CN208234640U - A kind of device improving sewage stripping tower bottom reuse purified water water quality - Google Patents

Abstract

The utility model discloses a device for improving the water quality of reused purified water at the bottom of an acidic water stripping tower. Reuse the purified water input pipeline to the inlet of the pre-filter, the outlet of the lower layer of the pre-filter is connected to the inlet of the first-stage reverse osmosis device, and the outlet of the first-stage reverse osmosis device is connected to the inlet of the second-stage reverse osmosis device and the input pipeline of the reused purified water, The outlet of the secondary reverse osmosis device is connected to the inlet of the third-stage reverse osmosis device and the inlet of the first-stage reverse osmosis device, the upper outlet of the third-stage reverse osmosis device discharges the third-stage concentrated liquid, and the lower outlet of the third-stage reverse osmosis device passes through the third-stage purification water pump Connect to secondary reverse osmosis unit inlet. The utility model improves the water quality of the reused purified water by shunting a small amount of reused purified water into a multi-stage reverse osmosis or electrodialysis device, only produces a very small amount of concentrated wastewater, greatly reduces the concentration of ^Cl- and Fe ²⁺ in it, and ensures reused purification The water quality is stable and up to standard, and it is suitable for reuse of purified water at the bottom of the sewage stripping device in the petrochemical and coal chemical industries.

Description

A device for improving the quality of purified water reused at the bottom of an acidic water stripping tower

technical field

The utility model relates to an acidic water stripping purification water reuse process in the fields of petrochemical industry, coal chemical industry, etc., in particular to a device for improving the water quality of acidic stripping tower bottom reuse purified water.

Background technique

Acidic water stripping device is an important processing device for sulfur-containing and nitrogen-containing wastewater in the energy and chemical industry. The treated acid water pollutant content can only be discharged after reaching the standard. At present, there are three main processes for sour water stripping devices in my country, namely, single-tower low-pressure full-blown stripping, single-tower pressurized sideline stripping, and double-tower pressurized stripping. Among them, the single-tower process separates at the bottom of the stripper to obtain purified water that meets the discharge or reuse standards, and the double-tower process obtains purified water at the bottom of the ammonia stripper.

In recent years, as the processing proportion of low-priced low-quality crude oil such as high sulfur, high nitrogen, high acid and chlorine in China has increased year by year, the concentration of corrosive media such as NH ₃ , H ₂ S and CO ₂ in acid water discharge devices in the petrochemical industry has increased year by year. Rising, and other corrosive media, such as Cl ^- and CN ^- concentrations are also rising. After the acidic water is stripped through the stripping tower, some trace impurities, such as ^Cl- and Fe ²⁺ , etc. cannot be completely stripped to the top of the tower, especially in the single tower pressurized side stripping process, the temperature of the top of the tower is relatively low ( 40～50℃), Cl ^- can hardly be stripped to the top of the tower, resulting in most of the Cl ^- in the acidic water existing in the purified water at the bottom of the tower, causing serious corrosion problems.

At present, with the increasingly stringent environmental protection policies, higher requirements are put forward for the utilization rate of water resources in enterprises. The reuse of purified water at the bottom of the sour water stripping unit has become one of the important means for petrochemical enterprises to save energy, reduce emissions and reduce consumption. . Therefore, it is urgent to design and implement a reasonable process for reuse and purification of water. Generally, equipment that uses reused purified water is generally designed, manufactured, and operated and maintained according to the standard of deaerated water. Compared with the water quality of deoxygenated water, the content of impurities in the purified water at the bottom of the tower is higher, and the reuse of purified water will also lead to the continuous accumulation of impurities such as Cl ^- and Fe ²⁺ in the purified water, which will gradually deteriorate the water quality and significantly intensify the pollution of the petrochemical industry. The flow corrosion rate of medium pressure vessels and pressure pipelines will cause corrosive leakage, perforation, pipe burst, unplanned shutdown accidents, and heavy economic losses. Therefore, there is an urgent need in the petrochemical industry for a device to improve the quality of purified water reused at the bottom of the sour water stripping tower, to improve the operation adaptability of the sour water stripper under variable working conditions, and to ensure the long-term safe and stable operation of petrochemical equipment.

