CN210176660U

CN210176660U - Device for concentrating and reducing desulfurization wastewater

Info

Publication number: CN210176660U
Application number: CN201921081637.2U
Authority: CN
Inventors: Xianlong Ren; 任显龙; Rui Li; 李睿
Original assignee: Harbin Boiler Co Ltd
Current assignee: Harbin Boiler Co Ltd
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2020-03-24
Anticipated expiration: 2029-07-11

Abstract

A device for concentrating and reducing desulfurization waste water and a working method thereof; the utility model relates to the technical field of wastewater desulfurization, in particular to a wastewater inlet pipe; the wastewater inlet pipe is communicated with the high-density clarification tank through a water supply pipeline, a lime dosing system and a sodium bicarbonate dosing system are arranged on the water supply pipeline between the wastewater inlet pipe and the high-density clarification tank, the high-density clarification tank is communicated with a filtering water tank through a self-cleaning filter and an ultrafiltration device respectively, and the filtering water tank is communicated with the ion exchange bed; the ion exchange bed is connected with the two-stage nanofiltration device through a group of nanofiltration high-pressure pumps; the two-stage nanofiltration device is connected with a high-pressure reverse osmosis device; the high-pressure reverse osmosis device is connected with the electrodialysis device; the electrodialysis device is connected with the MVR device; the utility model discloses the realization really realizes waste water zero discharge to the concentrated processing of high salt waste water.

Description

Device for concentrating and reducing desulfurization wastewater

Technical Field

The utility model relates to a waste water desulfurization technical field especially relates to a device that is used for concentrated decrement of desulfurization waste water.

Background

Under the background of zero discharge of wastewater, wastewater of power plant production links such as circulating water sewage, reverse osmosis concentrated water, chemical workshop drainage and the like are collected into a desulfurizing tower, so that the desulfurizing wastewater is terminal wastewater of the power plant, the water quality is the worst, and the process of treating the desulfurizing wastewater by using the technology is an effective way for realizing zero discharge of wastewater.

The zero discharge of the waste water is realized, and on one hand, a water-saving process is adopted, so that the water consumption is reduced; on the other hand, the water is recycled through the cascade utilization of the water.

Desulfurization wastewater generated by a limestone-gypsum wet thermal power plant, boiler make-up water and condensate polishing acid-base regeneration wastewater are high-salt content and strongly corrosive wastewater; the zero discharge of the wastewater is finally realized by the high-salinity wastewater zero discharge treatment.

SUMMERY OF THE UTILITY MODEL

The utility model overcomes the defects of the prior art and provides a device for concentrating and reducing desulfurization waste water and a working method thereof. The utility model is connected with an ultrafiltration device through a high-density clarification tank through a water pipe; the ultrafiltration device is connected with the secondary nanofiltration device; the secondary nanofiltration device is connected with the high-pressure reverse osmosis device; the high-pressure reverse osmosis device is connected with the electrodialysis device; the electrodialysis device is connected with the MVR device, so that the concentration treatment of the high-salinity wastewater is realized, and the zero discharge of the wastewater is really realized.

The technical scheme of the utility model:

a device for concentration and decrement of desulfurization wastewater comprises a wastewater inlet pipe, a lime dosing system, a sodium bicarbonate dosing system, a high-density clarification tank, a self-cleaning filter, an ultrafiltration device, a filtration water tank, a weak acid cation ion exchange bed, a nanofiltration high-pressure pump, a secondary nanofiltration device, a high-pressure reverse osmosis device, an electrodialysis device and an MVR crystallization device; the device comprises a high-density clarification tank, a waste water inlet pipe, a lime dosing system, a sodium bicarbonate dosing system, a self-cleaning filter, an ultrafiltration device, a filtration water tank and an ion exchange bed, wherein the waste water inlet pipe is communicated with the high-density clarification tank through a water supply pipeline; the ion exchange bed is connected with a secondary nanofiltration device through a group of nanofiltration high-pressure pumps; the secondary nanofiltration device is connected with a high-pressure reverse osmosis device; the high-pressure reverse osmosis device is connected with the electrodialysis device; the electrodialysis device is connected with the MVR device.

Furthermore, a heater and a nanofiltration cartridge filter are arranged between the ion exchange bed and the nanofiltration high-pressure pump.

