ELIEZER CARROZ CEMEX VENEZUELA Comminution manual © 2001Comminution manual _ Contents [Comminution manual Contents Ball mill = D: Closed circuit grinding Charge and power Grincing theory Calculation of charge a ee Commintton index snanD2 Caleuation of power as Cieulaton factor Specie arene By sive residues or weight Da Torque icons cs = Separator oticoney example Sas Descrtion D4 Max charges 7 Power reduction: sos DS sunatiagcomoarnert ar Max power reduction. D6 vinding mesa Yevalues SD? EQUIIUM CharGO8 nn . = Tromp euve Charges - Large bali. Ag Descrtion D8 Charges Smal bal oo eZ Example SCs Srages Ce ant Factors of influence D0 Standard charge compostions.-AT2 Standard charge composions........A10 MCE: Various Wear on grinding media Aa Fans Piece weight and specie surtace... 15 Fan calculations. &2 Sampling of grinding MEE ava ACTS Fan calculations... es Grinding an tneness Airand heat “Transport through mil sonsanAAT Densities and Cp-values e4 Norma snenaes nil At? Varous formulae es Heat balance, Example... Ate Wet and iy temperature £6 Closed Cicui grinding, Layout Ang + Water vapourin air E7 Pitt tube measurerienis e8 Bi Rollor press e Pitt tube measurements =9 Layout False air caloulation E10 Pre-tinsing co ay Moisture celeuiations, en Semitinsh gincing sien Sieve to mesn conversions E12 onatinan ona Cr Unit wanstormations E13 ole press calculations a7 SYMBOIS ont rnsnnnneS Fomlas 86 Typical values: er ea ©: Vertical mits Layout, lteratves 2. = Vertical mil ealeuations | Power consumption ca Grinding pressure woes Mit internals es Nozze cng ce Dam ng co = Heat balances, Example snnnvonnennans6® al(index Index A ‘arm of gravity in relation to mill diameter AS average moisture of feed en 8 barometric pressure ES Bra Ds bulk weight A2A5 bypass De ce caloulation o false air E10 centre distance AQ ‘charge A2 ‘charge and power, example AG charges - oyipeps AM ‘charges - large balls Ag charges - small balls AsO circulation factor D2 Circulation factor for roller press BS Cirevlation factor from mass flows Ds Circulation fator irom residues Ds comminution index D2 C-values of gases and materials Ea ctitcal speed AS cutsize Ds D dam ring height G7 dota De densities of gases Ea density of a gas ES ‘drying compartment Ar dynamic pressure Ea E efficiency, fan £2 efficiency, separator Da,D5 electical energy to heat ES cequilixium charge, definition AB examination ofa grinding mosia charge {alge air calculation fan calculations fan eficiancy fan power consumption fan speed fineness of grinding material in the mil finish grinding layout free height s (988 flow measurement Fae grinding bed ‘ringing madia, piece weight and specific surface 4 ro) heat balance fora ball mill heat balance for a vertical mill heat of evaporation of water heat transmission ! ‘deal separator D 1 1 geercimecccntl Figs eg ‘erase Initial charge, coal mill wth classifying lining A intial charge, fine grinding compartment A intial charge, frst compartment A A A 1 initial charge, intermediate compartment 1 initia charge, raw mil with classifying lining 1 kK kappa D L layout of closed circuit grinding Ad layout of finish grinding 8, layout of pre-grinding 5 layout of semifnish grinding 5 layouts of the VRM system ¢) [index M-s | Index s-W spect sutace Ass ee — Ag maxcharges 7 Standard charge compocttons Fert max power eduction a measurement of gas fow EBES mesh o stove conversions ete torque factor, ball mil ARAS moisture calculations E11 MERE torque actor, oer prose 25.8687 most rom Het and ry temperature es torque factor vera mil ea transport capacty of material through grates Me rea resco tony ar nazzo ring area oe ‘romp eune De z es. malin Bae uni wansfommatons E18 Prove weight fr equlovium charge ~ oe Y Pet tube measurements EB pone consumption by compartment 3 KERIB velo oraee ze ower consumption Nf rler prose Be Yolume of compartment a2 power consumption of drying compartment. AT Vs and Brnax O4 Power consumption of verte mil a =z | flower consumption tan E2 pre-grinding layout B2 Be water vapoyr in air rom dew point E7 7 wearon ging med ane recover of fines oC toler press Greiaton factor Be ral press parameters By roistonalspoe fhe mil 2 e ea sampling of rnding media, examples Ae semis grag layout 38 Separator ecioncy babs Separator efleoy a8 reovary of fes ba Separator eficieney as reduction ipower consumpion 0.5 EA sieve to mesh conversions ew poste charge Aa Speetedonsty ofa gos es Specie grinding pressure for vertical mil cs Specie pon sonsumpton for bal il ba Specie power consumption! rll press Be Specie oer pressure 26,87Page At A: Ball mill secoCharge and power Calculation of charge] Charge and Power Calculation of power Compartment power consumption: D: —_Elfestve ameter of compartment tn} Effective length of compartment im BB Aimet gravity inretation to mil diameter Rotational speed of he mil trom v: Volume