Device for recycling high-salinity wastewater in printing and dyeing industry

Abstract

The utility model relates to the field of wastewater recycling devices, in particular to a high-salinity wastewater recycling device in the printing and dyeing industry. A high-salinity wastewater recycling device in the printing and dyeing industry comprises a pretreatment device and a secondary treatment device, and the secondary treatment device comprises a raw water booster pump, a first security filter, a high-pressure pump, a reverse osmosis device, a reverse osmosis water producing pool, a flushing water pump and a second security filter which are sequentially arranged. And a pressure energy recovery device is also arranged between the reverse osmosis device and the first security filter. According to the utility model, the pressure energy recovery device is arranged, the pressure of reverse osmosis concentrated water is transferred to raw water through isobaric pressure exchange, and meanwhile, the circulating booster pump is arranged for cooperative operation, so that the energy loss in the recycling process is made up.

Description

Technical Field

[0001] The utility model relates to the field of high-salt wastewater recycling devices, and specifically designs a high-salt wastewater recycling device for the printing and dyeing industry. Background Art

[0002] The printing and dyeing industry, a key pillar of the global economy, generates wastewater containing significant amounts of organic pollutants and inorganic salts. Discharging this wastewater untreated not only severely damages the environment but also wastes precious water resources. Therefore, the use of dual-membrane technology to treat high-concentration printing and dyeing wastewater and achieve wastewater recycling has become a mainstream solution. However, wastewater quality is crucial to the design and operation of this system.

[0003] To efficiently reuse printing and dyeing wastewater, reverse osmosis membrane modules require high wastewater inlet pressure. This results in significant energy consumption during system operation, leading to high operating costs and impacting the economic benefits of wastewater reuse. Furthermore, the high-pressure brine discharged from reverse osmosis (RO) membrane systems can reach pressures of 4.0 MPa to 6.0 MPa. Directly discharging this brine without utilization would result in significant energy waste.

[0004] Currently, dyeing and printing wastewater treatment technology faces the following challenges: First, the complex and fluctuating water quality of dyeing and printing wastewater results in a relatively low industry-wide reuse rate for high-concentration dyeing and printing wastewater. Second, although the dual-membrane reuse system is the mainstream process for treating high-concentration dyeing and printing wastewater, its high reuse costs and the direct discharge of high-pressure concentrated water result in significant energy waste. These challenges urgently need to be addressed through technological innovation and optimization to achieve sustainable development of dyeing and printing wastewater treatment. Summary of the Invention

[0005] The utility model hopes to provide a high-salt wastewater recycling device for the printing and dyeing industry. The specific scheme is as follows:

[0006] A high-salt wastewater recycling device for the printing and dyeing industry includes a pre-treatment device and a secondary treatment device. The secondary treatment device includes a raw water booster pump, a first safety filter, a high-pressure pump, a reverse osmosis device, a reverse osmosis water production pool, a flushing water pump and a second safety filter, which are arranged in sequence. A pressure energy recovery device is also provided between the reverse osmosis device and the first safety filter.

[0007] A circulating booster pump is provided between the pressure energy recovery device and the reverse osmosis device, and the pressure energy recovery device is connected to the first safety filter.

[0008] The reverse osmosis device is connected to a cleaning device, and the cleaning device comprises a cleaning water tank, a cleaning water pump and a cleaning filter which are arranged in sequence.

[0009] The second security filter is connected to the reverse osmosis device through a flushing water pipe.

[0010] The pre-treatment device includes a blower, an HMF membrane tank, a suction pump, a reverse osmosis raw water tank, an HMF backwash pump and a backwash filter which are arranged in sequence. The reverse osmosis raw water tank is connected to the raw water booster pump of the secondary treatment device.

[0011] The HMF membrane pool includes a plurality of HMF membrane racks, each of which includes a frame body. The frame body is provided with an air inlet, a water outlet and a pulse aerator. The air inlet is coordinated with a blower.

[0012] The backwash filter is connected to the suction pump through a backwash water pipeline.

[0013] The utility model has the following advantages:

[0014] 1. The water quality of printing and dyeing wastewater is complex and fluctuates greatly. In order to improve the recovery rate, it is necessary to install a high-lift high-pressure pump (high-pressure pump). Through frequency conversion regulation, it can cope with the changes in solution osmotic pressure caused by water quality fluctuations and maintain a stable high recovery rate.

