Optimization of dosing tank emptying using spiral vibration

Ad ances in Science and Technology Resea ch Jou nal Volume 12, No. 3, Sep embe 2018, pages 143–149 DOI: 10.12913/22998624/94962 Resea ch A icle OPTIMIZATION OF DOSING TANK EMPTYING USING SPIRAL VIBRATION Da id Zu o ec1, Jan Necas1, Jan Di is1, Jakub Hlos a1, Ji i Zegzulka1, Ka e ina U bano a2 1 VSB-Technical Uni e si y o Os a a, ENET Cen e, 17. lis opadu 15/2172, 708 33 Os a a-Po uba, Czech Republic, e-mail: da id.zu o ec@ sb.cz 2 DSD-Dos al, a.s., Bys icka 38, 751 14 D e ohos ice, Czech Republic ABSTRACT This a icle add esses he op imiza ion o a dosing ank using a spi al ha monic mo- ion. The dosing ank is used o asho - e m s o age o cohesi e sand, which is hen eleased in o a ubula mold. O iginally, a solu ion based on he p inciple o wiping he ma e ial using o a y blades and b ushes was used o ill he molds. Howe e , his me hod was no e ec i e enough. This solu ion su e ed om une en dosing as well as a loss o ma e ial. The mold illing ime anged a ound 20 seconds. Du ing he cou se o op imiza ion o he dosing ank, a new design o he ank was c ea ed and ex e nal ene gy in a o m o ha monic spi al ib a ions was in oduced in o he sys- em. The chosen shape o he ha monic spi al mo ion p o ed o be he mos sui able o con inuous emp ying o he cohesi e sand om he dosing ank in o he ubula mold in a e y sho ime. The e was also a signi ican elimina ion o ma e ial losses. I was de e mined ha he equency o ha monic mo ion a ec s uni o m dispensing o ma e ial om anks. Keywo ds: spi al ib a ion, dosing ank, cohesi e sand. INTRODUCTION Indus ial en e p ises a e o ced o in es in he de elopmen o echnology due o echno- logical ad ances in all disciplines o mechani- cal enginee ing and e e -inc easing demands o speedy manu ac u ing p ocesses.When designing anspo and s o age acili ies, i is app op ia e o use s udies and knowledge om a ious a eas o anspo and handling equipmen designed no only o bulk ma e ials [1, 2, 3]. The p esen s udy add esses he op imiza ion o emp ying a dosing de ice designed o he sho - e m s o age o an exac amoun o cohesi e sand. In gene al, s o age acili ies such as anks o silos a e used o hold loose ma e ial in a closed space o he necessa y amoun o ime. The cons uc ion o he s o age acili ies is dimensioned acco ding o he equi ed s o age ime as well as he mechanical and physical p ope ies o he s o ed bulk ma e- ials. Mechanical and physical p ope ies signi i- can ly in luence he beha io o bulk ma e ials in s o age p ocesses [4, 5, 6]. In ac , nega i e beha iou such as aul ing a e no uncommon du ing emp ying anks. The op imal emp ying o anks equi es knowledge o he ope a ing con- di ions and de ailed in o ma ion abou he s o ed ma e ial. This abo e all includes he a o emen- ioned mechanical and physical p ope ies o he s o ed ma e ial, he shape and size o he ank, he hoppe and he discha ge opening. In e ms o he na u e o he ank emp ying, we dis inguish wo ways o ma e ial low: mass and co e low. Mass low is mani es ed by he g adual d aining o ma- e ial om he ank in o de , in which i was in o- duced o he ank. To achie e his, an op imal con- s uc ion design o he s o age de ice is equi ed depending on he p ope ies o he s o ed ma e ial [7]. Howe e , in eali y his is o en no achie ed, and i equi es he use o ex e nal sou ces o en- Recei ed: 2018.06.29 Accep ed: 2018.08.01 Published: 2018.09.01 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 144 e gy, such as ib a ions, acous ic wa es o ai [8, 9, 10]. The co e low is cha ac e ized by he p inciple ha he ma e ial loaded in he ank i s , discha ges las . He e, he ma e ial abo e he dis- cha ge opening is discha ged i s and he ma e ial adjacen o he walls o he ank emains s ill, c e- a ing so-called “dead zones”. The ma e ial loca - ed in such “dead zones” o en adhe es o he walls o he ank due o longe s a ic pe sis ence, which is pe cei ed as a ailu e s a e [11, 12]. O he ail- u e s a es