Metallurgy is holding main position all the time in fireproof data industry, iron and steel can relapse reclaim use, it is useless no matter steel reclaims or ore agglomeration fine needs fireproof data, every production gives a ton of rolled steel is to should use up certain proportion to be able to bear or endure of material, how does refine become introduce iron and steel for everybody today, what flow technology is there? Furnace of induction having core is to core crosses inductor to use power supply of labour frequency power source, use the device that electromagnetism induction principle makes metallic charging calorific and fused. Furnace of induction having core is had heat tall, metal burns fast, productivity caustic little, operation is convenient, invest little, economic benefits to wait for an advantage significantly, apply extensively at changing iron, change copper, change zinc, change the industry such as aluminium, have its advantage to the stock of smelt of onefold breed big batch especially. The choice that core induction furnace uses fireproof data is very fundamental, matter to the use effect of furnace directly. Furnace having core is with fireproof material cent: Back line is fireproof material and lining are fireproof material, material back line is brick of paper of heat preservation of pottery and porcelain, heat preservation and heavy qualitative brick commonly; And lining material, in body of heater, the place such as laryngeal and inductive body should press the sort of fusion metal, fusion temperature choose different fireproof material. 1, the structure of furnace of induction having core and working principle have core furnace cent to be fluctuation body of heater, body of heater has furnace lid, the chamber of a stove or furnace on; Next body of heater are inductive body, channel having frit, furnace itself is equivalent to a transformer that brings core, induction coil is equivalent to the primary coil of transformer, the metal in frit channel is equivalent to 2 coil of transformer. When introducing the alternating current of industrial frequency primary coil, pass electromagnetism induction, very big electricity produces in lieutenant general of frit channel metal. Below the action of thermal convection current and electric magnetism, the quantity of heat inside frit channel delivers the metal in forge of frit channel upside ceaselessly, make the metal inside whole bath fused thereby. Because close there is ability of core induction furnace to move normally below condition in frit channel only, so comfortable at activity in series. 2, furnace of induction having core is departmental the use requirement of a fireproof material has core induction furnace to be furnace lid, the chamber of a stove or furnace, laryngeal and frit channel by place cent 4 parts, the life that its laryngeal and frit channel are furnace of crucial and immediate impact and moving cost. Because 2.1 furnace lid are not contacted with fused metallic fluid, furnace lid is opposite to the requirement of fireproof material more comfortable, should have fight ability of high temperature radiate, heat preservation performance is good, combinative strength is high, won't drop. Mix by heat-insulation layer commonly hot facing is compound form, form by light qualitative insulation material and heavy simple fireproof stuff namely. The service life of liner of the chamber of a stove or furnace of 2.2 the chamber of a stove or furnace basically depends on the reaction between composition is eroded in fireproof material and broken bits, because this asks fireproof material is below the metallic liquid effect that experiences high temperature for a long time, chemical stability is close friends, can resist of metallic fluid and broken bits erode. Fireproof material should have liner of the chamber of a stove or furnace enough normal temperature and high temperature intensity, high temperature resistant of metallic fluid erode strongly reach action of machinery of susceptive of counteractive body of heater; Have good bulk stability even, take iron mouth and taphole place especially, had not had after high temperature or refrigeration expand greatly or contract. 2.3 inductor inductor includes frit channel place, heal makings, build smooth makings and packing material. Frit channel: Furnace having core is metallic fluid heats through frit channel induction, in flowing circularly implementation warms up or the purpose of heat preservation. Because this asks Gan Shizhen is moved makings is long-term high temperature resistant and not bate, have fight goodly erode reach fight aggressivity, have good chemical stability and higher strength. Heal makings: Requirement and material of frit channel makings are qualitative identical or close, and have high fireproof performance and proper low temperature and high temperature strength. Build smooth material: The requirement has little critical grain, high fireproof performance, good daub sex. Packing material: The requirement has very tall fireproof property, prevent agglomeration of butt joint face to be together, assure butt joint face not leakage metal fluid. 