Removing dust from steelmaking convertor smoke by dry and complementary energy retrieving arrangement
Technical field
The present invention relates to steel-making converter flue gas ash removal and complementary energy and reclaim the field, particularly dry method dust, the device of waste heat recovery.
Background technology
At present, the flue gas of national steel-making converter is handled, and the overwhelming majority adopts the wet processing flow process, is called " OG method ".This treatment scheme is: converter gas is through overskirt, gasification cooling flue recovered steam, flue-gas temperature is reduced to 800~1000 ℃ by 1400~1650 ℃, advance one-level Venturi meter, secondary Venturi meter dedusting cooling again, through induced draft fan, three-way switch valve, coal gas enters recovery system, qualified coal gas reclaims, and underproof coal gas enters and diffuses the tower burning and exhausting.Waste heat only reclaims a part, and underproof coal gas is because of diffusing the weakness that does not make full use of, and the defective coal gas of its discharging and a large amount of sewage, mud all cause great environmental stress.
Because it is intermittence that steel-making converter produces high-temperature flue gas, just there is the difficulty of industrialized utilization in this.
Summary of the invention
Of the present invention month be to design a kind of: utilize existing sophisticated high temperature fume dust removal system, and be equipped with efficient waste heat boiler, the explosion-proof control scheme and the power generating by remain energy device of safety, form brand-new dry method dust of a cover and complete complementary energy and reclaim technology, application by this technology, almost the waste heat with flue gas all reclaims, and 90% above flue gas is converted into qualified coal gas reclaims, simultaneously in the non-oxygen blowing phase, by in high-temperature flue, feeding an amount of coal gas and air mixed burning, produce the continuous high temperature flue gas and with Control for Oxygen Content in the flue gas below 1%, guarantee that coal gas is away from blast area, the while vapor recovery will reach 4 times of wet dedusting, the successive vapor recovery greatly improves generated energy, and the negative value that can make steel has obtained sufficient embodiment, and the successful Application of project will be filled up domestic blank.
Technical scheme of the present invention is: a kind of removing dust from steelmaking convertor smoke by dry and complementary energy retrieving arrangement, it is by the high temperature immediate action valve that is connected with steel-making converter, movable gas hood, combustion unit, gasification cooling flue, high-temperature cyclone dust extractor, tubular heat exchange, sack cleaner or electric precipitator, three-way switch valve, dedusting fan, coal gas diffusion device and gas chamber, waste heat boiler is formed, it is characterized in that being provided with in the flue after movable gas hood the combustion unit that replenishes collected coal gas, after gasification cooling flue, be provided with high-temperature cyclone dust extractor, after high temperature cyclone dust removal, connect one-level hosepipe superheater more successively, tubular heat exchange, secondary hosepipe superheater, the waste heat boiler economizer, sack cleaner, gas fan and gas chamber.
Described combustion unit is that steel-making converter utilizes collected coal gas to produce enough successive high-temperature flue gas and carry out work with air mixing afterburning in the non-oxygen blowing phase, blowing early stage and blowing later stage (CO output is lower than at 35% o'clock) utilize collected coal gas of converter by burner coal gas burner and the combustion chamber enters gasification cooling flue and unnecessary oxygen carries out combustion reactions (the CO content that makes the whole blowing process as far as possible is greater than 35%), consume unnecessary oxygen (O in the reduction flue gas
2Content is less than 1%), and then improve the coal-gas recovering amount and carry out work.
Described tubular heat exchange is the many tubules arranged side by side footpath flue that is connected with big caliber flue, and makes tubule footpath flue be in device among the water receptacle.
Described fly-ash separator is high temperature cyclone dust device, sack cleaner or electric precipitator.
Converter gas enters the high temperature fume dust removal device and carries out dedusting through petticoat pipe, gasification cooling flue, advances efficient tubulation waste heat boiler cooling again, and temperature is reduced to below 150 ℃ by 800~1000 ℃, and through cloth bag or electric precipitator dedusting, dust concentration is by 80~150g/m again
3Reduce to 10mg/m
3Below, the sensible heat of flue gas almost all is converted into steam; Last flue gas is through induced draft fan, three-way switch valve, and qualified coal gas enters recovery system.Simultaneously, the flue gas that does not reach the coal gas requirement enters and diffuses the tower burning and exhausting.
