Desulfurization wastewater Zero discharge treatment method and system
Technical field
The invention belongs to the flue gases purification field, relate to the processing of flue gas that coal firing boiler discharges, the method for particularly a kind of wet desulphurization construction waste water zero release, and a kind of system.
Background technology
It is the country of main energy sources with coal that China is one, and coal fired power generation is one of most important approach of coal in China utilization.According to the national conditions of China, 21st century coal fired power generation will occupy an leading position.In numerous atmospheric polluting materials of coal-fired fired power generating unit discharging, SO
2And dust is bigger to the harm of environment, is the principal pollutant that will control.Along with the progress and the expanding economy of society, thermal power plant has been subjected to people's common concern to the pollution of atmospheric environment, and therefore effectively reducing pollutant emission is the severe challenge that China's energy field Sustainable development is faced with the influence that improves environment.
At present, existing flue gas desulfurization technique comprises wet desulphurization and dry desulfurization etc.The utilization of wherein wet desulphurization technology is the most extensive.Wet process of FGD is the technical process that current 85% left and right sides large thermal power plant in the world adopts.Wet method fume desulfurizing system waste water is because mercury, lead, nickel, arsenic and chromium heavy metal ion content are higher, and directly Pai Fang harm is very big, and the general chemistry treatment process is too complicated again, and needs constantly to add pharmaceutical chemicals, labor intensive.Waste water chlorion (still do not have chemical agent at present and can remove chlorion) after the desulfurization wastewater chemical treatment method is handled in addition still can't be removed.This desulfurization wastewater zero discharge treatment technology can be passed through the heating power method of evaporating, is fixed with harmful substances in conjunction with the use of electric precipitator, can make full use of the purpose that fume afterheat reaches zero release again.
Summary of the invention
In view of this, one of purpose of the present invention provides a kind of desulfurization wastewater Zero discharge treatment method, and it is simple that this method has technology, saves manpower, and the characteristics that need not to add any pharmaceutical chemicals and make full use of fume afterheat can realize zero release truly; Two of purpose of the present invention provides a kind of desulfurization wastewater zero discharge treatment system.
One of purpose of the present invention is achieved through the following technical solutions: this desulfurization wastewater Zero discharge treatment method may further comprise the steps:
1) will enter preliminary sedimentation tank through the desulfurization wastewater after the thionizer desulfurization, in preliminary sedimentation tank,, isolated upper clear supernate will be transported in the Buffer Pool through slush pump through initial gross separation;
2) with the desulfurization wastewater in the Buffer Pool successively by atomisation unit and electrostatic precipitator, the waste water after the atomizing is removed by electrostatic precipitator with flyash after the salinity crystallization in the waste water by the high-temperature flue gas heating evaporation in the electrostatic precipitator preceding pipeline;
3) preliminary sedimentation tank bottom solid content is bigger waste water is transported to the mud Buffer Pool through sludge pump, after the waste water that the solid content in the mud Buffer Pool is bigger mixes under agitator stirs, is transported to pressure filter through another sludge pump;
4) waste water after will filtering is sent back in the preliminary sedimentation tank through slush pump;
Further, also comprise step 5), with the filter mud outward transport after filtering;
Further, described step 2) in, desulfurization wastewater is forced into the atomizing nozzle atomizing by high-pressure pump, and described atomisation unit is the combination of high-pressure pump and atomizing nozzle.
Two of purpose of the present invention is achieved through the following technical solutions:
This desulfurization wastewater zero discharge treatment system comprises preliminary sedimentation tank, supernatant liquid treatment unit and lower floor's solid-liquid processing device; Described preliminary sedimentation tank inlet links to each other by the desulfurization wastewater inlet duct with the waste water pump of outside thionizer;
Described supernatant liquid treatment unit comprises Buffer Pool, spraying plant, mud Buffer Pool and pressure filter; Described Buffer Pool is connected by filtration unit with the top of preliminary sedimentation tank, and described atomisation unit links to each other with Buffer Pool by pipeline, and the high-temperature flue with inputing to after the atomizing of the waste water exported in the Buffer Pool before the fly-ash separator carries out high temperature evaporation by high-temperature flue.
