Modeling and Simulation of Processes from an Iron Ore Sintering Plant

Transcription

1 odeling and Simulation of Pocesses fom an Ion Oe Sinteing Plant CORIA ARIA DIIŞ GABRIEL ICOLAE POPA AGELA IAGĂR Depatment of Electotechnical Engineeing and Industial Infomatics Politechnica Univesity Timişoaa Revoluţiei St., no 5, Hunedoaa, ROAIA Abstact: - This wo pesents the mathematic models of the basic pocesses fom an ion oe pocessing plant. Based on the mathematic models, using the atlab/simulin platfom, it was achieved the simulation of the dosing pocess and simulation of the sinteing pocess. The achieved mathematic model allows the detemination of the mateial flows in the chage at thei chemical composition vaiation, o at the vaiation of the efeence values of the paametes S, I,, c. Futhe the simulation, thee ae obtained the time-vaiations of the optimal speed fo the sinteing machine at diffeent distibutions of ion oe s tempeatues on the sinteing band. Key-Wods: - Sinteing pocess, Sinteing plant, Ion oes, Chage, Agglomeate, Sinteing machine, odeling, Simulation, Simulin 1 Intoduction Restuctuing of metallugical industy is stongly influenced by the modenization of manufactuing pocesses fom the sinteing plants. Sinteing, as physical-chemical pocess of ion oes pepaation and obtaining of a contolled situation, is of maximum impotance because the esulted agglomeate allows the obtaining of quality cast-ions as they ae equied cuently on the maet [1,2]. In this espect, the majo cast-ion poducing counties ae using ion oes peviously pepaed as agglomeate, meant to ensue the achievement of some chages with high ion content and homogeneous fom chemical and gading viewpoint. Fom the pocesses with special influence on pepaation, in this wo ae analyzed: dosing, sinteing and cooling (fig.1). Dosing flow includes the quantitative dosing of the chage components, thei pe-homogenization into the pimay mixing dum (TAP) and the conveying flow of the mixtue/blend fom the dosing station into the main body to the chage bune of the sinteing machine. ateials extaction fom the dosing station's bunes and thei futhe dosing is achieved by means of dozes with extacting belt. These ae mounted in the bune s enty and they extact the mateial fom the bune at the flow equied by the chage ecipe [3,4]. The mixtue, which is fomed in accodance with the calculated ecipe, is collected by the conveyo belts and tanspoted to the TAP pimay mixing station. Duing the pocess, to the dosed mixtue is added futhe the hot etun bought by the metallic belts to the etun bune. Fom the TAP, which has an inclination of 2 3, the chage mixtue is oveflowed on the conveyos and the tanspot is continued on othe two conveyo belts towads the main section of the sinteing plant fom the chage bune. Sinteing flow includes the following steps: mixing/blending, humectation and foming of mico-pellets in the seconday mixing dum (TAS); loading the mixtue on the sinteing machine s caies; buning-up the chage; sinteing of the mixtue/blend; sizing of the agglomeate and eciculation of the etun [5,6]. The mateial fom the chage bune is extacted by a gavimetic doze with extacting belt, and loaded futhe in the seconday mixing dum. Inside the TAS, the mateial is bought to the necessay humidity fo the sinteing pocess (7-1%), by adding wate. The humid mateial, homogenized and micopalletized in TAS, is loaded on the sinteing machine, unifomly on the entie machine s suface, by an oscillating belt. Repatition of the potection bed on the sinteing machine s gills should be made in a unifom laye on the entie width of the machine. The height of the laye on the sinteing machine is adjusted by changing the position of the shield against the machine s gills and is established depending on the mateial s gas pemeability. ISS: ISB:

