Knthl Super Electric heting elements Products nd ccessories
Knthl Super Electric heting elements Knthl is world-renowned brnd within the field of electric heting technology. The Knthl products offer possibilities for incresed nd qulity improved production for furnces while its long life cycle provides cost cutting due to less mintennce nd service. This hndbook is n id when instlling nd operting our Knthl Super resistnce elements tht re designed for ll types of electric heted industril furnces. When we introduced the now world-fmous Knthl iron-chromium-luminum electric resistnce lloys in the erly thirties this represented considerble rise in the mximum operting temperture of metllic resistnce elements. Agin, when Knthl Super molybdenum disilicide (MoSi 2 ) heting elements were introduced in 1956, this represented step upwrds on the temperture scle for resistnce elements. Specil fetures Knthl Super heting elements my be used in n oxidizing tmosphere up to n element temperture of 1850 C (3360 F) Long life combined with ese of replcing filed elements contributes to high degree of utiliztion of the furnce nd low mintennce costs New nd old elements cn be connected in series High power concentrtion my be pplied Cn be used continuously or intermittently Fst rmping Our im hs lwys been to constntly improve our mterils to enble their use t still higher tempertures. Through intense reserch work, we hve been ble to rise this temperture from 1650 C (3000 F) element temperture in 1956, to 1850 C (3360 F) tody. Knthl Super elements hve proved to be very useful not only t high furnce tempertures, but lso t lower tempertures, prticulrly in the field of het tretment of metllic products in controlled tmospheres nd melting of glss. The fields of possible pplictions re virtully unlimited nd hve yet to be fully explored. With the incresing interest in electric heting, we cn expect mny new designs nd pplictions in the future. In ddition to informtion on the properties of our Knthl Super mteril this hndbook will lso provide dt on our stndrd elements nd instructions for element instlltion, opertion, etc. Further, dvice is given on furnce designs, nd exmples of ctul Knthl Super element instlltions re shown in the instlltion section. The informtion provided in this hndbook enbles you to clculte nd instll the Knthl Super elements nd operte your furnces. Following the instructions you will get n efficient nd economicl instlltion of our equipment in your het tretment opertions. To get in contct with your locl representtive for further informtion, plese visit www.knthl.com or show this QR-code to your smrtphone.
Content Products nd ccessories This is Knthl Super 2 Guides for demnding pplictions 2 Properties 3 Resistivity 3 Chemicl resistnce 4 Performnce 7 Temperture dependence of resistivity 7 Element surfce lod 7 Wll loding 7 Oxide growth 8 Temperture loding digrms 9 Necessry distnces 11 Elements nd tubes 13 Two-shnk elements 13 Four-shnk elements 13 Tubes 17 Accessories 18 Element size 3/6 mm nd 4/9 mm 18 Element size 6/12 mm 20 Element size 9/18 mm 22 Element size 12/24 mm 23 Anchor system 24 Pssge bricks 26 Other ccessories 28
Products nd ccessories Rnge of Knthl Super 6/12, 9/18, 12/24 elements nd Superthl heting modules. 1
This is Knthl Super Knthl Super is dense cermet mteril consisting of molybdenum disilicide (MoSi 2 ) nd n oxide component, minly glss phse. Knthl Super heting elements hve the bility to withstnd oxidtion t high tempertures. This is due to the formtion of thin nd dhesive protective lyer of qurtz glss on the surfce. When MoSi 2 rects with oxygen in the tmosphere, the lyer of qurtz glss is formed nd under this thin lyer of molybdenum silicide with lower silicon content Mo 5 Si 3. When Knthl Super elements re operted t tempertures round 1200 C (2190 F) the mteril becomes ductile, whilst t lower tempertures the mteril is more brittle. The silic lyer possesses the cpcity to clen itself from dhering impurities. If the impurities rect with silic, the melting point will be lowered. The contminted lyer then flows down the element nd drops off. A new silic lyer is, however, spontneously rebuilt. Grdes for demnding pplictions Knthl progrm of MoSi 2 heting element includes severl grdes with specific fetures for use in demnding pplictions nd tmospheres. Knthl Super 1700 Knthl Super is unique mteril combining the best properties of metllic nd cermic mterils. Like metllic mterils it hs good het nd electricl conductivity nd like cermics it withstnds corrosion nd oxidtion nd hs low therml