A kind of minimum discharge dust arrester and process for deashingTechnical field
The invention belongs to dust removal and filtration technical field, specifically, it is related to a kind of minimum discharge dust arrester and ash disposal sideMethod.
Background technology
At present, reduce smoke dust discharge concentration, the mainstream technology improving dust pelletizing system efficiency has wet static dedusting technology, lowThe technology such as warm electrostatic precipitation technology, bag type dust removing technology.
After wet cottrell is usually placed in desulfuration absorbing tower, can effectively remove the smokeshade in flue gasPM2.5、SO3The pollutant such as the desulfurated plaster droplet carrying in flue gas after microlayer model, hydrargyrum and demister, are a kind of efficient electrostaticCleaner unit.Ash on pole plate being shaken by rapping from dry electric precipitation device drops down onto unlike ash bucket, wet electrical dust precipitator be byWater is sprayed onto in dust collecting electrode and forms continuous moisture film, and circulating water the flue dust of capture is washed in ash bucket and discharges with water.Due to not havingAfter rapping apparatus, will not produce reentrainment of dust in wet cottrell dust removal process, and discharge electrode is flooded profit so that electricityThere are a large amount of Charged Droplets in, greatly increase the submicron particle powered probability of collision, can under higher flue gas flow rate,Capture more microgranules.Wet cottrell can significantly improve dedusting and remove SO3Effect.
Low temperature electrostatic precipitation technology passes through to reduce electric cleaner entrance flue gas temperature, typically drops to below acid dew-point temperature, fromAnd reduce the ratio resistance of flue dust, so that performance of precipitator is improved, reach raising efficiency of dust collection effect.Low temperature dedusting technology can haveEffect prevents electric cleaner from corona occurring, and after flue-gas temperature reduces simultaneously, exhaust gas volumn reduces, and flue gas flow rate also accordingly reduces, and removes in electricityThe time of staying in dirt device increased, and electric dust collector can more effectively capture to flue dust, thus reaching preferablyDust removing effects.In addition, temperature is reduced to below acid dew point, the SO in flue gas3With H2SO4Microlayer model form exist, can adsorbCollect to collecting plate, thus removing most SO in flue dust and together with flue dust3, simultaneously the alkaline matter in flue dust can inAnd sulfuric acid droplets.
Bag type dust removing technology is come pollutant such as the dust in separation gas by filtering material, and dust passes through filtering materialWhen the filtration of filter screen that formed due to filtering material and be sized, adhere to, caught by filter screen by the effect such as inertia and electrostaticObtain.Continuing on with sack cleaner, the dust of screen surface accumulation thickens and leads to its hole less and less, such that it is able toCapture trickleer dust so that cleaner unit has more preferably dust removing effects.When the dust on filter screen is too thick, its dedusting resistanceGreatly enhance, now then need to carry out ash disposal to filter screen, thus keeping the long-term efficient stable of cleaner unit to work.
The classification of cleaner unit is mainly according to its construction features, such as filter bag shape, filtering direction, air inlet position and removeGrey mode is classified.
Wherein, the ash disposal mode of cleaner unit mainly has following three kinds：
(1) mechanical vibration mode.Hit filter bag by vibrating using machinery, so that being accumulated in the powder on filter bag surfaceDirt drops, can be so that using in the way of artificial or mechanical, this ash disposal mode is simple to operate, but effect deviation, and if shakeDynamic excessive it is easily damaged filter bag, therefore using not extensive.
(2) inverse streamer mode.Inverse streamer mode refers to make filter bag deform using the air-flow in opposite direction with filtered airflowThus allowing dust to drop, can by blowing afloat, air-breathing or pressure-vaccum revolution by way of reach dedusting effect.
(3) pulse mode.Pulse ash disposal mainly uses pulse valve and compressed gas high speed is sprayed into filter bag, in compressed gasWhile spraying into, because viscous effect also can bring the air being several times as much as spraying tolerance into, so that filter bag produces drastically swollenSwollen and vibration, and then leads to dust to drop.By numerical simulation being carried out to cleaner unit interior flow field it can clearly be seen that pulseFor the dust removing effects of system, thus by the intensity and the frequency that adjust pulse, therefore this dedusting method has and preferably removesDirt effect, is able to extensive utilization.
And its air inlet mode mainly has two kinds, a kind of be filter bag inside air intake, outside air-out (inward flow filtration-type)；AnotherIt is the outside air intake of filter bag, internal air-out (outside filtering type).Due to the bag-type dusting fairly simple, therefore general using outside air intakeDevice all employs outer filter technology.
The electric precipitations such as new wet static dedusting technology, low temperature electrostatic precipitation technology, rotating electrode type electrostatic precipitation technologyAlthough technology can reach relatively low concentration of emission, due to needing to use high voltage power supply, dedusting energy consumption is larger, equipment simultaneouslyMaintenance cost is higher.
The operation energy consumption of bag-type dusting is relatively low, but the concentration of emission of the dust of the flue gas after this technical finesse typically exists30mg/m3Below it is more difficult to reach 15mg/m3Below.In addition, the pulse ash cleaning technology used by existing bag-type dusting needs in a large numberCompressed air, ash disposal energy consumption is higher.Meanwhile, existing bag-type dusting running resistance is larger, and therefore operation energy consumption is also low.
Although new electrostatic precipitation technology can reach relatively low concentration of emission, its dust removal mechanism is by high voltage power supplyProduce highfield it is therefore desirable to larger energy consumption, in addition its relevant device is more, and the maintenance cost of equipment is higher.Additionally, adoptingWet type or ultralow temperature dedusting, the humidity in flue gas greatly improves, and the H2SO4 of production easily produces corrosion to electrode, furtherThe maintenance cost of increase equipment.
And bag type dust removing technology conventional at present employs the pulse ash disposal dedusting technology of outside filtering type mostly, the removing of outside filtering typeDirt device needs cage to support filter bag, easily produces the mutual abrasion between filter bag and cage during ash disposal.For manufacture and peaceDress technical difficulty, with and cage deformation etc. factor, the length of filter bag and cage can not be long, is typically less than 10m.Such oneCome under the situation of equal floor space, the effective filtration area of cleaner unit is low, filtration velocity higher so that the mistake of filterFilter efficiency is low, and dust emission concentration is higher, and equipment running resistance is higher.
Further, since the compressed air of outside that the source of the gas of existing pulse ash disposal adopts, therefore its ash disposal energy consumption is higher.
Content of the invention
Instant invention overcomes shortcoming of the prior art, there is provided a kind of minimum discharge dust arrester and process for deashing, makeThe efficiency of dust collection obtaining cleaner unit significantly improves, and after process, the concentration of emission of exhaust gas dust is less than 5mg/m3, the operation of equipment simultaneouslyResistance is low, ash disposal process need not external source of the gas, operation energy consumption is low, safeguards simple, operating cost is little, and life of bag filter is long.
In order to solve above-mentioned technical problem, the present invention is achieved by the following technical solutions：
A kind of minimum discharge dust arrester, including cleaner unit and ash bucket, described cleaner unit include air intake duct, gas off-take, onCard and lower face plate, dividing plate and shell, cleaner unit is divided into some filter chambers, the top of described filter chamber and air intake duct by described dividing plateConnection, and it is provided with intake valve, the middle part of described filter chamber connects with gas off-take, and is provided with air outlet valve, is provided with flower in described filter chamberPlate and lower face plate, are provided with vertical filter bag between described upper lower face plate, the lower section of described lower face plate is provided with described ash bucket, described filter bagInternal and described ash bucket connects, and the bottom of described ash bucket is provided with ash bucket valve.
Further, described upper face plate and lower face plate all have some circular holes, the circular hole of described upper face plate and described lower face plateCircular hole be correspondingly arranged, be equipped with described filter bag between the circular hole of the circular hole of described upper face plate and described lower face plate.
Further, described circular hole being welded with the joint that pipe is installed as described filter bag, the length of described pipe is 15～25cm, the interior diameter of described pipe is consistent with the diameter of described circular hole.
Further, the middle part of described pipe is provided with groove, and the depth of groove is 2～3mm, and width is 5～8mm.
Further, be provided with swash plate in described cleaner unit, described swash plate will described air intake duct and gas off-take separately, make described in enterThe section of air flue becomes narrow gradually, and so that the section of described gas off-take is gradually broadened.
Further, described intake valve and air outlet valve are poppet.
Further, the length of described filter bag is 12-20m, a diameter of 120-240mm.
Further, the side of described gas off-take is provided with blower fan.
Further, it is provided with heat-insulation layer outside described cleaner unit.
A kind of using a kind of described process for deashing of minimum discharge dust arrester,
Close intake valve, air outlet valve stays open, close air outlet valve after some seconds, open intake valve again after some seconds, beatTurn off intake valve some seconds after driving air valve some seconds into, then open air outlet valve, complete an ash disposal cycle.With prior artCompare, the invention has the beneficial effects as follows：
A kind of minimum discharge dust arrester of the present invention and process for deashing, have advantages below：
Compared with wet static dedusting, the equipment required for this technology is few, and plant maintenance workload is few, operation and maintenance costLow.
And compared with traditional bag type dust removing technology, the self-cleaning ash disposal mode of the present invention is the opening and closing by air valveFluctuation makes filter bag deform, shake forms dedusting effect so that the pressure inside and outside filter bag is produced.Ash disposal process need not be extraEnergy consumption, its energy consumption is energy consumption used when switching air valve, therefore greatly reduces the operation energy consumption of sack cleaner.
Meanwhile, due to using the overlength structure of filter bag of no cage, in the situation that cleaner unit floor space is constantUnder, effectively increase filter area, reduce filtration velocity.Thus can reach raising filtering accuracy, extend the ash disposal cycle andIncrease filtrate service life and other effects.The dust emission concentration of the flue gas after this technical finesse is less than 5mg/m3, the fortune of equipmentRow resistance is less than 1000pa.
Furthermore, the present invention decreases equipment investment and resource consumption without cage as the support of filter bag.
Finally, due to the change of ash disposal pressure process is little, the damage to filter bag is little, effectively extends the service life of filter bag.
Above-mentioned advantage why is had to be primarily due in the present invention, employ inward flow filtration-type intake method, during by filteringThe pressure reduction of filter bag surfaces externally and internally is as the power supporting filter bag.Do not need in filter bag internal unit cage structure, filter bag is without volumeOuter support, solves the difficulty installed and manufacture, effectively the length of filter bag is increased to 12～20 meters.Effectively increase filtering surfaceLong-pending, reduce filtration velocity, improve filter efficiency.
In above-mentioned technical foundation, with the use of new pressure differential self-cleaning ash cleaning technology, formed in system fanFixing negative pressure on the basis of, by the opening and closing of the order of air valve, the pressure of filter bag surfaces externally and internally has been fluctuated, thusFilter bag is made to produce deformation, shake and the dust releasing that leads to be attached on filtrate it is achieved that the effect of ash disposal.Ash disposal process need notExtra increase energy loss, its energy consumption is only the energy consumption switching used by air valve, and self-cleaning ash disposal mode significantly reducesThe operating cost of dust removal process.Simultaneously because ash disposal pressure change is little, the damage to filter bag is little, effectively extends the use longevity of filter bagLife.
Due to the independent ash disposal of each filter chamber, its time substantially can be staggered and carried out, the therefore dedusting of the entirety of cleaner unitEffect will not produce change because of ash disposal, and in flue gas, dust emission concentration will not change it is ensured that system because of ash disposalCan continuous workability.
Brief description
Accompanying drawing is used for providing a further understanding of the present invention, is used for together with embodiments of the present invention explaining the present invention,It is not construed as limiting the invention, in the accompanying drawings：
Fig. 1 is a kind of structural representation of minimum discharge dust arrester of the present invention；
The structural representation of the single filter chamber of Fig. 2；
Fig. 3 is the structural representation of pipe.
1 cleaner unit；2 upper face plates；
3 lower face plates；4 ash-laden gas inlet channels；
5 filter chambers；6 ash buckets；
7 circular holes；8 air intake ducts；
9 intake valves；10 gas off-takes；
11 air outlet valves；12 filter bags；
13 pipes；14 grooves；
15 swash plates；16 ash bucket valves；
17 dividing plates.
Specific embodiment
Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are illustrated it will be appreciated that preferred reality described hereinApply example to be merely to illustrate and explain the present invention, be not intended to limit the present invention.
As shown in Figures 1 to 3, a kind of minimum discharge dust arrester construction of the present invention is as follows：It is provided with outer outside cleaner unit 1Shell, cleaner unit 1 is divided into three parts by dividing plate 17, and top is ash-laden gas inlet channel 4, and middle part is filter chamber 5, and dividing plate 17 is sameWhen cleaner unit 1 is divided into some filter chambers 5, be provided with upper face plate 2 and lower face plate 3 in filter chamber 5, the lower section of lower face plate 3 is provided with ash bucket 6,Filter bag 12 is internal to be connected with ash bucket, and the bottom of ash bucket 6 is provided with ash bucket valve 16.Upper face plate 2 and lower face plate 3 are stainless steel structure,Circular hole 7 all had on upper face plate 2 and lower face plate 3, circular hole 7 position of upper face plate 2 and lower face plate 3 corresponds, vertical filter bag12 are arranged between upper and lower circular hole 7, and the diameter of circular hole 7, between 120 240mm, circular hole 7 is welded with pipe 13 as filter bag 12The joint installed, the length of pipe 13 is 15～25cm, and the interior diameter of pipe 13 is consistent with the diameter of card circular hole 7.Pipe 13Middle part be provided with groove 14, the depth of groove 14 is 2～3mm, and width is 5～8mm, and the installation for filter bag 12 fixes.FilterBag 12 is arranged on the pipeline of upper and lower circular hole 7 welding, and the distance between two cards are less than 20 meters at big 12 meters.
The outside of cleaner unit 1 is provided with heat-insulation layer.
The distance between two cards are less than 20 meters at big 12 meters, due to employing overlength filter bag 12 structure of no cage,The internal exoskeletal support of filter bag 12, the length of filter bag 12 greatly increases, and is 12～20 meters.
This is because this dedusting technology employs the intake method (inward flow filtration-type) within filter bag 12 on intake method, due toEmploy inward flow filtration-type, the presence of filtration pressure difference makes filter bag 12 without skeletal support, i.e. no cage structure, due to there is not cageFrame, the length of filter bag 12 can greatly increase.
The increase of filter bag 12 length can be effectively increased filter area on the premise of cleaner floor space is constant,Thus reducing filtration velocity, this improves filter efficiency and reduces running resistance.By increasing filter area thus wind will be filteredPrompt drop as little as below 0.8m/s, is preferably controlled between 0.5～0.8m/s.Filter efficiency is significantly improved, after its processIn flue gas, dust emission concentration can be less than 5mg/m3It is achieved that high efficiency filter.The reduction of filtration velocity also reduces overall simultaneouslyThe running resistance of cleaner, the running resistance of cleaner can ensure that less than 1000pa.
Especially during electrostatic precipitation transform bag-type dusting as, the floor space due to existing equipment can not increaseWhen, become apparent from using no cage overlength filter bag 12 structural advantage.
By setting of circular hole 7 diameter (diameter of filter bag 12) and the distance between quantity, two cards (length of filter bag 12)Meter, is reasonably filtered the gross area so that ash-laden gas is through filtration velocity≤0.8m/s during filter material.In order to reach preferablyFilter effect, its filtration velocity is preferably controlled in 0.5m/s.
, all at the middle part of cleaner unit 1, air intake duct 8 and gas off-take 10 are rectangle for the air intake duct 8 of cleaner unit 1 and gas off-take 10,Wherein air intake duct 8 employs the cross section structure becoming narrow gradually, and gas off-take 10 employs the cross section structure gradually broadening, its sectionGradual change be to be realized by the setting of swash plate 15, by the gradual change of air intake duct 8 and gas off-take 10 setting, to strengthen to filter bag 12Pressure, increased filter effect.Air intake duct 8 passes through swash plate 15, then enters dust constaining from upper face plate 2 top of cleaner unit 1Cleaner unit 1 is separated into multiple filter chambers 12 by dividing plate by gas inlet channel 4, refering to Fig. 2 (non-practical structures figure), each filter chamber12 are respectively equipped with independent intake valve 9 and air outlet valve 11 controls.Intake valve 9 and air outlet valve 11 all use poppet, eachThe pressure reduction of filter chamber 12 all has independent detecting instrument on-line checking.
Flue gas gas off-take 10 is arranged on the side of lower face plate 3, and the rear of flue gas gas off-take 10 valve is system main air blower, leads toThat crosses system fan rotates the negative pressure being formed, and promotes flue gas to flow to gas off-take 10 from air intake duct 8.
When filtering, intake valve 9 and air outlet valve 11 are all opened, and the ash bucket valve 16 of ash bucket 6 bottom is closed, the flue gas of dust-ladenEnter the ash-laden gas inlet channel 4 of upper face plate 2 top through air intake duct 8, then enter inside filter bag 12 through circular hole 7, through filter bagWhen 12, the loose structure that filtering material is formed after dust catching, discharge from the outer surface of filter bag 12, then passes through by clean flue gasAir outlet valve 11 and gas off-take 10 are transported at next procedure.
When the dust of the inner surface of filter bag 12 gathers to a certain extent, such as inside and outside the filter bag 12 in certain filter chamber 12When pressure reduction reaches 800pa, cleaner unit 1 will carry out ash disposal process.Ash disposal process is specific as follows：Close the intake valve 9 of this filter chamber 12,Air outlet valve 11 stays open, and closes air outlet valve 11, open intake valve 9 after some seconds again after some seconds.Open intake valve 9 some secondsAfter turn off intake valve 9 some seconds, then open air outlet valve 11, complete an ash disposal cycle.By opening of air valve 11And close, the air pressure of filter bag 12 surfaces externally and internally occurs in that regular fluctuation so that filter bag 12 produce deformation, shake and leadCause to be attached to dust releasing on filtrate it is achieved that the effect of ash disposal, the dust coming off drops to ash under gravity naturallyIn bucket 6, during, the ash bucket valve 16 of ash bucket 6 is closed all the time.
After such ash disposal cycle carries out 5 10 times, when filter bag 12 inside and outside differential pressure drops to below 300pa, ash disposal processTerminate, air valve 11 is opened simultaneously, enters into normal filtration state.When filter bag 12 surfaces externally and internally pressure reduction reaches againMore than 800pa, ash disposal process will re-start again.
On the basis of the fixing negative pressure that system fan is formed, made by the order opening and closing of intake valve 9 and air outlet valve 11Change in the pressure reduction of filter bag 12 surfaces externally and internally, due to the fluctuation of pressure reduction, when filter bag 12 is ash disposal by oxygen blast cyanidation when filteringContraction so that filter bag 12 produces larger deformation, shake and the dust releasing that leads to be attached on filtrate it is achieved that ash disposalEffect.Due to being overlength filter bag 12 and no cage structure, the therefore deformation degree of filter bag 12 is big, and dedusting effect is good.Due to removingGrey process is to be realized by the opening and closing of intake valve 9 and air outlet valve 11, and without out-source gas, ash disposal energy consumption is low, effectively reducesThe operating cost of dust removal process.
Finally it should be noted that：These are only the preferred embodiments of the present invention, be not limited to the present invention, althoughWith reference to embodiment, the present invention is described in detail, for a person skilled in the art, it still can be to aforementionedTechnical scheme described in each embodiment is modified, or carries out equivalent to wherein some technical characteristics, but allWithin the spirit and principles in the present invention, any modification, equivalent substitution and improvement made etc., should be included in the protection of the present inventionWithin the scope of.