Utility model content

The utility model aims at the prominent problem of strong corrosion of reused water existing in the existing acidic water stripping process, and proposes a device for improving the quality of reused purified water at the bottom of the acidic water stripping tower, and effectively controls the reuse under the premise of reducing the consumption of water resources The content of corrosive impurities in the purified water reduces the flow corrosion characteristics of the reused purified water, thereby improving the utilization efficiency of the reused purified water, prolonging the service life of the equipment, and avoiding the flow corrosion failure caused by the high concentration of corrosive media in the reused water.

The purpose of this utility model is realized by the following devices:

1. The first device to improve the quality of purified water reused at the bottom of the acidic water stripping tower

The device includes a pre-filter, a first-stage reverse osmosis device, a first-stage purified water pump, a second-stage reverse osmosis device, a second-stage purified water pump, a third-stage reverse osmosis device, and a third-stage purified water pump; the recycled purified water is connected to the pre-filter through a pipeline The inlet of the upper layer of the pre-filter is discharged from the upper layer of the suspension through the pipeline, the outlet of the lower layer of the pre-filter is connected to the inlet of the first-level reverse osmosis device through the pipeline, and the upper layer outlet of the first-level reverse osmosis device is connected to the inlet of the second-level reverse osmosis device through the pipeline The outlet of the lower layer of the first-stage reverse osmosis device is connected to the input pipeline of reused purified water through the first-stage purified water pump, the upper outlet of the second-stage reverse osmosis device is connected to the inlet pipe of the third-stage reverse osmosis device through the pipeline, and the second-stage reverse osmosis device The lower outlet of the third-stage reverse osmosis device is connected to the inlet of the first-stage reverse osmosis device through the second-stage purified water pump, the upper-layer outlet of the third-stage reverse osmosis device is discharged from the third-stage concentrate through the pipeline, and the lower outlet of the third-stage reverse osmosis device is connected to the second-stage reverse osmosis device through the third-stage purified water pump. The inlet pipe of the reverse osmosis unit.

Part of the reused purified water from the bottom of the acidic water stripping tower and after heat exchange enters the pre-filter to remove the suspended solids in the upper layer, and the other part of the reused purified water is mixed with the primary purified water output from the primary reverse osmosis device to form untreated recycled water. The mixed water of purified water and primary purified water is discharged; pre-filtered water is obtained after pre-filter treatment and enters a multi-stage separation device with reverse osmosis membrane: primary purified water and primary Concentrate, first-level purified water is pressurized by the first-level purified water pump and mixed with another part of recycled purified water that has not entered the pre-filter to form a mixed water of untreated reused purified water and first-level purified water, and then discharged; The concentrated liquid enters the secondary reverse osmosis device, and is separated by the secondary reverse osmosis device to obtain the secondary purified water and the secondary concentrated liquid. The secondary purified water is pressurized by the secondary purified water pump and returns to the input end of the primary reverse osmosis device. The pre-filtered water is mixed to form the mixed water of the pre-filtered water and the secondary purified water; the secondary concentrated liquid enters the tertiary reverse osmosis device, and is separated by the tertiary reverse osmosis device to obtain the tertiary purified water and the tertiary concentrated liquid, and the tertiary purified water After being pressurized by the tertiary purified water pump, it returns to the input end of the secondary reverse osmosis device and mixes with the primary concentrated liquid to form a mixture of the tertiary purified water and the primary concentrated liquid, and the tertiary concentrated liquid is discharged from the device for subsequent treatment.

The suspended matter in the upper layer includes suspended particles, oil and the like.

2. The second device for improving the quality of purified water reused at the bottom of the acidic water stripping tower

The device includes a pre-filter, a first-stage electrodialysis unit, a first-stage purified water pump, a second-stage electrodialysis unit, a second-stage purified water pump, a third-stage electrodialysis unit and a third-stage purified water pump; the recycled purified water is connected to the pre-filter through a pipeline The inlet of the upper layer of the pre-filter is discharged from the upper layer of the suspension through the pipeline, the outlet of the lower layer of the pre-filter is connected to the inlet of the first-level electrodialysis device through the pipeline, and the upper layer outlet of the first-level electrodialysis device is connected to the inlet of the second-level electrodialysis device through the pipeline The outlet of the lower layer of the first-stage electrodialysis device is connected to the input pipeline of reused purified water through the first-stage purified water pump; The outlet of the lower layer of the third-stage electrodialysis device is connected to the inlet of the first-stage electrodialysis device through the secondary purification water pump, the upper outlet of the third-stage electrodialysis device is discharged from the third-stage concentrate through the pipeline, and the lower outlet of the third-stage electrodialysis device is connected to the second-stage electrodialysis device through the third-stage purification water pump. The inlet pipe of the electrodialysis unit.