of compartment : 14D 1 I) es Accaleration of gravity ims hi: Cenire distance (W/D used in page A.4) & —_Angleof displacement nl b=H-DO2 [en] AD =H =$6 a . N: Power consumption by compartment at mill shell Hi: Free heigt N=F-g-D-a-sina-m 160 rane) H=(vD + %)-D Im) smi pmanereaigegeamagalne i sini the traue factor. Standard values tom page A we Bui weight (rom page As) tu Ne0514-Fen-psD-a noe er Bota y ‘i BB Woetecremnosi ie aren Critical speed: The eal speed ns the speed, were the contifugal force at the mil ining equal to the graational ore 423 nate tm) vo Normal mil speeds are 70-80% ofthe etical specs Page A2 Ball mill es Ball mill Page AS[Charge and power Specific charge eo Charge and power Torque factors) nD aq | WD a — T ~~ Wedia 000 aes 3000900 aT Matra) ining | ining] er Foxe 500s 0s0 9d | 0.205.658 aa ngs TYP my 0010 0435 487 | 0210 O85 Nene Bale] 43) 878 O01s oad! 481 | O23 685 arse 002 ods 475 0900 0.670 = and | Stoo | NOME | Rods | 80 | 085 0025 0.482 468 0.225 0.876 : Danuia | Bais | 48 | 075 00s 04s? © 482 | 0200 6a a mec 003s 0482456 | 025 68 [|_| Sie | Ba | | ood ass 449 | 0280 1609 Cament Nene | Bais > 4S~ 068 os 047s 443 | 0.245 0.699 So names (epee | ar | ‘Gad 00800479438 | 0250 0.705 vines a ne a meal None [Minos 4.7 08s 0080 0.490 424 | 0260 O77 in | || mn | oom | as | on 0085 0485 418 | 0205 0722 bee: GE | eee e-3 anus | cyoeds | 47 | a7s | 075 0.507 405 | 0273 o7a4 Dania |Minpebs) 47 | 086 0080 O5i2 999 | 0280 0740 L x ooss oie © 92 | 0203 OFA a ay | Se] Nene [aramie | 8 for 080 0823 «386 | 0290 0751 Silex | None | stone | 15 | 075 dos _o820 380. | 0295 _O787 ae] 18 ee | 1000594 97.4 | 09000769 coarse None | Bale [4S 68s 0108 oi «367 | 0505 768 ea | None | Reds | 60 | 050 O10 0846 361 | ORO O77 and | Steet Ons osst «885 | Oss Oe! seta Dawa | Bats | 49 | 967 0420 0557 m3 | 0220 0786 aa Sonex | als 49 | 058 O12 0862 a3 | 0.925.702 ain et te dts) O68 © 836 | 0880 798 i bee | Bas | 48 | ane 0135 0574 330 | 0335 0.804 es None | Cyioavs | 4.7 0.88 O10 0878 S24 | oad oat ie | Sl sie | ean | O15 0805 518 | 031 _08%6 ea ei |, (ats ast 0.150 0.501 912-0360 0822 Daruia | Cypebs | 47 | 067 0155 080) 808 | 098s ogee Were | Coram 4 fe te 8 as ae a Nene | Coane +8 035 0165 0608 204 | 0905 089 Steel None | Stone | 15 | 08s 04700613 268 | 0370 oes Woah eee [— 0.175 0619 262 | 0375 08st ee titers | stone 15 | 086 0180 082 © 276 | 0980 O8sr rum o485 0690 270 | 0305 0860 6.99 es Coarse Nore | Bale 43] ae 2490 0838 284 | 0300 0869 5.99 0195 062 358 | ons 087 B59 wee | 202 | MB | ion | | Bate | as | 088 1 car abo bo calouated as Mesum Nona | Cipebs | 47 | 060 essen a =. wesum |__| dana | cybebs | 47 | ot Page Aa Ball ral SS ain Page ASCharge and pai Example Example: In & UMS 42 x 19 mill running with 16.0 rpm, the following was measured: First compartment D=401m L=889m —H=2.75m ‘Second compartment: D=419m L=898m — H=281m Calculations for rst compartment 1/4 (4.01 my 3.89 m= 49.1 me WD =2.7614.01 - = 0.186 wy. From page A.4: q= 27.0%; trom page A: 227.0100: 4.9.um?.49.1m'=57.0t Calculations for second compartment 14 (4.43 mp «8.98 m= 112.3 me hO =2.8114.13-% From page At: q = 27.6%: from page AS: b = 4.5 vin? Fs27.6/100 4.5 tim? 112.4m° = 199.41 Power caleuations: N= 0818 Fonda bemoans First compartment From page At: a N 1630; From page AS: 73 514-57.01- 16.0 rpm 0.73. 4.01 m- 0.690 N 865 KAMnet ‘Second comparment From page A.4: a = 0.625; From page A.S: u = 0.69 N= 0514-18041. 16.0 mpm -0.69- 4.19 m- 0.625 N= 2002 KWingt TOCIC ITC Cn eee charzelned pa iMax charges ee oping RE | a ee ee specie cetge (eas er] Dy 6s um | wesshwm | a |S wecsnwnt | 23 | 3s Tuk] "Zeamparments-| se —] 35 ‘comparmente_|_ 3 TM 2-compartments 28 26 Tes % [aie Goa 38 Wash Blam st foaa |e i wy g sts ums. e sot conpertne 2 oa 5 aos 2 mas sf Sis second se ise commer e ws Gus Ste} 3B a3 Diora % soa Be 308 Power consumption of ding compartment oe Nominal ametor of dying conparinen! ta Loc Nominal length of ying comesemnent tm) Nuc wa’ consumpion of tying compartment Woe ‘The power consumption of drying compartment can be Calculated as illows For raw and cement mils Noe = 15° Doc®*> (toc 0.4) (kW (net) Fr coal mila Noc = 08: Dse® hoc -0.4) ikWinet) Page AG Ball mill Ball mill Page A?r erinaing media Equilibrium charges] SSM [Grinding meaia Charges - Large balls Equilibrium chat finition ER Siee eigaeo8 S33 ‘An squilovum charges the distribution ofbat szesihatwithe = WEB ge ghecabeses realised when operating a ball il fr along time, compensating Re Re BREE gles the weary atcng al of one pectic siz, and removing he Ea le bal tich are smalor tan Palfthe ameter ofthe bal size gees galsex Bebe ele Used for compensation Rp ole The equlivun cage sctenaeisedbythedanetert novos SS 3 |ge| ageee BRESE 20 used for compensation — PSF Sle EEquitbrium chargés may be mixed to adjust the required piece RRR | Seseen BSR ale weight