2 Fig.1. Technological diagam of the sinteing pocess Cooling flow includes the following steps: cooling of the agglomeate afte the hot sceening; conveying in cold condition to the sceening station; conveying to the funaces silos and to the agglomeate s shipment station [4]. Cooling of the agglomeate is made on two linea cooles, one fo each sinteing machine. The cooling ai is supplied by 5 fans with an ai flow of 2 m 3 /h, blow by each fan. At the entance on the coole, the agglomeate has a tempeatue of 7-8 C and leaves the coole with 8-1 C, fact which allows it to be tanspoted by some special ubbe belts [4,7,8]. 2 odeling the Sub-Pocesses fom an Ion Oe Sinteing Plant The mathematic model of the dosing sub-pocess is descibed by the following equations: 1 = S (1) 1 c ( Is ) ( Is ) K = S (2) 1 c ( Is ) R = S (3) 1 c Is ( ) C S = (4) 1 c c ( Is ) whee: mi ( Isi i ) cce( IsCe Ce ) ( Is ) (5) = n i= 1 In the above equations: epesents the ion oe flow; K limestone flow; R etun flow; C coe flow; S chage flow; I basicity index; s i, i lime and silica fom the ion oes ; s, lime and silica fom the limestone ; s Ce, Ce lime and silica fom the coe ashes; s, lime and silica fom the etun; the etun paticipation against the total ion oe ; c the coe paticipation against the total ion oe. The mathematic model of the sinteing sub-pocess is descibed by the following equations: Lu vm opt = vm (6) Tn 2 Tn Ln 1,5 pc Tn 2 2Tn 1 Tn Δ C = 1.25 Δc (7) Δ c = ( a b ) ( a b ) (8) S = vm opt H s B (9) L v = [m/min] (1) v u 3 m min wmin 1 H s u 3 m max wmax 1 H s L = [m/min] (11) ISS: ISB:

3 Fig.2. Bloc diagam fo calculation of the mateial flows fom the chage t Lu H s = = [min] (12) v w a = med med Q at ( 1 c) v 6 = B H η ρ [t/h] (13) s a v ρ v = 1.6 [t/m 3 ]; η a = ; c = In the above equations intevene the following quantities : v m sinteing machine s pescibed speed; H s laye s height (.4 m); popotionality facto (1.7); B sinteing machine s width (3 m); T n, T n-1, T n-2 tempeatues in the last thee suction chambes; = R/ - popotion of the etun against the total ion oe; =R mp / - popotion of the fine-gained poduced against the total ion oe; a, b constants which ae detemined statistically fo each installation in pat; w speed agglomeation in laye; t a agglomeation time; Q at total agglomeation flow; ρ v sinte density; η a agglomeation yield [9,1]. 3 Simulations of Sub-Pocesses fom an Ion Oe Sinteing Plant Based on the mathematic model and using the Simulin pogam fom atlab envionment, wee executed the diagams that achieve the simulation of the dosing sub-pocess of the sinteing oes, as well as the simulation of the ion oes sinteing subpocess [4,11]. The subsystem fom fig. 2 maes the calculation of the mateial flow that compose the sinteing chage, e.g.: the ion oe flow, limestone flow, coe flow and the etun flow consideing that in the agglomeate s manufactuing ecipe ente fou types of ion oe : Romanian ion oe (ion oe 1), Kivoi-Rog ion oe (ion oe 2), Basilian ion oe (ion oe 3) and scale (ion oe 4), each with its med own chemical composition, i.e. with diffeent lime and silica. Based on the laboatoy analysis, ae established the values of the following input measues: silica and lime of ion oes, silica and lime of the limestone, as well as the silica and lime fom the coe ashes. Othe input measues ae pescibed measues, i.e.: basicity index (I), coe ashes popotion (Ce%), c atio between coe and ion oe, atio between the etun and ion oe, m 1 popotion of ion oe 1 against the total ion oe, m 2 popotion of ion oe 2 against the total ion oe, m 3 popotion of ion oe 3 against the total ion oe and m 4 popotion of ion oe 4 against the total ion oe. Because in the sinteing chage the total ion oe is consideed 1%, it should be fulfilled the condition m 1 m 2 m 3 m 4 = 1. whee : m = 1 1 ; m = 2 2 ; m = 3 3 ; m = Romanian ion oe flow; 2 Kivoi-Rog ion oe flow; 3 Basilian ion oe flow; 4 scale flow; total ion oe flow. The input measues s (silica in etun) and (lime in etun) is calculated with a sepaate subsystem pesented in fig. 3. Because the etun is in fact finegained agglomeate which is ecycled in the pocess, the silica and lime fom the etun is equal with the silica and lime of the agglomeate. The subsystem fom fig. 3 maes the calculation of the silica and lime fom the etun based on the following fomulas: S s = mi si c Ce sce K s (14) s = s I (15) ISS: ISB:

4 s = m s i i c Ce s S Ce K s (16) Using the Simulin pogam fom atlab envionment it was detemined the sinteing machine s optimal speed vaiation. Fig.3. Bloc diagam fo calculation of the lime and silica fom the etun The simulation allowed also to computing the cabon coection fom the chage, as well as the chage flow [11]. The calculation subsystem of the sinteing machine s optimal speed fom fig. 4 has as input measues the following: tempeatues in the last thee suction chambes (T n, T n-1, T n-2 ), the sinteing machine s useful length (L u ), the length up to the penultimate suction chambe (L n-1 ) and the suction chambes distance (p C ). The sinteing machine s useful length, the length up to the penultimate suction chambe and the suction chambes distance ae consideed constant measues (L u =42 m, L n-1 =4 m, p C =2 m), and the tempeatues in the last thee suction chambes ae consideed measues that tae diffeent values at cetain moments of time. The sub-system fom fig. 5 calculates the cabons coection (coe) that should be made at dosing, in ode that the fine-gained etun poduced in the sinteing pocess (which is scaled) to be equal with the etun which is intoduced in the sinteing chage at dosing. This sub-system is achieved based on the equations (7) and (8). The input measue S (the sinteing chage s flow) is calculated with a sepaate subsystem pesented in fig. 6 based on the following paametes: the sinteing band s speed, the sinteing laye s height and the sinteing band s width. The calculation subsystem of the chage flow pesented in fig. 6 is achieved based on the equation (9). Fo the tempeatue values T n-2, T n-1 and T n (the tempeatues in the last thee suction chambes of the sinteing band) expessed at diffeent moments of time, will be obtained the vaiation cuve of the sinteing machine s optimal speed. This timevaiation cuve of the sinteing machine s optimal speed can be used successfully fo the optimal management of the pocess fom the sinteing band. Fig.4. Bloc diagam fo calculation of the sinteing line s optimal speed Fig.5. Bloc diagam fo calculation of the coe content s vaiation fom the chage Fig.6. Bloc diagam fo calculation of the chage flow The tempeatue values T n-2, T n-1 and T n at diffeent moments of time can be modified, obtaining, depending on these and the othe subsystem s inputs, othe time-vaiation cuves of the sinteing machine s optimal speed. ISS: ISB:

5 In fig. 8, 1, 12, 14 ae pesented the vaiations of the sinteing machine s optimal speed fo diffeent distibutions of the ion oe s tempeatues on the sinteing band. The tempeatue distibutions in time, fo the last thee suction chambes of the sinteing machine (T n-2, T n-1, T n ) ae given unde vectoial fom and ae pesented in fig. 7, 9, 11, 13. The pescibed speed (fo the simulations fom fig.8, 1, 12, 14) fo the adjustment system is 2.2 m/s. The tempeatues ae consideed to be measued each with a tempeatue tansduce fo each chambe. The simulation time is 15 s, and the tempeatue eadings ae made fom 3 to 3 s. The measuement of the mateial s tempeatue on the sinteing band is a difficult opeation. Fig.11. The tempeatue values fo the thee suction chambes, in time, fo the simulation fom fig.12 Fig.12. Vaiation of the sinteing machine s optimal speed case 3 Fig.7. The tempeatue values fo the thee suction chambes, in time, fo the simulation fom fig.8 Fig.13. The tempeatue values fo the thee suction chambes, in time, fo the simulation fom fig.14 Fig.8. Vaiation of the sinteing machine s optimal speed case 1 Fig.14. Vaiation of the sinteing machine s optimal speed case 4 Fig.9. The tempeatue values fo the thee suction chambes, in time, fo the simulation fom fig.1 Fig.1. Vaiation of the sinteing machine s optimal speed case 2 Fig.15. Distibution tempeatues, unde the laye: gaph 1: 2 cm laye; gaph 2: 3 cm laye; gaph 3: 4 cm laye ISS: ISB:

6 Fom pactice, ae nown the tempeatue domains fo each suction chambe: T n-2 [25-3] C; T n-1 [3-35] C; T n [25-3] C). Depending on the tempeatues measued (fig.15) in the suction chambes, the adjustment system imposes a cetain modification of the sinteing band. Fo simulations wee used the expeimental data fom fig.15 (gaph 3, 4 cm laye). 4 Conclusion The model achieved in atlab/simulin and its simulation allows the detemination of the mateial flows in the chage, eithe at the vaiation of thei chemical composition, o at vaiation of the efeence values of the paametes S, I,, c. Also, the achieved model allows the visualization of the optimal speed in time, which leads to the optimal chage of the sinteing machine fom the viewpoint of the chage s chemical and minealogical composition. The obtained esults ae in accodance with the pactical ones, and the model can be implemented to a eal installation. The cuent technology of cast-ion maing imposes moe and moe igoous conditions to the quality of the chage that should allow the optimization of the entie pocess, inceasing the poductivity and educing the coe consumption. As egads the modenization of the ion oes sinteing plants, will be consideed the following eseach diections [12,13,14]: - Development of an expet system fo coecting the sinteing belt s speed based on fuzzy logic; - Development of computeized contol systems fo adjusting the wate quantity in the aw mateials and the agglomeate s chemical composition; - Implementation of a suveillance system in the ion oes sinteing pocess. Refeences: [1] S. Simons, D. Rossetti,. Spyidopoulos, X. Pepin, ico-studies of ineal Pocessing Fundamentals, Physicochemical Poblems of ineal Pocessing, Vol.36, 26, pp [2] J.O.eé, F.A.Elías, A.. Gonzáles,.C. Limas, F.J..P. Ascacíba, Data ining and Simulation Pocesses as Useful Tools fo Industial Pocesses, Poceedings of the 5 th WSEAS Int. Conf. on Simulation, odeling and Optimization, Cofu, Geece, August 17-19, 25, pp [3] J. Tepá, L. Dočá, V. aduda, Combustion Pocess odelling and Contol, Acta ontanistica Slovaca, Vol.12, o.3, 27, pp [4] C.. Diniş, Reseaches Concening the odeling and anagement of the Pocesses fom the Sinteing Plants, PhD Thesis, Petoşani Univesity, Romania, 24. [5] S. Sato, T. Kawaguchi,. Ichidate,. Yoshinaga, elting odel fo Ion Oe Sinteing, Tans. of the Ion and Steel Institute of Japan, Vol.26, o.4, 1986, pp [6] J. ittelehne, G. Loeffle at all, odeling and Simulation of Heat Font Popagation in the Ion Oe Sinteing Pocess, ISIJ Intenational, Vol.44, o.1, 24, pp [7].V. Ramos, umeical odel of the Ion Oe Sinteing Pocess Diectly Descibing the Agglomeation Phenomenon of Ganules in the Paced Bed, ISIJ Intenational, Vol.4, o.5, 2, pp [8] H.C. Chuang, J.H. Kuo, C.C. Huang, S.H. Liu, W.S. Hwang, ulti-phase Flow Simulations in Diect Ion Oe Smelting Reduction Pocess, ISIJ Intenational, Vol.46, o.8, 26, pp [9].R. Vescovi,.. Lamega, A. Faquha, odeling and Simulation of a Complex Industial Pocess, IEEE Expet: Intelligent Systems and Thei Applications, Vol.12, o.3, 1997, pp [1] S. Huiping, L. HyoSoo, H. Yugiang, K. InYong, K. ChongOh, Contol of Ion anopaticles Size and Shape by Themal Decomposition ethod, IEEE Tansactions on agnetics, Vol.41, o.1, 25, pp [11] G. Savii, L. ilenco odeling and Simulation, Euostampa Publishing, Romania, 2. [12] C. Lupu, D. Popescu, A. Udea, Real-time Contol Application fo onlinea Pocesses Based on Adaptive Contol and the Static Chaacteistic, WSEAS Tans. on Systems and Contol,Issues 6, Vol. 3, June 28, pp [13] J. Aguila,. Ceada, F. Hidobo, J. Chacal, C. Bavo, Specification of a ultiagent System fo Planning and anagement of the Poduction Factos fo Automation based on the SCDIA Famewo and ASIA ethodology, WSEAS Tansactions on Systems and Contol,Issues 2, Vol. 3, Febuay 28, pp [14] C. Lupu, D. Popescu, A. Udea, C. Dimon, Solutions fo onlinea ultivaiable Pocesses Contol, WSEAS Tansactions on Systems and Contol,Issues 6, Vol. 3, June 28, pp ISS: ISB: