Electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system
Technical field
The present invention relates to the industrial furnace flue gas and handle and the recuperation of heat field particularly a kind of electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system that is applied in the metallurgical steel mill EAF Steelmaking Process.
Background technology
Steel mill's electric furnace rhythm of production is generally accelerated at present, and the hot metal charging ratio strengthens, and exhaust gas volumn increases considerably when causing electric furnace smelting thus.For electric stove dust, be mainly concerned with the disposable problem of electric furnace flue gas waste heat recovery and waste heat.
Existing most electric furnace flue gas waste heat does not reclaim, and the flue gas final dusting when high-temperature flue gas one-time dedusting that produces when adopting electro-smelting and electric furnace charging, tapping merges the cover electric stove dust system that is set to.Wherein, a high-temperature flue gas of discharging from the electric furnace steam vent during electro-smelting, adopting lowers the temperature earlier cools off, the mode of back dedusting.High-temperature flue gas adopts secondary cooling usually, promptly adopts water-cooled flue once to cool off and adopts the air blast cooling device or natural air cooling device secondary cools off.But in this mode, electric furnace high-temperature flue gas waste heat does not obtain reclaiming, and has therefore caused the waste of heat energy.
At present, the electric furnace flue gas of only a few has adopted waste heat recovery reluctantly.For example: a high-temperature flue gas more than 1400 ℃ of discharging from the electric furnace steam vent during with electro-smelting, employing is sneaked into a large amount of air earlier and is cooled to below 700 ℃, dedusting again after the secondary flue gas when using heat pipe waste heat boiler recovered steam, the cooled flue gas of cooling with electric furnace charging and tapping then mixes.But in this mode, wasted very big energy and made system become huge because of sneaking into a large amount of air, the what is more important electric furnace flue gas is without dedusting, containing a large amount of trickle caking property dust in the high-temperature gas also will be bonded on the heat pipe heating surface, thereby increased maintenance workload and running resistance, reduced the heat transfer efficiency and the service life of heat pipe heating surface simultaneously.
Summary of the invention
In order to overcome the defective of above-mentioned prior art, task of the present invention is to provide a kind of electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system, it has solved above-mentioned existing in prior technology problem, electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system are divided into two parts, absorb electric furnace respectively at smelt stage and different flue gas reinforced, that the tapping stage produces, possess simultaneously that flue gas ash removal efficient height, amount of steam withdrawn are big, security of system stable operation, characteristic of low energy consumption, realized that electric furnace bears the energy consumption dedusting.
Technical solution of the present invention is as follows:
A kind of electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system, it comprises: a first flue gas dust-removal and residual neat recovering system, connect the electric furnace exhaust smoke hole, absorb the high-temperature flue gas that electric furnace produces in smelt stage; And an electric furnace flue gas final dusting system, absorb electric furnace at flue gas reinforced and that the tapping stage produces;
The water-cooled that comprises described first flue gas dust-removal and residual neat recovering system moves pipe, an apparatus for vapour-cooling, a high temperature resistant dust collector, a waste heat boiler, a dedusting fan and a chimney; Described apparatus for vapour-cooling has substituted original water-cooled flue and combustion chamber, and the inlet of apparatus for vapour-cooling moves pipe by water-cooled and is communicated with the electric furnace exhaust smoke hole, and the outlet of apparatus for vapour-cooling is communicated with high temperature resistant dust collector; The outlet of described high temperature resistant dust collector is communicated with the inlet duct of waste heat boiler, makes the flue gas after the dedusting send into waste heat boiler; The outlet of described waste heat boiler is communicated with chimney by pipeline, and waste heat boiler absorbs the heat of flue gas; Described dedusting fan is installed on the pipeline between waste heat boiler and the chimney;
Described electric furnace flue gas final dusting system comprises a collecting hood, a normal temperature deduster, a dedusting fan and a chimney; Described collecting hood is communicated with the normal temperature deduster by pipeline; The outlet of described normal temperature deduster is communicated with chimney; Described dedusting fan is arranged on the pipeline between normal temperature deduster and the chimney.
The present invention takes following further technical measures:
Described first flue gas dust-removal and residual neat recovering system also comprise: a bypass pipe, and its two ends are communicated with the pipeline of exhaust-heat boiler inlet and outlet respectively; And a transfer valve, be arranged on the bypass pipe, to open and close bypass pipe; One mixer selector valve is arranged on the bypass pipe.
Described first flue gas dust-removal and residual neat recovering system also comprise: a pressure-regulating valve is arranged on the inlet duct of waste heat boiler, with control electric furnace fire door pressure.
High temperature resistant dust collector in described first flue gas dust-removal and the residual neat recovering system comprises: an insulation and filter, a pulse spraying equipment, an ash conveying device, a control system and the connecting line between them; Described attemperator is arranged on the deduster housing, and filter filters equably by the outer dust in flue gas of passing towards filter bag inside of filter bag; The enabled instruction that described pulse spraying equipment receiving control system sends is carried out automatic ash removing to filter bag; Described ash conveying device is communicated to the bottom of high temperature resistant dust collector to collect dust.
High temperature resistant dust collector in described first flue gas dust-removal and the residual neat recovering system also comprises: the grey storehouse of a storage connects ash conveying device, to store dust.
Described first flue gas dust-removal and residual neat recovering system also comprise: a frequency converter connects dedusting fan, with the rotating speed of control dedusting fan.
Normal temperature deduster in the described electric furnace flue gas final dusting system comprises a filter, a pulse spraying equipment, an ash conveying device, storage Hui Cang, a control system and the connecting line between them; Described filter filters equably by the outer dust in flue gas of passing towards filter bag inside of filter bag; The enabled instruction that described pulse spraying equipment receiving control system sends is carried out automatic ash removing to filter bag; Described ash conveying device is communicated to the bottom of normal temperature deduster to collect dust.
Normal temperature deduster in the described electric furnace flue gas final dusting system also comprises: the grey storehouse of a storage connects ash conveying device, to store dust.
Described electric furnace flue gas final dusting system also comprises: a frequency converter connects dedusting fan, with the rotating speed of control dedusting fan.
Collecting hood in the described electric furnace flue gas final dusting system comprises: an enclosed hood, surround electric furnace; And the roof cover, cover cap is in the electric furnace top.
Described electric furnace flue gas final dusting system also comprises: two control valves are separately positioned on the pipeline between enclosed hood and normal temperature deduster, layer overhead guard and the normal temperature deduster, to control pipeline flow.
Electric furnace flue gas waste heat recovery of the present invention and negative energy consumption dust-removal system make it compared with prior art owing to adopted above technical scheme and technical measures, have the following advantages and positive effect:
Efficiency of dust collection height of the present invention; The amount of steam withdrawn height; In the first flue gas dust-removal system, save water-cooled flue and once cooled off and secondary cooling devices such as air blast cooling device or natural air cooling device, saved the repeatedly equipment investment of cooling and the wearing and tearing maintenance cost of booster fan impeller; Before waste heat boiler,, guaranteed normal stable operation and the heat transfer efficiency of waste heat boiler earlier to flue gas ash removal; Bypass pipe is set, can adapts to the needs that electric furnace working conditions change and waste heat boiler plant maintenance do not influence environmental protection and production; And is enhanced about more than once the service life of the huge filter bag of dust collector of electric furnace flue gas final dusting system scale, saved a large amount of operation and maintenance costs.
Adopt electric furnace flue gas waste heat recovery of the present invention and negative energy consumption dust-removal system, the steam that reclaims is converted to annual electric energy, then comprise the electric energy consumption that waste heat boiler is paid every year far above the electric stove dust system.
Description of drawings
Fig. 1 is by first flue gas dust-removal of the present invention and residual neat recovering system schematic diagram.
Fig. 2 is by electric furnace flue gas final dusting system schematic of the present invention.
Drawing reference numeral:
1 is the electric furnace exhaust smoke hole, and 2 for water-cooled moves pipe, and 3 is apparatus for vapour-cooling, 4 is high temperature resistant dust collector, and 5 is pressure-regulating valve, and 6 is waste heat boiler, 7 is bypass pipe, and 8 is transfer valve, and 9 is mixer selector valve, 10 is dedusting fan, and 11 is frequency converter or coupling device, and 12 is chimney, 13 is ash conveying device, and 14 are the grey storehouse of storage, and 15 is control system, 16 is electric furnace, and 17 is enclosed hood or semi-hermetic kuppe, and 18 is the roof cover, 19 is control valve, 20 is the normal temperature deduster, and 21 is dedusting fan, and 22 is frequency converter or coupling device, 23 is chimney, 24 is ash conveying device, and 25 are the grey storehouse of storage, and 26 is control system.
The specific embodiment
Specifically introduce a preferred embodiment of the present invention below in conjunction with accompanying drawing 1~2.
The present invention is divided into two parts with electric furnace flue gas waste heat recovery and negative energy consumption dust-removal system, and a part is to be used to absorb first flue gas dust-removal and the residual neat recovering system of electric furnace at the high-temperature flue gas of smelt stage generation; Another part is to be used to absorb electric furnace in electric furnace flue gas final dusting the system reinforced and flue gas (containing the partial fume that smelt stage is overflowed from furnace lid) that the tapping stage produces.
Referring to Fig. 1, first flue gas dust-removal among the present invention is connected electric furnace exhaust smoke hole 1 with residual neat recovering system, described first flue gas dust-removal and residual neat recovering system mainly move pipe 2, one apparatus for vapour-cooling 3, a high temperature resistant dust collector 4, a pressure-regulating valve 5, a waste heat boiler 6, a bypass pipe 7, a transfer valve 8, mixer selector valve 9, a dedusting fan 10, a frequency converter or a coupling device 11 and a chimney 12 etc. by a water-cooled and form.
Wherein, apparatus for vapour-cooling 3 has substituted the water-cooled flue and the combustion chamber of original laying in this position, and the inlet of apparatus for vapour-cooling 3 moves pipe 2 by water-cooled and is communicated with electric furnace exhaust smoke hole 1, and the outlet of apparatus for vapour-cooling 3 is communicated with high temperature resistant dust collector 4.The outlet of high temperature resistant dust collector 4 is communicated with the inlet duct of waste heat boiler 6, and the flue gas after the dedusting is sent into waste heat boiler 6.Pressure-regulating valve 5 is arranged on the inlet duct of waste heat boiler 6, with control electric furnace fire door pressure.The outlet of waste heat boiler 6 is communicated with chimney 12 by pipeline, and waste heat boiler 6 absorbs the heat of flue gas.Dedusting fan 10 is installed on the pipeline between waste heat boiler 6 and the chimney 12.Frequency converter or coupling device 11 connect dedusting fan 10, with the rotating speed of control dedusting fan 10.The two ends of bypass pipe 7 are communicated with the pipeline of waste heat boiler 6 entrance and exits respectively, and bypass pipe is set, and can adapt to the variation of electric furnace operating mode and the needs that the waste heat boiler plant maintenance does not influence environmental protection and electric furnace production.Transfer valve 8 is arranged on the bypass pipe 7, to open and close bypass pipe 7.Mixer selector valve 9 is arranged on the bypass pipe 7.
High temperature resistant dust collector 4 is made up of an insulation and filter, a pulse spraying equipment, an ash conveying device 13, the grey storehouse 14 of a storage, a control system 15 and the connecting line between them.On the deduster housing attemperator is arranged, filter filters equably by the outer dust in flue gas of passing towards filter bag inside of filter bag.The enabled instruction that pulse spraying equipment receiving control system 15 sends is carried out automatic ash removing to filter bag.Ash conveying device 13 is communicated to the bottom of high temperature resistant dust collector 4, to collect dust.Store grey storehouse 14 and connect ash conveying device 13, to store dust.In the present embodiment, the filter bag of high temperature resistant dust collector 4 adopts special high temperature resistance filtration material to make.