The utility model discloses following beneficial effect has for prior art:

the utility model is connected with an ultrafiltration device through a high-density clarification tank through a water pipe; the ultrafiltration device is connected with the secondary nanofiltration device; the secondary nanofiltration device is connected with the high-pressure reverse osmosis device; the high-pressure reverse osmosis device is connected with the electrodialysis device; the electrodialysis device is connected with the MVR device, so that the concentration treatment of the high-salinity wastewater is realized, and the zero discharge of the wastewater is really realized;

the utility model discloses according to the characteristics of two alkaline processes + ultrafiltration + nanofiltration + high pressure reverse osmosis system concentration desulfurization waste water. The method comprises the following steps of removing hardness of the desulfurization wastewater by using a double-alkali method and a nanofiltration device, separating salt from the wastewater after hardness removal through nanofiltration, directly removing the wastewater from a concentrated water side to a flue spraying system, and further concentrating produced water by using high-pressure reverse osmosis, so that the water content of the desulfurization wastewater can be reduced to 30-50% of the original water discharge;

the utility model discloses an automatic frequent reverse electrode electrodialysis equipment carries out further concentration to the dense water of reverse osmosis, gets into the evaporation crystallization equipment at last. The ED ionic membrane technology is the combination of ionic membrane dialysis diffusion and an electrochemical process, adopts a homogeneous selective permeable ionic membrane, realizes the directional migration of ions at normal temperature and normal pressure under the drive of an external direct current electric field, and has high separation efficiency, high concentration ratio and high current efficiency. After the reverse osmosis concentrated water is concentrated by an ED ionic membrane, TDS can be concentrated from 30000mg/L to over 200000mg/L, the concentration multiple is 4 times of that of the traditional process, the water quantity entering the crystallization and salt separation subsequently is greatly reduced, the power consumption of per ton water treatment is less than 10 kW.h, and the system energy consumption of zero discharge of waste water is greatly reduced;

after the concentration of the ED ionic membrane, the main heavy metal indexes in two kinds of crystal salts, namely sodium chloride and sodium sulfate, produced by adopting the crystallization salt separation process are lower than the concentration limit value of the hazardous waste identification standard; the process realizes the zero discharge of the waste water, realizes the resource utilization of the crystallized salt, reduces the hazardous waste treatment amount by more than 90 percent, and greatly reduces the hazardous waste treatment cost. Meanwhile, the treatment scale of the subsequent evaporator can be reduced by 75 percent, and the overall investment can be reduced by more than 20 percent. After the evaporation area is greatly reduced, the system can save 60% of steam consumption and reduce more than 40% of operation energy consumption;

the desulfurization wastewater in the utility model is used as wastewater generated in the production process of a power plant, and the hardness of the wastewater is removed by a double-alkali method (a lime dosing system and a sodium bicarbonate dosing system), an ultrafiltration device and a weak acid cation exchange bed; separating salt from the desulfurized wastewater subjected to hardness removal through secondary nanofiltration, and directly removing the concentrated water from a flue spraying system; further concentrating the produced water after the secondary nanofiltration by using high-pressure reverse osmosis; carrying out electrodialysis system on the concentrated water obtained by concentration, and further concentrating the concentrated water by the electrodialysis system; and (4) the concentrated water enters MVR for evaporation and crystallization to obtain NaCl finished salt.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure 1-wastewater inlet pipe; 2-lime dosing system; 3-sodium bicarbonate dosing system; 4-a high-density clarification tank; 5-a high-density clarification tank; 6-ultrafiltration device; 7-filtering the water tank; 8-weak acid cation exchange bed; 9-a nanofiltration high-pressure pump; 10-a secondary nanofiltration device; 11-a high pressure reverse osmosis unit; 12-an electrodialysis unit; 13-an MVR crystallization device; 14-a heater; 15-nanofiltration cartridge filter.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

With reference to fig. 1, the device for concentration and reduction of desulfurization wastewater disclosed in this embodiment includes a wastewater inlet pipe 1, a lime dosing system 2, a sodium bicarbonate dosing system 3, a high-density clarification tank 4, a self-cleaning filter 5, an ultrafiltration device 6, a filtration water tank 7, a weak acid cation exchange bed 8, a nanofiltration high-pressure pump 9, a secondary nanofiltration device 10, a high-pressure reverse osmosis device 11, an electrodialysis device 12, and an MVR crystallization device 13; the wastewater inlet pipe 1 is communicated with a high-density clarification tank 4 through a water supply pipeline, a lime dosing system 2 and a sodium bicarbonate dosing system 3 are arranged on the water supply pipeline between the wastewater inlet pipe 1 and the high-density clarification tank 4, the high-density clarification tank 4 is communicated with a filtering water tank 7 through a self-cleaning filter 5 and an ultrafiltration device 6 respectively, and the filtering water tank 7 is communicated with a weak acid cation exchange bed 8; the weak acid cation exchange bed 8 mainly removes the cations such as calcium, magnesium, sodium and the like remained in water, so that the hardness of the water is reduced; the weak acid cation exchange bed 8 is connected with a secondary nanofiltration device 10 through a group of nanofiltration high-pressure pumps 9; the nanofiltration membrane model used by the secondary nanofiltration device is NF270-400 (or equivalent). Due to the selective permeability of the nanofiltration membrane, monovalent ions selectively permeate through the nanofiltration membrane, and divalent ions do not permeate through the nanofiltration membrane, so that the monovalent salt and the divalent salt in the solution are effectively separated, and the salt separation effect is realized; the secondary nanofiltration device 10 is connected with a high-pressure reverse osmosis device 11; the high-pressure reverse osmosis adopts a DTRO membrane, and the model of the DTRO membrane is CSDT-120 (or equivalent); the wastewater is concentrated by high-pressure reverse osmosis, and the concentrated solution enters an evaporator for evaporation and crystallization, so that the strong brine entering the evaporator is minimized, the size of the evaporator can be greatly reduced, and the investment cost, the operation cost and the energy consumption can be effectively reduced; the high-pressure reverse osmosis device 11 is connected with the electrodialysis device 12; the polarity switching time of the positive and negative electrodes in the electrodialysis device 12 is 3-4 times per hour, and the polarization layer is destroyed, so that the initial precipitation crystal is washed away by liquid flow before further growth and adhesion on the membrane surface, and the internal precipitation and scaling of the membrane are prevented. The ERR technology adopts a cation ion exchange membrane and an anion exchange membrane, and the membrane types are CMI-7000 and AMI-7001 respectively; the electrodialysis device 12 is connected with an MVR crystallization device 13; the particle size ranges of the substances removed by the self-cleaning filter, the ultrafiltration device and the nanofiltration cartridge filter are respectively more than 100 μm, more than 0.1 μm and more than 1 nm.