3, the chooses 3.1 cupola to be versed in frequency has core stove efficiency that core induction furnace uses fireproof data and power factor photograph are taller than having core furnace, medicinal powder heat is little, economy is consequently good. The iron fluid temperature of big tonnage furnace is stabler, long heat preservation is little to ferroalloy composition loss, use overheat iron liquid so, raise mould temperature, can improve cast quality significantly, suit big batch serial production particularly. At present a few big companies use the heat of induction of frequency of labour having core of 30 T above, furnace cannot stop arbitrarily after opening furnace especially, move to grow better more continuously, restrict the account that furnace runs, often be lining fireproof material damages and be forced to stop furnace, so analytic lining mars a reason, improve fireproof material service life, it is the hinge that produces equipment advantage. The component of furnace of induction having core that uses at changing iron is: Grey iron furnace and ball iron furnace. Temperature of taphole of grey iron furnace is ℃ of 1420 ℃ ~1470, fused to grey iron furnace, slag shows acidity; Temperature of taphole of ball iron furnace is 1530 ℃ , the chemistry of broken bits changes along with metallurgy process and show soda acid to change alternately, lining should pick neuter and fireproof material. As a result of revulsion of the temperature after taphole, although take one part molten iron, but drop in temperature to also be in ℃ of 300 ℃ ~400, what if change,inductor falls is lower, the heatproof shake sex of liner of reason the chamber of a stove or furnace is close friends, it is iron fluid and broken bits and ball next change an agent to be opposite of liner of the chamber of a stove or furnace erode, and iron rolls the machinery of generation erodes and erode to the machinery of liner when fluid face is fluctuant, the high temperature strength with ask liner has particular and fight erode ability. The craze of the lining after marring a phenomenon to basically be taphole of the chamber of a stove or furnace, law of the interstitial established rule or practice that do not have solid and aperture width is bigger, hand in chunk of the generation when collecting to flake when freely crackle, still have iron fluid infiltration, accelerate craze rate, mar into iron opening position especially serious. The analysis enters structure of wall of caustic of iron mouth corrode, furnace to flake with corrode caustic, inductor writtens guarantee tumour blocks channel up to wait for generation reason, choose right fireproof stuff: Furnace lid: Use siliceous aluminous fiber to make liner mostly. Or heat-insulation layer pledges with tall aluminous alumina bricky pink and hollow ball grain are given priority to gently, what mud of aluminous acerbity brine is united in wedlock is pouring makings, complementary with anchorage firmware or anchorage solid brick, use refractory steel rivet and refractory steel network more, secure its go up in furnace lid housing. The chamber of a stove or furnace: Use electric frit corundum to be aggregate and powdery makings, the low cement that aluminium acid calcic cement and SiO2, Al2O3 exceeds small pink to be united in wedlock is pouring makings. Fight thermal shock sex to rise, pouring can join in makings right amount contain the SiC pink with low iron. Very old rate gets furnace liner life fireproof material life reachs inductor change the influence of the frequency, it is 2~3 commonly year. Inductor: Include makings of frit channel place, heal, Xiu Ping makings and packing material. Frit channel: Use MgO ＞ generally the MgO-Al2O3 of 79% does type vibration to expect character or pouring makings. The dry formula that heal makings uses as same as frit channel capable person to pledge commonly pounds dozen of makings or wet and pouring makings, when choosing Al2O3 to pledge heal expects, also can use aluminium acid calcic cement or phosphoric acid to make bond, when changing inductor quickly especially, use phosphoric acid bond, can prevent joint face occurrence blowout, improve butt joint speed and efficiency. Xiu Ping makings pledges for Al2O3-SiO2 commonly wet daub makings, critical grain is 2 Mm. Packing material uses Cr2O3 noodles or vermicelli made from bean or sweet potato starch generally, the firing temperature of MgO- Al2O3 material of the Al2O3 material that Cr2O3 compares the chamber of a stove or furnace or inductor is high, do not produce layer of agglomeration of pottery and porcelain basically below use temperature, at inductor and laryngeal of body of heater with benefit fireproof material departs. Carry out a proof, low cement corundum is qualitative pouring makings, be versed in in induction having core frequency furnace body of heater is used, be in what 1500 ℃ issue fuse-element of classics high temperature for a long time to erode with erode, body of heater does not have craze, flake wait for a phenomenon, service life amounts to 3 years of above; The heal makings that MgO-Al2O3 pledges Gan Shizhen uses makings and its form a complete set, Xiu Ping makings, packing material is in in the service life on 700 KW inductor above of half an year, and on other inductor service life amounts to 1~2 year. The 3.2 furnace that change copper have core to be versed in frequency induction furnace has electric efficiency tall, heat fast, metal burns caustic to wait for an advantage less, the brass that looks preexistence bound has 90% above and copper alloy are planted in this the fusion in furnace. Capacity of our country's commonly used frit copper furnace has 1.5 T, 2.0 T, 5.0 T, have 30 T greatly, fusion copper temperature uprights at ～ of 1 200 ℃ 1350 ℃ , frit channel amounts to ℃ of ~ 1 450 of 1 350 ℃ . Cupreous fluid viscosity is small, density is big, have very strong osmotic, and osmotic cupreous easy oxidation, accompany bulk to expand, cause lining to produce chap, flake, lower lining life thereby. The factor that affects lining life is very much, depend on channel of the choice of fireproof material, method that build furnace, roast system, frit is safeguarded and monitor, and frit channel appearance and furnace structure. The labour frequency of copper of our country fusion has core induction stove, pound dozen of makings arenaceously to although cost is low, roast,make liner with quartz fast, but life is brief, raise the raw material level with arenaceous quartz, in elaborate construction, maintain and safeguard below, service life can achieve 1 year commonly; Add steel fiber with fancy tall aluminous alumina, phosphate is united in wedlock pound dozen of makings or work brace up makings, service life is in 4~7 year. The accurate method that build furnace is the basic premise that makes sure frit copper furnace opens furnace to succeed. Choose pound dozen of makings suitably, its grain grading is reasonable, adding certain proportional andalusite, carborundum is the significant step that increases agglomeration strength. When building furnace, use statified give fall the means of feed in raw material of ply: The exterior layer of knot layer pulls hair and draw out fine pink, be helpful for the felt between makings layer. Use a center annular radiate type pursues a knot method outwards, 2 class pound dozen of craft close-grainedly, undertake drying-out of 3 paragraphs of type starts oven, effective extension furnace life. Life of liner of general body of heater and inductive body life are not synchronous, photograph of inductive body life than going up body of heater decreases greatly, pressing the copper alloy breed of fusion to use different material to pound dozen of construction also is one kind settles a way, if use quartz brassily arenaceous pound dozen of makings; Bronze, red copper uses carborundum to pound dozen of makings to wait, major company inductor fireproof material chooses frit channel place the gives priority to brilliant photograph with Molaishi and corundum fancy tall aluminous alumina with better agglomeration is given priority to, join right amount carborundum fine white, improve the wetability of material, of counteractive copper fluid strong osmotic, construction method can use phosphatic bond pound dozen of construction, perhaps use join the dry method vibration that aids agglomeration agent to shape construction, obtain better use result. Frequency of labour of the 3.3 furnace that change zinc has core induction furnace to be used extensively at electroanalysising cathode zinc piece the zinc such as alloy of founding, galvanizing, zinc processes a trade. Zincic melting point is 419.5 ℃ , temperature of the bath when normal dip zinc is controlled in ℃ of 460 ℃ ~485, frit channel is controlled in ℃ of 600 ℃ ~670, zincic fluid flows particularly easily, osmotic very strong, be eroded when fireproof material lining, generation crackle, zincic fluid enters crackle implode bad body of heater, cause frit channel mouth to jam reach the phenomenon such as zinc of inductive body leakage. At present liner of frit zinc furnace uses Al2O3 content 85% tall aluminous alumina of the left and right sides are qualitative pouring expect or pound dozen of makings, service life can amount to 4~8 year reach above. The service life of inductive body is concerned besides the element that waits for inductive body itself with induction coil, cold technology, insulation technology outside, closely related the service life of as fireproof as frit channel still material. Current and large body of double channel induction is used wet and pouring makings, body of only channel induction basically uses dry type to pound dozen of makings and wet and pouring makings, material chooses Molaishi to pledge more character or tall aluminous alumina pledges, service life can amount to left and right sides of half an year. Because the 3.4 furnace that melt aluminium have the activity in series of core furnace and low specific power consumption, a