expnsion. Mximum temperture 1700 C (3090 F). Knthl Super 1800 Sme core chrcteristics s Knthl Super 1700. Mximum temperture 1800 C (3270 F). Knthl Super 1900 Sme core chrcteristics s Knthl Super 1700, but hs higher purity nd surfce with better dhesion. Mximum temperture 1850 C (3360 F). Knthl Super ER Knthl Super ER is new electric heting element with the unique bility to operte up to 1580 C (2875 F) directly in wide rnge of furnce tmospheres from very dry reducing to oxidizing. With Knthl Super ER heting elements it is possible, in just one furnce, to operte firing cycles where the tmosphere condition cn be ltered during the cycle between oxidizing, inert, crburizing, nitriding, reducing nd rough vcuum. Knthl Super RA Knthl Super RA offers long lifetime t high temperture in ll reducing nd oxygen deficient tmospheres. Specilly designed for working in nitrogen tmosphere. Mximum temperture 1700 C (3090 F). Knthl Super HT Knthl Super HT is designed for longer lifetime of smll dimension elements in temperture cycling conditions. The hot strength nd form stbility is improved. The mximum operting temperture is 1830 C (3330 F), nd the element is suitble for furnce tempertures between 1500 1750 C (2730 3180 F) pproximtely. Microstructure of Knthl Super element. Grey = MoSi 2, white = Mo 5 Si 3, drk = SiO 2. 2
Properties Knthl Super is unique mteril combining the best properties of metllic nd cermic mterils. Like metllic mterils it hs good het nd electric conductivity nd like cermics it withstnds corrosion nd oxidtion nd hs low therml expnsion. It is not ffected by therml shock nd is strong enough to withstnd mny yers of service s heting element. Resistivity The resistivity of Knthl Super increses shrply with temperture. This mens tht when the elements re connected to constnt voltge, the power will be higher t lower tempertures nd will be grdully reduced with incresing temperture, thus shortening the time for the furnce to rech operting temperture. Furthermore, s the power of the elements decreses, the dnger of overheting will be reduced. The resistnce of Knthl Super elements does not chnge due to geing even fter hving been in opertion for long time t high tempertures. There is only slight reduction ( 5%) during the first period of time. Due to these properties filed element cn esily be replced without the performnce of other elements connected in series being influenced. See pge 8, digrm Resistivity for Knthl Super. Mximum element temperture for Knthl Super Knthl Super ER 1580 C (2875 F) Knthl Super 1700 1700 C (3090 F) Knthl Super RA 1700 C (3090 F) Knthl Super 1800 1800 C (3270 F) Knthl Super HT 1830 C (3330 F) Knthl Super 1900 1850 C (3360 F) Mx. element temperture The mechnicl nd physicl properties of Knthl Super Knthl Super ER Knthl Super HT Other Knthl Super Tensile strength t 1550 C (2820 F) 100 MP ± 25% 100 MP ± 25% Bending strength t 20 C (68 F) 450 MP ± 10% 350 400 MP ± 10% 450 MP ± 10% Compression strength t 20 C (68 F) 1400 1500 MP 1400 1500 MP 1400 1500 MP Frcture toughness, KIC, t 20 C (68 F) 3 4 MPm 1/2 4 MPm 1/2 3 4 MPm 1/2 Hrdness, HV, t 20 C (68 F) 9 GP 8 GP 9 GP Density 5.6 g/cm 3 0.20 lb/in 3 7.0 g/cm 3 0.25 lb/in 3 6.5 g/cm 3 0.23 lb/in 3 Porosity < 5% < 1% < 1% Therml conductivity 20 600 C (68 1110 F) 600 1200 C (1110 2190 F) 30 Wm -1 K -1 30 Wm -1 K -1 30 Wm -1 K -1 15 Wm -1 K -1 15 Wm -1 K -1 15 Wm -1 K -1 Coefficient of liner expnsion 7 8 10-6 K -1 7 8 10-6 K -1 7 8 10-6 K -1 Specific het cpcity t 20 C (68 F) 0.42 kj kg -1 K -1 0.42 kj kg -1 K -1 0.42 kj kg -1 K -1 Emissivity 0.75 0.85 0.70 0.80 0.70 0.80 Resistivity s function of temperture See pge 8, digrm Resistivity for Knthl Super 3
Chemicl resistnce Atmospheres Knthl Super cn be used in most furnce tmospheres. Most fvorble re oxidizing tmospheres such s ir, crbon dioxide nd wter vpor, but Knthl Super elements re lso operting successfully in neutrl, reducing nd crburizing tmospheres. The digrm below indictes the mximum recommended element tempertures in some common types of furnce tmospheres nd gses. Air At low tempertures, n oxidtion of molybdenum nd silicon on the surfce of the elements cn occur t tempertures round 500 C (930 F). The oxidtion product is yellowish powder, MoO 3 nd hs normlly no detrimentl effect on the performnce of Knthl Super elements. Wter vpor nd crbon dioxide Wter vpor nd crbon dioxide in ny mount in the tmosphere hve n oxidizing effect. The presence of wter vpor in controlled tmosphere increses the mximum permissible operting temperture. Sulphur dioxide This gs sometimes occurs s n impurity in the tmosphere. It normlly hs no hrmful effect on Knthl Super elements. Endogs A typicl gs composition is: 20% CO, 40% H 2 nd blnce N 2. Since hydrogen is present in this gs composition, the dew point nd gs velocity re importnt for determining the mximum temperture. A heting solution with Knthl Super ER is recommended. Crburizing tmosphere Knthl Super elements re widely used in crburizing furnces. The elements re not ttcked by the tmosphere which normlly consists of n endogs or nitrogen with controlled dditions of crburizing gs such s propne or methnol. In this type of furnce, the element temperture is normlly kept below 1400 C (2550 F). If crbon is built up in the furnce becuse of high crbon potentil, it cn led to element filure. Regulr removl of the crbon by firing the furnce under oxidizing conditions is recommended. Nitrogen tmosphere Nitrogen is used for different purposes such s: Nitrtion of cermics (rection) Protective gs Blncing furnce tmospheres In the element temperture rnge of 1250 1550 C (2280 2820 F), nitrtion of cermics usully occurs. At such tempertures, when the protective glze is consumed, silicon in the silicide of the element my rect with nitrogen forming silicon nitride (Si 3 N 4 ), which could dmge the element by scling. The elements to be used for this purpose should be specilly het treted by Knthl in order to reduce nitrogen penetrtion into the mteril. This tretment is lwys dvisble when operting in nitrogen nd when the dew point is low. With opertion below 1250 C (2280 F) element temperture the rection is minor. Above 1500 C (2820 F) up to 1700 1800 C (3090 3270 F) the performnce of the element very much depends on dew point nd time t temperture. In cyclic conditions where the time t temperture is short, the oxide lyer on elements cn be restored by operting for short time in ir. Mximum recommended element temperture in different tmospheres C F 1800 3270 1600 2910 Knthl Super ER Knthl Super RA Knthl Super 1700 Knthl Super 1800 Knthl Super 1900, Knthl Super HT 1400 2550 1200 2190 1000 1830 4 0.01 P 13000 P -80 C Dp +40 C -80 C Dp +40 C -80 C Dp +40 C -112 F +104 F -112 F +104 F -112 F +104 F Vcuum Inert N 2 H 2 Air
When operting for extended periods t temperture (continuous furnces), the ctul formtion of thin lyer of Si 3 N 4 t the surfce of the elements, offers the best protection ginst further gseous rection. When specil het tretment is recommended, it cn usully be performed in the furnce where the elements re instlled, by operting them in ir bove 1550 C (2820 F) element temperture for couple of hours. A heting solution with Knthl Super RA is recommended when running continuous opertion. When running continuous or cyclic opertions, heting solution with Knthl Super ER is recommended. Noble gses, rgon nd helium These gses re inert nd do not rect chemiclly with Knthl Super. However, if there is gs flow round the elements, it will disturb the chemicl equilibrium existing round the elements. At high tempertures the glze is consumed. When using these gses, regenertion of the glze is recommended before the old glze hs disppered completely. A heting solution with Knthl Super ER is recommended. Hydrogen In dry hydrogen the silic lyer is reduced nd MoSi 2 disintegrtes by forming gseous silicon nd silicides with lower silicon content. This rection is dependent on temperture nd the reduction potentil of the hydrogen gs. By incresing the dew point the mximum permissible element temperture cn be incresed (see pge 6, digrm Mximum element temperture in hydrogen tmospheres ). Instlltion of the elements in niches cn reduce the gs flow round the elements, nd this cn help to reduce the chemicl ttcks. A heting solution with Knthl Super ER is recommended in dry hydrogen tmosphere. Nitrogen nd hydrogen The mixture of these gses should be considered s hydrogen. Although nitrogen reduces the rectivity of hydrogen, the effect of hydrogen is considerble, especilly with extended periods in opertion. The dew point of the gs mixture nd the gs velocity re lwys very importnt (see pge 6, digrm Mximum element temperture in hydrogen tmospheres ). Specil het tretment will improve the performnce. A heting solution with Knthl Super ER is recommended. Fluorine nd chlorine These hlogens ttck Knthl Super strongly, even oxidized elements, lredy t tempertures below 600 C (1110 F). Both fluorine nd chlorine cn be formed by dissocition of orgnic compounds, which my often enter the furnce together with unclen products. Vcuum Knthl Super elements re not suitble for opertion in high vcuum