Zero emission system for comprehensive external drainage treatment of converter station

Abstract

The invention discloses a zero discharge system for comprehensive external drainage treatment of a converter station. The zero discharge system comprises an electric drive concentration unit, an electric energy drying unit, a mother liquor tank and a product water tank, the electrically driven concentration unit comprises a filter connected with the mother liquor box, and an outlet of the filter is connected with the reverse osmosis device; a fresh water outlet of the reverse osmosis device is connected with the product water tank, and a concentrated water outlet is connected with the electric energy drying unit; the electric energy drying unit comprises a low-temperature drying device connected with an outlet of the reverse osmosis device, and the low-temperature drying device is connected with a steam outlet of the electric steam generator; the low-temperature drying device is provided with a produced water outlet and a solid salt outlet, and the produced water outlet is communicated with the product water tank. The low-temperature drying device and the reverse osmosis device are combined, the low-temperature drying device evaporates at normal temperature, scale is not prone to being generated, energy consumption is low, operation is stable, operation, maintenance and management are easy, and cost is saved; the reverse osmosis device greatly optimizes the hydrodynamic performance, is strong in anti-pollution capability, can deal with the high hardness problem of the wastewater of the converter station, and can be designed in an integrated manner.

Description

Technical Field

[0001] The invention relates to a water treatment system, in particular to a zero-discharge system for comprehensive external drainage treatment of a converter station. Background Art

[0002] At present, most converter stations (phase regulators) adopt the method of unified collection and transportation to the outside of the station for comprehensive external drainage. The wastewater in the water pool outside the station cannot be consumed by natural evaporation, and the pool water needs to be regularly cleared and transported by tank trucks. At present, the environmental risk prevention and control technology reserves for comprehensive external drainage of converter stations (phase regulators) are insufficient, and the effect of technical solutions is difficult to adapt to the actual needs of converter stations (phase regulators). There is a lack of external drainage treatment methods that are targeted at the operation mode of the water system of converter stations (phase regulators) and the water quality characteristics of external drainage.

[0003] CN113666564 discloses a converter station external drainage treatment system, in which the external drainage is recycled after passing through an electric drive enrichment unit and a steam recompression unit to obtain product water, and the mother liquor is discharged regularly. However, the start-stop operation of the steam compression unit is complicated, and the professional and technical requirements of the operator are high. Improper operation may cause the equipment to fail to start or even cause equipment damage, making operation and maintenance difficult and costly. Summary of the invention

[0004] Purpose of the invention: The purpose of the invention is to provide a zero-emission system for comprehensive external drainage treatment of converter stations with low energy consumption, stable operation and good treatment effect.

[0005] Technical solution: The zero-emission system for comprehensive external drainage treatment of the converter station described in the present invention includes an electric-driven concentration unit, an electric energy drying unit, a mother liquid tank, and a product water tank; the electric-driven concentration unit includes a filter connected to the mother liquid tank, and the outlet of the filter is connected to the reverse osmosis device; the fresh water outlet of the reverse osmosis device is connected to the product water tank, and the concentrated water outlet is connected to the electric energy drying unit; the electric energy drying unit includes a low-temperature drying device connected to the outlet of the reverse osmosis device, and the low-temperature drying device is connected to the steam outlet of the electric steam generator to provide a heat source to the low-temperature drying device; the low-temperature drying device is provided with a produced water outlet and a solid salt outlet, and the produced water outlet is connected to the product water tank.

[0006] The low-temperature drying device is provided with a steam purification device and a reflux structure for removing free organic matter and free water.

[0007] Wherein, the low-temperature drying device is connected to a cleaning device for cleaning the low-temperature drying device.

[0008] Wherein, the cleaning device feeds cleaning liquid into the low-temperature drying device through a cleaning valve for circulating cleaning.

[0009] Wherein, the low-temperature drying device is connected to a defoaming device for suppressing the formation of excessive foam.

[0010] Wherein, a safety filter is arranged between the filter and the reverse osmosis device to prevent dirt in the mother liquid tank from entering the reverse osmosis device.

[0011] Wherein, a high-pressure pump for accelerating the flow of external drainage is provided between the security filter and the reverse osmosis device.

[0012] Wherein, a raw water pump is provided between the mother liquid tank and the filter.

[0013] The filter adopts a three-stage filtering method of a self-cleaning activated carbon filter, a bag filter and a core filter.