Specifically, a heater 14 and a nanofiltration cartridge filter 15 are further arranged between the weak acid cation exchange bed 8 and a group of nanofiltration high-pressure pumps 9.

Example two:

a working method of a device for concentrating and reducing desulfurization wastewater comprises the following steps:

step a: hardness removal of wastewater: the desulfurization wastewater is used as wastewater generated in the production process of a power plant, and hardness of the wastewater is removed by a double alkali method, an ultrafiltration device 6 and a weak acid cation exchange bed 8;

step b: and (3) secondary nanofiltration: separating salt from the desulfurized wastewater subjected to hardness removal through secondary nanofiltration, and directly removing the concentrated water from a flue spraying system;

step c: high-pressure reverse osmosis: the produced water after the second-stage nanofiltration is further concentrated by a high-pressure reverse osmosis device 11;

step d: electrodialysis: carrying out electrodialysis system on the concentrated water obtained by concentration, and further concentrating the concentrated water by the electrodialysis system;

step e: MVR evaporative crystallization: the concentrated water enters MVR for evaporation and crystallization to obtain NaCl finished salt and secondary wastewater;

step f: and (3) secondary circulation treatment: the secondary wastewater is treated by the lime dosing system 2 and the sodium bicarbonate dosing system 3 again and then flows into the high-density clarification tank 4, the wastewater in the high-density clarification tank 4 is cleaned and filtered by the self-cleaning filter 5 and then flows into the ultrafiltration device 6, and the wastewater is subjected to ultrafiltration treatment by the ultrafiltration device 6; and (3) the water treated by the ultrafiltration device 6 enters an ion exchange bed for hardness removal treatment after passing through a filter water tank 7, and the treatment is finished.

Specifically, the double alkali method is to add an alkaline chemical agent into the wastewater through a lime dosing system 2 and a sodium bicarbonate dosing system 3; in the two-alkali method, the dosage of calcium hydroxide is about 9 kg/ton water, and the dosage of sodium bicarbonate is about 1 kg/ton water.

And (3) comparing the conventional 2 x 330MW unit desulfurization wastewater treatment energy consumption data:

the above embodiments are merely illustrative of the present patent and do not limit the scope of the patent, and those skilled in the art can make modifications to the parts thereof without departing from the spirit and scope of the patent.

Claims

1. The utility model provides a device for concentrated decrement of desulfurization waste water which characterized in that: comprises a wastewater inlet pipe (1), a lime dosing system (2), a sodium bicarbonate dosing system (3), a high-density clarification tank (4), a self-cleaning filter (5), an ultrafiltration device (6), a filtration water tank (7), a weak acid cation exchange bed (8), a nanofiltration high-pressure pump (9), a two-stage nanofiltration device (10), a high-pressure reverse osmosis device (11), an electrodialysis device (12) and an MVR crystallization device (13); the wastewater inlet pipe (1) is communicated with a high-density clarification tank (4) through a water supply pipeline, a lime dosing system (2) and a sodium bicarbonate dosing system (3) are arranged on the water supply pipeline between the wastewater inlet pipe (1) and the high-density clarification tank (4), the high-density clarification tank (4) is communicated with a filtering water tank (7) through a self-cleaning filter (5) and an ultrafiltration device (6), and the filtering water tank (7) is communicated with a weak acid cation exchange bed (8); the weak acid cation exchange bed (8) is connected with a two-stage nanofiltration device (10) through a group of nanofiltration high-pressure pumps (9); the two-stage nanofiltration device (10) is connected with a high-pressure reverse osmosis device (11); the high-pressure reverse osmosis device (11) is connected with the electrodialysis device (12); the electrodialysis device (12) is connected with an MVR crystallization device (13).

2. The device for concentrating and reducing desulfurization waste water according to claim 1, wherein a heater (14) and a nanofiltration cartridge filter (15) are further disposed between the weak acid cation exchange bed (8) and a set of nanofiltration high-pressure pumps (9).