t high tempertures due to silic vporiztion. (Pge 6, digrm Mximum element temperture in vcuum ) shows the mximum permissible element tempertures t different ir pressures. A heting solution with Knthl Super ER is recommended. Metls All metls in direct contct with Knthl Super rect with MoSi 2, forming silicides. At higher furnce tempertures, vpors from molten metl, (zinc, copper, bronze) my lso ttck the elements. Dust from metl oxides in the furnce tmosphere rects with the glze. It is lso importnt tht the elements re protected from splshes of molten metl. Any metl or lloy with melting point lower thn pproximtely 1300 C (2370 F) my be melted in Knthl Super furnce if necessry precutions re tken. In smll crucible furnces where the elements re protected from metl fumes pprox. 1550 C (2820 F) is possible. Alkli Compounds such s K 2 O nd N 2 O in the furnce tmosphere will ct s fluxing gent on the silic lyer nd ttck the elements. Their slts lso ttck elements which my occur in glss melting furnces. The choice of lining mteril for furnces operting t tempertures bove 1550 1600 C (2820 2910 F) in prticulr is very importnt. Cstbles lwys contin lklis. Due to how these re chemiclly bound in the cstble they could be more or less ggressive to the Knthl Super elements. Avoid cstbles contining lkli bove 1550 1600 C (2820 2910 F) furnce temperture. Cermics As the operting temperture of Knthl Super elements is normlly rther high, rections cn esily tke plce between the silic lyer on the element surfce nd most slts nd oxides. This is of prticulr importnce when the elements re supported by cermics. The cermics in these cses must consist of stble compounds, silictes, which do not rect with silic. Suitble cermics re sillimnite nd mullite. At element tempertures exceeding 1600 C (2910 F) rections cn nevertheless occur. This element temperture should not be exceeded when the element rests on cermic support. Firing of cermics Green cermics (before firing) contin binders or similr, which during firing fume off, developing residul products. These residul products must be removed in order to minimize the contmintion of furnce tmosphere nd wlls. At higher element tempertures, these residul products my ttck the elements. Glss The tmosphere in glss furnce normlly hs slightly fluxing effect on the silic lyer, thus lowering the viscosity nd cusing the glze to flow slowly down the element. However, this normlly hs no detrimentl effect on the life of the element. 5
Mximum element temperture in hydrogen tmospheres Element temperture, C 1700 Element temperture, F 3080 1600 2910 1500 2730 1400 2550 1300 2370 1200 2190 1100 2010-80 -60-40 -20 0 +20 +40 C -112-76 -40-4 +32 +68 +104 F Dew point Knthl Super ER in 100% H 2 All other Knthl Super in 100% H 2 Mximum element tempertures in vcuum Element temperture, C Element temperture, F 1700 3080 1600 2910 1500 2730 1400 2550 1300 2370 1200 2190 1100 2010 10-4 10-3 10-2 10-1 1 10 100 Torr 0.013 0.13 1.33 13.33 133.3 1333 13330 P Knthl Super ER All other Knthl Super 6
Performnce Temperture dependence of resistivity The digrm on pge 8 shows tht the resistivity of Knthl Super increses shrply with temperture. Element surfce lod The curves shown in the digrms on pge 9, which pply to furnces with suspended, freely rditing Knthl Super elements show the pproximte element temperture t vrious furnce tempertures, element surfce lods nd currents. For exmple, t n element surfce lod of 14.4 W/cm 2 (92.9 W/in 2 ) nd furnce temperture of 1300 C (2370 F) the element temperture of Knthl Super 1700 will be 1525 C (2780 F) with current of 156 A for 6 mm Ø nd 286 A for 9 mm Ø. Wll loding A chrcteristic property of furnces equipped with Knthl Super elements is tht the surfce lod on the furnce wlls cn be much higher thn with metllic elements. This is due to the high mximum operting temperture of the Knthl Super elements. Consequently, the heting-up time cn be considerbly reduced. The wll loding is lso dependent on how the elements re instlled: long the wlls or perpendiculr. The digrms on pge 10 shows mximum recommended wll loding s function of the furnce temperture for different element dimeters nd mode of instlltion. Knthl Super in rotry herth furnce. Knthl Super in seled quench furnce. Knthl Super in pot melting furnce. 7