and suave area, Two or more bal sizes are then used for per ele compensation SA Ee alee KRgeeo Paes “The avorage piece weight and the specific surtace of an Epes Swleale eau arg win rma sets cane acs a 5 ses Raskes BSB 2\5 0.001913 :0,? ia) a Bese] SBSeE+ Bees B/ées| abazheo gles on 8 wm = OEE Beis sls Bese 8), faeegno Essie here is he dati mm of ba io ne for oe: 5 Bap Sr compensation es Ele les| ealszelew Beleok eB] = IF 2 Bese Fleck aeasie Sele ole SS EES E EEE REPEAT f Pee ESE To oealt em | Peeesbsse sce ee ; Se[soteis gag 5 F/iGeeessecscks < ze 2/5 BS Sessa sere sk si, |B ReTREE eal 2) @ PERE EEE ESS oz a/e B/S lEEEEcEE EE 2 gle F|S BEsesesse sig gis ge 6 BaP Ball mill Tye) Page AS ‘Ball millCharges -Cyipeps | ublen Aq stunowe renbe wy paonporius ave Ketp ‘paves 18 uopesuedtiioD 10} SOzI8 OF AYA) sa] ve] v9] 6s] ] os] oF] er] we] ze] ve | ze] ez | vew ] nba conyns oyoods se | uo} es {es | is | uv | ov | iv | oe | ce | ee | oe | wz | yeun|_pegna coens ayoads S [2 ]e [st foe lve] ie} se | er use| os fear] 6 ‘nb 1yBiom S004 st | ve{ez| vc |r| es}eolealcn| 5 + jiwack Joe1 paw oxo le ele ewes foe fuwexg ov sfe @ juew ze 89 fu orxoy se v2] ou 6 L lve eo [B11 fu zexe1 ey | ov | ge | ee Www er [Bez fu srxor lvator [Bey uw gixe. z 9 1 | ez er] 6 jes [659 fw zexas v2] ct hewaoe [806 [uusexcz , se | ze fworsz |6s01 haw oexoe $ 1 | 62 haw oze [5.92 uw cece 4 e @ oporpa far farfer] et fot uw lsu edonn 3| ot 6 zz|zz|ez{sz| oe} oe} ce} ce [xe] *9muey? uisdedKo 3 a a 8 % |e | | 06 | % | ce [us | (opens uonesuac | [o a a 212 |e 1% | x [oe | [se (s)e2 uonesuaduog| 5) [sdaat Winjgi)nbS 10) SOGse9 Tenia popuauWoT_y Charges - Small bails] Grinding media DODEDIDID002 auBisés Aq siunoure jen u, peonpoill axe feu} “poIeIs axe LOVeSUEditod 10} 5621S 01 O10UNA so [es] is [or |i [ze] ve [oe | sz | ez [roz|zerozt| vw] -unbs eoepns oupedg) so | 9 | 9» | a | ee | ve | ve | vz | oe | iz Jett lect] yw | remus aonuns owoods| se] rest | oz for | ee | es | ex fzzr|ear|eszfeoe|err| 6 nbs 1yBiom Daye, | on | 94 | iz | ez | op | e5 | ee | zi lors ove lore |aiv| 6 z wan vst [Bs0 seliz/o}e]z lew zz [Bp zoles|er|oclu}ul + Wwe is [Ov sefis[orliv[ tele] a] e wee [Bcc oz | ov | ov | or | zz earl ale wie [5 b9 silse|ec}ec|reler| 6 | ¢ hewoe [ois ge [is fer | ay | 26 | oz juwerer [bcoz te |e | uy | ov hawys Jeers Wwew eres [5.998 ‘UM sforfor]orfor|a}ar|o seqwiey U $9715 fee st | oz | oz | sz | cz | oe | & | o» xu SL 02 se Of uu |, (s)ez1s uowesuedwo, oz | | oe | | Ge | 0 | OF (sh 0 ea news ‘ingHTNBS 103 sat Page ATi Ball mill Ball mill Page A10rinding mi ‘Standard charge compositions First compartment initial charge: Bail size 7oma_[ 6mm _| I Bate Compensation 90mm ina pices weight 1509 Equlibium pisce weight 1395 Coal mil - Salsie Ham [40mm [30mm 25%, o% | 3% Compensation 508 40mm ina piece woigh 1839 Equlibrum piece weight: 1626 Intermediate compartment inital charge {tare compartment mils Balaze Sama mm mm ae 22% 16% Compensation som inital pieoe wight 2800 Equibrium piece weight: 259 Page A.12 Ball mill = = = Ess Ea ss [Grinding medi Standard charge compositions Fine grinding compartment initial charge: ‘Non-classitying lining: Bal se Mil system 2mm 20mm iSmm ‘Open 20% 40% | 40% Closed 40% | 40% [20% pen Closed Compensation: Ok 25mm 25mm Initia piece weight: 239 30g Equilibrium piece weight: §=— 20g 809 CClassitying ting: Ball size Bomm [4mm | somm | 25mm | 20mm | omm 10% | 10% | 5% —[ 30% | 30% | 15% Compensation: 50mm 25% 25mm 75% Initial piece weight 39g Equilbium piece weight! = 38g Raw mill with classifying lining (one compartment mills Ball size 30mm | 80mm [70mm | 60mm [0mm [5 mem | 20mm 44% [19% [13% J 14% [ 14% [16% [10% Compensation: 90 mm: 60% 30 mm; 40% Initia place weight 1399 Equilibrium piece weight: 122g Coal mill with classitying lining (one compartment mills) —Ballsize somm | aomm [om | 26mm | 20mm | mm V8 18% 6% | 22% | 23% | 10% ‘Compensation: 0mm: 22.5% 40mm: 22.5% 20mm: 55% Initial piece weight 70g Equilirium piece weight: 75. Ball mill Page A138Grinding media Wear on grinding media Oem (Grinding media Piece weight and specific surface Page Ata Ball mill Page ATS 4 Diameter of ba im Cast Pp: ‘Specific weight of material Ig’em®) Meste Chrome alloy Piece weight [— Te e286 Lap ‘ol % 10-12 . Analysis vm 8 glom (normal steel): % Or ue o.oo a? tal ene 02-05 hi | ©: Specific surface: Hardness HRC 35 oon wet Wear in lkWh taken up by compartment P iaigetale ae |i p=7.8 glom? (normal steel) 768 Wt Smal balls io 7a (rey , 18-30 5; 123 » [eee | vr (may “Largo als i Raw | Stall bale 1-3 For exarination of a grinding media charge, toke out net less ‘han 200 plces, tom each sampling spot in Compartment I, snd ‘6 less than 2600 form compartment 2. Exact fom under te L centoline and dig 2s deeply as possi. Broken media sored EM ai Separate in actons so stom in exampes orang small balls a ‘Cement Snell bak w Calculation of surtace is based on the average piece weight and Cyipes 1-3 WEE aitteascumpton hat al ne mesa or of prone eae a assumption also appies to cyincicl eyipoue WG iscce vot and spec sutace of charg 6 ltd tom the main facton by slsregarding madia less. tan hal te WES aiametor ofthe largest size usd for compensation for woar In compartments wih cessing ing the charge normaly ESB consist oto eguionum charges consttung « Coste. grding and atine-ginding chage, ther proporions bong detained Kesar Te cme an asta ag rng ‘Tho classying elect is most cieary expressed in the proportion between the plece weights inthe inlet end and outst end othe eR rpariment Ball mill(Grinding media pling of grinding me WEBB iinding and fineness Transport through ell Normal fineness in mill Example: Ballcharge Compartment 1-compersates EA Bam co an boas Transpen capacity of material through grates mam Wear a ae) = [Wath afaias Open cieat Smear] (mm) (xg) (gram) | _(méit) | (m*) Closed circuit 8- 12mm 30-85 | 7052 | 250 | 24 | 2008 | 858 [0.805 Es 1st partion 85-75 | 81.87 | 290] 38 2154 | 9.52 | 0.779 Dry | 2nd. partition approx, 5 vidmi?h) reoes| e008 | 213 | a2 | ‘ses | 1108 |oece | gem Gite grata t-s5| eos | 149 | 40 | 1000 | 1220 | o4es who Tonal 6 55-45 | 2388 | 8.5 49. 4e7__| 15.63 | 0.373 ‘Wet | 1st. partition 8 ms(dm?-h) <45 | 291 | 1.0) 13 | 224 | 2025 es 2nd. partion 2 mifldmehy Broken | 3.02 td. 7 431 16.28. Outlet grate 40. mr(dm*h) [Teta [ e262 3 25S) geegy. (| WS Pessoa cro 30 avan=h) ‘Main fraction >45 mm: 276.69 kg ~ 0.27669 ton ~ 97.9 % ~ 195. drum _| Inciined outlet grate 25 mkom*h) mesa, hoc went 276860 sary HEB spa capac of mater tough ml body ° 195 a 20-30:thim? 29100 2/ ecific surface = m = °* p27669 A = Normal finan. o rncing mater in tne i Example 2: — Cylpebs charye | Compartment 2- Normal th igh ie A Compencated fox woar wth 25 x 25 mm cyipebs. PB ive compertment mi Facion [Wee] a, Jan ).1 8, |S 20% 402mm com) _| eg Ne gram | corny | cn’ | ell savomaion 25-235 | 223 [222] 26 65.7 | 27.89 | 0.062 ponti ws-205| 365 |o64| 52 | e30 | p00 [ors | em 20s-173| 210 |200| <9 | ase | 3488 | 0073 ts 160| 43 |iae| 36 | 266 | ais9 | ooo: io-125| 038 | as | 30 | 127 | 270 loco] Ties | vier | 10] 18 | 65 | e398 Bown | bo |os| > | se | See =a Fis pation Total 10.04 | 241 0.330, Win raion 25 rans BS Kg = 0GBBSTON ~ 981% — 218 meda =a Second partion | Piece weight 9853 452 g es 218 “he samples ar taken Inside oF immer in ont of he es Me Specific surface ee 2.00885 Page A16 Ball mill Ball mil Page ATTHeat balance Example] Closed Circuit grinding Layout ‘An example of a heat balance fora ball mill (ball mil tube only) Cp kealiagC Temp iw wh °C Feed, ary 50 959 0.186 1516 Water in teed 02 200 1.000 «4 tun mat, 1020 1180 ©0186 2188 Isrinaing hoat 2498 lair 28 250 oad 180 Fate aiciniet 00 «250 ata Fate air, outer 22 2500 ate [water in [TOTAL IN out raterai otal Water in product Water evap 20 1180 © 0.483 1295, ot aie 239 1180 «= 0.244678 Surface lose 199 Water evap : The water in the food and the water from the water Injection s evaporated at 0 °C and the steam is heated 0116 °C: 2.0 (695 40.453 - 116) Mean = 1295 Meath ‘The amount of ai out ofthe mil tube is 24.9 Uh (Arn + Water evaporated). At the oullat the air has a density of: 0.90 kai? ‘The ait amount is thus 7.7 ms. Ao 4.2 m mil wil have a tree area of 9.70m® (with 30% filing degree). The velocity in the mill tube is thus 0.80 mvs, Far Gp values see page 2 , grinding heat calculation and Surface loss, soe page Es ‘Typical layout of closed circuit grinding Separator with product collection in eyciones: Offers maximurn heat preservation for maximum drying in the il, ‘smallest possibie fiter and pressure drop over separator system, ‘Separator with product collection in fiter. Ofers maximum cooling of the product: © Both sysiems may be designed to offer partly recycling of the ‘separator air fr the best compromise between the two solutions Page A18 Ball mill Tos Ball mill Page A19Roller press: TAA B: Roller press Page BtDECQCECCEICCCOONOOES, re ee | Control [re Recycled | Govtce Magnet) | pressed 2 material 5 Presses | i matorato bal il Pre-arinding layout ‘+ Flow splitter controls rato between material recycled to roller press and pressed material to ball mil + Roller press speciic power consumption ~210 ~5 kWhit material to ball mil ‘+ Roller press circulation factor = Roller press throughputinaw feed: 1-20 Page B2 Roller pressTayout Semisinih grinding Tayeut Finish grinding eta deter t seers, Feed tin i wea | . | press||. Fine o maton to Finished Feed ball product Deagglomerator 3) ‘Separator, Recycled material ins finish grinding layout + Separator controls ratio between material recycled to roller press and pressed material to ball ml + Deagglomeration and separation may be combined in one. machine + Roller press specific power consumption 6 to ~14 kWhit material to ball mill ‘© Roller pross citculation factor Faller press throughpuvnew feed: 25-6 Separator New maT feed Recycled Magnet coarse material Finish grinding layout + Separator controls ratio between material recycled to roller press and pressed materia to ball mil + Deaggiomeration and separation may be combined in one machine + Separator may be divided into a grit separator and separator ‘working in series * Roller press specific powar consumption (cement grinding) 14 to ~30 KWhit finished product ‘+ Roller press circulation factor = Roller press throughputriew feed “61014 Roller press Page BS DERCCCOCCLCC CONT OL Page Ba Rollor press[Roller press calculations ‘Symbols Roller press calculations Formulas, Move ‘otal roller force Ts calculated trom the hydraulic pressure and the number and area of the hycraulic cylinders: T=c-A-B: 102 Ny ‘Specific roller pressure ks the total force divided by the projected roler area: kr=TD-W) (Nin?) rol aCe Peripheral velocity v of the rollers is calculated from the roller BR ahecd and the ole ameter i W=P"D (60) ims} L ctr nates eset casts es applied total force, the peripheral velocity and the rolling torque factor between materia and roller sutace | D: Roller diamete im) NapeTew [kW] TE ar iton using tho spac or pressure W: Roller width im uk owe ew) a: Roller speed (pm) Ea i ‘Throughput capacity M ofthe roller press is calculate rom tho el, Raver peripr etal ey a) BR _iekness ol tne grinding bes tne density ofthe pressed materi, Grinding best thicaness im the width of thé rollers and the peripheral velocity a ua Ma36.3°0-W-v wn) F— Rolorforeo | 8: Hydrate prossure toad Specific power consumption E1 appied tothe material at exch Bass trout tne rer press isthe power consumption dided by aw Piston area Im] ‘the throughput capacity: nt 0 c ‘Number of hydraulic cylinders a es a M [kwhit) 3° Density of pressed materal igh Roller press circulation factor Cis the throughput capacity yore 8 Bee aiedty no new toe rate us Torque factor u CemP u kei Specie roller pressure ous | M: Roller press capacity (uh =a roller press system (finished product or product to ball mill) is the a Sonesta Spectic power consumption applied tothe material at oach pass N Power conauenet 1 through the roller press multiplied by the circulation factor: E: ° Specific power consumption rw) es =C-EI tkwha | c: Roller press circulation factor a P: New feed to roller press toh eS Roller press Page BS Bee Fees Roller pressRoller press calculations _—_—_—_—_—‘Typical val Typical roller press parameters Flier press velocity Ima] [13-16 6000 (Cement and slag) Specific roller prossure —_(kNim*] 4500 (Raw materials) Torque factor a | 007-04 | | Grinding bed — eotoy | 18-23 | Density of pressed material [ume] | 22-27 Roller press. PageB7 Notes Page BS Roller pressDOGG EE CCCP Vertical mill C: Vertical Mills Page 1Layout ‘There are two basic layouts of the VAM system; product collection in eyclone(s} or product collection in fiter. Below only the ducting used with the mill in operation is shown Product collection in eyeione(s To dedusting . » ' Heat source Product collection in fiter: « q q 4 y Heat source Page 02 Vertical mill IH |OO ee [Vertical mili calculations Semboie | MEM yericat ant cacaatons ——Pomersonsmaption WES re tnecratcal poner consumption ot vorical te i A Sele nen nae oR ee Oe a Nozte ring area ta Forthe Atox mil folowing applies: Grinding table diameter im) = Kx Typicaly 500-700 [Nine Day Hygraulo ylinder ciameter tm = Daa: Wate tm Dn Hyde pol lemeter im a] Baits fi Deets eller clameter tr Dy = Mit size 40 imi F —Geincing force ay es 4 Fis Hyer rnin force KN] — ‘aeoven eal Fe: Roller grading force KN) Bundlb-by ia x Specie gindng pressure tevin es Ma Roller assembly weight, one roller kg) es For the OK mill following applies: HTorque ctor 4 Kr Typically 700-1000 Nin N Mill power uptake kw) SS A= Dror Wear [my Grinding table speed (pm) Drotor = 0.89 Do (OK 25-3: 0.69 Da) Im] Pea Hytaule ong pressure een = aar™ 024- Dy to Grinding track speed rvs] es (ro) Waser Roller weth tm a Number of allers a Ld (rvs) =a i HR 76 lorUe factor, wil norma be in tho range [ ial -Repeaton Ty =range — 8 le remo es [eat arnaing 007-008 Comentgending —0.08-070 BB LK | Secrecy [oso Vertical mi Page C3 GB eo Vertical iVertical mill calculations Grinding pressure Will nternats Nozzle ring] Formulas apply for Atox and OK milis only ‘The nozzle ring area isthe free area, perpendicular tothe rection ofthe gas flow, as measured at the shortest distance between the table and the air guide cone: Piston rod | Aes Pos | stock Z || abso i| | Aouide cone, Hyer i eviinder L) - Anazzie 7 | 3 ‘The grinding pressure, F, consists of: Dam ring \ = 4. = Fat Fu en Fa=Ma-981/ 1000 te Grinding table are whore \ Fia= Piya (Dey)? (Dpeon}") Bla = 100 kN] ‘The specific grinding pressure will then be: 1 | KreFiA (kav Gas ow direction The mechanical instrucion wil mast often enclose a graph giving the correlation betwoen Pays and Kr. 35-50 mis, ‘The higher the velocity, the lass material falls through the nozzle ting, a ‘The gas volociy in the nazz rig wl normaly bein the range: =3 es es es Page 6.6 Vertical mill Page C5‘ermal Dam ring] Heat balances Example ‘The dam ring height isthe height measured from the grinding table segment to the top of the dam ring For Atox mills: Dam ring height Table segment Grinding table For Atox mill the dam ring height is often refered to as "% of {able diameter". The optimum height normally being in the range 25 - 4% of table diameter. Example: ‘Adam ring of 120 mm in an Atox 32.5 will give a relative height, of 120 mm /3250 mm For OK mills: Dam fing height “Table segment | Grinding table} For OK mils the dam ring height is given in mm only N th SC __KCalkg’C Mean [Feed, ry B00 a0~COaIe Cae Water in feed 74 20 1.00088 [Reciee mat. (#) [Grinding heat (2) 1376 Icas 02-5222 18405 lFalco air) 20 2 © 02M, 847 water injection 0 FrOTALIN 7, Ze our [water in product pe Water evap 164 0453 10389 loas,total =. | axe 2d 6833 |surtace loss 200 ecire mat. (#) ‘An example of a heat balance for a vertical mill Case: 200 th, 8 KWhit{net), drying from 896 to 0.5% moisture Flow Temp Op Heat [fora our (2): Recirculated material isnot included in the heat balance since the inlet and outlet temperature of this is virtually the same. (©): 1600 kW * 9800 sth / 4.186 J/Cal = 1376 MCalh (C): False air from mil inlet to mill outlet is calculated based upon (CO; and O: measurements. Standard value is 10% Us (S95 + 0453.85) = 10.384 Vertical mill Page G7 Page C8 Vertical millTOC D: Closed circuit grinding Closed circuit grinding Page Dui[Grinding theory ComnTnon Indo] (Circulation factor By sieve residuos or weight] Fo: Sieve residue of feed to mill system (es) SC comsiove rositues: Re Sieve residue of product 6) — a Re: Sieve residue of separator reject [ee] Fa: Stove ideo separator teed 1 =a "s Ws Comminutian index ten : €:—_Specitc power consumption for ball mill (AW < © Girulation factor ra ‘Tho spectc power consumption for a ball mil, grinding fom sieve | 5 residue Ri to Re, can be described by the falloving equator RY T I E-water Re) tent u Wis the cammiution index spect or the patcuar mil Mato balance: OxRy = R, +(C~1)xR ‘operating wh tho partcularmateras, and states the spactic energy consumption in KWvt required for reduction ofthe sieve _Ro-Rr ee erate Gielaton ator c= FF ‘The specie power consumption plotled agains the sieve residue pay A wil form a straight ine, when the residue values are plotted using Byweiants —- son Blogante scale For open cult grinding the equation is & tol) teen Ry For closed circuit grinding, with a circulation factor C: a remeron Ro +R x(C-1) =Wxex x(0-1) jew Re Ee OR Re [writin] A — I ‘The comminution index, being a measure forthe grinding t eticieney, can be usefl when making comparisons between two ieee mil, or produts with éfferent fineness, ea = +P ey tent cn Ss Page D2 Closed circuit grinding BSR Glosed circuit grinding PageD.3 |[Separator efficiency Separator efficiency as reduction in power consumption: ‘Operating in closed circuit with a separatar, normally results in a reduction in the specific power consumption, Description The size ofthe reduction depends on the efficiency of the separator, the fineness level of the product and ofthe circulation factor. By applying the formulas for Vs and Bs, the saving in kWhit ‘oblained by using a separator can be determined. The Ccalcuations are based on the residues found in the samples Fi, Pres Fl Typical values for efficiency, Vs, relating to residues inthe interval 82-45 micron: 4st ganeration separators: CV, Heya, Sturtevant ‘2nd generation separators: REO, Wedag, ZUB 3.rd generation separators: Vs =25- 40% Vs = 40-60% Sepax O-Sepa, Sepol Vs =75 -85% ‘Separator officioncy as recovery of fines Ur Separator efficiency as recovery of fines [%] ‘Separator eficiency measured as Recovery of Fines is calculated according to the expression: ‘The msthod can be used for comparison between separators operating atthe same circulation factor. The method does not quantify the power reduction, Power reduction Separator efficiency Vs: Separator efficiency as reduction in power consumption Pe) Obtained power reduction ical Baxi Maximum possible power reduction I ‘The separator eficiency (Vs), is defined as the reduction in Specific power consumption in the mil, obtained with the ‘separator in question (B), in relation to the reduction which could have been obtained if the separator were ideal Bn. vs=—5 100 ra) Ban hence the saving (B) can be expressed as: B= Bypgy XV5/100 ‘The sionficance of an deal soparator isa residue in the retume, Ry = 100%. The value of Bax can be calculated using the expression: Ry +100x(C-1) The soparator efficiency Vs is calculated according to the expression: R Ry +Ryx(C-1) tog Ro _extog Ro * Ra fC-1) TR, OR sR, (OT) Ro Gntog eo = 100%(0=1} 10982 extog Re y 08 pO Oa F00x(O=7) Vs= }«400: 4] ‘The speciic energy consumption or closed circuit operation is Calculated from the expression: ee oWato Bas | [kwon 10000 Page D4 Closed circuit grinding =a a ea = ea ea Ss Closed circuit grinding Page DS[Separator efficiency Max power reduction [Separator efficiency Ve values Max power reduction, Bmax) Soparator efficiency, approximate values Valid for = 1.8 -5 Dinan Page D6 Closed circuit grinding (Closed circuit grinding Page D7 TOC CCRC HeTromp curve Description T: Tromp curve value ea ‘The tromp curve is used to evaluate the performance of a separator, ‘The curve describes the percentage of the feed material, of any ‘fain size, which is found inthe return material The construction af a Tromp cure requires particle size distrioution curves for the material streams going into and leaving the separator. ‘The panicle size distriaution curves, representing Rt, Rim, Rg, are divided into particle size intervals, where each interval represents a patticle size, ‘The Tromp values are caloulated according to the expression: C-1,, ARG 409 ABO 4 © “Rm where: he percentage of reluin material in the interval representing the particle size. ‘fim = the percentage of material leaving the mil, in the interval representing the particle size, Cutsize: Parca size corresponding to the Tromp-value 50 % Depends on rotor speed and fineness fevei Kappa: ‘Slope of the curve in the interval 25 - 75.%, Eg.: x25/x75 Normal range: 0.5-0.6 Delta = Byoass: ‘Tromp value at lowast point on curve. Normal range: 5-15 % Page D8 Closed circuit grinding TOLCCte [Tromp curve Example 100 2 @ 7” 2 2 w 5 8 20 z 8 40 5 e x 2» re | 0 Closed circuit grinding Page 0.9Factors of influence: Trompecuves | EMD [Notes ‘The shape ofthe Tremp curve i influenced by the folowing a | factors ‘Separator desian, = Later generation separators designed with more favourable es geometry, resulting in higher valves for Kappa and low By-pass an ea Material load, es Excassive material loading sults i increased by-pass and lower Kappa value. = Normal ranges: Productload: 0.85 koi? Feedload: 2-25 kg/m? es Insufficient aidiow resus in higher by-pass value and lower a Keppa value —_ Creulation factor Increase in cculation factor leads to Increase inthe by-pass = value. Grinding ala a ‘The use of grinding eid may counteract agglomeration, resulting es in reduced by-pass value and increased sharpness of separation ‘Analysis method. = Different laser analysis methods may ajve cifferent results es Comparison of Tromp cures should be done using the same rebeana wen ea Page 0.10 Closed circuit grinding BSE Closed ci Page D.1tPage Ext E: Various Various DDDQDDDDDDLDDDDDDID2rai FamST=ufonsi] Fane an calcoalons no or ‘Te carats of an cn be change by changing he Eaiges kya) tiemeter a given impolior os br shen Tela rosie atornce oer fan a ae (rn =O i N Fan power consumption (KW) a Volume flow at inlet [mvs] y ° tm mee) a fn: Fan effilency ul = D: Diameter an impel tm Fi pens of clean gas kan tae (2) ww 5 Disteinentingee tom th changing fan sped andor dns = Quy pts a Cod reer where the subscript "ref refers to the values the fancurva is based upon. “The fan power consumption can be calculated from the flow and the pressure diference over the fan: Gp, pts 9.81 pa/mmWs Nw 1p 1000 W/W tw) 1 can vary from 0.89 for oft type open blade impeller types to 10.85 for a modem closed impeller with curved blades. Changing the diameter ofthe fan impeller causes the same changes as changing the fan speed. Page E2 Various = es | | Ll es eas ea es es Various Page ESainandtieat Densities and p-values [Air and heat Various formulas foi Specie density ofa gas Ikon Gases: ni f — Densiy ofa ges thoi} = po) Op average” . Gas inka mo T Temperature rej erry 7a] b: —Barometic pressure as be ie bp: Barometic pressure at sea level ed y=760 mmmHG, 1013 mBar or 10833 mmiNG. 1.486 | Height: Height above sea level fm) *: Air with 7596 rel. humid at 20 °C at soa level Relative pressure mmwe} 2. Kiln gas’ Oz vat 4.0%; CO2 ma: 32.0% and moisture content of gh gs eters re] 0.05 kg H:0 kg dy gas. Ve: Gas amount at Normal conations {Nm >. Cp-average fr the gases are the average vals in the interval Ve © Gai ernoupt at acted condetons: kl 0 400°C Ikcabkgi"C) aR sinker 8 “Goat igh vile | 027 — Coal, low volaile oi «| “Sag 0.197 rr Ho waioy OY *. Gp-average for the materials are the average values in the interval 0-200 °C Barometric pressure: b= by «ef 2020128 Hey Density: 273 bby -10393+p 1 Reo met 10333 fore Volume: Vevy 27324, 10299 ii “273 Bly 10333 +p A gas volume V; with temperature t and pressure p; will change 0 Ve when temperature andior pressure changes to t and pe 273+ tp bilby 10833 +p, "Dre, Bly 10353 + Pp (ont) Heat of evaporation of water: 595 kealkg at O°C 539 koalig at 100° Electrical eneray to heat: ‘kWh equals 660 kcal Heat transmission from a surface: 8 kealh/*Cim for free convection, 4012 callie from forced convection. 