CN208406509U - A kind of white-smoke-removing system of accurate control corrosion rate - Google Patents

Abstract

The utility model discloses a kind of white-smoke-removing systems of accurate control corrosion rate, the system includes gradient fin controlling temp type heat exchanger, cooling scrubber, sewage-treatment plant, demister, the gradient fin controlling temp type heat exchanger passes through tube bank arrangement and the outer fin height stepped design of pipe, continually strengthen the heat transfer of high temperature former fume side in cooling procedure to control wall surface temperature greater than acid dew point, so as to realize its Anti-corrosion design with lower material cost, simultaneously, using the dehumidifying of spray forced condensation and recycle former smoke heat energy heating neat stress, it works along both lines, its absolute moisture content is greatly reduced and opposite water capacity declines to a great extent, white cigarette phenomenon can be thoroughly eliminated under no extra heat source and low water consumption.

Description

A kind of white-smoke-removing system of accurate control corrosion rate

Technical field

The utility model belongs to energy conservation and environmental protection, is related to a kind of white-smoke-removing system of accurate control corrosion rate, especially suitable For desulphurization system chimney white plume treatment process.

Background technique

With making constant progress for China's economy, energy demand increasingly increases, wherein coal and petroleum as China most The main burning energy causes great environmental pollution, especially sulfur dioxide although meeting the demand of economic development It pollutes, in existing gas cleaning Treatment process, the overwhelming majority uses Limestone-gypsum Wet Flue Gas Desulfurization Process technique, and absorption tower exports band There is the neat stress of saturated water to form drop in throat discharge process partial condensation, moisture can not be effectively diffused into greatly in flue gas In gas, cause flue gas that cannot dissipate rapidly, when relative air humidity is high, temperature is low, atmosphere moisture content is wet close to saturation state When cold air and the gas of throat discharge contact, ambient atmosphere can not absorb the vapor in tail gas, the gas of chimney discharge Cognition is down to dew point and forms a large amount of " white cigarettes ", causes apparent visual pollution, on the other hand, a small amount of dust for being carried in flue gas and Drop is gathered near chimney, falls to the ground to form " gypsum rain " or acid rain, generates pollution to power plant and surrounding enviroment, or even rotten Lose equipment.

On the one hand, by the definition of dew-point temperature it is found that dew-point temperature be humid air saturation when temperature, if at this time temperature after Continuous decline, vapor therein can condense precipitations, and absolute moisture content will be less in flue gas, it is possible to pass through reduction flue gas temperature Collection hereinafter, to realize moisture in flue gas is spent to dew point；On the other hand, flue gas can be made to discharge by increasing temperature When the process that Cheng Zhong, not yet completion flue gas cool-down-dew point-vapor are largely condensed, just sufficiently spread, to reduce white cigarette The generation of phenomenon.So white cigarette solve the phenomenon can from reduce flue gas dew point temperature (dehumidifying) and raising flue-gas temperature (heating) Two aspects are set about.

In existing conventional measure, no matter temperature-raising method (being heated up using natural gas or steam to flue gas) or cooling and dehumidifying Method (directly cools down flue gas with chilled water), can all consume a large amount of energy, does not meet the requirement of energy-saving and emission-reduction.Therefore specially Sharp CN201720940981 provides a kind of self-loopa white cigarette removal device, using GGH method using the heat of former flue gas to net cigarette Gas discharges after carrying out 30-50 DEG C of heating, has certain white-smoke-removing effect, and be not necessarily to external heat source, but no matter former flue gas (SO₂, SO₃Content is high) and neat stress (SO₃, temperature is low, and water capacity is big) there are problems that serious corrosion of sulfuric acid at dew point, heat exchanging material A series of problems, such as it is required that very high, not only heat exchanger cost is excessively high, but also heat exchanger is easy to happen corrosion and collaborates, blocking.

In response to the above problems, patent CN201611107000 provides a kind of secondary hot-air heating technique, utilizes former flue gas Heat, hot water is as intermediate medium, and heating obtains hot Secondary Air and neat stress carries out mixed wind, by neat stress dilution heating from cigarette Chimney discharge.This approach avoid the etching problem of neat stress, but when former flue gas and hot water are exchanged heat, tube wall temperature is at 100 DEG C Left and right still remains etching problem lower than former flue gas dew point, it is often more important that, the mixing cigarette that secondary hot-air heating technique obtains Tolerance is that twice of neat stress amount is even more, and smoke stack emission amount is made to increase severely, and entire chimney needs to redesign, and increases project and throws Money amount.

In conclusion in the prior art, white cigarette Processing tecchnics have the defects that high energy consumption, seriously corroded mostly.Therefore, such as What researches and develops a kind of low energy consumption, uses safely and new process that effect is good becomes this field to achieve energy-saving and emission reduction purposes The important topic of technical staff.

Utility model content

To solve the problems, such as existing white-smoke-removing, the utility model provides a kind of white-smoke-removing of accurate control corrosion rate System and technique.

The technical solution that the utility model is taken is as follows:

A kind of white-smoke-removing system of accurate control corrosion rate, the system include heat exchanger, washer, mesh mist eliminator and sewage Processing unit, the hot side import of the heat exchanger pass through former flue and connect desulfurization original flue gas, the hot side outlet of heat exchanger with The gas inlet of the washer connects, and the exhanst gas outlet of washer and the cold side import of heat exchanger are connected by neat stress pipeline It connecing, the cold side outlet port of heat exchanger is connect with chimney, by smoke stack emission neat stress, and the exhanst gas outlet of washer and heat exchanger Neat stress pipeline between cold side import is equipped with the mesh mist eliminator, the spray water out of washer and mesh mist eliminator After condensation-water drain collects, be connected to the sewage-treatment plant by plumbing drain, the outlet of sewage-treatment plant again with The spray water inlet of washer is connected to.

Preferably, the heat exchanger is gradient fin controlling temp type heat exchanger, which is tubulation Heat exchanger, and its heat-exchanging component used is high-frequency welding finned tube, managing interior neat stress side is shiny surface, managing outer former fume side is Fin face, two sides are increased the heat exchange area of former fume side by pipe external finned tube arrangement, tube wall temperature are made to tend to high temperature original cigarette Gas side.

Preferably, the washer is combined type double-cyclone washer, and being internally provided with prevents flue gas from corroding to washer The anti-lining of glass flake.

Preferably, desulfurizing tower is equipped between the hot side outlet of the heat exchanger and the gas inlet of the washer.

Preferably, water circulating pump is equipped between the outlet of the sewage-treatment plant and the spray water inlet of washer.

Preferably, smoke exhaust fan is equipped between the cold side outlet port and chimney of the heat exchanger.

White-smoke-removing system in using the above scheme carries out fume treatment, specifically includes the following steps:

Cold section at the beginning of former flue gas: gradient fin controlling temp type heat exchanger is configured to the former flue gas tentatively to cool down and neat stress exchanges heat, The heat of secondary recovery original flue gas, the flue gas after cooling enter desulfurizing tower；

Neat stress cryogenic: former flue gas is changed into saturation neat stress and enters cooling scrubber after desulfurizing tower purified treatment, By neat stress forced cooling in the way of cold water spray, washer connects sewage-treatment plant by leakage fluid dram, the water after washing Through settling, recycled after neutralisation treatment；

Neat stress demisting section: after washing, purifying, neat stress enters demister, and entrained drip in most flue gases is gentle Sol particle trapping, to reduce subsequent heat exchange load and corrosivity；

Neat stress hot arc again: neat stress returns to the heat exchanger in cold section at the beginning of former flue gas, and neat stress temperature mentions after heat exchange It rises, after relative humidity decline, chimney is discharged into, to reach elimination white cigarette.

The beneficial effects of the utility model are as follows:

1, it arranges by the tube bank of gradient fin controlling temp type heat exchanger and manages outer fin height stepped design, in conjunction with specific After condition calculating, the accurate tube wall temperature that controls, relative to traditional heat exchangers, is effectively reduced acid in the range of being greater than dew point Dew point corrosion, simultaneously as the Anti-corrosion design of heat exchanger, heat exchange element can reduce material requirement, without prohibitively expensive Resistant material, advantageously reduce cost；

2, in the utility model using the heat exchanger without using hot Secondary Air by the way of avoid etching problem, total cigarette Tolerance remains unchanged, it is not necessary that chimney is transformed again；

3, it is corrosion tendency most serious that neat stress cryogenic, which is generally believed that, and thermic load is maximum, the highest work of heat transfer requirements Skill section, the utility model are cooled down using cold water spray mode, are exchanged heat by cold and hot physical contact between media, this mode is conducted heat effect Rate is high, good cooling results, relative to biggish heat exchange area required for condenser indirect heat exchange and expensive heat exchange material, this Technique has good economic sexual clorminance；

4, relative to condenser is arranged in other techniques, the mode of this spray washing on the one hand can be by stone in neat stress Impurity in emplaster or inorganic salts is dissolved down, and avoids blockage problem and gypsum rain phenomenon common in condenser, on the other hand, It can be with the SO in double purification neat stress₂, SO₃, the ingredients such as HCl reduce corrosion to follow up device, reach the mesh of ultra-clean discharge 's；

5, the cleaning solution recycled contains a small amount of impurity and acid ingredient, settles by water treatment facilities, can be with after neutralization Circulation continues to use；During deep cooling, large quantity of moisture is condensed in cleaning solution in neat stress, without additional supplement water；

6, by the way that neat stress cryogenic and again hot arc is arranged, respectively from cool-down dehumidification (reducing flue gas absolute moisture content) and liter Temperature (reducing Gas phase Smoke to water capacity) two aspects set about, work along both lines, to achieve the purpose that thoroughly to eliminate white cigarette.