Resistivity of Knthl Super Resistivity, Ω mm 2 /m 4.0 3.6 3.2 2.8 r = ρ l 4 π d 2 r = resistnce, Ω/m ρ = from digrm l = rod length, m d = dimeter, mm 2.4 2.0 1.6 1.2 0.8 0.4 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 C 32 390 750 1110 1470 1830 2190 2550 2910 3270 3630 F Element temperture Knthl Super ER Knthl Super 1700 nd RA Knthl Super HT Knthl Super 1800 Knthl Super 1900 OXIDE GROWTH For Knthl Super grdes the oxide growth t certin temperture s function of time hve prbolic growth. The growth of the oxide lyer, the glze, of Knthl Super HT is much reduced, compred to Knthl Super 1800 nd 1900, see digrm below. A thin oxide lyer results in much-improved service life, becuse the tension is reduced between the bse mteril nd the surrounding oxide, depending on the different therml expnsion coefficient. Oxidtion properties Oxide thickness, μm 160 140 1800 C (3270 F) 1750 C (3180 F) 120 100 80 60 1800 C (3270 F) 1750 C (3180 F) 40 20 0 0 100 200 300 400 500 600 700 800 900 1000 Time, h Knthl Super HT All other Knthl Super 8
Temperture loding digrms Temperture loding digrm for Knthl Super 1700 nd 1800 W/cm 2 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 3 mm 75 A 4 mm 116 A 6 mm 212 A 9 mm 390 A 12 mm 600 A 3 mm 70 A 4 mm 108 A 6 mm 198 A 9 mm 364 A 12 mm 560 A 3 mm 65 A 4 mm 100 A 6 mm 184 A 9 mm 338 A 12 mm 520 A 3 mm 60 A 4 mm 92 A 6 mm 170 A 9 mm 312 A 12 mm 480 A 3 mm 55 A 4 mm 85 A 6 mm 156 A 9 mm 286 A 12 mm 440 A 3 mm 50 A 4 mm 77 A 6 mm 141 A 9 mm 260 A 12 mm 400 A 3 mm 45 A 4 mm 69 A 6 mm 127 A 9 mm 234 A 12 mm 360 A 3 mm 40 A 4 mm 62 A 6 mm 113 A 9 mm 208 A 12 mm 320 A 3 mm 35 A 4 mm 54 A 6 mm 99 A 9 mm 182 A 12 mm 280 A 3 mm 30 A 4 mm 46 A 6 mm 85 A 9 mm 156 A 12 mm 240 A Element temperture W/in 2 194 181 168 155 142 129 116 103 90 77 64 52 39 26 13 Knthl Super 1800 1800 C (3270 F) Knthl Super 1700 1700 C (3090 F) 0 0 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 C 1470 1650 1830 2010 2190 2370 2550 2730 2910 3090 3270 F Furnce temperture Knthl Super 1700 Knthl Super 1800 Temperture loding digrm for Knthl Super 1900 W/cm 2 W/in 2 20 18 16 14 12 10 8 6 4 3 mm 60 A 4 mm 92 A 6 mm 170 A 9 mm 312 A 3 mm 55 A 4 mm 85 A 6 mm 156 A 9 mm 286 A 3 mm 50 A 4 mm 77 A 6 mm 141 A 9 mm 260 A 3 mm 45 A 4 mm 69 A 6 mm 127 A 9 mm 234 A 3 mm 40 A 4 mm 62 A 6 mm 113 A 9 mm 208 A 3 mm 35 A 4 mm 54 A 6 mm 99 A 9 mm 182 A 3 mm 30 A 4 mm 46 A 6 mm 85 A 9 mm 156 A Element temperture Knthl Super 1900 1850 C (3360 F) 129 116 103 90 77 64 52 39 26 2 13 0 0 1500 1550 1600 1650 1700 1750 1800 1850 1900 C 2730 2820 2910 3000 3090 3180 3270 3360 3450 F Furnce temperture Knthl Super 1900 9
Mximum recommended wll loding s function of the furnce temperture for different element dimeters nd mode of instlltion kw/m 2 200 kw/ft 2 21.5 L e 500 mm 150 L e 1000 mm 16.5 Mode of instlltion L e 500 mm L e 1000 mm 100 L e 500 mm L e 1000 mm 10.7 50 5.3 0 0 1100 1200 1300 1400 1500 1600 1700 1800 C 2010 2190 2370 2550 2730 2910 3090 3270 F Furnce temperture Element dimeter: 6/12 9/18 12/24 kw/m 2 150 kw/ft 2 16.5 L e 500 mm 100 L e 1000 mm 10.7 Mode of instlltion L e 500 mm L e 1000 mm L e 500 mm 50 L e 1000 mm 5.3 0 0.0 1100 1200 1300 1400 1500 1600 1700 1800 C 2010 2190 2370 2550 2730 2910 3090 3270 F Furnce temperture Element dimeter: 6/12 9/18 12/24 10
Necessry Distnces Distnce to wll It is importnt tht the distnce between wll nd heting zone of the element is lrge enough to void contct. In the cse of long elements t high tempertures, electromgnetic forces nd bd centering when instlling the elements my cuse the elements to come in contct with the wlls, cusing dmge. The minimum distnce, e, between the heting zone of the element nd the furnce wlls depends on the length of the element (see the figures to the right). When instlled long the wll it is: For L e < 1000 mm (39.4 in); e = L e /20 For L e < 300 mm; e = min. 15 mm (0.6 in) For L e > 1000 mm (39.4 in); e = min. 50 mm (1.97 in) A When instlled perpendiculr to the wll, the deformtion due to the electromgnetic forces must lso be considered. The reson is tht the deformtion cuses reduction of the distnce between prt of the heting zone nd the wll. After clculting the mgnitude of deformtion (see the figure on pge 12 Deformtion of Knthl Super elements ), the distnce E cn be clculted nd e is estimted in the sme wy s for elements instlled prllel to the wll. E min = e + A 2 e E Distnce to bottom In order to prevent the elements from coming into contct with ny mteril deposited on the bottom of the furnce nd to compenste for the elongtion of the elements t high tempertures, the recommended verticl distnce h between the element bend nd the furnce floor should be t lest: L e L i L u h L e ; min. 10 mm 20 g Distnce between elements Minimum distnces, b, between djcent elements re given in the figure on pge 12 Necessry distnces. w L e h e Instlltion prmeters. 11
