CN206476848U - A kind of desulfurization wastewater zero-discharge treatment system - Google Patents

Abstract

The utility model discloses a kind of desulfurization wastewater zero-discharge treatment system, including regulation sedimentation basin, three headers, clarifier and the nanofiltration device being sequentially connected, the concentrated water port of export of nanofiltration device is connected with atomizer, and atomizer sprays into concentrated water in flue；Three header includes neutralization case, reaction chamber and the flocculation tanks being sequentially connected, wherein, the delivery port for neutralizing case with the regulation sedimentation basin is connected, the pH value for adjusting desulfurization wastewater, to remove the bicarbonate radical in desulfurization wastewater；There is provided the reaction chamber for removing the calcium ion sum in desulfurization wastewater for reaction chamber；Flocculation tanks are connected with the clarifier.The medicament expense use for removing magnesium ion in desulfurization wastewater is eliminated by the utility model, sludge quantity is reduced, reduces operating cost, not using milk of lime, improves field working conditions.The utility model realizes the recovery of desulfurization wastewater sodium chloride salt, reduces fixed-end forces expense, and generate certain economic benefit by will be crystallized in waste water after sodium chloride salt purification.

Description

A kind of desulfurization wastewater zero-discharge treatment system

Technical field

The utility model is related to field of industrial waste water treatment, and in particular to arranged outside a kind of heat-engine plant wet flue gas desulphurization system The zero-discharge treatment system of desulfurization wastewater.

Background technology

Desulfurization wastewater originates from wet method fume desulfurizing system, current flue gas desulphurization it is most widely used be lime stone-stone Cream wet process of FGD, in order to maintain the balance of desulfurizer serum recycle system material, prevents desulfurization slurry chlorine ion concentration More than setting and guarantee gypsum quality, it is necessary to discharge a certain amount of waste water from system.Desulfurization wastewater pH4~6, also have big Suspension (gypsum, silica) is measured, salt content is high, mainly contains the salts such as sodium chloride, sulfate and sulphite, and calcium Magnesium ion content is very high.

At present, conventional desulfurization wastewater zero discharge treatment technology, mainly have chemical tendering+counter-infiltration+evaporator, clarification+ Flue evaporates.In order to avoid fouling, it is necessary to control calcium-magnesium content to be less than 100mg/L in evaporator running, desulfurization wastewater contains There are a large amount of calcium and magnesiums, it is therefore desirable to which water demineralization is handled, the process needs to consume substantial amounts of chemical agent precipitation calcium ions and magnesium ions, and production Raw substantial amounts of sludge, sludge heavy-metal content overproof belongs to dangerous waste, it is necessary to transport outward landfill disposal, overall operation cost is very high.Cigarette Road evaporation is that by high-pressure pump desulfurization wastewater is forced into atomizer, and the waste water after atomization enters in the flue of steam power plant, profit With high-temperature flue gas by waste water heating evaporation, water evaporation turns into quiet with flyash after the salt crystallization in a part for flue gas, waste water Electric cleaner is removed, the part as flyash, and the substantial amounts of chlorion in waste water also enters in flyash.Flyash is main For concrete, cement industry, the relevant criterion of concrete and cement industry《GBT 1596-2005 are used for cement and concrete In flyash》、《JGJ55-2011 design of common concrete proportioning codes》Content requirement to chlorion is very strict, takes off Sulphur waste water directly can influence the quality of flyash using flue evaporation technology, be allowed to cannot be used for the industries such as concrete, cement, only Energy landfill disposal, causes the waste of resource.In addition, desulfurization wastewater is in acidity, and containing a large amount of chlorions, when evaporating incomplete, Corrosion is easily caused under hot conditions to flue.

Utility model content

In order to solve technical problem present in above-mentioned prior art, a purpose of the present utility model is to provide a kind of Desulfurization wastewater zero-discharge treatment system, can be to desulfurization wastewater zero discharge treatment, and can reduce the medicine in wastewater treatment process Agent expense and the pollution for avoiding flyash, and then reduce the processing cost of contaminated flyash.