Referring to Fig. 2, the electric furnace flue gas final dusting system among the present invention mainly is made up of collecting hood, two control valves 19, a normal temperature deduster 20, a dedusting fan 21, a frequency converter or coupling device 22, a chimney 23, an ash conveying device 24, a grey storehouse 25 of storage and a control system 26 etc.Collecting hood comprises an enclosed hood or semi-hermetic kuppe 17, roof cover 18.
Wherein, enclosed hood 17 surrounds electric furnaces 16, and layer overhead guard 18 cover caps are in electric furnace 16 tops, and is communicated with normal temperature deduster 20 by pipeline respectively.Two control valves are separately positioned on the pipeline between enclosed hood 17 and normal temperature deduster 20, roof cover 18 and the normal temperature deduster 20, the control pipeline flow.The outlet of normal temperature deduster 20 is communicated with chimney 23.Dedusting fan 21 is arranged on the pipeline between normal temperature deduster 20 and the chimney 23.Frequency converter or coupling device 22 connect dedusting fan 21, the rotating speed of control dedusting fan 21.
Normal temperature deduster 20 is made up of a filter, a pulse spraying equipment, an ash conveying device 24, the grey storehouse 25 of a storage, a control system 26 and the connecting line between them.Filter filters equably by the outer dust in flue gas of passing towards filter bag inside of filter bag.Control system 26 detects the rising resistance of normal temperature deduster 20, optionally sends enabled instruction.The enabled instruction that pulse spraying equipment receiving control system 26 sends is carried out automatic ash removing to filter bag.Ash conveying device 24 is communicated to the bottom of normal temperature deduster 20, to collect dust.Store grey storehouse 25 and connect ash conveying device 24, to store dust.In the present embodiment, the filter bag of normal temperature deduster 20 adopts special normal temperature filtrate to make.
The operating process of electric furnace flue gas waste heat recovery of the present invention and negative energy consumption dust-removal system is as follows:
Electric furnace is at about 1400 ℃ of high temperature dust gases of melting generation in period, enter water-cooled by the electric furnace exhaust smoke hole 1 on the electric furnace and move pipe 2, apparatus for vapour-cooling 3 recovered steams also are reduced to about 550 ℃ gas temperature, enter high temperature resistant dust collector 5 purifying and dedustings then, clean gas after the dedusting enters waste heat boiler 6 recovered steam again, simultaneously gas outlet temperature is controlled at about 200 ℃, inserts chimney 12 qualified discharges by dedusting fan 10 at last.
In the high temperature resistant dust collector 4, dusty gas is outer when filter bag inside is passed by filter bag equably, dust is trapped in outer surface by filter bag and clean gas is passed through filter bag, along with thickening of filter bag outer surface dust layer, high temperature resistant dust collector 4 running resistances rise, control system detects Resistance Value, when resistance reaches going up in limited time of setting value, control system starting impulse spraying and blowing organ such as compressed air or nitrogen mechanism carry out automatic ash removing, dust is stripped from and is fallen into the bottom ash bucket and unloads ash, enter ash conveying device 13 to the grey storehouse 14 of storage, loaded, transport by the cleaning truck then.
Feeding in raw material as adding the dusty gas that steel scrap and hot metal charging and tapping stage produce for electric furnace 16, mainly capture by enclosed hood or semi-hermetic kuppe 17 and the roof cover 18 of cover cap on electric furnace 16, enter normal temperature deduster 20 purifying and dedustings by pipeline, the clean gas after the dedusting inserts chimney 12 qualified discharges by dedusting fan 21.Normal temperature deduster 20 bottom ash buckets unload ash and enter ash conveying device 24 to the grey storehouse 25 of storage.
In the normal temperature deduster 20, dusty gas is outer when filter bag inside is passed by filter bag equably, dust is trapped in outer surface by filter bag and clean gas is passed through filter bag, along with thickening of filter bag outer surface dust layer, normal temperature deduster 20 running resistances rise, control system detects Resistance Value, when resistance reaches going up in limited time of setting value, control system starting impulse spraying and blowing organ carries out automatic ash removing, dust is stripped from and is fallen into the bottom ash bucket and unloads ash, enter ash conveying device 24 to the grey storehouse 25 of storage, loaded, transport by the cleaning truck then.