The effect that following each device plays respectively is:
Steel-making converter: steelmaking equipment produces a large amount of coal gas and partial fume during oxygen blast is smelted;
Gasification cooling flue: heat exchanger, reclaim the sensible heat in 900~1650 ℃ of intervals of flue gas;
The high temperature immediate action valve: the quick acting switching-off device, open during converter oxygen blowing, close during non-oxygen blowing;
Combustion unit: 1, the non-oxygen blowing phase, by add the burning of suitable coal gas and air mixed in combustion unit, high-temperature flue gas enters gasification cooling flue, makes the high-temperature flue gas that remains q.s in the flue, guarantees that vapor recovery carries out continuously; Simultaneously the coal gas that does not meet recovering condition in the wet dedusting process is entered gasification cooling flue by feeding the qualified coal gas of converter of part, improve CO content in smoke and make it, reduce O simultaneously greater than 35%
2Content (consumes O as far as possible
2) make it less than 1%, satisfy the coal-gas recovering condition, the coal gas that reclaims in the steelmaking process as far as possible to be produced.2, bessemerizing early stage and later stage, by process for making as can be known, this stage CO and O
2Ratio is the maximum stage of gas explosion possibility in the limits of explosion scope, suitable feeding coal gas in high-temperature flue fully consumes the oxygen in the flue gas, guarantees whenever oxygen level is lower than 1%, eliminates the condition of gas explosion;
1# vapor-recovery unit: reclaim the steam that the gasification cooling flue heat-exchange system produces;
2# vapor-recovery unit: reclaim flue gas by 800~1000 ℃ of steam of reducing between 150 ℃;
High-temperature cyclone dust extractor: eliminate the above grit of 10um (removing oarse-grained kindling material in the flue dust), prevent that the kindling material of enough energy from entering coal gas system, eliminate explosion condition;
Tubular heat exchange: 1, reclaim 800~1000 ℃ of waste heats of reducing between 150 ℃.When 2, being lower than 600 ℃, if having the oxygen of q.s and kindling material will make generation gas explosion owing to flue-gas temperature.When flue gas enters the tubule footpath tubulation of interchanger fast by original big caliber flue, will make the flame in the flue gas lose communication space and velocity of propagation, kindling material extinguishes fast, eliminates the gas explosion condition;
The hosepipe superheater: it is overheated that saturation steam is carried out;
The waste heat boiler economizer: it is overheated that deaerated water is carried out;
Cloth bag or electric precipitator: flue dust is carried out smart dedusting, smoke content is controlled at 10mg/m
3Below;
Flow measurement device: the flow of measuring flue gas;
Gas blower: dedusting fan;
Gas chamber: reclaim coal gas;
The turbine generator system: the high temperature and high pressure steam that is produced by waste heat boiler enters steam turbine power generation, continues circulation through the condensed water of condensation of steam turbine and supplies with waste heat boiler.
Its high-temperature flue gas dry method dust characteristics are: flue gas is through high-temperature dust removal, cloth bag () dedusting, with dust content by 80~150g/m
3One step was purified to 10mg/m
3Below, to compare with original one-level Venturi meter, the dedusting of secondary Venturi meter, flow process obtains simplifying, and efficiency of dust collection improves greatly, and hot precipitator is removed oarse-grained grit kindling material simultaneously, fully reduces the possibility of gas explosion; Flue gas after the dedusting is just reduced to flue-gas temperature about 150 ℃ by 800~1000 ℃ of one step through waste heat boiler, and water is by preheating, evaporation, overheated three phases, and is accomplished at waste heat boiler.Obvious heat of smoke effectively is converted into steam generates electricity, make waste heat obtain effective recycling, suitable heat exchange structure reduces the possibility of exploding greatly; In the non-blowing process of coal gas of converter, by feed an amount of coal gas and air mixed burning in high-temperature flue, recovery waste heat guarantees the realization that gap of converter production steam reclaims continuously, and the Steam Recovery of Convertor amount almost is four times of wet dedusting.Simultaneously, in time, can guarantee that all the time the oxygen level in the flue gas is lower than 1%, also improve the yield of coal gas when waste heat is fully reclaimed the consumption of fully burning of the oxygen in the high-temperature flue.Make total system away from blast area; Total system is moved under air-tight state, and explosion-proof automatic control reliably makes this flow process safety and reliability in addition.The high temperature cyclone system is selected wear-resisting high-temperature components for use, under 1000 ℃ of flue gas operating modes, can steady in a long-term move; The dust that fly-ash separator is collected all is a dry dust, delivers to powder-storage bin by handling equipment and concentrates storage, regularly outward transport.This and wet method are removed the sludge treatment of getting off and compared, and be more energy-conservation, more environmental protection; This equipment layout is flexible, can be according to the place flexible arrangement, and floor space is little; Because dry method dust efficient height, reliable, make the whole stove of converter after environment improve greatly.
The invention has the advantages that: reclaim complementary energy to greatest extent and be used for generating, the continuous production of high-temperature flue gas solves the swollen shrinkage problem of equipment heat that the rapid heat cycle of former converter flue causes, and stable cigarette temperature has prolonged the work-ing life of flue equipment.And Design of device has guaranteed the security of coal-gas recovering, and has improved the pressure of converter steelmaking to environment.
Description of drawings
Fig. 1 is dry dedusting technology flow process and complementary energy retrieving arrangement synoptic diagram;
Fig. 2 is former Wet-way dust-collector synoptic diagram.
1 is steel-making converter among the figure, 2 high temperature immediate action valves, and 3 is combustion unit, 4 is gasification cooling flue, and 5 is the 1# vapor-recovery unit, and 6 is the 2# vapor-recovery unit, 7 is high-temperature cyclone dust extractor, and 8 is one-level hosepipe superheater, and 9 is tubular heat exchange, 10 is secondary hosepipe superheater, and 11 is the waste heat boiler economizer, and 12 is bag-type dust or electric precipitator, 13 is flow measurement device, and 14 is gas fan, and 15 are coal gas diffusion burning chimney, 16 is 1# drum feed-water intake, 17 is 2# drum feed-water intake, and 18 is vapour outlet, and 19 is coal-gas recovering, 20 is steel-making converter, 21 is gasification cooling flue, and 22 is vapor-recovery unit, and 23 is one-level Venturi meter dedusting heat sink, 24 is the gravity water trap, 25 is secondary Venturi meter dedusting heat sink, and 26 is elbow separator, and 27 for keeping off cyclone again, 28 is flow measurement device, 29 is gas fan, and 30 are coal gas diffusion burning chimney, and 31 is the drum feed-water intake, 32 is vapour outlet, and 33 is coal-gas recovering.
Specific embodiment
With elder brother's steel No. 6 removing dust from steelmaking convertor smoke by dry of three steel-making and complementary energy retrieving arrangement is example.
The converter technical parameter:
1, converter nominal volume: 50t
2, average smelting cycle: 33min
3, oxygen blow duration: 14~17min
4, maximum furnace gas amount: 35600m
3/ h (mark condition)
5, furnace gas export enters the temperature of petticoat pipe: the burning phase: 1400 ℃~1650 ℃
Payback period: 1200 ℃~1400 ℃
6, initial dust concentration: 80~150g/m
3(mark condition)
7, flue dust dispersity:
Footpath grain/um |
<0.5 |
0.5~1 |
1~2 |
2~10 |
10~40 |
>40 |
Combustion method/% |
50 |
45 |
5 |
|
|
|
Do not fire method/% |
|
|
|
30 |
53 |
17 |
8, flue dust main component: FeO Fe2O3 MFe CaO SiO2 other
67.2% 16.2% 0.6% 9.0% 3.6% 3.4%
9, gasification cooling flue: smoke inlet temperature: 1400~1650 ℃
10, one-level tornado dust collector: remove the above particle of 10 μ, efficiency of dust collection is: 90%,
11, primary superheater smoke inlet temperature: 800 ℃~1000 ℃
12, tubular heat exchange smoke inlet temperature: 800 ℃
13, tubular heat exchange exhanst gas outlet temperature: 450 ℃
14, two stage superheater smoke inlet temperature: 450 ℃
15, economizer smoke inlet temperature: 300 ℃
16, economizer exhanst gas outlet temperature:<150 ℃
The average-volume composition of the furnace gas when 17, bessemerizing:
18, the non-coal-gas recovering phase of converter is controlled the combustion product gases temperature that enters in the gasification cooling flue: 1400 ℃~1600 ℃ by the mixed firing of combustion air and coal gas of converter
Complementary energy reclaimed and consumes synopsis before and after scheme was used:
Ton steel converter waste heat complementary energy reclaims
The energy consumption of ton steel converter
As can be known, by suitable gas consumption, nearly 44 tons of the steam of 225 ℃ of 2.25Mpa can hour be reclaimed in 50 tons of converters from table, and this steam can also can improve the coal-gas recovering amount hour more than the generating 8MVA simultaneously after superheater is overheated, and economic benefit is considerable.
The configuration of main technique equipment:
1, steel-making converter: nominal capacity 50t;
2, high temperature immediate action valve: model specification: GFM-2000-I (nonstandard)
3, combustion unit: form model specification by burner and combustion chamber: GRSQ-30000/30000-I (nonstandard)
4,1# waste heat boiler (vaporization cooling heat transferring device+vapor-recovery unit), model specification: GTQ25/2.5-I-1 (nonstandard); Vapor pressure: 2.5Mpa; Heat exchange evaporation flow: 22t/h.
5, PV type high temperature high efficiency cyclonic dust collector, model specification: PV2 * (DN2800 * 16000 * 18mm) (nonstandard).
6, one-level hosepipe superheater, model specification: GRQ 50/2.5-I (nonstandard); Vapor pressure: 2.5Mpa; Superheat steam flow: 44t/h.
7,2# waste heat boiler (tubular heat exchange+vapor-recovery unit), model specification: GTQ25/2.5-I-2 (nonstandard); Vapor pressure: 2.5Mpa; Heat exchange evaporation flow: 22t/h.
8, two hosepipe level superheaters, model specification: GRQ 50/2.5-I (nonstandard); Vapor pressure: 2.5Mpa; Superheat steam flow: 44t/h.。
9, waste heat boiler economizer, model specification: GSQ 50/2.5-I (nonstandard); Feed pressure: 2.5Mpa; Feedwater flow: 50t/h.。
10, sack cleaner, model specification: LCM-D-1350.
11, gas fan, model specification: GFJ-105000-25000 (nonstandard).
The formation of this device: the high temperature immediate action valve is loaded on the movable gas hood below, combustion unit is loaded between movable gas hood and the gasification cooling flue, gasification cooling flue links to each other with high-temperature cyclone dust extractor, connects one-level hosepipe superheater, tubular heat exchange, secondary hosepipe superheater, waste heat boiler economizer, sack cleaner, gas fan and gas chamber more successively.
The high-temperature flue gas that converter smelting produces or the high-temperature flue gas of combustion air and coal gas mixed firing are introduced into gasification cooling flue, reclaim 800 ℃~obvious heat of smoke more than 1000 ℃ by the 1# waste heat boiler, carry out dedusting just through high-temperature cyclone dust extractor again, eliminate the above kindling material grit of 10 μ m, it is overheated through primary superheater steam to be carried out again, flue-gas temperature is guaranteed at about 800 ℃, obvious heat of smoke between the 2# waste heat boiler reclaims 450 ℃~800 ℃ again, it is overheated through two stage superheater steam to be carried out again, make flue-gas temperature be controlled at about 350 ℃, through economizer oiler feed is heated again, flue-gas temperature is reduced to below 150 ℃, carry out smart dedusting through sack cleaner again, make smoke content reduce to 10mg/m
3Below (mark condition), qualified coal gas cools after 60 ℃~70 ℃ by coal gas, enters gas chamber, and underproof gas-fired is diffused.