Another purpose of the present utility model is to provide a kind of processing method of desulfurization wastewater zero-emission.

For up to above-mentioned purpose, the utility model is adopted the following technical scheme that：

A kind of desulfurization wastewater zero-discharge treatment system, including be sequentially connected regulation sedimentation basin, three headers, clarifier and receive Filter, the concentrated water port of export of nanofiltration device is connected with atomizer, and atomizer sprays into concentrated water in flue；

Three header includes neutralization case, reaction chamber and the flocculation tanks being sequentially connected, wherein, neutralize case and the regulation is heavy The delivery port connection in shallow lake pond, the pH value for adjusting desulfurization wastewater, to remove the bicarbonate radical in desulfurization wastewater；

There is provided remove the calcium ion in desulfurization wastewater and the reaction chamber of heavy metal ion for reaction chamber；

Flocculation tanks are connected with the clarifier.

Herein, regulation sedimentation basin provides the space that desulfurization wastewater is stopped, and desulfurization wastewater is stopped in regulation sedimentation basin After a period of time, on the one hand, the most suspended substances in waste water precipitate so that enter and contain in the desulfurization wastewater in three headers Some suspension reductions, and then reduce the precipitation capacity produced in three headers, it is to avoid follow-up equipment is because precipitation is excessive and blocks.This Outside, desulfurization wastewater suspension object amount is high, but particle is tiny, and main component is dust and desulfurization product (CaSO₄And CaSO₃), if will not Precipitate the CaSO in clarifying treatment, suspension₄And CaSO₃Can be with the sodium carbonate added in softening process (in order to remove calcium ion) Reaction, increases sodium carbonate consumption, increases cost for wastewater treatment.

On the other hand, desulfurization wastewater is that desulphurization system slurries reach and discharged after finite concentration, and specific discharge process is It is intermittent, there is a situation where that water quality is unstable, desulfurization wastewater is various in different quality in regulation sedimentation basin holding process Ion spreads, and stops after setting time, and the water quality in regulation sedimentation basin tends to be uniform.After water quality is uniform, into follow-up When equipment is handled, the sludge quantity of generation tends to be uniform, and the load of follow-up equipment reaches unanimity, and will not cause excessive to equipment Impact, extend the service life of equipment, and improve desulfurization wastewater treatment effect.

Three headers, for the neutralization case, reaction chamber and flocculation sediment case being sequentially connected.Desulfurization wastewater contains big in acidity The calcium bicarbonate and magnesium bicarbonate of amount, calcium bicarbonate and magnesium bicarbonate solubility are very big, and will not be in the organic sulfur subsequently added Removed with the presence of sodium carbonate, and can collect in after nanofiltration clear water side, into evaporator heat resolve into carbonic acid Calcium and magnesium carbonate, the precipitation of formation are attached to the surface of evaporator, influence heat exchange efficiency.It is therefore desirable to be added in case is neutralized Alkaline matter, removes the bicarbonate ion in desulfurization wastewater.

Nanofiltration is a kind of pressure-driven membrane separating process between counter-infiltration and ultrafiltration, is with Selective Separation work( The material of energy.Core texture in nanofiltration device is NF membrane, it is possible to achieve Selective Separation.

Herein, the desulfurization wastewater of heavy metal ion and calcium ion is removed, after flocculation, precipitation clarification, by receiving The materials such as the sodium chloride that the materials such as magnesium sulfate, sodium sulphate in filter, waste water are collected in concentrated water side, waste water collect in clear water side, Concentrated water is atomized in the presence of atomizer in flue, and the vapor that water evaporation is produced turns into a part for flue gas, finally de- Sulphur system is cooled into a part for desulfurization moisturizing.Removed, turn into by electrostatic precipitator with flyash after salt crystallization in waste water A part for flyash.

Because magnesium ion can collect in concentrated water side after nanofiltration, and flyash is not limited the content of magnesium ion, So, in three Header portions of the utility model process system, without the magnesium ion in desulfurization wastewater is removed, it is only necessary to by calcium Ion is removed.In the case where magnesium ion need not be removed, can only it be added by way of controlling desulfurization wastewater pH value Precipitating reagent removes calcium ion, greatly reduces the addition of precipitating reagent, reduces cost for wastewater treatment.