Necessry distnces, b, to counterct the effect of the electromgnetic force on Knthl Super elements L e mm L e in 1400 55.1 1200 47.3 1000 39.4 b 800 31.5 600 23.6 b 400 15.8 200 7.9 0 0.0 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 b/ b 8 W/cm 2 (52 W/in 2 ) 12 W/cm 2 (77 W/in 2 ) 18 W/cm 2 (116 W/in 2 ) 30 W/cm 2 (194 W/in 2 ) Deformtion of Knthl Super elements due to electromgnetic forces, vlid for ll sizes L e mm 1400 L e in 55.1 1200 47.3 1000 39.4 800 31.5 600 23.6 Min. A 400 15.8 L e 200 7.9 0 0.0 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 A/ 12 W/cm 2 (77 W/in 2 ) 16 W/cm 2 (103 W/in 2 ) 20 W/cm 2 (129 W/in 2 ) 24 W/cm 2 (155 W/in 2 ) 28 W/cm 2 (181 W/in 2 ) A Importnt instlltion prmeters for pssge brick nd skew brick Element size 3/6 4/9 6/12 9/18 12/24 mm in mm in mm in mm in mm in Hole dimeter of pssge brick 9 0.35 12 0.5 15 0.6 23 0.9 30 1.2 Recommended min. width of opening in skew brick, w 15 0.6 20 0.8 25 1.0 30 1.2 40 1.6 The minimum length of opening A is clculted ccording to the digrm bove. 12
Elements nd tubes The most commonly used design is two-shnk U- shped element (fig. 1, pge 14). The heting zone is welded to terminls which normlly hve dimeter double tht of the heting zone. The two-shnk element cn be bent 45 or 90 either in the heting zone or in the terminls (fig. 2 5, pges 14 15). Four-shnk elements re used only horizontlly (fig. 5). Knthl Super is lso vilble s Superthl heting unit. Two-shnk elements Two-shnk elements with stright terminls re defined by: The qulity Heting zone dimeter, mm (in) Terminl dimeter, mm (in) Terminl length, Lu, mm (in) Heting zone length, Le, mm (in) Center distnce between shnks,, mm (in) Exmple: Knthl Super 1700 9/18 L u = 450 mm (17.7 in) L e = 560 mm (22 in) = 60 mm (2.36 in) The mximum length of the heting zone depends on the element temperture. The digrm on pge 16, Mximum recommended heting zone lengths, shows the mximum recommended heting zone lengths for verticlly suspended 6/12, 9/18 nd 12/24 elements. * Note: 3/6 nd 4/9 mm Knthl Super 1800 elements re not normlly mnufctured with heting zone L e longer thn 400 mm (15.8 in). Two-shnk bent elements Bent elements re used when the electricl connections for some reson cnnot be mde bove the roof. When the furnce is too high to permit instlltion of elements suspended from the roof, due to the limittion regrding the mximum permitted heting zone length, it my lso be necessry to instll elements with bent terminls or heting zones. By instlling severl rows of such elements it is lso possible to control the power t different levels in the furnce. The terminls re supported by brick or fiber, which normlly limits the mximum temperture to 1600 C (2910 F) furnce temperture. Four-shnk elements Four-shnk Knthl Super 1700 elements for horizontl use In mny cses, prticulrly in furnces with low chmber height, the best choice is horizontlly mounted elements. The dvntge of this shpe is tht fewer elements re needed thn in the cse of two-shnk elements, with lower terminl losses, mking the four-shnk elements more economicl. Mximum element temperture 1600 C (2910 F). Avilble s 6/12, 9/18 nd 12/24 elements. Four-shnk elements with stright terminls (fig. 5, pge 15) re defined by: The qulity Heting zone dimeter, mm Terminl dimeter, mm Terminl length, L u, mm (in) Heting zone length, L e, mm (in) Heting zone length, B, mm (in) Center distnces between shnks,, mm (in) Exmple: Knthl Super 1700 9/18 L u = 450 mm (17.7 in) L e = 450 mm (17.7 in) B = 400 mm (15.8 in) = 3 60 mm (3 2.36 in) Rnge of Knthl Super elements Grde Element size, mm heting zone dimeter/terminl dimeter 3/6 4/9 6/12 9/18 12/24 Knthl Super 1700 Knthl Super 1800 Knthl Super 1900 * Knthl Super RA Knthl Super ER Knthl Super HT * 9/12/18 13
Terminl shpes L u = l+ k+ m f l k L u r Ø c f Ø c m n g g L e L e Ø d Ø d Fig. 1 Stright terminls. Fig. 2 Element bent 90 t the terminls. The following prmeters re vlid for ll Knthl Super elements (metric) Element, mm c, mm d, mm f, mm g, mm k 90, k 45, m, n, mm r, mm size Stnd. Min. mm mm mm Stnd. Min. Stnd. Min. 3/6 25 16 6 3 25 15 19 9 30 42 30 12 4/9 25 19 9 4 25 15 19 9 35 47 42 12 6/12 50 26 12 6 45 25 47 24 60 90 70 30 20 9/18 60 38 18 9 75 30 71 35 90 135 100 45 30 12/24 80 54 24 12 100 40 Dimensionl tolernces ± 5% (except c nd d) The following prmeters re vlid for ll Knthl Super elements (imperil) Element, in c, in d, in f, in g, in k 90, k 45, m, n, in r, in size Stnd. Min. in in in Stnd. Min. Stnd. Min. 3/6 0.98 0.63 0.24 0.12 0.98 0.59 0.75 0.35 1.18 1.65 1.18 0.47 4/9 0.98 0.75 0.35 0.16 0.98 0.59 0.75 0.35 1.38 1.85 1.65 0.47 6/12 1.97 1.02 0.47 0.24 1.77 0.98 1.85 0.94 2.36 3.55 2.76 1.18 0.79 9/18 2.36 1.50 0.71 0.35 2.95 1.18 2.80 1.38 3.71 5.31 3.94 1.77 1.18 12/24 3.15 2.13 0.95 0.47 3.94 1.57 Dimensionl tolernces ± 5% (except c nd d) 14
