separation, and the supernatant enters the evaporation device 60.

[0036] The evaporation device 60 performs evaporation and crystallization treatment on the reverse osmosis concentrated water after deep silicon removal to obtain crystallized mixed salt. The crystallized mixed salt is discharged from the system as solid waste and enters the solid waste treatment and disposal system.

[0037] The evaporated condensed water produced by the evaporation device 60 can be returned to the front end of the circulating cooling tower for reuse. In this regard, in some embodiments, the circulating cooling water zero-discharge treatment system of the utility model may also include a first return pipe 91 connected between the evaporation device 60 and the cooling tower forebay 80, and the first return pipe 91 is used to transport the evaporated condensed water to the cooling tower forebay 80.

[0038] The circulating cooling water zero-discharge treatment system may further include a second return pipe 92 , which is connected between the reverse osmosis device 40 and the cooling tower forebay 80 to transport the reverse osmosis produced water to the cooling tower forebay 80 .

[0039] In addition, the sludge formed after being processed by the hardness removal device 10, the first silicon removal device 20 and the second silicon removal device 50 can be discharged out of the system through the sludge discharge pipe 100 respectively and processed in a unified manner.

[0040] As an option, the circulating cooling water zero-discharge treatment system of the utility model may also include a circulating cooling tower 70 and a cooling tower forebay 80. The circulating cooling tower 70 is connected to the hardness removal device 10 through a drainage pipe; a sewage pump is provided on the drainage pipe. The circulating water in the circulating cooling tower 70 enters the hardness removal device 10 under the action of the sewage pump.

[0041] The cooling tower forebay 80 is connected to the circulating cooling tower 70 via a circulating pipeline, and forms a circulating loop with the circulating cooling tower 70 .

[0042] In summary, the utility model can highly concentrate the soluble inorganic salts in the water through the cooperation of various devices, and finally discharge the system in the form of crystallized mixed salts. The reverse osmosis water and evaporation condensate are used as supplementary water for the circulating cooling water system, which can achieve the zero-discharge operation requirements of the circulating cooling water system of the power plant. - and SO4 2 - and other anions, so the utility model has a positive effect on delaying the corrosion of circulating cooling equipment in power plants.

[0043] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A circulating cooling water zero discharge treatment system, characterized in that: It includes a hardness removal device, a first silicon removal device, a second silicon removal device, a microfiltration device, a reverse osmosis device and an evaporation device; The first desiliconization device is connected to the hardness removal device to receive the cooling water after hardness removal from the hardness removal device; the microfiltration device and the reverse osmosis device are connected to the first desiliconization device in sequence to perform microfiltration treatment and reverse osmosis treatment on the cooling water after desiliconization; The second desiliconization device is connected to the reverse osmosis device, receives the reverse osmosis concentrated water and performs deep desiliconization treatment; The evaporation device is connected to the second desiliconization device to evaporate the reverse osmosis concentrated water after deep desiliconization.

2. The circulating cooling water zero discharge treatment system according to claim 1 is characterized in that: The hardness removal device comprises a hardness removal reaction tank, a hardness removal flocculation tank and a hardness removal sedimentation tank which are sequentially connected to each other; The hardness removal reaction pool comprises a first hardness removal pool for adding a hardness removal agent therein and a second hardness removal pool for adding a flocculant therein; the first hardness removal pool and the second hardness removal pool are connected.

3. The circulating cooling water zero discharge treatment system according to claim 1 is characterized in that: The first desiliconization device comprises a desiliconization reaction tank, a desiliconization flocculation tank and a desiliconization sedimentation tank which are connected to each other in sequence; The desiliconization reaction pool comprises a first desiliconization pool for adding a desiliconizer and a second desiliconization pool for adding a flocculant; the first desiliconization pool and the second desiliconization pool are connected.

4. The circulating cooling water zero discharge treatment system according to claim 1 is characterized in that: The second desiliconization device comprises a deep desiliconization reaction tank, a deep desiliconization flocculation tank and a deep desiliconization sedimentation tank which are connected to each other in sequence; The deep desiliconization reaction pool comprises a first deep desiliconization pool for adding a desiliconizer therein and a second deep desiliconization pool for adding a flocculant therein; the first deep desiliconization pool and the second deep desiliconization pool are connected.

5. The circulating cooling water zero discharge treatment system according to claim 1 is characterized in that: The circulating cooling water zero-discharge treatment system also includes mud discharge pipelines respectively connected to the hardness removal device, the first silicon removal device, and the second silicon removal device.

6. The circulating cooling water zero discharge treatment system according to claim 1 is characterized in that: The hardness removal device, the first silicon removal device and the second silicon removal device are respectively integrated equipment.

7. The circulating cooling water zero-discharge treatment system according to any one of claims 1 to 6, characterized in that: The circulating cooling water zero-discharge treatment system also includes a circulating cooling tower, and the circulating cooling tower is connected to the hardness removal device through a drainage pipe; a sewage pump is provided on the drainage pipe.

8. The circulating cooling water zero-discharge treatment system according to claim 7, characterized in that: The circulating cooling water zero-discharge treatment system also includes a cooling tower forebay, and the cooling tower forebay is connected to the circulating cooling tower via a circulating pipeline to form a circulating loop with the circulating cooling tower.

9. The circulating cooling water zero-discharge treatment system according to claim 8, characterized in that: The circulating cooling water zero-discharge treatment system also includes a first reflux pipeline connected between the evaporation device and the cooling tower forebay for transporting evaporated condensed water to the cooling tower forebay.

10. The circulating cooling water zero-discharge treatment system according to claim 8, characterized in that: The circulating cooling water zero-discharge treatment system also includes a second reflux pipeline connected between the reverse osmosis device and the cooling tower forebay, and the reverse osmosis produced water is transported to the cooling tower forebay.

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