Due to there is no chlorion in concentrated water, so the chloride ion content in the flyash formed is less, will not be exceeded, obtain Flyash can be used for preparing the materials such as concrete and cement, be effectively utilized resource, it is to avoid the waste of resource.Moreover, If sprayed into the concentrated water in flue containing a large amount of chlorions, if concentrated water is evaporated not exclusively, under the high temperature conditions in flue Corrosion is easily caused to flue, the chlorion in concentrated water is removed completely herein by nanofiltration, can avoid causing corruption to flue Erosion, extends the service life of flue.

Meanwhile, nanofiltration can remove the ion of the easy fouling in desulfurization wastewater, make evaporator in evaporation process not Fouling is easily produced, the service life of evaporator is extended.And the purity of the sodium chloride contained in the clear water after nanofiltration Higher, the sodium chloride produced by evaporative crystallization is easily purified, and is sold outside the sodium chloride after purification, can bring certain warp Ji benefit.

Flocculation, makes suspended particulates collection fusion in water or liquid big, or forms floc sedimentation, so as to accelerate the coagulation of particle, reaches The purpose of solid- liquid separation, this phenomenon or operation, which are referred to as, flocculates.Generally, the implementation of flocculation is by adding appropriate flocculant, and it is made With being adsorbent particles, between particulate " bridge formation ", so as to promote to gather.Flocculation tanks, being just to provide a kind of equipment of flocculation, there is provided appearance Receive the chamber of liquid, add in a liquid after flocculant, the suspension in liquid is gathered precipitation.

Clarifier is a kind of device for unifying the quick mixing of the medicaments such as water and flocculating agent, coagulation, three kinds of processes of precipitation, The device for the process for realizing precipitation can singly be referred to herein, waste water has been realized in the mixing and coagulation with medicament in three headers Process.

Atomization, is to make liquid dispersion into the operation of fine droplet by nozzle or with high velocity air.Atomizer is can be with Realize the device of atomization.The method of liquid atomization has pressure atomization, rotary disk atomisation, gas atomization, sound wave atomization etc., herein In, as long as realizing atomization of the concentrated water in flue, restricted without the structure to atomizer.

Flue is that flame and cigarette are sent to the duct of exterior space in chimney, because flue gas has higher temperature, can be with The concentrated water being atomized in flue is heated, makes the rapid carburation by evaporation of small water droplet after atomization, obtained moisture conduct is evaporated The supply of moisture in flue gas, due to adding the humidity of flue gas, the de- of deduster is easy in the cohesion for the ash content being easy in flue gas Remove.The salt of evaporative crystallization is attached on cigarette ash, after removing dust device dedusting, the part as flyash.

It is preferred that, it is connected with ultrafilter between the clarifier and nanofiltration device.

Ultrafiltration is one of membrane separation technique using pressure as motive force, for the purpose of the separation of macromolecular and small molecule, film Aperture size is substantially between 1.5 nanometers to 0.2 micron, and it filters the pressure differential that power is liquid, and filtration mechanism is by film Hole sizer is separated except effect.The core parts of ultrafilter are milipore filter, it is possible to achieve ultrafiltration, to the desulfurization wastewater after clarification Ultrafiltration is carried out, part big molecular impurity is removed, reduces the load of subsequent nano-filtration process, extends the service life of nanofiltration device.

It is further preferred that being also associated with pH value regulating box between the ultrafilter and nanofiltration device.

PH value regulating box, is body structure, it is understood that be tank structure, and basic structure is tank body, water inlet and gone out The mouth of a river, the desulfurization wastewater after ultrafiltration is entered in tank body by water inlet, by adding acid in the desulfurization wastewater into tank body Matter, to adjust the pH value of desulfurization wastewater, after regulation is finished, desulfurization wastewater flows into nanofiltration device by delivery port and carries out nanofiltration.