Described lower floor solid-liquid processing device comprises mud Buffer Pool, pressure filter and agitator, and described mud Buffer Pool links to each other with preliminary sedimentation tank by pipeline, and the pipeline that both link to each other is provided with sludge pump; Be furnished with agitator in the described mud Buffer Pool; Described pressure filter links to each other with the mud Buffer Pool by pipeline, is furnished with sludge pump on the pipeline that links to each other, and is connected by the pipeline that is provided with slush pump II between described pressure filter and the preliminary sedimentation tank, and filtering clear water is drawn back to preliminary sedimentation tank through slush pump II.
Described filtration unit is to be arranged on the strainer I on the connecting pipe between Buffer Pool and the preliminary sedimentation tank, and the rear portion pipeline of described strainer I is provided with slush pump I, and the inlet of slush pump I is arranged in the top of preliminary sedimentation tank;
As the another kind of design of filtration unit, described filtration unit is a filtering net, passes through filtering net between the top of described preliminary sedimentation tank and the Buffer Pool at interval;
Further, described spraying plant comprises atomizing nozzle and high-pressure pump, by high-pressure pump the waste water in the Buffer Pool is forced in the atomizing nozzle that is arranged on the anterior flue entrance of fly-ash separator to atomize;
Further, the pipeline between described high-pressure pump and the Buffer Pool is provided with strainer II;
Further, the official road between described high-pressure pump and the atomizing nozzle is provided with well heater;
Further, the size droplet diameter 50 ~ 200um of described atomizing nozzle.
The invention has the beneficial effects as follows:
By system of the present invention very easily desulfurization wastewater carry out zero discharge treatment, and technology is simple, does not need to use any pharmaceutical chemicals, saves manpower;
2. make full use of fume afterheat, evaporate the heavily contaminated desulfurization wastewater fully, and improve the humidity before ash-laden gas enters fly-ash separator, help improving the dust removing effects of fly-ash separator;
3. system architecture compactness of the present invention, method is implemented simple, and can realize desulfurization wastewater zero release truly, and not only environmental protection but also safety have promotional value.
Other advantages of the present invention, target and feature will be set forth to a certain extent in the following description, and to a certain extent, based on being conspicuous to those skilled in the art, perhaps can obtain instruction from the practice of the present invention to investigating hereinafter.Target of the present invention and other advantages can realize and obtain by following specification sheets and claims.
Description of drawings
In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing, wherein:
Fig. 1 is the system architecture synoptic diagram of the embodiment of the invention one;
Fig. 2 is the structural representation of the embodiment of the invention two.
Embodiment
Hereinafter with reference to accompanying drawing, the preferred embodiments of the present invention are described in detail.Should be appreciated that preferred embodiment only for the present invention is described, rather than in order to limit protection scope of the present invention.
Embodiment one
As shown in Figure 1, desulfurization wastewater zero discharge treatment of the present invention system comprises preliminary sedimentation tank 2, supernatant liquid treatment unit and lower floor's solid-liquid processing device; Described preliminary sedimentation tank 2 inlets link to each other by desulfurization wastewater inlet duct 1 with the waste water pump of outside thionizer;
The structure of preliminary sedimentation tank comprises the top of a column and is connected the bottom of the similar funnel of below an upper section, and wherein, top is to be used for holding isolating clear liquid, and the bottom is used for holding contains the more turbid liquid of solid matter because of gravity settling is isolating.