[0015] 2. A pressure energy recovery device is installed to transfer the reverse osmosis concentrate pressure to the raw water through isobaric pressure exchange. A circulating booster pump is also installed to work in tandem to compensate for energy loss during the recovery process. This reduces energy waste and significantly lowers the energy consumption of the reverse osmosis system, thereby reducing the flow rate of the system's high-pressure pump and saving operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of a secondary treatment device and a cleaning device in a high-salt wastewater recycling device in the printing and dyeing industry according to the utility model;

[0017] Figure 2 This is a structural diagram of a pre-treatment device in a high-salt wastewater recycling device in the printing and dyeing industry according to the utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the HMF membrane frame in a high-salt wastewater recycling device in the printing and dyeing industry of the utility model;

[0019] The labels are: 1. Raw water booster pump; 2. First safety filter; 3. High-pressure pump; 4. Reverse osmosis device; 5. Reverse osmosis water production tank; 6. Flushing water pump; 7. Second safety filter; 8. Pressure energy recovery device; 9. Circulation booster pump; 10. Cleaning water tank; 11. Cleaning water pump; 12. Cleaning filter; 13. Blower; 14. HMF membrane tank; 15. Suction pump; 16. Reverse osmosis raw water tank; 17. HMF backwash pump; 18. Backwash filter; 19. HMF membrane frame; 20. Frame; 21. Air inlet; 22. Water production port; 23. Pulse aerator. DETAILED DESCRIPTION

[0020] The following combination Figure 1-3 For further explanation:

[0021] A high-salt wastewater recycling device for the printing and dyeing industry includes a pretreatment device and a secondary treatment device. The secondary treatment device comprises a raw water booster pump 1, a first safety filter 2, a high-pressure pump 3, a reverse osmosis device 4, a reverse osmosis water production tank 5, a flushing pump 6, and a second safety filter 7, arranged in sequence. A pressure energy recovery device 8 is also provided between the reverse osmosis device 4 and the first safety filter 2. A circulating booster pump 9 is provided between the pressure energy recovery device 8 and the reverse osmosis device 4, and the pressure energy recovery device 8 is connected to the first safety filter 2. The reverse osmosis device 4 is connected to a cleaning device, which comprises a cleaning water tank 10, a cleaning water pump 11, and a cleaning filter 12, arranged in sequence. The second safety filter 7 is connected to the reverse osmosis device 4 via a flushing water pipe.

[0022] The pretreatment unit includes, in sequence, a blower 13, an HMF membrane tank 14, a suction pump 15, a reverse osmosis raw water tank 16, an HMF backwash pump 17, and a backwash filter 18. The reverse osmosis raw water tank 16 is connected to the raw water booster pump 1 of the secondary treatment unit. The HMF membrane tank 14 includes several HMF membrane racks 19, each comprising a frame 20 equipped with an air inlet 21, a water outlet 22, and a pulse aerator 23. The air inlet 21 is coordinated with the blower 13. The backwash filter 18 is connected to the suction pump 15 via a backwash water pipeline.

[0023] After undergoing biochemical and physicochemical treatment, the wastewater from the secondary sedimentation tank is reused as raw water. This utility model utilizes a combined HMF (pretreatment unit) and reverse osmosis (secondary treatment unit) process. First, the HMF system uses negative pressure suction filtration to trap suspended solids, colloids, and other contaminants on the membrane surfaces. The filtration process utilizes a continuous reflux, intermittent water production, and continuous aeration. This ensures a constant tangential velocity across the membrane surfaces. Air bubbles (pulse aerator 23) scrub sludge from the membranes, preventing the accumulation of pollutants. The HMF-filtered water enters the reverse osmosis system for desalination. The HMF system's water is boosted by a raw water booster pump 1, then passes through a safety filter and a high-pressure pump before entering the reverse osmosis unit 4. After desalination, the water enters the reuse water tank (reverse osmosis water tank 5), serving as both reuse water and freshwater replacement for the reverse osmosis unit. The concentrated water enters the pressure energy recovery device 8 from the concentrated water discharge port of the reverse osmosis device 4. At the same time, the outlet water of the circulating booster pump 9 enters the energy recovery device 8. The high-pressure concentrated water contacts the outlet water of the circulating booster pump 9 and exchanges pressure with the outlet water of the circulating booster pump 9. The high-pressure concentrated water pressure is transmitted to the outlet water of the circulating booster pump 9. The high-pressure concentrated water is then pressurized by the circulating booster pump 9 and merged with the outlet water of the high-pressure pump 3 to enter the reverse osmosis device 4, realizing the energy recovery of the reverse osmosis high-pressure concentrated water.