Although by controlling the pH value of desulfurization wastewater to be 9.6 or so, can only precipitate calcium ion, and prevent magnesium hydroxide Separate out, but the pH value of desulfurization wastewater it is too high when, after nanofiltration is concentrated, the fouling tendency of magnesium, magnesium ion fouling meeting can be increased Can all have a negative impact to nanofiltration device, concentrated water conveyance conduit and atomizer.So, adjusted in the upstream increase pH value of nanofiltration device Case is saved, the pH value of regulation desulfurization wastewater is faintly acid, it is to avoid the fouling of magnesium ion is separated out.

It is preferred that, nanofiltration concentrated water case is connected between the concentrated water port of export and atomizer of nanofiltration device.

Nanofiltration concentrated water case is conventional tank, after concentrated water is stored, then carries out atomization process, it is ensured that atomization process Continuity.

It is preferred that, the clear water output end of the nanofiltration device is connected with evaporator.

Clear water is crystallized through evaporator evaporation, realizes the zero-emission of desulfurization wastewater, at the same the sodium chloride to crystallization reclaimed, Purifying, sale, can obtain certain economic benefit.

It is preferred that, nanofiltration filtered water tank is connected between the clear water output end of the nanofiltration device and evaporator.

Nanofiltration filtered water tank is conventional tank, is that storage effect is played to the clear water after nanofiltration.

It is further preferred that being connected with reverse osmosis unit between the nanofiltration filtered water tank and evaporator.

Counter-infiltration be it is a kind of bring pressure to bear on the concentrate solution that pellicle is in contact, produced and naturally osmotic phenomenon phase Anti- process.Inorganic salts, organic impurities, bacterium and virus that can be used in further removing clear water etc., enters clear water One step is purified.Chlorine in Solution sodium by counter-infiltration has higher purity, the sodium chloride obtained by evaporative crystallization it is pure Du Genggao, it is possible to reduce the purifying cost of sodium chloride.

It is preferred that, connect having heaters on the pipeline between the concentrated water port of export and atomizer of nanofiltration device.

If the temperature of concentrated water is too low, after concentrated water is atomized in flue, heat absorption evaporation process needs the regular hour, if Not in time, liquid is dropped in flue inner wall for evaporation, easily produces certain corrosiveness to flue inner wall under high temperature action. Heater is connected on pipeline between the concentrated water port of export and atomizer, concentrated water can be heated to higher temperature, into flue After atomization, it can be crystallized with rapid evaporation, it is to avoid corrosion to flue inner wall.

It is further preferred that the heater is tubular heat exchanger.

It is a kind of during tubular heat exchanger to apply wider heat exchanger, mainly by housing, tube sheet, heat exchanger tube, end socket and baffling The structure compositions such as plate, heat exchanger is prepared from titanium.Thermal source uses steam, and steam walks shell side, and concentrated water walks tube side, and concentrated water is carried out Heating.

A kind of processing method of desulfurization wastewater zero-emission, comprises the following steps：

Desulfurization wastewater adds alkaline matter after preformed precipitate, balanced water quality, and regulation pH value is 8-8.5, removes desulfurization and gives up Bicarbonate ion in water；Then precipitating reagent is added into desulfurization wastewater, the pH value of control desulfurization wastewater is no more than 9.6, gone Except the heavy metal ion and calcium ion in desulfurization wastewater；Desulfurization wastewater by flocculation, precipitation clarification, after nanofiltration, what nanofiltration was produced Concentrated water is sprayed into flue, and the salt produced after moisture evaporation is attached on ash content, and flyash is formed through trapping.

Requirement of the N-process to pH value is very strict, and when pH value is more than 9.6, the precipitation for having magnesium hydroxide is formed, due to Magnesium ion need not be removed in technique of the present utility model, after magnesium ion formation precipitation is removed, carrying for cost for wastewater treatment can be caused The waste of high and resource, it is therefore desirable to which the strictly pH value of control desulfurization wastewater, makes magnesium ion be retained in desulfurization wastewater, to drop The cost of low wastewater treatment.

It is preferred that, the preformed precipitate, the time of balanced water quality are 6-9h.