L u g h l L u = l+ k+ m f f Ø c Ø c k h = 15 mm (0.59 in) 6/12 20 mm (0.79 in) 9/18 30 mm (1.18 in) 12/24 L eh = L e 9 mm (0.35 in) 6/12 11 mm (0.43 in) 9/18 21 mm (0.83 in) 12/24 L eh L e g m L e Ø d Ø d Fig. 3 Element bent 90. Fig. 4 Element bent 45 t the terminls. = 1 + 2 + 3 f L u Ø c g Ø d B L e 1 2 3 Fig. 5 Four-shnk element for horizontl use. 15
Mximum recommended heting zone lengths for verticlly suspended 6/12, 9/18 nd 12/24 mm elements L e, mm L e, in 1400 55 1200 47 1000 40 800 32 600 24 400 16 200 8 0 0 1500 1550 1600 1650 1700 1750 1800 1850 1900 C 2730 2820 2910 3000 3090 3180 3270 3360 3450 F Element temperture Knthl Super ER Knthl Super 1700 nd Knthl Super RA Knthl Super 1800 Knthl Super 1900 nd Knthl Super HT 16
Tubes Tubes re normlly mnufctured in qulity corresponding to Knthl Super 1700. As the sme mteril is used in the tubes s in the elements the dt regrding properties previously given in the hndbook is lso vlid for tubes. Stndrd sizes re mnufctured s per tble to the right. Mximum lengths For outer dimeter 7 25 mm (0.28 0.98 in) mximum 2000 mm (78.7 in). Knthl Super bubble tubes The stndrd Knthl Super bubbler tube hs n ID of 3 mm (0.12 in) nd OD 12 mm (0.47 in). Some glss works inquire smller end holes for genertion of smller ir bubbles. Knthl Super typicl tube sizes Outside dimeter ± 5% Inside dimeter ± 5% mm in mm in 12 0.47 3 0.12 12 0.47 6 0.24 22 0.87 13 0.51 25 0.98 15 0.59 Knthl cn now supply 12/3 tubes with 5 mm (0.20 in) welded end cp with min 0.7 mm (0.03 in) hole mde by wter jet. Exmples of pplictions for Knthl Super tubes Protection tubes for thermocouples. Ø min. 0.7 Ø 12 Ø 3 L tube Bubbler tubes for glss melting. Tubes for electrodes for glss melting. 17
Accessories Element size 3/6 mm nd 4/9 mm Contct strps Type 5826 Lengths (L): 100, 150, 200 Type 5827 Lengths (L): 75, 100, 150, 200 Ø 6.5 L 18 L Type 5828 Lengths (L): 75, 100, 150, 200 Type 5829 Lengths (L): 75, 100, 150, 200 Spring clips to be used t both ends. 18 L L 18
Spring clips Type 10434 for element size 3/6 mm Element holder Type 5830 Type 10435 for element size 4/9 mm 47 25 30 Single-shnk holders Type 10421 for element size 3/6 mm Type 10424 for element size 4/9 mm Ø 6.5 Ø 9.5 10.5 Ø 14 13 Ø 22 19
Element size 6/12 mm Contct strps Type 5766 Lengths (L): 80, 100, 150, 200, 250, 300 Type 3579 Lengths (L): 80, 100, 150, 200, 250, 300 L L 30 Ø 8.3 Type 5768 Lengths (L): 150, 200, 250, 300 Note: Two pcs per shnk for 9/18 Ø 8.3 30 L Contct clmp Type 5758 Expnsion tool for clmps Type 21690 30 18 30 20
Single-shnk holders Type 6248 Type 5778 Ø 13.5 41 14 Ø 32 20 47 Two-shnk holder Type 5776 = 40, 45, 50, 55, 60 +24 52 22 21
Element size 9/18 mm Contct strps Type 3801 Lengths (L): 100, 150, 200, 250, 300 L 65 Ø 8.3 Single-shnk holders Type 6249 Type 5779 Ø 19.5 41 14 Ø 42 20 47 Two-shnk holders Type 5776 = 40, 45, 50, 55, 60 +24 Type 5777 = 80 nd 150 for element size 6/12 lso +24 52 Ø 12 = 45 Ø 18 = 52 22 22 22
Element size 12/24 mm Contct strps Type 10432 Lengths (L): 150, 200, 250, 300 Note: Two per shnk Type 10439 L 40 85 L Ø 8.3 Single-shnk holder Type 10433 Ø 26 14 Ø 48 Two-shnk holders Type 10437 = 60 Type 10438 = 80 +24 +24 60 60 22 22 23
Anchor systems Stndrd nchor system Type 5987 Element holder Stndrd design Fstening yoke 5925 Element holder 5776 Anchor pin 5926-1 Locking pin Air cooled nchor system Type 5927 Element holder with ir nozzle for Knthl Super 9/18 mm = 60 Type 6031 Element holder for Knthl Super 6/12 mm = 50 Type 6033 Element holder for Knthl Super 6/12 mm = 40 Fstening yoke 5925 Element holder 5776 Upper gsket Lower gsket Anchor pin 5926-1 Locking pin Air nozzle 5887 24
Seled element nchor system Type 5965 Element holder with seled terminl led through for Knthl Super 9/18 mm = 60 Element holder 5776 Fstening yoke 5925 Type 6037 Element holder with seled terminl led through for Knthl Super 6/12 mm = 50 Stetite rings Silic cord Flt brs 30 8 mm Plte 5986 Gsket 5953 Locking pin Grphite lterntive Grphite cord Cut the ends 45 Flt brs 30 8 mm Plte 5986 Grphite gsket 10436 25