including s a ic aul s, ca i ies o un- nels may also occu in s o age de ices, which all nega i ely a ec con inuous emp ying. Howe e , he ad ancemen o echnology p o ides me hods such as he Disc e e Elemen Me hod (DEM), o de ec and moni o ailu e s a es in anspo and s o age acili ies. The ad an age o using he DEM simula ion me hod lies in so wa e e i i- ca ion o planned changes in design o a de ice being de eloped o op imized [13, 14]. DESCRIPTION OF THE CURRENT TECHNOLOGICAL PROCESS Du ing he cou se o his esea ch, an analysis o he cu en echnology o sand dosing in o u- bula molds was pe o med. The echnology was de eloped many yea s ago and i no longe mee s oday’s equi emen s. The exis ing echnology is based on he p inciple o wiping sand wi h a o al dose weigh o 4 kg in o a ubula mold using o- a y blades and b ushes loca ed in a cubical dosing ank. Fig. 1 summa izes he dosing me hod in o h ee s eps: I, II, III. In he i s s ep (I), he dos- ing ank a i es abo e he pai o openings o he ubula mold and he discha ge ou le is opened. In he second s ep (II), he p ocess o ma e ial wip- ing using a sys em o o a y blades and b ushes is ini ialized. This p ocess akes place o almos 15 seconds. In he hi d s ep (III), he dosing ank e- u ns o he illing a ea o s a a new illing cycle. Du ing he illing o he dosing ank, he ubula mold is p epa ed o he nex illing cycle. Howe e , his me hod was no e ec i e enough as i o en esul ed in une en dosing and ma e ial loss, as shown in Fig. 1 in s eps (I) and (III). Fu he mo e, he mold illing ime was no longe su icien o mee cu en equi emen s and i was necessa y o p oceed o a comp ehen- si e op imiza ion o he p ocess. The aim o he op imiza ion was o ensu e a uni o m illing o he ubula mold o elimina e ma e ial losses as well as dec ease he illing ime by wo- hi ds. In he i s s ep o he op imiza ion, he cu en s a e was e alua ed while he mechanical and physical cha ac e is ics o he sand we e mea- su ed. Based on he da a collec ed abou he p o- cess and he bulk ma e ial used, he op imiza ion di ec ion was de e mined. Du ing he cou se o op imiza ion o he dosing ank, a new design o he ank was c ea ed and ex e nal ene gy in a o m o ha monic spi al ib a ions was in o- duced in o he sys em. Fig. 1. The p inciple o dosing cohesi e sand in o ubula molds [15] Fig. 2. A sample o sand used du ing he expe imen 145 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 MECHANICAL AND PHYSICAL PROPERTIES OF SAND In o de o op imize he p ocess o emp ying he dosing de ice, a sample o he bulk ma e ial was analyzed. The bulk ma e ial used he e was he sand used o he p oduc ion o i ings in he ound y indus y, which is shown in Fig. 2. Angle o in e nal ic ion φe The angle o in e nal ic ion φe cha ac e izes low p ope ies o bulk ma e ials. This includes mo emen s, esis ances and bonds be ween indi- idual pa icles. The angle o in e nal ic ion de- e mines he shea p ope ies o he mass, which de ine he lowabili y o he sample being exam- ined. The angle o in e nal ic ion was measu ed using a ing shea es e Schulze RST-01. Fig. 3 shows he esul s o measu ing he angle o in e - nal ic ion o he sand (φe = 43°). The dependence o no mal s ess σ on shea s ess τ is shown as well. Based on he measu ed alues o he angle o in e nal ic ion o he sand, i was necessa y o p o ide mo e ene gy o o e come he in e -pa i- cle bonds and esis ances. Wall ic ion angle ϕw The measu emen o he wall ic ion angle was pe o med on he Jenike di ec shea es e . The measu emen p inciple consis s o measu ing he ime dependence o he shea s ess τ, which is equi ed o shi bulk ma e ial o e he con ac ma e ial, while g adually inc easing no mal s ess σ. The ollowing con ac ma e ials we e used: A) s ainless s eel shee ; B) Mu eld s anda d “S” plas ic; C) polyu e hane. The esul s o measu ed alues o wall ic ion angle ϕw and he wall ic- ion coe icien μw a e summa ized in a single g aph, which is shown in Fig. 4. F om a compa i- son o he esul s o ex e nal ic ion measu ed on indi idual con ac ma e ials, i is seen ha he s ainless-s eel shee exhibi ed he lowes esis- ance o mo emen . Angle o epose Ψs The angle o epose was measu ed using a measu ing s and consis ing o a s eel bowl on which he ma e ial was g adually ed h ough a ib a o y eede . The bowl was placed on a o a y s and ha allowed he pile o be moni o ed om 0° o 360°. The nume ical angle o epose alues a e shown in Table 1, while Fig. 5 shows g aphi- cal esul s o he angle o epose measu emen s. The a e age angle o epose was Ψs = 52.1°. This implies ha sand is e y cohesi e when illed and emp ied du ing s o age p ocesses. Pa icle size dis ibu ion A CILAS 1190 lase pa icle size analyz- e was used o g anulome ic analysis o he Fig. 3. Resul s o in e nal ic ion and lowabili y measu emen using he RST-01 es e Fig. 4. Resul s o wall ic ion angle measu emen s Table 1. The nume ical angle o epose alues Posi ion 1 2 3 4 5 6 7 8 Angle o epose 52.6 53.4 52.4 52.09 52.3 50.2 51.1 51.8 Angle o epose-A g. 52.1 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 146 sample. Cohe en ligh om low-powe lase diodes, emi ed a 830 nm wa eleng h, passes h ough a cu e e con aining a sample o he analyzed ma e ial dispe sed in he co espond- ing liquid and he ligh beam issca e ed. The pa icle size dis ibu ion o sand anges om 1μm o 600 μm, see Figu e 6. Mos pa icles in he sample anged om 100 μm o 400 μm. OPTIMIZATION OF DOSING TANK Based on he measu ed mechanical and physical p ope ies, sand was added in o a g oup o cohesi e ma e ials and an ex e nal powe sou ce was equi ed o uni o m emp ying o he dosing de ice. Mic o- ib a ions wi h spi- al pa h oscilla ion we e selec ed as an ex e nal powe sou ce. The shape o he spi al ib a ion was achie ed by using a pai o NO12 ib a ion Fig. 5. Resul s o angle o epose measu emen s Fig. 6. Resul s o pa icle size dis ibu ion measu emen s Fig. 7. a) new design o he dosing de ice, b) expe i- men al s and a) b) 147 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 mo o s ins alled on he ib a ing pa and o- a ed by 90° wi h espec o each o he , see Fig. 7b). Vib a ion mo o s posi ioned his way p o- ide a combina ion o wo ha monic mo ions: pa ial o a ion a ound he “Z” axis and pa ial eed in he “Z” axis. The combina ion o hese wo mo ions c ea es spi al mic o-oscilla ion. In his way, he s abili y and symme y o he o e all assembly du ing g a i a ional emp y- ing o he dosing ank a e ensu ed. F om he measu emen o he ex e nal ic ion angle, a s ainless-s eel shee was chosen o he p oduc- ion o he dosing ank. Based on a comp ehen- si e assessmen o he measu ed mechanical and physical p ope ies o he used sand, a new shape and size o he ank was designed, and he minimum dimensions o he discha ge ou - le we e de e mined, depending on he pa icle size dis ibu ion o he sand. Figu e 7 shows: a) new design o a dosing de ice, b) expe imen- al measu ing s and. The expe imen al measu - ing s and consis s o he ollowing basic pa s: 1-Fixed ame; 2-Flexible Elemen s 4x; 3-Vi- b a ing pa including he dosing ank; 4-Vib a- o mo o s NO12. EXPERIMENT AND RESULTS In o de o expe imen ally e i y he unc- ionali y o he op imized dosing ank, a measu - ing appa a us was assembled consis ing o he ollowing: a PC, expe imen al s and, ensome ic scale and equency con e e . The assembly o he measu ing appa a us is shown in Figu e 8. Du ing he expe imen al measu emen s, he e - ec o ib a ions on he e iciency o emp ying he dosing ank was assessed. Table 2 shows se - ings o he d i ing o ce FB depending on he os- cilla ion equency p oduced by pai o he N012 0.15kW ib a ion mo o s. The o al s i ness em- ana ing om he ou elas ic elemen s was kp = 123N.mm-1. A 4 kg sand sample was loaded in o he dosing ank. Figu e 9 shows he emp ying p ocess o he dosing ank in a ious ope a ing modes. In he i s expe imen , he sand beha io una ec ed by ib a ions was moni o ed. I u ned ou ha he ma e ial is so cohesi e ha he ank could