Preformed precipitate, balanced water quality reached after time enough, can be by the suspension in desulfurization wastewater, oversaturated sulfurous Hydrochlorate and sulfate precipitation, remove, reduce the sludge quantity produced in lower procedure.The water quality of desulfurization wastewater can also be made more Uniformly, make the load of follow-up equipment uniform, the service life of extension device.

It is preferred that, the alkaline matter is sodium hydroxide.

The alkaline matter of traditional regulation desulfurization wastewater pH value is milk of lime, i.e. calcium hydroxide, and calcium hydroxide is in addition During easily cause the unstable of concentration and flow, it is not easy to realize the accurate control to desulfurization wastewater pH value, and add Excessive calcium hydroxide can increase the calcium ion concentration in desulfurization wastewater, it is necessary to consume more precipitating reagent, cause wastewater treatment The raising of cost.And during dosing, the concentration and flow of sodium hydroxide are stable, desulfurization wastewater pH value is easily realized Accurate control, moreover, the sodium hydroxide added will not consume precipitating reagent, the usage amount of medicament can be saved to greatest extent, saved The cost of wastewater treatment.

It is preferred that, the precipitating reagent is organic sulfur and sodium carbonate.

Inorganic sulfur and organic sulfur may be used to remove the heavy metal ion in desulfurization wastewater, but add inorganic sulphide Sulfide in water and sulfate can be made exceeded, easily environment is caused harm.

Organic sulfur is a kind of sulfur-containing compound, and it can be concurrent biochemical anti-by sulfur family and heavy metal ion stable bond Should, the stable organo-metallic compound of formation is not readily dissolved, and solid precipitation, and then the removing that is separated are formed in water.It is almost All heavy metals can be adsorbed, in the treatment of waste water, the residual heavy metal of all dissolvings can be just removed by simply handling, And metal-sediment has good temperature stability, heavy metal is difficult to be re-released into environment, is environment-friendly Heavy metal chelating agent.And, the toxicity of organic sulfur is very low, with good storage stability and processing safety, is not belonging to danger Article, no bad smell, does not decomposite noxious material.

Sodium carbonate can provide the carbanion for removing calcium ion, and dissolution of calcium carbonate degree is smaller than magnesium carbonate, so First precipitate, and the addition of sodium carbonate will not introduce foreign ion.

It is preferred that, the flocculant is FeCl₃, flocculation aid is polyacrylamide.

Flocculant can totally be divided into inorganic flocculating agent and the class of organic flocculant two according to its chemical composition, wherein, inorganic wadding Solidifying agent includes inorganic flocculant and inorganic polymer flocculant again；Organic flocculant again include Syn-Organic flocculants, Natural organic high-molecular flocculant and microbial flocculant.

Theoretical foundation is：" coalescence " is theoretical, and flocculant is mainly negative with being carried in just (negative) electrical group and water (just) electrical some particles or particle for being difficult to separation are close to each other, reduce its potential, are at unstable state, and Using its aggregation property these particles are concentrated, and separated by physics or chemical method.

Flocculation aid, for when coagulant is used alone and can not attain the results expected, it is necessary to add certain assistant medicament to carry The medicament of high coagulation effect.

Herein, flocculant and flocculation aid are used cooperatively, and can faster improve the coagulative precipitation of suspension in desulfurization wastewater Effect.Flocculant is iron chloride, and flocculation aid is polyacrylamide, the suspension in water is turned into floccule, and is easy to precipitate, It is easy to the separation of solid and liquid of water and sludge.

It is preferred that, also include adding acidic materials into desulfurization wastewater before the nano-filtration step, given up with adjusting desulfurization The pH value of water is weakly acidic step.

It is further preferred that the acidic materials are hydrochloric acid solution.

Still more preferably, while adding acidic materials into desulfurization wastewater, desulfurization wastewater is aerated.

Aeration refers to artificially be passed through air into clear water reserviors by appropriate equipment, with up to the purpose of Expected Results.Herein Aeration on the one hand by increasing the dissolved oxygen in desulfurization wastewater, with the purpose for the COD for reducing desulfurization wastewater；On the other hand, lead to Desulfurization wastewater is moved in overexposure gas mixing, makes the mixed in hydrochloric acid that is added in desulfurization wastewater uniform, balanced water quality, it is to avoid local ph it is too high or It is too low.Aerator is the structure for realizing aeration, and it should at least include housing, and housing surrounds hollow chamber, the opening of housing Place is connected with blower fan, more through hole is distributed on housing, blower fan is delivered air in chamber, is bypassed air through logical in chamber Hole enters in filtered water tank.

Still further preferably, the air water volume ratio of aeration is 15-20:1.

It is preferred that, the clear water that nanofiltration is produced carries out evaporative crystallization after counter-infiltration.

It is further preferred that the temperature of evaporative crystallization is 80-85 DEG C.

Due to enter evaporator in clear water in chlorion concentration it is larger, when the temperature of evaporative crystallization is higher, chlorine from Son is larger to the corrosiveness of equipment, so, on the premise of evaporation efficiency is ensured, it should suitably reduce evaporating temperature.At this At a temperature of, it can effectively slow down corrosion of the chlorion to equipment, while evaporation efficiency can be ensured.

It is preferred that, the step of above-mentioned processing method also concentrated water including nanofiltration is produced sprays into flue after being heated.

Still more preferably, the temperature after concentrated water is heated is 95-100 DEG C.

The beneficial effects of the utility model are：

1st, the utility model is to desulfurization wastewater after precipitation, clarification, nanofiltration, and chlorion collects in clear water side, by nanofiltration The concentrated water of generation is sprayed into flue, and chloride ion content will not be exceeded in the flyash that collection is obtained, it is ensured that the matter of flyash Amount.And the limitation in flyash not to magnesium ion content, so in desulfurization wastewater precipitation process, without entering to magnesium ion Row precipitation, eliminates the medicament expense use for removing magnesium ion in desulfurization wastewater, reduces sludge quantity, reduce operating cost, do not have Using milk of lime, improve field working conditions.

2nd, concentrated water is evaporated crystallization by the utility model using flue gas residual heat, and humidification can be to coal-fired flue-gas flying dust Effectively reunited, particle is easier to be trapped by electrostatic precipitator.Particulate matter takes off after reuniting to improving routine intravenous electric cleaner Except the ability of fine particulates is obviously improved, the degree of purification of flue gas is improved.

3rd, the utility model realizes returning for desulfurization wastewater sodium chloride salt by will be crystallized in waste water after sodium chloride salt purification Receive, reduce fixed-end forces expense, generate certain economic benefit.

Brief description of the drawings

Fig. 1 is flowage structure schematic diagram of the present utility model.

Wherein：1st, sedimentation basin is adjusted, 2, neutralize case, 3, reaction chamber, 4, flocculation tanks, 5, clarifier, 6, ultrafilter, 7, pH adjusts Save case, 8, nanofiltration device, 9, nanofiltration concentrated water case, 10, atomizer, 11, nanofiltration filtered water tank, 12, reverse osmosis unit, 13, evaporator.

Embodiment

With reference to the accompanying drawing in the utility model example, the technical scheme in the utility model embodiment is carried out clear Remove, be fully described by, it is clear that described embodiment is only a part of embodiment of the utility model, rather than whole realities Apply example.Based on the embodiment in the utility model, those of ordinary skill in the art institute under the premise of creative work is not made The every other embodiment obtained, belongs to the scope of the utility model protection.

The utility model is described in further detail with reference to the accompanying drawings and examples, as shown in figure 1, its specific work Skill is as follows：

(1) desulfurization wastewater enters regulation sedimentation basin 1, and the residence time is 6h, balanced waste water quality, under gravity will be useless Suspension, oversaturated sulphite, sulfate precipitation in water.

(2) neutralization case 2 is then sent to, the pH of desulfurization wastewater is adjusted to 8.0-8.5, water is from flowing to reaction chamber 3, to anti- Answer and organic sulfur and sodium carbonate are added in case 3, the pH of control reaction chamber 3 is no more than 9.6, neutralize case 2 and the bottom of reaction chamber 3 is provided with pH Meter, once water quality is more than 9.6, plus alkali pump just stops dosing, and pH opens dosing less than 8.The water outlet of reaction chamber 3 gravity flow enters flocculation tanks 4, add flocculant FeCl to flocculation tanks 4₃With flocculation aid polyacrylamide, waste water small particles are made to be easy to sedimentation.

(3) after the clarified device 5 of desulfurization wastewater of above-mentioned steps processing is clarified, ultrafilter 6 filters, into pH regulating boxs 7, throw Plus hydrochloric acid, while being aerated, the gas-water ratio of aeration is 15-20:1, the pH value of desulfurization wastewater is adjusted to 6, and water outlet is pumped to Nanofiltration device 8 carries out nanofiltration, and the clear water that nanofiltration is obtained is stored into nanofiltration filtered water tank 11, and obtained concentrated water enters nanofiltration concentrated water case 9 Storage.

(4) after desulfurization wastewater is handled through nanofiltration, magnesium sulfate, sodium sulphate are collected to the concentrated water in concentrated water side, nanofiltration concentrated water case 9 In the flue that steam power plant is sprayed into through atomizer 10, water evaporation, which turns into vapor, turns into a part for flue gas, finally in desulphurization system A part for desulfurization moisturizing is cooled into, salt is divided into little particle absorption on cigarette ash, handled through electric dust collector, as fine coal A part for ash.

Having heaters is set on the pipeline that nanofiltration concentrated water is exported between flue vaporising device, and heater exchanges heat for shell and tube Device, heat exchanger selects titanium, and thermal source uses steam, and steam walks shell side, and concentrated water walks tube side.Desulfurization wastewater is heated to 95-100 DEG C, waste water is directly vaporized into flue, it is to avoid form droplet erosion flue.

(5) evaporator 13 is entered after the clear water in nanofiltration filtered water tank 11 is concentrated through reverse osmosis unit 12, final distilled water is returned With selling processing outside crystal salt.

Evaporator 13 selects MVR evaporators, and waste water evaporating temperature is 80-85 DEG C, and compressor selects centrifugal compressor, herein At a temperature of can effectively slow down chlorion to the corrosion of equipment while taking into account evaporation efficiency.Evaporative condenser Water circulation, realizes desulfurization The zero discharge treatment of waste water.

By taking a Practical Project as an example, the power plant desulfurization wastewater water is 10t/h, and part water quality parameter is as follows：PH value 4-6, Ca²⁺1600mg/L, Mg²⁺2500mg/L, HCO₃ ^-260mg/L, Cl^-10000mg/L, SO₄ ^2-12000mg/L。

Desulfurization wastewater, average water 10m are discharged in desulphurization system not timing³/h.Desulfurization wastewater enters regulation sedimentation basin, stops Time is 6h, balanced waste water quality, and the suspension in waste water, oversaturated sulphite, sulfate sink under gravity Form sediment.Supernatant liquor is delivered to neutralization case with pump, and sodium hydroxide solution is added to case is neutralized using measuring pump, neutralizes case and is provided with pH Meter monitoring water quality, pH opens sodium hydroxide measuring pump less than 8, and pH closes sodium hydroxide measuring pump higher than 8.5.Neutralize case water outlet certainly Stream enters reaction chamber, and sodium carbonate and organic sulfur are added in reaction chamber, sets pH meter to monitor water quality in reaction chamber, and pH is opened higher than 9 Sodium carbonate dosing is opened, pH closes sodium carbonate chemicals dosing plant higher than 9.5.Desulfurization wastewater after softening is through flocculation sediment, ultrafiltration apparatus Turbidity, which is down to, after filtering can enter NF membrane standard.

It is 6 that the desulfurization wastewater of above-mentioned steps processing is adjusted to pH value into pH regulating boxs.Fouling tendency is further reduced, is passed through Effect balancing water quality is aerated, waste water COD is down within 60, gas-water ratio is 15：1.

Then nanofiltration system is entered through high-pressure pump, after nanofiltration point salt, nanofiltration concentrated water water is 3.5m³/ h, nanofiltration clear water Water is 6.5m³/h.Use steam for thermal source, nanofiltration concentrated water is through 50m³Pipe heat exchanger be heated to after 95~100 DEG C, enter Flue vaporising device is pressurizeed, atomization process, and flue is sprayed into afterwards.Water evaporation, which turns into vapor, turns into a part for flue gas, most Be cooled into a part for desulfurization moisturizing in desulphurization system eventually, salinity crystallization turn into little particle with cigarette ash through electric dust collector at Reason, the part as flyash.The salinity of nanofiltration clear water is mainly sodium chloride, and clear water evaporates into reverse osmosis membrane concentration+MVR Crystal system.Vapo(u)rization system designed rating is 3t/h, and vaporising device is provided with temperature sensor, and temperature stops supplement higher than 85 DEG C Live steam, less than 80 DEG C supplement live steams, evaporating temperature is controlled at 80~85 DEG C.Final distillation Water circulation, sodium chloride salt Sell processing outside.

The amount of sodium hydroxide that whole desulfurization wastewater processing procedure is added is 180mg/L, common process (chemical tendering+reverse osmosis Thoroughly+evaporator handling process) milk of lime 8000mg/L need to be added, counted with 2000 yuan/t of sodium hydroxide unit price, 550 yuan/t of lime, Organic sulfur saves 44 yuan/h of medicament expense in terms of 8000 yuan/t of unit price.Reduction sludge quantity is to sell processing outside 0.1t/h, such as sludge, is pressed 2000 yuan/t of handling is counted, and needs 200 yuan/h of processing cost.Part water evaporates into flue, and flue evaporation operation power is only 3KW, while more conventional technique reduces MVR evaporator evaporation amount 3.5t/h, reduces 70 yuan/h of evaporation operating cost.It is total to save 314 yuan/h of expense.It can be seen that, method economic benefit of the present utility model is fairly obvious.

Although above-mentioned embodiment of the present utility model is described with reference to accompanying drawing, not to utility model The limitation of protection domain, one of ordinary skill in the art should be understood that on the basis of the technical solution of the utility model, this area Technical staff need not pay the various modifications that creative work can make or deform still in protection domain of the present utility model It is interior.

Claims (9)

1. a kind of desulfurization wastewater zero-discharge treatment system, it is characterised in that：Including the regulation sedimentation basin being sequentially connected, three headers, Clarifier and nanofiltration device, the concentrated water port of export of nanofiltration device are connected with atomizer, and atomizer sprays into concentrated water in flue；

Three header includes neutralization case, reaction chamber and the flocculation tanks being sequentially connected, wherein, neutralize case and the regulation sedimentation basin Delivery port connection, the pH value for adjusting desulfurization wastewater, to remove the bicarbonate radical in desulfurization wastewater；

There is provided remove the calcium ion in desulfurization wastewater and the reaction chamber of heavy metal ion for reaction chamber；

Flocculation tanks are connected with the clarifier.

2. processing system according to claim 1, it is characterised in that：Ultrafiltration is connected between the clarifier and nanofiltration device Device.

3. processing system according to claim 2, it is characterised in that：PH is also associated between the ultrafilter and nanofiltration device It is worth regulating box.

4. processing system according to claim 1, it is characterised in that：Connect between the concentrated water port of export and atomizer of nanofiltration device It is connected to nanofiltration concentrated water case.

5. processing system according to claim 1, it is characterised in that：The clear water output end of the nanofiltration device connects with evaporator Connect.

6. processing system according to claim 5, it is characterised in that：The clear water output end of the nanofiltration device and evaporator it Between be connected with nanofiltration filtered water tank.

7. processing system according to claim 6, it is characterised in that：It is connected between the nanofiltration filtered water tank and evaporator Reverse osmosis unit.

8. processing system according to claim 1, it is characterised in that：Between the concentrated water port of export and atomizer of nanofiltration device Having heaters is connected on pipeline.

9. processing system according to claim 8, it is characterised in that：The heater is tubular heat exchanger.