few large companies use furnace of induction having core extensively to fuse aluminous ingot, abandon the material such as aluminous material and aluminium alloy. Aluminous melting point is 660 ℃ , frit fluid viscosity is small, osmotic very strong, chemical active is tall, high temperature plays strong reducer effect, send unripe chemical response easily with fireproof material, be in especially fireproof material - aluminous fluid - boundary of gas phase three-phase, al reachs its alloying element, if the easy infiltration such as Mg, Si, Mn is fireproof material is medium, produce oxidation reductive reaction, bring about fireproof material metamorphism, the structure is loose and attaint. The lining material cent of furnace having core is furnace lid (basic and as identical as frit iron furnace lid) , the chamber of a stove or furnace, laryngeal and inductor frit channel 4 parts are fireproof material. The tall aluminous alumina that the chamber of a stove or furnace collects corundum of in order to, Molaishi generally to give priority to brilliant photograph in recent years is qualitative, what with aluminium acid calcic cement is bond is pouring makings, lukewarm in the expression when be being used below the condition such as adscititious expander intensity is high, expand condition, impervious is appeared, fight erode, service life can amount to 4~5 year. Laryngeal and frit channel structure are complex, basically use indeterminate form fireproof material, basically be the tall aluminium that gives priority to brilliant photograph with corundum, Molaishi pledges pouring makings, responses sign is not had in use process, fight erode, wear-resisting caustic. What aluminous to frit furnace should take aluminous fluid seriously particularly is osmotic, in entering air hole and crackle when aluminous fluid, produce reaction with respect to meeting and fireproof material, produce bulk effect, destroy liner, lower the service life of inductive furnace. Current aluminous industry does not touch aluminium pouring makings can show good aluminous fluid through joining the additive such as BaSO4 to wait not wetability, it is better also to join chromic corundum and nitrogen to change boron, but cost is higher; BaSO4 or CaF2 and Na3AlF6 compound join, and will pouring makings matrix undertakes leveling is handled, the osmosis of the fluid that fight aluminium performance is better. 4, the maintenance that the maintenance of core induction furnace has made oven of induction having core and monitor, discover the problem is handled in time, discover the part that liner damages especially, repair in time, it is to make sure furnace is run continuously normally, raise the important step of service life. Safeguard with monitor when furnace moves normally, should strengthen lining, especially of frit channel moving condition monitor with control. Had done daily maintenance to work. In process opening furnace, should control frit channel example strictly cast quality, what knot expects all round frit channel is compact degree, water-cooling covers cooling water discharge, temperature of the chamber of a stove or furnace, the craft element such as frit channel temperature and power input, break channel in case. Long-term since, frit channel accident is the main problem of furnace of induction having core, if processing is undeserved, cause body of heater extremely easily to discard as useless, produce all fronts stop production. To be being safeguarded of lining daily, should the following item: (1) any moment, do not get aleatoric cut off the water supply or power cut; (2) special caution wants in process of feed in raw material, avoid crack up hearth and clear in time the slag of frit channel upside; (3) the voltaic change case that often notes fused furnace and holding furnace; (4) the attention watchs frit channel figure; (5) decrease as far as possible stay furnace and place time, the operation is undeserved, often can cause frit channel to rupture; (6) gather up regularly except the slag inside the chamber of a stove or furnace, observe have without lump charging; (7) the cooling water that monitor is entered, the difference in temperature of exit; (8) measure body of heater and inductor surface temperature regularly, have comprehensive trade off study. Adopt fusion - heat preservation - the producer type that fusion has alternately, channel is broken when stopping furnace in order to prevent. Fireproof material occurrence craze, fall off, easy how to wear away to do? Want to solve a problem thoroughly, need to be dug from germ, the analysis gives real reason, flourish Cheng Naicai is engaged in be able to bear or endure service of timber production, research and development is old, can solve all sorts of difficulty problems of liner of furnace of high temperature kiln, offer kiln furnace liner to be able to bear or endure the production of material and construction service, welcome broad new old friend to seek advice reach technical communication.
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