1000 keal/nvm from a cement mil surface. PageEs Various =a es =a esa =a es Various Page ES[Air and heat Water vapour in air [Air and hi Wet and dry temperature Dow point temperature °C Wet thermometer Dew Point Temperature Dry thermometer Kiln Gases: Subtract 2.5 °C from the actual dewpoint and use the graph, PogeEs Various Various Page Ey?[Air and heat Pitot tube measurements Il (Air and hi Pitot tube measurements Pe Dynamic pressure Immwa} = State pressure immu] o* —Spocte gravity of gus B73. oy 10559 +p, eet 8 Brat 70333 ve Valo of gas va [20-80 ime 2 D: Inside diameter of duct imi @: Volume ow of gas Q=5.0?-y [ois] Mass fow of gas Q=5-D? v-p Ikg’s} 3: Quantity in Nine =Q-2 [Nm¥s} ‘Measuring points must as far as possible be situated on a straight stretch of pipe with uniform flow, without obstructions like blends fr dampers, There should be a straight stretch of minimum 5xD before and 2x0 ater the measuring point. conectoe: Pe Meroe branches both rere Ho Semnacreae oe —— — — ° | IL [Normal pitot tube Stlype pitot tube is usa6, if the gas stream is dust filed. The dynamic pressure is corrected with a factor of (0.86 before the normal formulas ara used, Page 68 Various ‘The gas flow in @ pipe is never uniform throughout ts cross Section, and Ps should be calculated as an average value of the ‘measured values taken atthe tabulated points below. i SyPameensa) ‘hore n is the number of measurements included Pewee fm) a |S fe fe fe | ~~ as. points | 2x2 | 2x4 | 2x6 [2x8 | 2xf0 = a [0.850/0.930]0.96D)0.970]o.970 @_{0150/0.750]0.850|0900|0.920 a [0250 ]0.700]0.81-0/0.850) a 9.07.0 0.800 | 0.68.0| 0.77.0) a (0.15:0/032.0 0.660 as | (0.04-0)0.190|0.360 a (0.100/0.23) ae 0.030/0.15) ae 0.080 a 0.03.0 For rectangular oross sections a fictive diameter of D=¥(HsB) is Calculated, and use the number of tabulated measuring points as indicated in the table. In a rectangular duct, the measuring paints are evenly distributed inthe cross-section, Example: ‘A duct measures inside: mm = %@ - (800+800) = 650 mm Corresponding to the a 650 mm cireviar duct, or & measurements ag indicated. ot Various Page £8‘Air and heat False air calculation Molsture calculations ] “The faise air between two points can be calculated based on O: ‘and CO: measurements, if the main gas stream is kin gas. False air in the mil lowers the temperature and thereby the drying capacity. False air atthe aullet does not directly influence drying burtinereases the load on fans and fers, n extreme cases false air may bring this load to a point where sufficient air ean no longor be drawn through the mil False air is expressed in percent of unmixed gases at the inet. ‘The amount of false air through the mill and cyclones may be calculated from the contents of COs and Opin the gas. ‘Atmosphere air contains 0% COs and 21 % Oz. In the ‘calculations the term “gas” signifies the unmixed gases and the term *mixure” the mixture of false air and gases. From COs-measurements: 60,(gas)—CO,{mixtre) e COstmictue)— a) From Ormeasuroments Op{ mixture) 0988). 99 a ef mtu) F Feed (wet) (uh) P: Production (ary) (uh) wi Moisture of feed 1 Wp Moisture in product fel E: Water evaporated (un ‘A: Dry proportion of component ea) B: Wet proportion of component (Pa Production of @ mil system with moist feed 100-w, P=F ay {uh Feed necessary to produce P is 400 FeP Se teh ‘The average moisture of feed with dtferent components: os 100 wy = 100-- A [%) 200-5, or in terms of the wet proportions: Wy =38,-w,/100 where Ais the dry proportion ofthe ith component and the moisture of the same component, ‘The wet proportion of the nth component is calculated as: ‘The dry proportion is calculated from the wet proportions as: fg =By 100 400-58, -w, 7700 Page E10 Various Various Page E11Sieve to mesh conversions [Unit wansformations rT, | Dita wi | Mesto | Meetho thn 0621 les tle = 1.900km neal are Pee ORtisveom ved” sesame Cases iow - Oates jr 2 ie te 41mm =0.0384 inch Yinch = 254mm ‘to ‘a ‘4 1780 ae | 6 Weight: Hes ® ts ie) ce remmnen taht. wow0ri - erage ie te coast ig eo Ty ota jer 226350 coo 2B 2 | aoe = |» | s TES OMEnKO Imei tdi 33 tmBar =102mmH.0 tmmH:0 =0.098 mBar “ © {Ba 07mm imme. cLassmoer a +0 see: Soi moer al re 0 eo 1 Bar 1.033 atm. tat. = 0.969 Bar re 70 Tpsi "= 0.0690 Bar 1 Bar 14.5 psi 85 80, 1 kgtiem? = 0.98 Bar 1 Bar = 1.02 kato? a0 toon iz | 0 Force, power, eneray and to 106 150 5) sc tke =8BN 90 170 isd | tkpm 981d WW 102 kom 200 x0 tien Sastw tw =o.t02rpms 20 20 tre tw L3eh— 00 270 1kWh seo ws | | eT tery =o250.iat —* | aa = fi), =o a ‘Temperature: BB xc xe V5 X-+92°C. ae XK Lxeane a Verous RY Various Page E78