[0024] For example, a reverse osmosis system with a daily processing capacity of 3,500 tons has a 50% recovery rate, a designed influent conductivity of 20,000 μs / cm, and a sodium chloride-based solution system. The reverse osmosis membrane uses a proprietary, anti-fouling brackish water membrane, configured with 132 membrane elements and a designed water flux of 14.93 LMH. The pressure vessel uses a six-element 8040 side chain, operating at 600 PSI, and the system is designed with a 14:8 two-stage arrangement.

[0025] The configuration of its main high-voltage equipment is as follows:

[0026] .

[0027] The comparison of daily energy consumption is as follows:

[0028] (1) Under conventional configuration, the power consumption of high-pressure pump is:

[0029] Daily electricity consumption = 200KW×24h×0.7=3360 degrees.

[0030] (2) Power consumption of high-pressure pump and energy recovery system when using energy recovery device:

[0031] Daily electricity consumption = (90+15)×24×0.7+3×24×0.95≈1832 kWh.

[0032] The electricity consumption that can be saved per day = 3360-1832 = 1528 degrees

[0033] If the unit price of electricity is 0.75 yuan per kWh and the annual operating time is 350 days, the electricity bill can be saved by about 400,000 yuan each year.

[0034] If the high-pressure pump and energy recovery device are both domestic first-line brands, the equipment investment can be recovered within one year.

[0035] The above content describes the technical principles, beneficial effects and characteristics of the utility model. It should be pointed out that the above is only a preferred implementation method of the utility model, but is not limited to the above embodiments. For technicians in the technical field to which the utility model belongs, they can make some improvements and optimizations without departing from the content of the utility model, which should be regarded as belonging to the scope of protection of the utility model.

Claims

1. A high-salt wastewater recycling device for the printing and dyeing industry, characterized by: It includes a pre-treatment device and a secondary treatment device. The secondary treatment device includes a raw water booster pump, a first safety filter, a high-pressure pump, a reverse osmosis device, a reverse osmosis water production pool, a flushing water pump and a second safety filter, which are arranged in sequence. A pressure energy recovery device is also provided between the reverse osmosis device and the first safety filter.

2. The high-salt wastewater recycling device for the printing and dyeing industry according to claim 1, characterized in that: A circulating booster pump is provided between the pressure energy recovery device and the reverse osmosis device, and the pressure energy recovery device is connected to the first safety filter.

3. A high-salt wastewater recycling device for the printing and dyeing industry according to any one of claims 1 or 2, characterized in that: The reverse osmosis device is connected to a cleaning device, and the cleaning device comprises a cleaning water tank, a cleaning water pump and a cleaning filter which are arranged in sequence.

4. The high-salt wastewater recycling device for the printing and dyeing industry according to claim 1, characterized in that: The second security filter is connected to the reverse osmosis device through a flushing water pipe.

5. The high-salt wastewater recycling device for the printing and dyeing industry according to claim 1, characterized in that: The pre-treatment device includes a blower, an HMF membrane tank, a suction pump, a reverse osmosis raw water tank, an HMF backwash pump and a backwash filter which are arranged in sequence. The reverse osmosis raw water tank is connected to the raw water booster pump of the secondary treatment device.

6. A high-salt wastewater recycling device for the printing and dyeing industry as claimed in claim 5, characterized in that: The HMF membrane pool includes a plurality of HMF membrane racks, each of which includes a frame body. The frame body is provided with an air inlet, a water outlet and a pulse aerator. The air inlet is coordinated with a blower.

7. The high-salt wastewater recycling device for the printing and dyeing industry as claimed in claim 5, characterized in that: The backwash filter is connected to the suction pump through a backwash water pipeline.

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