New 2014 castigatory " project of blast furnace puddling designs a standard " in regulation: The working fixed number of year of battle of furnace of blast furnace generation should achieve 15 years of above. During battle of furnace of blast furnace generation, the yield of cubage of unit blast furnace iron quantity should be achieved or be more than 1~1.5 10 thousand T. Current, blast furnace of our country great majority did not achieve afore-mentioned goals, especially a few in life of small blast furnace is in low-level phase generally, individual in occurrence life of small blast furnace is in 3 years of the following phenomena. Say so, improve life of our country blast furnace hard, it is a of puddling bound very main task, also be to raise blast furnace to produce efficiency and economic benefits, implementation puddling system is energy-saving the important step that decreases a platoon, the height that ought to cause steely industry leaders of all levels takes seriously.
1, the great sense of blast furnace long life
Blast furnace long life is steely company takes a when can develop continuously major move. The integrated iron and steel works produces content of each working procedure to flow is a closely linked. Stop production of blast furnace overhaul, can make the enterprise produces catenary to disconnect, cause puddling around working procedure to all want reduction in production, cause significant pecuniary loss to the enterprise, product output falls, facility work rate falls, economic benefits glides substantially; at the same time, pay a huge sum fund for overhaul blast furnace even, the overhaul charge of a large blast furnace is in 100 million yuan or so about.
Around of blast furnace overhaul, all want those who increase company natural resources and the sources of energy to use up, contaminant is discharged also should increase, cause bigger negative effect to producing an environment.
The great sense of blast furnace long life, be versed in in puddling not only foreword itself, and also can bring tremendous effect to whole integrated iron and steel works, include to produce cost to reduce, the sources of energy is used up decrease, contaminant is discharged decrease, those who realize an integrated iron and steel works is efficient change production, successive change and compact change production to be able to continue undertake. Prolonging blast furnace life is not only but charge of direct and managing overhaul, and of the stop production loss that because heavy repair,still can decrease and causes and economic benefits rise.
2, the target of blast furnace long life works
The blast furnace design that the basis already mastered now, material and facilities alternative and make, construction, blast furnace is operated and safeguard the advanced puddling science and technology that waits for a respect to develop the current situation, blast furnace life can have achieved following goal:
Furnace life of blast furnace generation (in undertaking, repair) in; of 15 years of above
Blast furnace can is in daily efficient change, automation, successive change, long life is changed, the stability with manufacturing process friendly environment produces condition, furnace of unit of generation blast furnace allows quantity yield iron to be able to be in; of above of 12 thousand T/m3
Take all significant technology step (include section to tear open outfit, crucible beforehand the) such as build by laying bricks or stones, big limit ground shortens time limit for a project of blast furnace overhaul (overhaul of general and large blast furnace should be in) of 2 months less than, optimize stop furnace and technology of operation opening furnace, implementation stops scientificly furnace and amount to quickly produce, because couplet of blast furnace overhaul adds up to the adverse effect of the enterprise,reduce.
According to statistic, the main reason with at present small life of our country most blast furnace is difference in temperature of damaged of crucible carbon brick, water elevatory, make the weak point of blast furnace long life.
3, the concept of blast furnace long life
Blast furnace long life is a systematic project: Include blast furnace design, the assurance of quality of the choice of material and equipment, construction, the science that blast furnace operates and stability, charging contains the control of harmful impurity, the maintenance of body of heater and management, the scientific processing of lash-up accident. There is immanent and mutual associated factor between afore-mentioned each elements, mutual influence, also have complementary effect.
The core technology of blast furnace long life is the reasonable furnace that form and safeguards good generation blast furnace model, those who had protected intermediate sex lining is complete.
4, carry out seriously " design of engineering of blast furnace puddling is normative "
National construction ministry and quality were supervised in July 2014 examine quarantine total bureau is announced newly jointly " design of engineering of blast furnace puddling is normative " , GB50427-2014. This standard shares 21 chapters, main content has: Fuel of general principles, term, main provision, raw material and technical index (index of technology of production of raw material fuel, blast furnace, condition sending wind) , general drawing is carried, mine chamfer anxious chamfer and on iron of field, hot-blast stove, broken bits handles platform of makings system, roof, body of heater, a place with a draught and taphole. Having many content among them is as macrobian as blast furnace implementation about, it is to fill fission to reveal the blast furnace long life that pays attention to whole to optimize a design, undertake all-around improvement, execute integrated processing, of efficient and cooling equipment and high quality fireproof lining match effectively, the high quality former fuel that ensures the service mass of synchronous and macrobian; of each place stabilizes blast furnace, assure next taking to blast furnace produces the premise that; of stable direct motion is reducing puddling fuel to compare high yield; is used monitor and defending a measure effectively is long life of implementation blast furnace is important assure.
The design is a foundation, this is the premise of blast furnace long life:
(1) notices to design deepness of appropriate dead iron layer. Those who reduce molten iron is fore-and-aft and circumfluent with circumferential direction circumfluent, avoid as far as possible in iron mouth area of 300-500mm of two side lower part is handed in collect, form eddy current; to want to consider the impact of molten iron quiet pressure to carbolic brick again.
(2) cooling system optimizes a design. Cooling power size and whether produce effect adequately, it is the crucial factor that decides crucible life. The fireproof material that the cooling system with working good position can make crucible build by laying bricks or stones is built does not produce overheat, lengthen working life; a few experts think, cooling water capacity is insufficient often crucible burns the main reason that wear, accordingly, when cooling system is designed, should take the water amount that refrigeration of aggrandizement of later period of battle having stove needs.
The rationality of blast furnace furnace design, it is implementation high yield the fundamental condition of high quality, low cost, long life and environmental protection. Reasonable furnace choice principle is requirement furnace model can suit very well to be mixed at dropping smoothly of charging coal air current stabilizes ground ascendant motion equably. The heat in the process is produced in blast furnace model be changing ceaselessly. The furnace when opening furnace furnace when be being designed namely. After blast furnace put into production, through period of time, the different position of boiler setting can be eroded by the charging of different level, chemistry is corroded, especially the boiler setting that soft frit heads section can get the chemical dip corrode of iron of high temperature, thermal stress, broken bits. In certain production the condition falls, the furnace after change can form a relative stability, suit at that time the working furnace of productivity (or call operation furnace) . Puddling worker should adopt all sorts of measure, make work hard furnace can maintain long, also can prolong blast furnace long life, those who realize blast furnace production is efficient change.
If unreasonable furnace appear, can make blast furnace index exasperate, want to undertake in time repairing, restore reasonable furnace model, it is wanted measure, be economy.
Current, apt of design of our country blast furnace designs “ dumpy model blast furnace, recommend use Bao Bigao inside furnace model dimension, windy mouth, layer of deep dead iron, use the characteristic such as equipment of refrigeration of soft watertight closed loop. Relevant and specific content will be in the following part undertake dividing narrating.
5, raise product level to be able to promote blast furnace long life
Blast furnace puddling is it is a foundation with product, product level is in to the influence rate of blast furnace production target 70% the left and right sides, macrobian to blast furnace influence also is very important.
Contain iron grade into charging tall the core that is product technology, high grade can bring enormous economic benefits, especially ton iron broken bits is measured under when 300kg/t is the following, not only be helpful for raising gush coal to compare, the permeability that raises furnace charge (especially soft frit takes) , make coal air current distributings even, stable, reduce brim coal to enrage those who shed pair of boiler setting to erode, stimulative blast furnace is macrobian. Current, technology of mineral separation of our country red mine already pass a barrier. Use the company of low grade raw material to taking ore deposit of a hunderd schools, ought to add mineral separation equipment, have low grade ore deposit reelection, can make the benefit of blast furnace times add. Reduce broken bits amount effectively, reduce puddling fuel to compare. Price of current entrance iron ore is reduced, be helpful for purchasing high grade ore. Industry leaders of all levels wants change idea, rise in effort raise blast furnace to go up into furnace iron grade reach consensus, can bring to the enterprise energy-saving decrease a platoon, fall the effect of cost.
Blast furnace long life asks to harmful impurity is contained to want in what using furnace charge little. Harmful impurity basically points to K, Na, Pb, Zn, F, S, As, Cl- to wait. In " project of blast furnace puddling designs a standard " in pointed out to harmful impurity the quantity controls a cost clearly (Kg/t) : K2O+Na2O≤3.0, zn≤0.15, pb≤0.15, as≤0.1, s≤4.0, cl-≤0.6. Loading area is opposite into alkali metal and fluoride the destruction of lining is quite serious, the material of low melting point that they form can cause tumor of knot of bricky line surface directly, exasperate blast furnace produces direct motion. Allow easy attaint boiler setting again when treating knot tumor. In shaft bottom charging by reductive vapour meets the metal of the low boiling point such as the lead that come out, zinc rise as coal air current, to area of the upside in shaft meeting deposit is seamed to the brick in, partial metal can get oxidation again, manufacturing oxide is met bulk expands, cause bricky line craze, damaged. In recent years, harmful impurity is contained to have apparent ascendant tendency in charging of our country puddling, this creates division of a place with a draught of a batch of blast furnace become warped on the brick, tumour of shaft upside knot, affected blast furnace badly to produce the long life with blast furnace normally. This respect, the enterprise blast furnace such as Hang Gang and day iron is having deep lesson. Should control charging strictly the content of harmful impurity, the dirt sludge with harmful to containing tall impurity (agglomeration nose removes dust ash and blast furnace hop-pocket remove dust grey) ought to undertake pretreatment reentry uses; integratedly all right or add these ash lime to build ball, dry, in rejoin converter (use scale is charging <5% , avoid occurrence boiling) the circular catenary that cuts off harmful impurity to return blast furnace. Saddle steel already had successful experience.
Attention: The K destruction to lining and charging action wants bigger than Na decuple above. The content that should control K strictly so (include coke, coal fines, ore) .
6, the option that blast furnace uses fireproof data
The design of body of blast furnace build by laying bricks or stones should be allowed according to furnace and cooling structure, and the working requirement of each place chooses high quality fireproof material. The choice of fireproof material quality and build by laying bricks or stones build quality to have huge effect to blast furnace life. Different position should choose the blast furnace of different cubage and blast furnace different fireproof material. Raise crucible, hearth and shaft quantity of constitution of build by laying bricks or stones of medium, bottom is the fundamental condition that prolongs blast furnace life. When buying fireproof material not only should have cold property, have hot property even, and the assurance of service life.
Blast tuyere takes appropriate to use assorted brick structure. Crucible, hearth should use charcoal brick or charcoal brick and data of pottery and porcelain complex formula construction, use build by laying bricks or stones of brick of high quality charcoal to build.
Severe be able to bear or endure material quality and construction quality close
(1) takes carbolic brick quality seriously: Take heat conduction seriously rate, permeability, fight oxidation rate, fight the; such as sex of corrode of the alkalescent, Tie Rong that fight broken bits from happen burn the brick of blast furnace carbon that wears an accident to detect in light of,
(The build by laying bricks or stones of brick of 2) crucible carbon is built should carry out strictly according to the standard, want to control over all dimension, sufficient roast strictly, because erode,avoid and often form air gap thermal resistance, block up crucible caloric derives, offerred passageway; fully for molten iron ooze even
(3) takes charcoal element seriously to pound the microtherm function of dozen of makings all the more, notice especially: Pound dozen of makings working temperature is general and inferior, using the thermal conductivity below high temperature to evaluate is unscientific.
6.1 shaft upside
Shaft upside appropriate uses wall of the refrigeration that set a brick. The concussion that line of shaft upside brick should be dropped by charging and wear away, the eroding when be risen even by coal air current, still have vapour of alkali metal, zinc and deposit carbon at the same time erode etc. For this, this place chooses to send the clay brick of density or brick of phosphoric acid clay or tall aluminium brick high. Shaft upside appropriate uses wall of the refrigeration that set a brick.
This place wants to replace a Liang Huo water tank with wall of refrigeration of nodular cast iron, can improve the cooling condition of this one area apparently, can better land has safeguarded this part furnace model, achieve the goal that prolongs blast furnace long life.
The bottom in 6.2 shaft and belly
This place appropriate uses wall of the aggrandizement cast-iron refrigeration that set a brick, cupreous refrigeration wall or dead plate of concentrated type copper, also can use dead plate and the form that cooling wall combines. The lining of this area basically is suffer vapour of alkali metal, zinc and deposit carbon erode, erode into broken bits first, charging flakes with what boiler setting thermal shock causes and of air current of high temperature coal erode etc.
This part appropriate uses freeboard alumina fireproof material, the firebrick; that if corundum not comes,union of stone brick, chromic aluminous silicate makes is brick of silica brick of carbonization of half graphitization —— , Si3N4-SiC, aluminous carbolic brick or tall aluminous brick. 1994, brick of aluminous carbon of small hole of Wu Gang and success of fireproof mill development, price is low as good as function, get popularizing in the steely enterprise such as saddle steel, Bao Gang. Carborundum brick has coefficient of thermal conductivity tall, fight the characteristic with thermal shock good sex, use in the bottom in body of heater aptly.
In the past, shaft bottom and belly use high quality fireproof material, will resist high temperature and chemistry are eroded. In recent years, this place uses cupreous refrigeration wall, undertake dredge to quantity of heat, wall of refrigeration letting copper forms stable broken bits skin to protect cooling facility, will realize the long life of blast furnace. When opening furnace, in the firebrick that build by laying bricks or stones builds a thick 50cm besides cupreous refrigeration wall or adventitious fireproof material, can make the service life of this part is in 15 ～ 20 years. The thermal conductivity of cupreous refrigeration wall is good, temperature of cooling wall body is even, exterior work temperature is very low, once broken bits skin falls off, also can form stable broken bits skin quickly, desalt the action of blast furnace liner, be helpful for using thin wall structure. So, use cupreous refrigeration wall, having apparent effect to prolonging blast furnace life, had gotten the general self-identity of bound of domestic and international puddling. But price of cupreous refrigeration wall is high, below tall smelt intensity, a few blast furnace also had appeared the problem of different level. Class blast furnace does not use 5000m3 of treasure steel Zhan Jiang cupreous refrigeration wall, can reduce cost, also those who realize blast furnace long life hold.
Bosh appropriate uses cast-iron and cooling wall or cupreous refrigeration wall, also can use dead plate of concentrated type copper or wall of cast steel refrigeration.
Appropriate of medium, lower cooling equipment uses belly and furnace stack aggrandizement set a brick wall of refrigeration of wall of cast-iron and cooling wall, cast steel refrigeration, copper or dead plate of concentrated type copper, the configuration of thin lining body of heater that also can use dead plate and combination of cooling wall photograph.
Design of style of blast furnace build by laying bricks or stones should be allowed according to furnace and cooling structure, and the working requirement of each place is reasonable choose fireproof material. Blast tuyere takes appropriate to use assorted brick structure. Crucible, hearth should use charcoal brick or charcoal brick and data of pottery and porcelain complex formula construction, use build by laying bricks or stones of brick of high quality charcoal to build.
6.3 crucible, hearth
" design of engineering of blast furnace puddling is normative " in put forward: Appropriate of blast furnace hearth uses water-cooling, sidewall of crucible, hearth should install effective cooling establishment, appropriate uses furnace casing starting a hole little, interface is little, easy construction, conduct heat reliable cooling means. The choice of the alternative that when using cooling wall means, should notice to the indeterminate form material between cooling wall and charcoal brick is reached between cooling wall and construction method, air gap appears in preventing to produce a course, those who affect crucible conduct heat systematic work effect.
Crucible, hearth should use complete carbon brick or structure of hearth of compound carbon brick, should use build by laying bricks or stones of brick of high quality carbon to build. It is very important to prolonging blast furnace life that large blast furnace uses carbolic brick, SiC brick. After using cupreous refrigeration wall, the weak point of blast furnace long life already changed crucible position from the bottom in shaft, belly, bosh. The focal point that increases macrobian to lengthening crucible life to already made blast furnace job so works. In recent years, the phenomenon with elevatory difference in temperature of water of occurrence crucible of a batch of blast furnace of our country, burn even wear. Ought to take integrated step, solve this respect problem.
Blast tuyere takes appropriate to use assorted brick structure, general use corundum not comes stone brick, or palm corundum brick, also can use NMA of brick of hot pressing carbon or NMD brick.
The reason that blast furnace crucible erodes has: Chemistry is eroded, the destruction of the oxidation of water vapour, zinc and alkali metal, thermal stress.
Use the brick of small hole carbon of tall thermal conductivity, cooling to crucible wall executes aggrandizement refrigeration, make broken bits iron forms remaining of caky 1150 ℃ temperature at carbolic brick in, should make be far from cooling wall. At present structure of crucible of domestic and international blast furnace, hearth is to have 3 kinds of basic kinds: Build for build by laying bricks or stones of chunk carbon brick, hearth sets pottery and porcelain to fill up; 2 it is brick of hot pressing is small carbon, hearth sets pottery and porcelain to fill up; 3 it is chunk or build by laying bricks or stones of small carbon brick are built, hearth sets cup of pottery and porcelain. 3 kinds of afore-mentioned configuration all have the practice example of blast furnace long life.
Domestic and international blast furnace already all used brick of brick of carbon of tall heat conduction, small hole carbon and structure of mat of pottery and porcelain. The blast furnace that tall gush coal compares, emphasize wanting active crucible center on the operation, ask hearth center wants to maintain proper temperature again. Accordingly, people takes the block that pottery and porcelain fills up seriously to heat up action gradually, also take what pottery and porcelain fills up life seriously to rise, the hope can obtain the moderate of hearth center temperature.
Aggrandizement refrigeration forms caky layer theory: The fireproof data that has tall heat conduction is used in crucible sidewall [600 ℃ , 18.4W/(mK) , 20 ℃ , 60 ～ 80W/(mK)] . After undertaking aggrandizement cools, tall heat conduction is able to bear or endure the osmosis that material, low porosity can prevent broken bits iron, have Gao Kang alkaline property, can absorb partial thermal stress, deserve to condition of efficient water refrigeration system falls, can deliver the quantity of heat of crucible quickly cooling water, outside giving area of quantity of heat heat, can reduce the temperature gradient of crucible wall effectively, be able to bear or endure in crucible sidewall lining thereby the coagulation that the hot side of material forms a stability covering layer (namely molten iron is caky under 1150 ℃ isothermal, make hearth forms) of stable covering layer of “ iron carapace, resist crucible parietal “ is eroded like the foot, acquire crucible long life then, its key is ability of crucible parietal heat conduction. This part chooses to be able to bear or endure the key of material is thermal conductivity, prevent osmotic and those who prevent to produce annular crack is high quality be able to bear or endure material. To the maintenance of crucible, it is the effect that emphasizes developing refrigeration, cool in time to crucible mural water difference in temperature and furnace skin temperature undertake monitoring, often have be in the milk to forming the place of space easily.
The integrated hearth that takes hearth refrigeration is more reasonable construction. There is carbon to pound a layer on cooling pipe, above its on build by laying bricks or stones 2 ～ 3 carbon brick. To differring place should use the carbolic brick of different function. Iron mouth is the place that is eroded badly easily below, the carborundum brick; that should appear the ground floor of the hearth of; of brick of small hole carbon with tall sex to want appliance to have tall thermal conductivity with impervious is other place is to use common carbon brick or brick of small hole carbon. The length of brick of circumjacent to the hearth under iron mouth carbon should increase, counteractive iron and alkali metal are permeated strongly to here and erode the aperture between ability; brick and brick in order to raise its to want will wide seam instead fine seam (<0.5mm) undertakes build by laying bricks or stones is built.
To having the integrated hearth structure of cup of “ pottery and porcelain, learned open to question. A few people think the effect of cup of “ pottery and porcelain is big, should grant to strengthen; another some of person thinks, cup of “ pottery and porcelain can disappear inside proper time, carbolic brick has dominant effect, also use what molten iron permeates Gao Kang and tall thermal conductivity, high density spends to press small carbon brick in crucible sidewall. Comment on the whole, two kinds of means have actor drawback each, all can realize blast furnace long life, economic cost somewhat difference.
The small hole of high quality, exceed brick of small hole carbon (the carborundum brick of high density is to be in be more than 1400 ℃ , the roast below condition of 8 hours of above) and after pressing small carbon brick to get popularizing, life of our country blast furnace gets rising significantly.
The brick of small small empty carbon that beautiful couplet carbon produces, hot pressing shapes, without high temperature roast, it is to be similar to our country to burn charcoal brick oneself for its essence, it applies to complete carbon structure, if use its at structure of cup of pottery and porcelain,do not apply to; of structure of cup of pottery and porcelain, carbolic brick does not have the opportunity of roast, once cup of pottery and porcelain damages, brick of carbon of molten iron contact causes corrosion easily and appear leakage iron or burn if be used in complete carbon structure,wear accident; , carbolic brick is attainable from roast, bricky quality is good, build by laying bricks or stones builds a standard, can acquire long life, 3 4350m3 blast furnace uses Bao Gang it, furnace life achieves 19 years, brick of the small hole of this kind of hot pressing that our country produces oneself is small carbon, quality is good, do not compare the difference of beautiful couplet carbon, but the life of partial blast furnace is brief, its reason depends on build by laying bricks or stones building quality to differ, build furnace management to be short of namely break or do not reach the designated position, build by laying bricks or stones is built with the oar undeserved, the brick has been seamed air gap appears after creating go into operation greatly, even brick of molten iron edge is seamed permeate.
Learned, brick of carbon of small sky of small to using hot pressing, have different view. Think to be below temperature of 800 ℃ roast, carbolic brick cannot get char, build by laying bricks or stones builds aperture big, use cup of pottery and porcelain again, crucible carbon brick did not form beautiful state, can affect life of blast furnace crucible.
Home is large and medium-sized whether was blast furnace basically decided use charcoal makings to pound dozen of hearth, make the engineering technology of carbolic brick from roast.
7, lining build by laying bricks or stones is built
Build by laying bricks or stones of blast furnace lining is built is to have metallurgy industry regulation, each construction team all also has with steely industry consensus " blast furnace builds furnace manual " , the article is divided no longer narrate. The standard brick that uses to place, nonstandard brick, also relevant build by laying bricks or stones builds a standard. It is in concrete step the rate that in building, implements wants to undertake in time check and be supervisoried only. Current, affecting build by laying bricks or stones of blast furnace liner to build the main problem of quality is, the brick of body of each place build by laying bricks or stones seams effective control to be worth, especially the discretion that build by laying bricks or stones of brick of crucible, hearth builds mass, macrobian to blast furnace impact is bigger. Watch 1 for blast furnace brick of body of each place build by laying bricks or stones seams ply.
8, system of refrigeration of blast furnace body of heater
Appropriate of blast furnace body of heater, hearth uses soft watertight closed loop to cool. In fountainhead the area with enough, good water quality also can use refrigeration of loop of industrial water open a way. To blast furnace lining should undertake cooling. Cooling action: It is to reduce be able to bear or endure the temperature of material, make its retain particular strength, the furnace that can manage reasonable operation, implementation lengthens blast furnace life and safe production; 2 it is to make lining form carapace of skin of protection broken bits, iron and black lead layer, protect lining and replace lining job; 3 it is protective furnace casing and metallic component, avoid the effect that suffers high temperature to reach reduce damaged; 4 it is a few refrigeration lining of the part that prop up arrives since equipment.
8.1 cooling medium are phyletic
Cooling medium has water, wind, vapour 3 kinds. What use generally is water, its thermal capacitance is big, conduct heat coefficient is big, facilitate carry, cost is low, it is idealer cooling medium.
Natural water should be reached through precipitation filter after processing, want the suspension matter foreign matter in purify water, and deliquescent impurity did not produce change, call common industry to purify water. In our country south, cost of the PH in water is low, its hardness <3.57mmol/L, under 40 ℃ , suspension content <200mg/t, usable.
" project of blast furnace puddling designs a standard " in regulation: With Jiang He the surface water such as water, lake water is raw water, when the water that produces low hardness via groovy processing, blast furnace can use system of cooling water of open circuit loop. Be in the area with water quality tall or higher hardness, answer manufacturing new water to undertake bate, should use system of refrigeration of soft watertight closed loop. Be in the area that weather condition allows, appropriate uses water of loop of air condenser refrigeration.
Bate water: The calcium in passing sodium ion ion exchange agent and water, magnesian ion has transition, namely bate processing, take out calcium, magnesium is ionic, reduce the hardness of water, obtain bate water.
The good point that blast furnace uses system of refrigeration of soft watertight closed loop is: It is cooling dependability tall, the 2 quantities that it is water use up cooling efficiency tall; little; 3 use up low; for motivation 4 for low; of water treatment charge 5 in shedding conduit for cooling water and do not have inside cooling component corrode, phenomenon of knot dirty, oxidation, also won't produce biology bilge; 6 detect to applied what Gao Lingmin spends leak hunting system, can undertake to every cooling loop discharge, velocity of flow, actuating pressure and pressure drop the essence of the circumstance follows an analysis.
8.2 cooling means
" project of blast furnace puddling designs a standard " in regulation: Blast furnace body of heater, hearth should use soft watertight closed loop to cool. In fountainhead enough, the area with good water quality can use refrigeration of loop of industrial water open a way.
Cast-iron and cooling wall asks the amount containing oxygen of water quality is small.
Blast furnace should use water water quality and pressure demand according to differring, install water supply respectively, answer to string together class to use according to the requirement with different water quality and warm water.
A form canal that the refrigeration of hearth is had have return by conformity is medium, should one expands coal tub. Detect in flow control and leak in, should make its wave motion amounts to the degree of ±0.3% .
Execute section water supply: Big blast furnace adopts hearth belt of refrigeration of cooling, iron mouth area, soft frit is cooling, the cooling departure of shaft undertakes.
Intensity of 8.3 thermal current and cooling water are measured
Thermal current intensity is to show cooling medium cools from every 1m2 the quantity of heat that area place area gives. The cooling area of blast furnace should be a basis to have consideration with the watch area inside furnace casing.
Those who use cooling wall inside exterior accumulating has consideration as cooling area. The area with large intensity of blast furnace thermal current is in shaft bottom. Shaft is lower thermal current intensity is erode degree as bricky line and have very big change. Be eroded completely in bricky line, or when because operate conditional change to cause broken bits skin,falling off, the thermal current intensity of this part will be acuteness rise. The numerical value that shows at this moment is value of intensity of big thermal current. Susceptive of place of equipment of refrigeration of initial stage opening furnace is value of intensity of small thermal current. In whole furnace the arithmetical average of intensity of the thermal current inside battle period makes the same score soaking to shed intensity to be worth. The referenced value of thermal current intensity sees a table 2.
The level that safety of 70 time hearth operates the century on sets: <16.7MJ/m2h of intensity of hearth thermal current is normal value, achieve 29.3 MJ/m2h to be worth to call the police, achieve 33.6 MJ/m2h to be cautionary value, achieve 50.23MJ/m2h to be breakdown state. Thermic load achieves 12000kcal/m2h is critical condition.
Big negative charge of the system is the summation of the great value of intensity of each section thermal current and their area product. It is one of main parameter that decide cooling system capacity.
When cupreous refrigeration wall uses industrial water to cool, its water fast be more than 2m/s, the hardness of water is less than 8, avoid to produce horniness to dirty, need to undertake regularly antiseptic without alga. When using soft water or pure water refrigeration, ask water fast be more than 1.5m/s.
Body of heater: It is advisable that cooling water pressure wants taller than force of furnace internal pressure 0.1MPa. To prevent deposit of content of float of water horizontally pivoted hung, low water fast should be more than 0.8m/s. Cooling water of blast furnace a place with a draught fast > 7.2m/s, the cooling water of blast furnace a place with a draught of 2000m3 above cubage fast > 9m/s. Water consumption of refrigeration of blast furnace body of heater is with every stere effective cubage uses up water quantity to express hourly. Blast furnace is effective volume is larger, water consumption of unit volume hour can decrease relatively, its consult data sees a table 3.
8.4 safe water supply
" design of technology of blast furnace puddling is normative " put forward: Blast furnace installs safe water supply. Label mandatory clause, strict requirement. 50% what the ration of pump of safe water supply is norm internal circulating load, lift and dynamoelectric loop pump are same. Requirement diesel engine starts time 15 ～ 30s. The pressure of cooling water depends on the water resistance caustic of condenser and force of furnace internal pressure. Every meters of pipe can consider the total block caustic of vertical refrigeration wall to be in for Bi of water of chamfer of backwater of platform of 0.27 ～ 0.78kPa; blast furnace low hydraulic should keep taller than wind pressure 50% . Area of proposal a place with a draught uses alone water supply, it is advisable that pressure is 1 ～ 1.6MPa.
8.5 water are gentle water difference in temperature
Blast furnace the thermal current intensity of each place and water fast, difference in temperature of water of lukewarm, imports and exports is having water to concern directly. The temperature that drink water is with atmosphere temperature and backwater condition are concerned, average company is: Summertime season is 30 ～ 35 ℃ , it is 23 ～ in the winter 25 ℃ .
8.6 water-cooling hearth
Water-cooling hearth relatively cooling strength is great by wind Leng Lu, specific power consumption is low. Current, domestic and international large blast furnace uses means of its water supply of; of water-cooling hearth form generally to be able to have two kinds, one kind furnishs by crucible catchment, another kind for water supply of manager of water supply of body of heater.
9, blast furnace body of heater is safeguarded
To body of heater each place lining undertakes monitoring, the margin that controls air current of the coal inside furnace develops, undertake gush fettling line and science are safeguarded wait for a method to all can have the effect that prolongs blast furnace life.
9.1 build perfect monitoring establishment
It is very important to undertake monitoring to cooling water difference in temperature, strengthen in place of blast furnace weakness especially monitor. At present major blast furnace is labour of choose and employ persons is monitored. Water difference in temperature is to reflect a corresponding position directly cooling wall bears the condition of thermic load, can judge the situation of lining damaged. Accordingly, ask every class all wants change of pair of circumstance of difference in temperature of cooling wall water to undertake surveying a record, undertake an analysis in time. To exceeding limit water difference in temperature metabolic place should take corresponding step in time. Especially the water difference in temperature of crucible place is elevatory should undertake science is judged in time, can adopt clean cooling wall, increase water supply pressure, increase water supply amount, reduce the measure such as amount of series connection of cooling wall water supply. When to difference in temperature of cooling wall water the value provides a value more than, can block corresponding place a place with a draught up, cloth accentuates appropriately brim ore, convert so that; of refrigeration of new water aggrandizement raises furnace temperature, undertake vanadium titanium mine protects the measure such as furnace. The monitoring system with good job can in time status of early-warning crucible job, take effective measures thereby, reduce crucible to burn wear a risk. Crucible of many blast furnace is burned wearing happen below the premise that does not have omen.
When blast furnace is built, all answer in liner of hearth, crucible, bosh, belly, shaft the setting surveys lukewarm plant a certain quantity ofly, the temperature that can master corresponding place liner directly, erode a circumstance, its sensitivity and dependability all prep above cooling water water difference in temperature.
Put the main problem that be in at present: It is monitoring point too little, 2 it is malfunction of the equipment that monitor.
Damaged of 9.2 cooling equipment is monitored and handle
Cooling equipment damaged is slack should discover in time, undertake in time handling. Slack can immediate impact reachs the life of crucible carbon brick after cooling equipment damaged. Carbon and black lead can oxidize in oxidation atmosphere gaseous, 400 ℃ can be oxidized, 500 ℃ and water produce aerification effect, begin to react with CO2 happening when 700 ℃ , all make CO gas, and make carbolic brick damaged. Carborundum also meets slow happening below high temperature condition oxidation. In crucible slack, it is the main source of oxygen. The place with serious damaged of crucible carbon brick discovers after many overhaul, great majority is there ever had been a large number of slack records in producing a course. So, slack to cooling equipment, must undertake in time handling. Especially blast tuyere is bad, do not allow to wait for collect to change to going again.
When cooling wall damage is serious, cooling club can be inserted in corresponding place () of condenser of copper of column form casting, press horniness fireproof mud, tenability blast furnace is produced normally. Cooling cliff bedding face accumulates damaged, can be in in when repairing, undertake changing. Backside of new cooling wall wants form a vesicle, the surface wants spray a fireproof material, should prevent to appear board the clearance between. To the second birth law of bad already cooling wall: The wave article that is less than wirereinforced suction hose with the diameter is in charge of (compression, stainless steel) wear cooling wall inner tube in. The fireproof stuff stuff with good thermal conductivity is used between two canals.