The additional aspect and advantage of the utility model will be set forth in part in the description, partially will be from following description In become obvious, or recognized by the practice of the utility model.

Detailed description of the invention

Fig. 1 is the utility model white-smoke-removing system flow diagram；

Wherein: 1- desulfurization original flue gas, 2- heat exchanger, 3- washer, 4- mesh mist eliminator, 5- sewage-treatment plant, 6- are followed Ring water pump, 7- spray pipeline, 8- plumbing drain, 9- smoke exhaust fan, 10- chimney, 11- discharge neat stress.

Fig. 2 is the utility model gradient fin controlling temp type heat exchanger schematic diagram of internal structure.

Specific embodiment

The utility model is described in detail in the following with reference to the drawings and specific embodiments.

As shown in Figure 1, a kind of white-smoke-removing system of accurate control corrosion rate, within the system, desulfurization original flue gas 1 and gradient wing 2 hot side import of piece controlling temp type heat exchanger passes through former flue connection, and 2 hot side outlet of gradient fin controlling temp type heat exchanger is by de- It after sulphur tower, is connect with 3 gas inlet of efficient combined-type double-cyclone washer, 3 exhanst gas outlet of combined type double-cyclone washer and ladder It spends 2 cold side import of fin controlling temp type heat exchanger to connect by neat stress pipeline pipe, centre is equipped with mesh mist eliminator 4, gradient fin 2 cold side outlet port of controlling temp type heat exchanger is connect with chimney 10；Washer spray water out and 4 condensation-water drain of mesh mist eliminator collect Afterwards, it is connected to sewage-treatment plant 5 by plumbing drain, the outlet of sewage-treatment plant 5 sprays water inlet with washer 3 and connects Logical, intermediate duct is equipped with water circulating pump 6.

This system carries out fume treatment, specifically includes the following steps:

1, cold section at the beginning of former flue gas: the gradient fin controlling temp type heat exchanger is configured to the former flue gas tentatively to cool down and neat stress Heat exchange, the heat of secondary recovery original flue gas, the flue gas after cooling enter desulfurizing tower；

2, neat stress cryogenic: former flue gas is changed into saturation neat stress and enters cooling washing after desulfurizing tower purified treatment Device, by neat stress forced cooling in the way of cold water spray.Cooler connects water treatment facilities by leakage fluid dram, the water after washing Through settling, recycled after neutralisation treatment；

3, neat stress demisting section: after washing, purifying, neat stress enters demister, by entrained drip in most flue gases and Aerosol particle trapping, to reduce subsequent heat exchange load and corrosivity；

4, neat stress hot arc again: neat stress returns to the heat exchanger in step 1, and neat stress temperature is promoted after heat exchange, phase After humidity decline, it is discharged into chimney, to achieve the effect that eliminate white cigarette.

The utility model gradient fin controlling temp type heat exchanger is tubular heat exchanger, no matter former in desulfurization fume white-smoke-removing engineering Flue gas and neat stress are provided with strong corrosive, and traditional light pipe type Tube Sheet of Heat Exchanger wall temperature is substantially former flue gas and neat stress Average value, so heat exchanger tube wall temperature is inevitably reduced under flue gas dew point under practical situations, to occur tight The corrosion of sulfuric acid at dew point problem of weight.

For the heat-exchanging component that the utility model heat exchanger uses for high-frequency welding finned tube, managing interior neat stress side is shiny surface, Managing outer former fume side is fin face, and two sides are increased the heat exchange area of former fume side by pipe external finned tube arrangement, make tube wall temperature Tend to high temperature former fume side.Single backhaul heat exchange or the heat exchange of more backhaul multiple groups finned tubes can be arranged in heat exchanger according to the actual situation, Heat exchanger front end is former gas inlet, and rear end is outlet, and multiple rows of finned tube, wing is arranged in enclosure interior between former smoke entrance Piece pipe increases fin height along former flow of flue gas vertical scale direction step by step, and outer fin height staged is arranged and managed by tube bank Design, is gradually increased former fume side heat exchange area；As former flue gas is constantly cooled, fume side heat transfer effect is strengthened more and more brighter Aobvious, tube wall temperature is more nearly former flue-gas temperature therewith, is based on principles above, in entire heat transfer process always by heat exchanger tube wall temperature Control prevents acid mist condensation to be precipitated on flue gas dew point, to reduce the corrosion of heat exchanger tube to greatest extent.

The utility model cooling scrubber is efficient combined-type double-cyclone washer, to prevent corruption of the flue gas to washer Erosion, inside sets the anti-lining anti-corrosion of glass flake.In the way of cold water spray, directly exchanged heat with neat stress, it will be exhausted in flue gas Most of vapor condensation reaches depth dehumidifying, the effect of flue gas dew point is greatly reduced, while utilizing two-stage swirl vane The drop atomizing effect and gas-liquid mixed efficiency of spray liquid are significantly improved with the arrangement of Multi-layer sprinkling head, improves waste gas stream Logical section coverage rate achievees the purpose that minimum discharge to strengthen the double purification effect to neat stress.

The operation principle and process of this system are as follows:

According to background technology part, ambient temperature is lower, and white cigarette phenomenon is particularly acute, therefore this example is according to winter Consider under operating condition.In wet desulfurizing process, operating condition is set as 100000 Nm3/h desulfurization original flue gases, SO₂Content is 500mg/ Nm3, water capacity are 6%(volume fraction), the calculation of dew-point temperature of acid formula through being fitted according to experimental result calculates: T=186+20lgH₂O +26lgSO₃(H in formula₂O and SO₃For the volumn concentration of vapor in flue gas and sulfur trioxide, consulted according to documents and materials SO₂It is converted into SO₃Conversion ratio be 2 ~ 4%, this operating condition be set as 3%), calculate acid dew point be 116 DEG C.

Desulfurization original flue gas is about 155 DEG C after waste heat boiler is discharged, into gradient fin controlling temp type heat exchanger and subsequent processing Neat stress afterwards carries out heat exchange, and former flue gas tentatively cools to 120 DEG C.Former flue gas walks shell side, neat stress inside heat exchanger Tube side is walked, heat exchange element uses finned tube, conducts heat using outside fin reinforcing tube side, makes tube wall temperature closer to high temperature original flue gas Side；And in temperature-fall period, according to the temperature changing trend of cold and hot media of both sides, heat exchanger is set using fin height staged Meter, as former flue gas is constantly cooled, heat exchanger tube fin height is gradually increased, and the reinforcing of fume side heat transfer effect is more and more obvious, Tube wall temperature is more nearly former flue-gas temperature therewith, is shown according to tube bank wall surface temperature simulation calculated result, in former exhanst gas outlet End, heat exchange tube wall temperature are 120 degree or more, still control more than acid dew point, reduce sulfuric acid corrosion to greatest extent It may.

Flue gas is changed into about 45 DEG C of neat stress of saturation and enters combined type double-cyclone washer after desulfurizing tower purified treatment, It is generally acknowledged that the humidity of saturation neat stress is inlet temperature saturated humidity, neat stress forced condensation is removed in the way of cold water spray It is wet.Firstly, traditional indirect-type condenser, because film coefficient of heat transfer is insufficient, expensive heat exchange material and drag losses limitation etc. are former Because being difficult to the problem of being cooled to the temperature of white-smoke-removing needs, inorganic salts or lime paste is also brought to block in condensation process；And this is washed Neat stress and spray water direct contact heat-exchanging, increase flow perturbation effect by spiral board, improve gas-liquid mixed during washing Effect, this mode has heat transfer efficiency height, the advantage of easy to clean dirt, while the interior Glass Flake Substrate that sets does Anti-corrosion design, The problem of effective solution above traditional condenser；Secondly, the effect of its spray can be with the SO in double purification neat stress₂, SO₃, The generation for phenomena such as ingredients such as HCl reduce the corrosion to follow up device, achieve the purpose that ultra-clean discharge, also avoid gypsum rain； In addition, a large amount of water can be precipitated during flue gas condensing, it is not necessarily to additional make-up water source in entire water cycle process, fully demonstrates The energy saving of the technique.Through calculating, water spray is set in 350m³/ h, neat stress temperature is reduced to 30 DEG C after washing, water capacity It declines to a great extent, dehumidifying rate is 50%.Through water circulating pump, sewage-treatment plant sedimentation can be recycled water after washing after neutralization.

Neat stress after deep cooling dehumidifying enters mesh mist eliminator, carries the gentle colloidal sol of acid drop in most flue gas secretly Grain is captured down, through Drainage pipe together with shower water, is collected to sewage-treatment plant.It can reduce by the above process subsequent Exchange heat load and flue gas corrosion, improves white-smoke-removing effect.

Then, neat stress comes back to gradient fin controlling temp type heat exchanger, carries out reheating mistake by recycling former fume afterheat Journey.It is generally believed that the neat stress SO after desulfurization process₂Removing amount is up to 95% or more, and SO₃Export content not substantially under Drop (about 50-60%), and its water capacity greatly increases, therefore its acid dew point do not decline relative to neat stress how much, in reality Because its temperature is low in, neat stress corrosivity is become apparent.Water capacity 4.2%, SO are saturated according to it₃Content is set as 8mg/ Nm3, calculating its acid dew point by above formula is 106 DEG C.This heat exchanger is accurate to control by above-mentioned heat exchange tube fin chip architecture optimization design Heat exchanging pipe wall temperature processed is shown according to tube bank wall surface temperature simulation calculated result, at neat stress import and export end, outside heat exchanger tube Wall temperature is held in 108 DEG C or more, still controls more than acid dew point, also plays good control to the corrosion of neat stress Effect.During flue gas reheat, neat stress is warming up to 65 DEG C, and relative humidity is greatly reduced to 13%.

In entire treatment process, by carrying out condensation and reheating, absolute moisture content and opposite water capacity respectively to flue gas It declines to a great extent, at 0-5 DEG C of north of china in winter environment temperature, from during smoke stack emission, a small amount of water contained steams neat stress Gas is difficult to be cooled into enough drops in a short time, can not generate the apparent white cigarette of range estimation；It is analyzed simultaneously from Energy Angle, This technique sufficiently recycles the partial heat of former flue gas itself during reheating, also has a large amount of elutriations to go out in condensation process, entirely Technique is not necessarily to extra heat source, and water consumption is less, meets the main trend of current national energy conservation and emission reduction.

The basic principles and main features and advantage of the utility model have been shown and described above.The ordinary skill of this field Personnel are not it should be appreciated that above-described embodiment limits the protection scope of the utility model, all use equivalent replacements etc. in any form Mode technical solution obtained, falls in the protection scope of the utility model.

The parts not involved in the utility model is the same as those in the prior art or can be realized by using the prior art.

Claims (6)

1. a kind of white-smoke-removing system of accurate control corrosion rate, it is characterised in that the system includes heat exchanger, washer, silk screen demisting Device and sewage-treatment plant, the hot side import of the heat exchanger pass through former flue and connect desulfurization original flue gas, the heat of heat exchanger Side outlet is connect with the gas inlet of the washer, and the exhanst gas outlet of washer and the cold side import of heat exchanger pass through neat stress Pipeline connection, the cold side outlet port of heat exchanger connect with chimney, by smoke stack emission neat stress, and the exhanst gas outlet of washer with change Neat stress pipeline between the cold side import of hot device is equipped with the mesh mist eliminator, and spray water out and the silk screen of washer remove It after the condensation-water drain of day with fog collects, is connected to the sewage-treatment plant by plumbing drain, sewage-treatment plant goes out Mouth is connected to the spray water inlet of washer again.

2. a kind of white-smoke-removing system of accurate control corrosion rate according to claim 1, it is characterised in that the heat exchanger is Gradient fin controlling temp type heat exchanger, the gradient fin controlling temp type heat exchanger are tubular heat exchanger, and its heat-exchanging component for using for High-frequency welding finned tube, managing interior neat stress side is shiny surface, and managing outer former fume side is fin face, and two sides pass through pipe external finned tube cloth The heat exchange area for increasing former fume side is set, tube wall temperature is made to tend to high temperature former fume side.

3. a kind of white-smoke-removing system of accurate control corrosion rate according to claim 1, it is characterised in that the washer is Combined type double-cyclone washer is internally provided with the anti-lining of glass flake for preventing flue gas from corroding to washer.

4. a kind of white-smoke-removing system of accurate control corrosion rate according to claim 1, it is characterised in that the heat exchanger Desulfurizing tower is equipped between hot side outlet and the gas inlet of the washer.

5. a kind of white-smoke-removing system of accurate control corrosion rate according to claim 1, it is characterised in that the sewage treatment Water circulating pump is equipped between the outlet of device and the spray water inlet of washer.

6. a kind of white-smoke-removing system of accurate control corrosion rate according to claim 1, it is characterised in that the heat exchanger Smoke exhaust fan is equipped between cold side outlet port and chimney.