The granular material discharged concentration of the electric furnace flue gas after implementing the technology of the present invention is marked m at 20mg/
3Below, system's running resistance is below 5kPa, and electric furnace ton steel amount of steam withdrawn is on average more than 190kg.Recovered steam is converted to annual electric energy and comprises the electric energy consumption that waste heat boiler is paid every year far above the electric stove dust system.For example, after the 150t electric stove dust adopted the technology of the present invention, the annual electric energy consumption of being paid amounted to about 2,000 ten thousand kWh/a, amounted to about 9,000 ten thousand kWh/a but the annual steam that reclaims is converted to electric energy, about 7,000 ten thousand kWh/a of actual annual callable electric energy have realized the negative energy consumption dedusting of electric furnace.
Technology of the present invention is applicable to the flue gas ash removal and the waste heat recovery of the newly-built electric furnace project of steel mill.Take: first flue gas dust-removal and residual neat recovering system are arranged with electric furnace flue gas final dusting system branch.The high-temperature flue gas that the electro-smelting stage produces is mainly born by first flue gas dust-removal and residual neat recovering system; The flue gas that electric furnace charging and tapping stage produce, system bears by the electric furnace flue gas final dusting.Adopt water-cooled to move pipe 2 and be connected with apparatus for vapour-cooling 3, apparatus for vapour-cooling 3 is connected with high temperature resistant dust collector 4, and high temperature resistant dust collector 4 is connected with waste heat boiler 6, and waste heat boiler is connected with dedusting fan 10; Bypass pipe 7 is set behind the high temperature resistant dust collector 4, and waste heat boiler is safeguarded does not influence environmental protection and electric furnace production; Before waste heat back boiler inlet, pressure-regulating valve 5 is set, with control electric furnace fire door pressure; Enclosed hood or semi-hermetic kuppe 17 are connected with dedusting fan 21 with roof cover 18; Dedusting fan all adopts frequency converter or coupling device arrangements for speed regulation.
Technology of the present invention also is applicable to the technological transformation to existing electric stove dust system.Take: the method that one-time dedusting systematic pipeline and equipment are separated from existing electric stove dust system: the deduster and the blower fan of existing electric stove dust system will be served the electric furnace final dusting, transform the combustion chamber in the existing electric furnace one-time dedusting system or expansion chamber and water-cooled flue as apparatus for vapour-cooling 3, remove existing air blast cooling device or equipment such as natural air cooling device and booster fan, keep existing water-cooled and move pipe 2.Newly-increased: high temperature resistant dust collector 4, pressure-regulating valve 5, waste heat boiler 6, bypass pipe 7, transfer valve 8, mixer selector valve 9, dedusting fan 10, frequency converter or hydraulic coupler-speed regulation device 11, chimney 12, ash conveying device 13, the grey storehouse 14 of storage and control system 15 etc.
In summary, use electric furnace flue gas waste heat recovery of the present invention and negative energy consumption dust-removal system, efficiency of dust collection height, particle are stabilized in 20mg/ mark m
3Below; The amount of steam withdrawn height, electric furnace ton steel amount of steam withdrawn is on average more than 190kg; In the first flue gas dust-removal system, save water-cooled flue and once cooled off and secondary cooling devices such as air blast cooling device or natural air cooling device, saved the repeatedly equipment investment of cooling and the wearing and tearing maintenance cost of booster fan impeller; Before waste heat boiler,, guaranteed normal stable operation and the heat transfer efficiency of waste heat boiler earlier to flue gas ash removal; Bypass pipe is set, can adapts to the needs that electric furnace working conditions change and waste heat boiler plant maintenance do not influence environmental protection and production; And is enhanced about more than once the service life of the huge filter bag of dust collector of electric furnace flue gas final dusting system scale, saved a large amount of operation and maintenance costs.
Certainly, those skilled in the art in the present technique field will be appreciated that, the foregoing description only is to be used for illustrating the present invention, and be not as limitation of the invention, as long as in connotation scope of the present invention, all will drop in the scope of claim of the present invention conversion, the modification of the foregoing description.