Pssge bricks Note: Under certin conditions, long pssge bricks my result in excessive tempertures on the terminls, unless specil precutions re tken when designing the furnce. For nchor systems, seled design Type 6038 for 6/12 mm Ø d Type 5984 for 9/18 mm Type no. Grde A B C d Element size 6038-1 28 115 64 229 50 15 6/12 5984-1 28 115 64 229 60 23 9/18 C 5984-2 28 115 76 229 60 23 9/18 5984-3 28 152 76 305 60 23 9/18 B A For nchor systems, typicl design Type 6036 for 6/12 mm Type 5985 for 9/18 mm Ø D Ø d Type 10943 for 12/24 25 Type no. Grde A B C d D Element size 6036-1, -3, -6 G28, 30, 33 115 64 229 40 15 25 6/12 C 6036-9, -4,-8 G28, 30, 33 115 64 229 45 15 25 6/12 6036-2, -5,-7 G28, 30, 33 115 64 229 50 15 25 6/12 5985-1, -4,-8 G28, 30, 33 115 64 229 60 23 35 9/18 5985-2, -5,-10 G28, 30, 33 115 76 229 60 23 35 9/18 5985-3, -6,-11 G28, 30, 33 152 76 305 60 23 35 9/18 10943-1, -4, -7 G28, 30, 33 115 64 229 60 30 40 12/24 10943-2, -5, -8 G28, 30, 33 115 76 229 60 30 40 12/24 B 10943-3, -6, -9 G28, 30, 33 152 76 305 80 30 40 12/24 A 26
For nchor systems, ir cooled design Type 6035 for 6/12 mm Ø d Type 5930 for 9/18 mm for 12/24 mm C Type no. Grde A B C d D Element size 6035-1, -3, -6 G28, 30, 33 115 64 229 40 15 25 6/12 6035-, -4, -7 G28, 30, 33 115 64 229 45 15 25 6/12 6035-2, -5, -8 G28, 30, 33 115 64 229 50 15 25 6/12 5930-1, -4, -7 G28, 30, 33 115 64 229 60 23 35 9/18 5930-2, -5, -8 G28, 30, 33 115 76 229 60 23 35 9/18 B 30 5930-3, -6, -9 G28, 30, 33 152 76 305 60 23 35 9/18 A Bottom plte: Alfrx coted grde 33 27
Other ccessories Stetite rings Silic cord nd grphite cord 8 Ø d Ø D Element size 6/12 9/18 D 20 27 d 13 19 Element size 6/12 9/18 Length of silic cord 2 180 2 230 Length of grphite cord 4 60 4 80 Pltes Gsket for pltes B 25 B 2 Ø D Ø d A Ø d A Type A B d D 5986-1 150 150 60 20 28 5986-2 160 160 60 20 28 5986-3 180 180 60 20 28 5986-4 160 200 60 20 28 5986-5 130 180 60 20 28 5986-10 150 150 50 13 21 Grphite Cermic fiber A B d 10436-1 5953-1 150 150 60 18 10436-2 5953-2 160 160 60 18 10436-3 5953-3 180 180 60 18 10436-4 5953-4 160 200 60 18 10436-5 5953-5 130 180 60 18 10436-10 5953-10 150 150 50 12 10436-1-5 d = 30 mm 10436-10 d = 24 mm 28
Air nozzles Gskets for ir nozzles d 110 d D 8 2 D 20 Type Element size D d 5887-A 6/12 40 36 13.5 5887-B 6/12 50 36 13.5 5887-C 9/18 60 42 19.5 Element size 6/12 9/18 d D d D Upper gsket 11 32 17 38 Lower gsket 16 36 22 42 Anchor pins Silicon rubber hose For connection to ir nozzles. 2 81 33 43 Ø 3 2 1 2 3 4 4 Locking pin Type Anchor system Ø 2.8 5926-1 Stndrd nd ir cooled 25 5926-2 Seled 1) 5926-3 Seled 5926-4 Air cooled 2) 1) Without locking pin. 2) Element size 6/12 mm nd distnce between shnks () = 40 mm Fstening yoke Type 5925 12 25 29
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Sndvik Group The Sndvik Group is globl high technology enterprise with 47,000 employees in 130 countries. Sndvik s opertions re concentrted on five business res in which the group holds leding globl positions in selected niches: Sndvik Mining, Sndvik Mchining Solutions, Sndvik Mterils Technology, Sndvik Construction nd Sndvik Venture. Sndvik Mterils Technology Sndvik Mterils Technology is world-leding developer nd mnufcturer of products in dvnced stinless steels nd specil lloys for the most demnding environments, s well s products nd systems for industril heting. Knthl is Sndvik owned brnd, under which world clss heting technology products nd solutions re offered. Sndvik, Knthl nd Superthl re trdemrks owned by Sndvik Intellectul Property AB. Environment, helth nd sfety Environmentl wreness, helth nd sfety re integrl prts of our business nd re t the forefront of ll ctivities within our opertion. We hold ISO 14001 nd OHSAS 18001 pprovls. Recommendtions re for guidnce only, nd the suitbility of mteril for specific ppliction cn be confirmed only when we know the ctul service conditions. Continuous development my necessitte chnges in technicl dt without notice. This printed mtter is only vlid for Sndvik mteril. Other mteril, covering the sme interntionl specifictions, does not necessrily comply with the mechnicl nd corrosion properties presented in this printed mtter. Qulity mngement Sndvik Mterils Technology hs qulity mngement systems pproved by interntionlly recognized orgniztions. We hold, for exmple, the ASME Qulity Systems Certificte s mterils orgniztion, pprovl to ISO 9001, ISO/TS 16949, ISO 17025 nd PED 97/23/EC. We lso hve product nd/or shop pprovls from bodies such s TÜV, JIS, DNV nd Lloyd s Register.
Sndvik Mterils Technology Sndvik Heting Technology AB, Box 502, 734 27 Hllsthmmr, Sweden, Phone +46 220 210 00, Fx +46 220 211 66 www.knthl.com, www.smt.sndvik.com S-KA058-B-ENG, 2-A-1-3, 01.2012, Printed in Sweden