[0014] Beneficial effects: Compared with the prior art, the present invention has achieved the following significant effects: (1) The system of the present invention combines a low-temperature drying device with a reverse osmosis device. The low-temperature drying device evaporates at room temperature, is not easy to produce scale, has low energy consumption, is the most economical, and has stable operation and simple operation and maintenance management, saving equipment costs and operation and maintenance costs. It is suitable for the scenario of zero-discharge treatment of small water volume external drainage in converter stations (phase regulators); the reverse osmosis device combines the advantages of both open channel and roll membrane assembly designs, has a narrow and open channel, which greatly optimizes the fluid dynamics performance and is anti-fouling (1) The low-temperature drying device has a strong dyeing capacity and can cope with the high hardness problem of the wastewater from the converter station (phase-shifting device), and can be integrated to reduce the footprint; (2) The low-temperature drying device has a built-in steam purification device and a reflux structure, which can remove more than 95% of free organic matter and free water, and the effluent heavy metals are zero. The effluent COD is 70% higher than that of the traditional low-temperature evaporator before iteration, and the effluent water quality is better and more transparent; (3) The energy consumption is low, and the system is suitable for the small water volume scenario of the comprehensive external drainage of the converter station (phase-shifting device). The product water quality can meet the water quality standard of "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T 19923-2005), and is reused in the station as circulating water replenishment for the spray tower or as replenishment for the fire water pool. The solid salt moisture content is less than 20%, achieving zero discharge of drainage inside and outside the station. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0017] The present invention is described in further detail below.

[0018] like Figure 1 As shown, the present invention provides a zero-emission system for comprehensive external drainage treatment of a converter station, including an electric drive concentration unit 1, an electric energy drying unit 2, a mother liquid tank 3, and a product water tank 4.

[0019] The electric drive concentration unit 1 includes a filter 11 and a reverse osmosis device 12. The inlet of the filter 11 is connected to the mother liquid tank 3. The filter 11 adopts a three-stage filtration method of self-cleaning activated carbon filter, bag filter, and core filter, which can effectively remove suspended matter from the external drainage. A security filter 13 and a high-pressure pump 14 are also arranged in sequence between the outlet of the mother liquid tank 3 and the inlet of the reverse osmosis device 12; the external drainage enters the reverse osmosis device 12 after being filtered by the security filter 13, further preventing the dirt in the mother liquid tank 3 from entering the reverse osmosis device 12, and the flow of the external drainage is accelerated by setting the high-pressure pump 14. The treated external drainage flows into the reverse osmosis device 12 through the outlet of the filter 11. The reverse osmosis device 12 is provided with a fresh water outlet and a concentrated water outlet, wherein the fresh water outlet is connected to the product water tank 4, and the concentrated water outlet is connected to the inlet of the electric energy drying unit 2; the reverse osmosis device 12 can adopt a high-pressure STRO anti-pollution osmotic membrane, and the device divides the external drainage into fresh water and concentrated water through the osmotic membrane, and the fresh water flows into the product water tank 4 from the fresh water outlet, and the concentrated water flows into the electric energy drying unit 2 from the concentrated water outlet. The membrane assembly combines the advantages of both open channel and rolled membrane assembly designs, and has a narrow and open channel, which overcomes the shortcomings of other common reverse osmosis membrane assemblies, greatly optimizes the fluid dynamics performance, and greatly reduces membrane pollution and scaling problems. The single membrane area of ​​the reverse osmosis device 12 used is large, and an integrated design can be performed to reduce space occupation. The membrane flux of the osmotic membrane of the reverse osmosis device 12 can reach 15 to 25 L / m 2 ·h.

[0020] The concentrated water produced by the electric drive concentration unit 1 flows into the electric energy drying unit 2 from the concentrated water outlet of the reverse osmosis device 12. The electric energy drying unit 2 includes a low temperature drying device 21 and an electric steam generator 22. The inlet of the low temperature drying device 21 is connected to the concentrated water outlet of the reverse osmosis device 12; the steam outlet of the electric steam generator 22 is connected to the low temperature drying device 21 to provide a heat source for the electric energy drying unit 2. The electric steam generator 22 can greatly improve the water output effect through the three-stage steam filtration device. The low-temperature drying device 21 is provided with a water outlet and a solid salt outlet, wherein the water outlet is connected to the product water tank 4. The condensed water in the product water tank 4 meets the water quality standard of "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T 19923-2005), and can replace fresh water. It can be reused in the station as a replenishment for the spray tower as circulating water or as a replenishment for the fire water pool; the solid salt produced by the low-temperature drying device 21 is discharged from the system through the solid salt outlet. The water content of the solid salt is less than 20%. The device is fully automated, and a loading ton bag can be set at the outlet. The solid salt enters the ton bag through the automatic unloading port of the system for storage. After the ton bag is full, it is transported to a temporary stacking point by a forklift for temporary stacking, achieving zero discharge of external drainage. The low-temperature drying device 21 evaporates at room temperature and is not prone to scale. The low-temperature drying device 21 can use a skid-mounted heat pump mother liquor dryer with a built-in steam purification device and reflux structure, which can remove more than 95% of free organic matter and free water. The outlet water has zero heavy metals, and the outlet water COD is 70% higher than the traditional low-temperature evaporator before iteration. The outlet water quality is better and more transparent; low energy consumption, the most economical, and stable operation, simple operation and maintenance management, saving equipment costs and operation and maintenance costs. All the above inlets and outlets are equipped with valves to open and close according to the needs of external drainage treatment.

[0021] The electric energy drying unit 2 of this embodiment is also provided with a cleaning device 23 and a defoaming device 24. The cleaning device 23 is connected to the low-temperature drying device 21. After the cleaning mode is turned on, the cleaning liquid is introduced into the low-temperature drying device 21 through the cleaning valve for circulated cleaning. In order to clean the entire device according to the settable number of cleaning cycles, an automatic flushing loop can be installed on the equipment to realize intelligent operation, without manual operation, and reduce personnel configuration. The number of cleaning cycles depends on the degree of dirtiness of the internal pipe bundle, and this value must be adjusted during continuous operation. The defoaming device 24 is connected to the low-temperature drying device 21. By adding a suitable defoaming agent to the low-temperature drying device 21, excessive foam formation can be suppressed, thereby ensuring the functional reliability of the low-temperature drying device and the quality of the solid salt. The choice of defoaming agent depends on the process water to be treated.

Claims

1. A zero-emission system for comprehensive external drainage treatment of a converter station, characterized in that: The invention comprises an electric drive concentration unit (1), an electric energy drying unit (2), a mother liquid tank (3), and a product water tank (4); the electric drive concentration unit (1) comprises a filter (11) connected to the mother liquid tank, and the outlet of the filter (11) is connected to a reverse osmosis device (12); the fresh water outlet of the reverse osmosis device is connected to the product water tank, and the concentrated water outlet is connected to the electric energy drying unit; the electric energy drying unit (2) comprises a low-temperature drying device (21) connected to the outlet of the reverse osmosis device, and the low-temperature drying device (21) is connected to the steam outlet of an electric steam generator 22 for providing a heat source to the low-temperature drying device (21); the low-temperature drying device (21) is provided with a produced water outlet and a solid salt outlet, and the produced water outlet is connected to the product water tank (4).

2. The zero-emission system for comprehensive external wastewater treatment of a converter station according to claim 1 is characterized in that: The low-temperature drying device (21) is provided with a steam purification device and a reflux structure for removing free organic matter and free water.

3. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 1 is characterized in that: The low-temperature drying device (21) is connected to a cleaning device (23) for cleaning the low-temperature drying device (21).

4. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 3 is characterized in that: The cleaning device (23) feeds cleaning liquid into the low-temperature drying device (21) through a cleaning valve for circulated cleaning.

5. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 1 is characterized in that: The low-temperature drying device (21) is connected to a defoaming device (24) for suppressing the formation of excessive foam.

6. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 1, characterized in that: A safety filter (13) is provided between the filter (11) and the reverse osmosis device (12) to prevent dirt in the mother liquid tank (3) from entering the reverse osmosis device (12).

7. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 6, characterized in that: A high-pressure pump (14) for accelerating the flow of external drainage is provided between the security filter (13) and the reverse osmosis device (12).

8. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 1, characterized in that: A raw water pump (5) is provided between the mother liquid tank and the filter (11).

9. The zero-discharge system for comprehensive external wastewater treatment of a converter station according to claim 1, characterized in that: The filter (11) adopts a three-stage filtering method of a self-cleaning activated carbon filter, a bag filter and a core filter.

Images