Part of the reused purified water from the bottom of the acidic water stripping tower and after heat exchange enters the pre-filter to remove the suspended solids in the upper layer, and the other part of the reused purified water is mixed with the primary purified water output from the primary electrodialysis device to form untreated recycled water. The mixed water of purified water and primary purified water is used; pre-filtered water is obtained after pre-filter treatment and enters a multi-stage separation device with electrodialysis ion exchange membrane: the primary purified water and primary purified water are separated by a primary electrodialysis device First-level concentrated liquid, the first-level purified water is pressurized by the first-level purified water pump and mixed with another part of the reused purified water that has not entered the pre-filter to form a mixed water of untreated reused purified water and the first-level purified water, and then discharged; The first-level concentrated liquid enters the second-level electrodialysis device, and is separated by the second-level electrodialysis device to obtain the second-level purified water and the second-level concentrated solution. The second-level purified water is pressurized by the second-level purified water pump and returns to the input end of the first-level electrodialysis device. Mixed with pre-filtered water to form the mixed water of pre-filtered water and secondary purified water, the secondary concentrated solution enters the tertiary electrodialysis device, and is separated by the tertiary electrodialysis device to obtain the tertiary purified water and the tertiary concentrated solution, and the tertiary purification After the water is pressurized by the three-stage purified water pump, it returns to the input end of the second-stage electrodialysis device and mixes with the first-stage concentrated solution to form a mixture of the third-stage purified water and the first-stage concentrated solution, and the third-stage concentrated solution is discharged from the device for subsequent treatment.

The suspended matter in the upper layer includes suspended particles, oil and the like.

The pre-filter device of the utility model can select filter devices such as activated carbon, microfiltration membrane or ultrafiltration membrane according to actual conditions.

The beneficial effects of the utility model are:

The utility model improves the water quality of the reuse purified water at the bottom of the acidic water stripping tower by shunting a small amount of recycled purified water into a multi-stage reverse osmosis or electrodialysis device, and only produces a very small amount (<0.05%wt) of concentrated waste water, which is reused at the same time Purified water Cl ^- and Fe ²⁺ concentrations were reduced by more than 70% and 60% respectively, and reused purified water mixed with untreated purified water had Cl ^- and Fe ²⁺ concentrations reduced by 4% and 3% respectively The above can ensure the stable compliance of the water quality of reused purified water.

The utility model can be applied to reuse purified water at the bottom of a sewage stripping device (especially a single-tower pressurized side line stripping device) in the fields of petrochemical industry and coal chemical industry. The process is simple and practical, the equipment investment cost is small, and the device configuration is flexible Changeable, no need to change the sewage stripping device.

Description of drawings

Figure 1 is a diagram of the water quality improvement process device for reused purified water using a three-stage reverse osmosis process.

In Figure 1: 1-Reuse of purified water, 2-Pre-filter, 3-Suspended matter in the upper layer, 4-Pre-filtered water, 5-Mixed water of pre-filtered water and secondary purified water, 6-First-stage reverse osmosis device , 7-first-level concentrated liquid, 8-first-level purified water, 9-first-level purified water pump, 10-mixed water of untreated recycled purified water and first-level purified water; 11-third-level purified water and first-level concentrated solution Mixture, 12-secondary reverse osmosis device, 13-secondary concentrated solution, 14-secondary purified water, 15-secondary purified water pump, 16-tertiary reverse osmosis device, 17-tertiary concentrated solution, 18-tertiary Purified water, 19-three-stage purified water pump.

Fig. 2 is a diagram of a process device for improving the water quality of reused purified water using a three-stage electrodialysis process.