9.3 lining spray is repaired
In the later period that blast furnace produces, lining damaged is more serious, manage reasonable operation hard furnace, cooling equipment is exposed easily also come out, easy attaint. For this, have should stop furnace, control makings route, undertake coming loose shape is fireproof material gush fills (ordinary in season fills, spear gush fills and remote control gush fills) of 3 kinds of methods, adhere to in remaining brick or condenser surface of certain ply be able to bear or endure material, can replace the firebrick lining that new step builds, restore furnace model. Expect to make gush fills conglutinate force is powerful, a few rivet or iron network can be installed on pump motherboard. Wet gush fills should use water less, or need not water, can increase its strength. Gush fills maintained effect can come 1 year in 6 months above, peaceful of Min of big, Suzhou overcomes associated flourish and the enterprise such as enterprise of beautiful solid beautiful special grade all has better technical outstanding achievement.
After gush fettling line, blast furnace has reasonable stove model, good to coming true production target has major effect. The enterprise such as treasure steel, steel all has successful experience.
9.4 grouting mend a way
Aglow to furnace skin, gas collude with serious place, the position with high difference in temperature of water of crucible refrigeration wall can have be in the milk. Use special press facility, below constant pressure, pass conduit specific fireproof data from furnace exterior the position that carries need to safeguard, achieve fill the action that fills space and long fettling line. This is OK undertake maintaining to lining below ceaseless furnace circumstance. Buy of place of bureau of be confined to, the amount is smaller also. Pressing of form a vesicle has into maintenance fill up type is maintained maintain two kinds with the type that make line.
9.5. crucible is pouring
Wind gap is big the following, the boiler setting of above of line of iron mouth center undertakes whole pouring, use a kind of high strength, tall heat conduction, be able to bear or endure the stuff of new-style crucible liner that broken bits iron eats, more severe case is destroyed to fall in charcoal brick, can form a new lining. Its ply can be in 200-400mm. The Yao Xianqing before construction has managed, a few loose material also should clear. After raising good pattern, undertake pouring, pouring hind should undertake roast. Choose combination glory is great, or beautiful solid beauty is special pouring makings, the normal production that can come true several years.
10, blast furnace operation is safeguarded
Blast furnace long life is project of a system, want perforative in the whole process that produces at blast furnace, want to undertake be safeguarded meticulously and be operatinged to body of heater in producing a course, run from opposite directions 3 furnace initial stage, level that produce metaphase and furnace battle later period should adopt different maintenance method, will promote blast furnace long life.
The 10.1 high quality that assure cooling equipment are installed
Cooling equipment should undertake examining to factory hind, include the exterior and immanent quality. The exterior wants level, flawless, connect of conduit of pass in and out wants firm, silk buttons. Undertake sweeping first to cooling equipment, reentry connects ball experiment all right, undertake water makes the hour that control number connecting again, whether does observation have leak to wait.
Want to press concerned state level to undertake installing to of all kinds and cooling equipment, want to have construction inspect reason. Fine to installation cooling installation wants to undertake with high-pressured water conduit is swept, inside cleared canal sundry, should undertake those who count a hour try approach level. After purifying water to rinse with industry, should undertake chemistry is cleaned except rusty spot. The conduit after cleaning should undertake passivation beforehand velar processing.
10.2 reasonable operations opening furnace
Iron grade is used when opening furnace charging of generous of low, broken bits, in order to produce a large number of slag, form broken bits skin very quickly, protect lining, prevent coal air current erode.
The level of high furnace temperature that there should be proper time when opening furnace, make deposit of stable broken bits iron is formed inside crucible, also be helpful for the water portion inside lining be able to fill at protecting; of crucible, hearth with benefit distribute land evaporate, spill over.
Current, our country some blast furnace open furnace to execute amount to quickly produce, it is to go against lining water from evaporate, bricky line expands gradually fixed position, it is to go against blast furnace long life.
10.3 improvement charging quality, to optimize blast furnace the operation creates good condition
Charging turns bosomy intensity is high, granuality is even, contain harmful impurity little, metallurgy performance is good, can make blast furnace implementation efficient turn production. Charging quality is high, it is good to can make charging and soft frit take permeability, coal air current distributings even, gas pressure loss is little, be helpful for blast furnace undertaking aggrandizement smelt. " craft of blast furnace puddling designs a standard " the specific requirement that raised pair of charging quality.
10.4 have scientific material, air current of control brim coal develops
Use can realize big mine to approve without equipment of makings bell roof, dividing outfit, the center is added anxious, burn the material on the means such as cloth surely. Section chief operation can control the beyond the mark development of air current of coal of the brim inside furnace completely, reduce gas to boiler setting erode, it is to be helpful for blast furnace long life.
Later period of battle of blast furnace furnace, furnace irregular, brim coal air current is controlled not easily, broken bits skin is not stable, skin of local district furnace is aglow, cooling equipment easy damaged, blast furnace produces bad operation. At this moment, section chief people be about to had made full use of to fluctuate a step that regulates photograph union, use can promote the operation method that prolongs blast furnace life to have the job. For example, in cloth matrix change not big premise falls, region of escalate cloth mining area, face of makings of do one's best tends evenness, develop central air current moderately, restrain; of brim coal air current to change long a place with a draught in place of flimsy of cooling wall, a place with a draught, diameter of narrow wind gap, raise wind speed and blast kinetic energy, improve crucible job state to wait.
A few in small blast furnace uses strength of large wind force, tall smelt, achieve high yield, can develop brim coal air current overly, destroy boiler setting, make blast furnace life is reduced. Now, want puddling of change blast furnace to manage a concept, cannot seek high yield again, realize medium smelt intensity to operate, want to go after low fuel to compare, low cost, blast furnace long life.
10.5 undertake vanadium titanium mine protects furnace
In crucible difference in temperature of cooling wall water sets range more than when, want to undertake integrated technology analyses: Is the volume of water of cooling wall pass in and out with water elevatory difference in temperature normal? Whether does difference in temperature of circumjacent cooling wall water also have change subsequently? The speed with water elevatory difference in temperature and development trend how? Want to examine the historical record that water difference in temperature changes, should be opposite with exterior thermometer the furnace skin temperature of corresponding place undertakes the phenomenon undertakes be judginged integratedly metrical waiting. If affirm, difference in temperature of this cooling wall water rises report of high-energy enough bona fide to give this place lining to erode serious hind, want to take all significant step in time, fall value of water difference in temperature as soon as possible. Include cooling to this area wall to undertake sweeping, increase the pressure that connect water and water amount, can undertake cooling; technically with clean cold water even; of solid to be being applied inside this part furnace grouting blocks corresponding place a place with a draught up, change cast iron of refine high grade to wait. Mine of use vanadium titanium undertakes furnace is the effective method that has protective to lining of crucible, hearth protecting.
Vanadium titanium mine protects the mechanism of furnace: TiO2 is inside blast furnace but reductive become TiC, TiN and Ti(CN) of fuse-element of its link firm. Because the carbon of Ti, nitride is fused temperature is very high, pure TiC is 2950 ℃ for 3150 ℃ , TiN, the melting point of Ti(CN) solid fuse-element is very high also, they all rise to protect action to the liner of crucible, hearth. Maintain normal production to make blast furnace can continue, white of 3% essence of vanadium titanium magnet are joined in agglomeration mine, or use vanadium of 5 ～ 7kg/t titanium piece mine enters furnace, can produce the result that protects furnace.
Beginning phase, dosage of vanadium titanium magnetite takes the furnace charge that contain iron 2.5% the left and right sides, the Ti content in cast iron is in 0.10% ～ 0.15% . Keep period of time, the difference in temperature that need water drops somewhat, when relative stability, reduce dosage of vanadium titanium mine stage by stage, maintain after Ti is contained to be controlled in 5kg/t in every tons of cast iron can. During this, the water difference in temperature of cooling wall should be maintained it is under 0.8 ℃ .
11, build blast furnace long life to work beforehand case make
In blast furnace the meeting in producing a course for a long time encounters a few sudden incident and special situation, each puddling enterprise answers the preliminary plan of a few major sudden event and special situation processing. Preliminary processing program is a course of scientific Shen Mi ponder over next making to come out. Carry out beforehand case make can make the production of the enterprise and pecuniary loss little, blast furnace still attainable long life. Influential to blast furnace long life special situation lists the following kinds of situations:
◆ abrupt cut off the water supply, power cut is handled to the protection of cooling equipment.
◆ boiler setting writtens guarantee how processing of tumour of thick, knot has protected fireproof liner.
How is the processing washing furnace that ◆ crucible piles up operated.
◆ iron mouth gives the judgement of water and processing.
The crucible of later period of ◆ furnace battle is safeguarded, the judgement that lifts to local water difference in temperature especially and processing.
Blast furnace water supply should have go against stop a powerful person, when preventing to cut off the water supply, the current inside cooling system is broken.
12, blast furnace safe production
Crucible ooze iron or burn wearing is to be able to have sign, need operates personnel to observe carefully, discover as early as possible, apparent is crucible difference in temperature of cooling wall water is unusually elevatory, temperature of crucible parietal thermocouple is unusually elevatory. Cause elevatory reason to have two kinds: One kind is the dot lifts, another kind is the face lifts, because this wants serious observation and analysis,be the dot lifts or the face lifts, molten iron or change of gas edge aperture come out to cause the dot lifts, the face lifts great majority is bricky line corrodes, operation personnel should observe an analysis seriously according to the circumstance, reach scientific conclusion, adopt different measure processing.
Difference in temperature of occurrence water of crucible of a few blast furnace is elevatory, because of,be carbolic brick damaged, because have water infiltration,damaged is. So, want to take strict precautions against the ooze water to crucible. Cooling wall damaged, blast tuyere is bad, must change in time, have main effect to blast furnace long life.
Difference in temperature of cooling wall occurrence water is elevatory, unusual the processing of the circumstance:
After difference in temperature of 1) occurrence water is unusually elevatory, can show data according to thermocouple, ply of remain of computational boiler setting, if do not have thermocouple to be able to pass the discharge of cooling wall and difference in temperature, cipher out thermal current, divide again gain thermal current strength with cooling wall area, calculate leftover ply again. If leftover ply is less than 300mm to should stop furnace to heavy repair if; is more than this value, be about to adopt want measure to protect furnace, should take step of the following lash-up:
① blocks the blast tuyere; of temperature high position up
② increases cooling water amount, good drop the temperature that drink water, or raise hydraulic;
③ reduces intensity of blast furnace smelt, for example short-term fall 20% or so;
④ adds the makings that contain Ti to protect furnace, ti contains in should achieving molten iron commonly: 0.15%~0.2% , when ply of bricky line remains is thinner but short when increase 0.25% . Additional, answer to contain molten iron silicon to raise 0.45% above at the same time, should make the Ti+Si=0.6% in molten iron is controlled (do not answer under 0.5%) , form TiC in molten iron with benefit, tiN and separate out of black lead carbon form covering layer;
Cool furnace answers when ⑤ is serious, should make molten iron contains Ti to be in before cool furnace 0.2% or 0.25%;
2) strengthens taphole management, lower taphole rate, assure; of iron mouth length
What 3) water difference in temperature lifts is local undertake form a vesicle is handled, the effect will be better;
Because charging is harmful,4) part blast furnace is matter content is exorbitant, make crucible carbon brick is destroyed, the water difference in temperature that cause is elevatory, should short when in dropping furnace charge substantially harmful matter content, strengthen the; that protect furnace or undertake low alkalinity is operated, fixed platoon is alkaline.
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