The supernatant liquid treatment unit comprises Buffer Pool 5, spraying plant, mud Buffer Pool 12 and pressure filter 15; Described Buffer Pool 5 links to each other by slush pump I 4 with preliminary sedimentation tank 2, and the inlet of slush pump 4 is arranged in the top of preliminary sedimentation tank 2; Atomisation unit links to each other with Buffer Pool 5 by pipeline, inputs to the high-temperature flue before the fly-ash separator 10 after the waste water atomizing with output in the Buffer Pool 5, carries out high temperature evaporation by high-temperature flue; In the present embodiment, spraying plant comprises atomizing nozzle 9 and high-pressure pump 7, the waste water in the Buffer Pool 5 is forced into atomizing in the atomizing nozzle 9 that is arranged on fly-ash separator 10 anterior flue entrances by high-pressure pump 7.
Lower floor's solid-liquid processing device comprises mud Buffer Pool 12, pressure filter 15 and agitator 13, and described mud Buffer Pool 12 links to each other with preliminary sedimentation tank 2 by pipeline, and the pipeline that both link to each other is provided with sludge pump 11; Be furnished with agitator 13 in the mud Buffer Pool 12; Described pressure filter 15 links to each other with mud Buffer Pool 12 by pipeline, is furnished with sludge pump 14 on the pipeline that links to each other, and is connected by the pipeline that is provided with slush pump II 16 between described pressure filter and the preliminary sedimentation tank, and filtering clear water is drawn back to preliminary sedimentation tank 2 through slush pump II 16.
As further improvement, effusive clear liquid impurity still less is furnished with strainer I 3 in the Buffer Pool on the anterior pipeline of slush pump I 4 in order to make.
As further improvement, the impurity that contains in the clear liquid is further reduced, more help next step evaporation, the pipeline between high-pressure pump 7 and the Buffer Pool is provided with strainer II 6.
As further improvement, in order further to improve evaporation effect, the pipeline between high-pressure pump and the atomizing nozzle is provided with well heater 8, is used for clear liquid is shifted to an earlier date preheating.
As further improvement, in order to satisfy the requirement of high temperature evaporation institute's heat requirement and reusing of energy source, fly-ash separator 10 anterior flue entrances are connected with outside air preheater, to utilize the flue gas that sends from air preheater.
As further improvement, the size droplet diameter 50 ~ 200um of described atomizing nozzle is preferably 150 um, and arranges at the flue wall, can reduce cost.
Embodiment two
As shown in Figure 2, present embodiment is with the difference of embodiment one: the structure of filtration unit is different.
In the present embodiment, filtration unit is a filtering net 17, passes through filtering net between the top of preliminary sedimentation tank 2 and the Buffer Pool at interval.The benefit of this mode is to have saved a slush pump, and cost is reduced.Being suitable for the less occasion of treatment capacity uses.
Based on the above system, desulfurization wastewater Zero discharge treatment method of the present invention may further comprise the steps:
1) will enter preliminary sedimentation tank through the desulfurization wastewater after the thionizer desulfurization, through initial gross separation, disengaging time is 3 ~ 5 minutes, and isolated upper clear supernate is transported in the Buffer Pool through slush pump in preliminary sedimentation tank;
2) with the desulfurization wastewater in the Buffer Pool successively by atomisation unit and electrostatic precipitator, the waste water after the atomizing is removed by electrostatic precipitator with flyash after the salinity crystallization in the waste water by the high-temperature flue gas heating evaporation in the electrostatic precipitator preceding pipeline; In actual use, desulfurization wastewater is forced into the atomizing nozzle atomizing by high-pressure pump, and described atomisation unit is the combination of high-pressure pump and atomizing nozzle.
3) preliminary sedimentation tank bottom solid content is bigger waste water is transported to the mud Buffer Pool through sludge pump, after the waste water that the solid content in the mud Buffer Pool is bigger mixes under agitator stirs, is transported to pressure filter through another sludge pump;
4) waste water after will filtering is sent back in the preliminary sedimentation tank through slush pump.
5) outward transport of the filter mud after will filtering.
Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the aim and the scope of the technical program, it all should be encompassed in the middle of the claim scope of the present invention.