In Fig. 2: 20-recycled purified water, 21-pre-filter, 22-upper suspension, 23-pre-filtered water, 24-mixed water of pre-filtered water and secondary purified water, 25-first-stage electrodialysis device , 26-first-level concentrated liquid, 27-first-level purified water, 28-first-level purified water pump, 29-mixed water of untreated recycled purified water and first-level purified water; 30-third-level purified water and first-level concentrated solution Mixture, 31-secondary electrodialysis device, 32-secondary concentrated solution, 33-secondary purified water, 34-secondary purified water pump, 35-tertiary electrodialysis device, 36-tertiary concentrated solution, 37-tertiary Purified water, 38-three-stage purified water pump.

Detailed ways

In order to further illustrate the technical solution of the present utility model, the specific implementation examples are further described below.

The utility model embodiment is as follows:

Example 1: In this example, a three-stage reverse osmosis process is used to improve the quality of reused purified water.

As shown in Figure 1, the device includes recycled purified water 1, pre-filter 2, primary reverse osmosis device 6, primary purified water pump 9, secondary reverse osmosis device 12, secondary purified water pump 15, and tertiary reverse osmosis device 16 and a three-stage purified water pump 19; the recycled purified water 1 is connected to the inlet of the pre-filter 2 through a pipeline, the upper outlet of the pre-filter 2 is discharged from the upper suspension 3 through the pipeline, and the lower outlet of the pre-filter 2 is connected to the first-level through the pipeline The inlet of the reverse osmosis device 6, the outlet of the upper floor of the first-stage reverse osmosis device 6 is connected to the inlet of the second-stage reverse osmosis device 12 through pipelines, and the outlet of the first-stage reverse osmosis device 6 lower floor is connected to the reuse purified water 1 through the first-stage purified water pump 9 Input pipeline, the upper floor outlet of the secondary reverse osmosis device 12 is connected to the inlet pipeline of the three-stage reverse osmosis device 16 through the pipeline, and the lower floor outlet of the secondary reverse osmosis device 12 is connected to the first-stage reverse osmosis device 6 through the secondary purified water pump 15 The inlet of the three-stage reverse osmosis device 16 is discharged from the upper layer of the outlet through the pipeline. The three-stage concentrate 17, and the lower floor outlet of the three-stage reverse osmosis device 16 is connected to the inlet pipeline of the secondary reverse osmosis device 12 through the three-stage purified water pump 19.

The specific process flow is shown in Figure 1. The recycled purified water 1 from the bottom of the acidic water stripping tower and after heat exchange splits a part into the pre-filter 2 to remove the upper suspension, and the other part reuses the purified water 1 and the output of the first-stage reverse osmosis device 6. The primary purified water 8 is mixed to form a mixed water 10 of untreated recycled purified water and primary purified water, which enters the devices at all levels. The pre-filtered water 4 treated by the pre-filter 2 enters the multi-stage separation device with a reverse osmosis membrane: firstly, it is separated by the first-stage reverse osmosis device 6 to obtain the first-class purified water 8 and the first-class concentrated solution 7, and the first-class purified water 8 After being pressurized by the first-stage purified water pump 9, it returns to the input end of the pre-filter 2, and mixes with untreated recycled purified water 1 to form a mixed water 10 of untreated reused purified water and primary purified water. The concentrated solution 7 enters the secondary reverse osmosis device 12 for separation to obtain the secondary purified water 14 and the secondary concentrated solution 13, and the secondary purified water 14 returns to the input end of the primary reverse osmosis device 6 after being pressurized by the secondary purified water pump 15. And mixed with the pre-filtered water 4 to form the mixed water 5 of the pre-filtered water and the secondary purified water, the secondary concentrated solution 13 enters the tertiary reverse osmosis device 16 for separation to obtain the tertiary purified water 18 and the tertiary concentrated solution 17, and the tertiary purified water The water 18 returns to the input end of the secondary reverse osmosis device 12 after being pressurized by the tertiary purified water pump 19, and is mixed with the primary concentrated solution 7 to form a mixture 11 of the tertiary purified water and the primary concentrated solution, and the tertiary concentrated solution 17 is discharged The device proceeds to subsequent device processing.

The purified water flow of the utility model entering the purified water treatment device (reverse osmosis or electrodialysis device) accounts for 1% to 20% of the total recycled purified water flow. The recycled purified water entering the purified water treatment device has a ^Cl- content of 0-200ppmw, an Fe2 ⁺ content of 0-20ppmw, and a total non-volatile impurity content of no more than 200ppmw. The pre-filter can choose activated carbon, microfiltration membrane or ultrafiltration membrane and other filtration devices according to the actual situation.