no be emp ied by employing only a g a i a- ional me hod. In he second expe imen , i- b a ions o 15Hz equency co esponding o a d i ing o ce o 325N we e used. E en in his case, he sand could no be emp ied om he ank and he en i e olume emained in he ank. A e inc easing he equency o 20Hz, he sand s a ed o eely low immedia ely a e opening he discha ge ou le . The emp- ying p ocess was smoo h wi h only sligh de- ia ions. Subsequen ly, he ib a ion equency was se o 25Hz, which co esponds o he d i - ing o ce o 904N. In his case, he emp ying was e y smoo h and s able wi hou signs o impac e ec s. A 30Hz, he e we e signs o g ea e dynamic e ec s du ing he emp ying p ocess, which a e undesi able o he ollow- ing p ocesses. The emp ying ime o he es ed equencies was a ound 2.5s. Based on he esul s om he expe imen- al es s, he inal design o he dosing ank was c ea ed, and sui able pneuma ic ib a ion d i es we e selec ed which we e posi ioned 90° ela i e o each o he . The d i ing o ce o a pai o pneu- ma ic ib a ion d i es was se o allow he op i- mal emp ying o he dosing ank. Fig. 10 shows he inal e sion o he dosing ank design used in eal ope a ion. Fig. 8. Assembly o he measu ing appa a us Table 2. Se ings o he d i ing o ce FB depending on he oscilla ion equency p oduced by pai o he N012 0.15kW ib a ion mo o s F equency [Hz] 15 20 25 30 Speed n [ pm] 852 1136 1420 1704 D i ing o ce FB [N] 325 579 904 1302 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 148 CONCLUSIONS The aim o his esea ch was o op imize he me hod o emp ying a dosing de ice de- signed o weighing and sho - e m s o age o sand. Fi s ly, an analysis o he cu en p o- cess echnology was pe o med. In he ollow- ing s ep, he mechanical and physical p ope - ies o he used sand we e measu ed, namely: angle o ic ion, wall ic ion, angle o e- pose and pa icle size dis ibu ion. Based on he measu ed alues, he sand was assessed as e y cohesi e wi h a pa icle size anging om 1μm o 600μm. I was ound, ha he mos sui able con ac ma e ial o he p o- duc ion o he inne space o he dosing ank was s ainless s eel, which showed he lowes esis ance o sand mo emen . On he basis o he collec ed da a, a new shape and size o he dosing ank was designed, and he minimum size o he ou le was de e mined, depending on he pa icle size dis ibu ion o he sand. Due o he high cohesion o he sand, i was necessa y o in oduce ex e nal ene gy o he sys em. The mos sui able ib a ions o he p ocess we e selec ed. The shape o he ib a- ion, in he o m o ha monic spi al mo ion, p o ed o be he mos sui able o he uni o m and symme ical discha ge o sand om he ank. The expe imen al es s showed ha he op imal d i ing o ce o a pai o ib a ion d i es was 900N, depending on he weigh o he ib a ing pa s and he s i ness o he lexible elemen s. The emp ying ime o he equi ed olume o sand anged a ound 2.5 seconds. Op imiza ion o he emp ying me h- od me all equi emen s and was applied o eal-li e ope a ion. Acknowledgemen s This pape was conduc ed wi hin he ame- wo k o he p ojec LO1404: Sus ainable de- elopmen o ENET Cen e,p ojec SP2018/47: Calib a ion and expe imen al de ices o he esea ch and alida ion o simula ion models AND p ojec SP2018/132: Resea ch and de el- opmen o inno a i e anspo equipmen o e i ica ion DEM me hod in p ocess o bulk solid anspo a ion. Fig. 10. Dosing ank design Fig. 9. The cou se o dosing ank emp ying p ocess 149 Ad ances in Science and Technology Resea ch Jou nal Vol. 12 (3), 2018 REFERENCES 1. Klepka T., Debski H., Ryda owski H. Cha ac e is- ics o high-densi y polye hylene and i s p ope ies simula ion wi h use o ini e elemen me hod, Po- lime y, 54(9), 2009, 668-672. 2. Fedo ko G, Molna V., Do ica M., e al The use o indus ial me o omog aphy in he ield o main- enance and eliabili y o ubbe - ex ile con eyo bel s in closed con inuous anspo sys emsm, Eksploa acja i niezawodnosc-main enance and e- liabili y, 18(4), 2016, 539-543. 3. 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