The hydrogenation wastewater of an enterprise is stripped by a single-tower pressurized side stripping process. The process data are shown in Table 1. The treatment capacity of the reverse osmosis device is 5t/h, the concentration of Cl ^- in the untreated reused purified water is 10μg/g, and the concentration of Fe ²⁺ is 3μg/g.

Table 1 Three-stage reverse osmosis process parameters

Process parameter name value Process parameter name value Reuse purified water flow rate (t/h) 100 Primary reverse osmosis membrane area (m ² ) 400 Device operating temperature (°C) 40 Secondary reverse osmosis membrane area (m ² ) 50 Pre-filter operating pressure (MPaG) 3 Tertiary reverse osmosis membrane area (m ² ) 7 The ratio of purified water treated by reverse osmosis to the total amount (%) 5 Untreated recycled purified water Cl ^{-concentration} (ppmw) 10 Operating pressure of reverse osmosis unit (MPaG) 2 Concentration of Fe ²⁺ in untreated reused purified water (ppmw) 3 Reverse osmosis membrane water permeability coefficient (kg/(m ² ·h·MPa)) 6.3 Ratio of wastewater to total reused purified water (wt/wt) <0.05%

The flow rate of the primary purified water treated by this device is 96t/h, the concentration of Cl ^- is 2ppmw, which is 80% lower than that of untreated reused purified water ^, and the concentration of Fe ²⁺ is 1ppmw, which is lower than that of untreated reused purified water The concentration of Fe ²⁺ decreased by 66.7%; the flow rate of primary purified water mixed with untreated recycled purified water was 99.96t/h, and the concentration of Cl ^- was 9.6ppmw, which was 4% lower than that of untreated reused purified water ^. The concentration of Fe ²⁺ is 2.9ppmw, which is 3.3% lower than the concentration of Fe ²⁺ in the untreated reused purified water; the flow rate of the third-stage concentrate is 0.04t/h, accounting for the treated purified water flow rate of the reverse osmosis device and the total reused purified water flow rate 0.8% and 0.04%, Cl ^- concentration is 1000ppmw, Fe ²⁺ concentration is 251ppmw.

It can be seen from the above-mentioned experimental results that the utility model uses the multi-stage reverse osmosis process for the purified water treatment after the stripping of acidic water in the petrochemical and coal chemical industries, and reduces the non-volatile impurities (Cl ^- concentration, Fe ²⁺ Concentration) content of more than 60%, the ^Cl- and Fe ²⁺ concentrations of the recycled purified water mixed with the primary recycled purified water and untreated purified water are reduced by more than 4% and 3% respectively, so as to avoid the cyclic accumulation of impurities in the reused purified water , can effectively improve water quality, reduce the flowing corrosion of sewage solution on equipment pipes after water injection, and only produce waste water that does not exceed 0.05% of the total flow of reused water purification, which can ensure the stable quality of reused purified water up to the standard.

Example 2: In this example, a three-stage electrodialysis process is used to improve the quality of reused purified water.

As shown in Figure 2, the device includes recycled purified water 20, pre-filter 21, primary reverse osmosis device 25, primary purified water pump 28, secondary reverse osmosis device 31, secondary purified water pump 34, and tertiary reverse osmosis device 35 and a three-stage purified water pump 38; reuse the purified water 20 input pipeline to the inlet of the pre-filter 21, the outlet of the upper layer of the pre-filter 21 discharges the upper suspension 3, and the outlet of the lower layer of the pre-filter 21 is connected to the first-stage reverse osmosis device 25 The inlet of the first-stage reverse osmosis device 25 upper floor is connected to the inlet of the second-stage reverse osmosis device 31, and the outlet of the first-stage reverse osmosis device 25 lower floor is connected to the reuse purified water 20 input pipeline through the first-stage purified water pump 28, and the secondary reverse osmosis device The upper floor outlet of the osmosis device 31 is the inlet of the three-stage reverse osmosis device 35, the lower floor outlet of the two-stage reverse osmosis device 31 is connected to the inlet of the first-stage reverse osmosis device 25 through the secondary purified water pump 34, and the upper floor outlet of the three-stage reverse osmosis device 35 The three-stage concentrated liquid 36 is discharged, and the lower outlet of the three-stage reverse osmosis device 35 is connected to the inlet of the two-stage reverse osmosis device 31 through a three-stage purified water pump 38 .

The specific technological process is shown in Fig. 2, and a part of reuse purified water 20 from the bottom of the acid water stripping tower and heat exchange enters the pre-filter 21 to remove the upper suspension, and the other part reuses the purified water 20 and the first-stage reverse osmosis device 25 output The primary purified water 27 is mixed to form a mixed water 29 of untreated recycled purified water and primary purified water, which enters the devices at all levels. The pre-filtered water 23 treated by the pre-filter 21 enters the multi-stage separation device with an electrodialysis ion-exchange membrane: first, it is separated by a first-stage electrodialysis device 25 to obtain a primary purified water 27 and a primary concentrated solution 26, and the primary purification The water 27 is pressurized by the primary purified water pump 28 and returned to the input end of the pre-filter 21, and mixed with the untreated recycled purified water 20 to form a mixed water 29 of the untreated recycled purified water and the primary purified water. The primary concentrated solution 26 enters the secondary electrodialysis device 31 to separate and obtain the secondary purified water 33 and the secondary concentrated solution 32, and the secondary purified water 33 returns to the input of the primary electrodialysis device 25 after being pressurized by the secondary purified water pump 34 and mixed with pre-filtered water 23 to form mixed water 24 of pre-filtered water and secondary purified water, and the secondary concentrated solution 32 enters the tertiary electrodialysis device 35 for separation to obtain tertiary purified water 37 and tertiary concentrated solution 36. The first-level purified water 37 is pressurized by the third-level purified water pump 38 and returns to the input end of the second-level electrodialysis device 31, and is mixed with the first-level concentrated solution 26 to form a mixture 30 of the third-level purified water and the first-level concentrated solution, and the third-level concentrated solution 36 out of the device for subsequent device processing.

The specific process flow is shown in Figure 2. The hydrogenation wastewater of a petrochemical enterprise is stripped by a single-tower pressurized side stripping process. The process data are shown in Table 2. The treatment capacity of the electrodialysis unit is 9.6t/h, the concentration of Cl ^- in the untreated reused purified water is 15μg/g, and the concentration of Fe ²⁺ is 5μg/g.

Table 2 Three-stage electrodialysis process parameters

Process parameter name value Process parameter name value Reuse purified water flow rate (t/h) 160 Primary ion exchange membrane area (m ² ) 900 Device operating temperature (°C) 45 Secondary ion exchange membrane area (m ² ) 120 Pre-filter operating pressure (MPa) 2 Tertiary ion exchange membrane area (m ² ) 15 The proportion of purified water treated by electrodialysis unit to the total (%) 6 Untreated recycled purified water Cl ^{-concentration} (ppmw) 15 Operating voltage of electrodialysis unit (V) 110 Concentration of Fe ²⁺ in untreated reused purified water (ppmw) 5 Water permeability coefficient of ion exchange membrane (kg/(m ² ·h·V)) 0.01 Ratio of wastewater to total reused purified water (wt/wt) <0.05%

The flow rate of primary purified water treated by this device is 9.547t/h, and the concentration of Cl ^- is ^4ppmw , which is 73.3% lower than that of untreated reused purified water ^. The concentration of Fe ²⁺ in water is reduced by 60%; the flow rate of primary purified water mixed with untreated reused purified water is 159.95t/h, and the concentration of Cl ^- is 14.3ppmw ^, which is 4.7% lower than that of untreated reused purified water , the Fe ²⁺ concentration is 4.8ppmw, which is 4% lower than the Fe ²⁺ concentration of the untreated reused purified water; the flow rate of the third-stage concentrate is 0.053t/h, accounting for the treated purified water flow rate of the electrodialysis device and the total reused purified water 0.55% and 0.033% of the flow rate, the Cl ^- concentration is 2000ppmw, and the Fe ²⁺ concentration is 530ppmw.

It can be seen from the above experimental results that the utility model uses the multi-stage electrodialysis process for the treatment of purified water after acid water stripping in the petrochemical and coal chemical industries, and reduces the non-volatile impurities (Cl ^- concentration, Fe ²⁺ Concentration) content of more than 60%, the Cl ^- and Fe ²⁺ concentration of the recycled purified water mixed with the primary recycled purified water and untreated purified water is reduced by more than 4%, avoiding the cyclic accumulation of impurities in the reused purified water, which can effectively improve Water quality, reduce the flowing corrosion of the sewage solution on the equipment pipeline after water injection, and at the same time only produce waste water not exceeding 0.05% of the total flow of reused water purification, which can ensure the stable quality of reused purified water up to the standard.

In addition, the number of stages of the reverse osmosis or electrodialysis separation device of the present invention includes but is not limited to three stages, and two, three, four or more stages can be selected according to actual conditions. For example, for the two-stage reverse osmosis separation device, the three-stage reverse osmosis device 16 and the three-stage purified water pump 19 in Fig. 1 are not placed; The dialysis unit 35 and the three-stage purified water pump 38 are not placed. For the four-stage reverse osmosis separation device or electrodialysis separation device, a fourth-stage reverse osmosis device or four-stage electrodialysis device is installed behind the three-stage reverse osmosis device or three-stage electrodialysis device, and a four-stage purified water pump is added to connect back Two-stage reverse osmosis unit or two-stage electrodialysis unit. By analogy, when setting n-level (n>3) reverse osmosis devices or electrodialysis devices, that is, after n-1-level reverse osmosis devices or n-1-level electrodialysis devices, add n-th-level reverse osmosis devices or An n-level electrodialysis device, and an n-level purified water pump is added to connect back to an n-level reverse osmosis device or an n-level electrodialysis device.

Claims (6)

1. it is a kind of improve sewage stripping tower bottom reuse purified water water quality device, it is characterised in that: including prefilter (2), First-stage reverse osmosis device (6), first class purification water pump (9), second level reverse osmosis apparatus (12), secondary purification water pump (15), three-level are anti- Permeability apparatus (16) and three-level clarified water pump (19)；Reuse purified water (1) is connected to the entrance of prefilter (2) through pipeline, in advance Upper layer suspension (3) are discharged by the road in the outlet of filter (2) upper layer, and the outlet of prefilter (2) lower layer is communicated to level-one by the road The entrance of reverse osmosis unit (6), the outlet of first-stage reverse osmosis device (6) upper layer are communicated to second level reverse osmosis apparatus (12) by the road Entrance, first-stage reverse osmosis device (6) lower layer export the intake line that reuse purified water (1) is connected to through first class purification water pump (9), The upper layer outlet of second level reverse osmosis apparatus (12) is communicated to the inlet duct of three-level reverse osmosis unit (16), second level reverse osmosis by the road The lower layer outlet of saturating device (12) is connected to the entrance of first-stage reverse osmosis device (6), three-level reverse osmosis through secondary purification water pump (15) Three-level concentrate (17) are discharged by the road in the upper layer outlet of saturating device (16), and the lower layer of three-level reverse osmosis unit (16) exports through three Grade clarified water pump (19) is connected to the inlet duct of second level reverse osmosis apparatus (12).

2. a kind of device for improving sewage stripping tower bottom reuse purified water water quality according to claim 1, feature exist In: the reuse purified water (1) from sewage stripping tower bottom and after exchanging heat shunts a part and enters prefilter (2) removing upper layer Shape after first class purification water (8) mixing of suspended matter (3), another part reuse purified water (1) and first-stage reverse osmosis device (6) output It is discharged at the mixing water (10) of untreated reuse purified water and first class purification water；Pre-filtering is obtained after prefilter (2) processing Water (4) simultaneously enters the multi-stage separation device with reverse osmosis membrane:

By the isolated first class purification water (8) of first-stage reverse osmosis device (6) and primary concentration liquid (7), first class purification water (8) warp It is formed after being mixed after first class purification water pump (9) pressurization with the reuse purified water (1) that another part does not enter prefilter (2) and is not located Reason reuse purified water and the mixing water (10) of first class purification water are discharged afterwards；Primary concentration liquid (7) enters second level reverse osmosis apparatus (12), through the isolated secondary purification water (14) of second level reverse osmosis apparatus (12) and secondary concentration liquid (13), secondary purification water (14) input terminal that first-stage reverse osmosis device (6) is returned to after secondary purification water pump (15) pressurization mixes shape with pre-filtering water (4) At the mixing water (5) of pre-filtering water and secondary purification water；Secondary concentration liquid (13) enters three-level reverse osmosis unit (16), through three-level The isolated three-level purified water (18) of reverse osmosis unit (16) and three-level concentrate (17), three-level purified water (18) are purified through three-level The input terminal of second level reverse osmosis apparatus (12) is returned to after water pump (19) pressurization and primary concentration liquid (7) are mixed to form three-level purified water With primary concentration liquid mixture (11), three-level concentrate (17) discharger carries out subsequent processing.

3. a kind of device for improving sewage stripping tower bottom reuse purified water water quality according to claim 2, feature exist In: the upper layer suspended matter (3) includes suspended particulate and oil.

4. a kind of device for improving sewage stripping tower bottom reuse purified water water quality, it is characterised in that:

Including prefilter (21), level-one electrodialysis plant (25), first class purification water pump (28), second level electrodialysis plant (31), Secondary purification water pump (34), three-stage electrodialysis device (35) and three-level clarified water pump (38)；Reuse purified water (20) connects through pipeline It is connected to the entrance of prefilter (21), upper layer suspension (22) are discharged by the road in the outlet of prefilter (21) upper layer, prefilter (21) lower layer outlet is communicated to the entrance of level-one electrodialysis plant (25), level-one electrodialysis plant (25) upper layer outlet warp by the road Pipeline connection is to the entrance of second level electrodialysis plant (31), and the outlet of level-one electrodialysis plant (25) lower layer is through first class purification water pump (28) it is connected to the intake line of reuse purified water (20), the upper layer outlet of second level electrodialysis plant (31) is communicated to three by the road The lower layer outlet of the inlet duct of grade electrodialysis plant (35), second level electrodialysis plant (31) is connected through secondary purification water pump (34) Three-level concentrate is discharged by the road to the upper layer outlet of the entrance of level-one electrodialysis plant (25), three-stage electrodialysis device (35) (36), the lower layer of three-stage electrodialysis device (35), which exports, is connected to second level electrodialysis plant (31) through three-level clarified water pump (38) Inlet duct.

5. a kind of device for improving sewage stripping tower bottom reuse purified water water quality according to claim 4, feature exist In: the reuse purified water (20) from sewage stripping tower bottom and after exchanging heat shunts a part and enters in prefilter (21) removing The first class purification water (27) of layer suspended matter (22), another part reuse purified water (20) and level-one electrodialysis plant (25) output is mixed The mixing water (29) of untreated reuse purified water Yu first class purification water is formed after conjunction；Pre- mistake is obtained after prefilter (21) processing Drainage (23) simultaneously enters the multi-stage separation device with electrodialysis-ion exchange film:

By the isolated first class purification water (27) of level-one electrodialysis plant (25) and primary concentration liquid (26), first class purification water (27) reuse purified water (20) mixing of prefilter (21) is not entered with another part after first class purification water pump (28) pressurization The mixing water (29) for forming untreated reuse purified water and first class purification water afterwards is discharged afterwards；Primary concentration liquid (26) enters second level electricity Electrodialysis apparatus (31), through the isolated secondary purification water (33) of second level electrodialysis plant (31) and secondary concentration liquid (32), second level Purified water (33) returns to the input terminal and pre-filtering water of level-one electrodialysis plant (25) after secondary purification water pump (34) pressurize (23) it is mixed to form the mixing water (24) of pre-filtering water Yu secondary purification water, secondary concentration liquid (32) enters three-stage electrodialysis device (35), through the isolated three-level purified water (37) of three-stage electrodialysis device (35) and three-level concentrate (36), three-level purified water (37) input terminal and primary concentration liquid (26) that second level electrodialysis plant (31) is returned to after three-level clarified water pump (38) pressurization are mixed Conjunction forms three-level purified water and primary concentration liquid mixture (30), and three-level concentrate (36) discharger carries out subsequent processing.

6. a kind of device for improving sewage stripping tower bottom reuse purified water water quality according to claim 5, feature exist In: the upper layer suspended matter (22) includes suspended particulate and oil.