Magnetic water treatment for scale control in heating and alkaline conditions

Magnetic water treatment (MWT), an alternative solution for scale control, is discussed with emphasis on the construction of the magnetic devices and the mechanism of MWT influence on the scale formation. Two applications in high-temperature and high-pH conditions are presented. The treatment noticeably reduced the scale thickness on the heating spiral and removed preciously precipitated scale from hot tap-water outlet pipeon the walls in the zone with heated alkaline water, instead of hard scale, only thin, brittle coating was formed. The morphology analyses showed the acceleration of aragonite nucleation and raised formation of fine suspended particles

Statistical Process Control

Praktikum Statistični nadzor procesa je študijski pripomoček za izvajanje vaj pri predemetu Metode eksperimentalnega dela. Opisom osnovnih orodij vodejna kakovosti sledijo zgledi in delovne naloge s postopki, ki temeljijo na principih statističnega preverjanja kakovosti proizvoda. Vaje obsegajo meritev vzorcev in ovrednotenje rezultatov v progamu Excel ter z makri QI Macros. Druga izdaja. E-knjiga dostopna le za študente Univerze v Mariboru, Fakultete za strojništvo.The practicum Statistical Process Control is a study aid for conducting exercises in the subject Methods of experimental work. Descriptions of basic quality management tools are followed by examples and work tasks with procedures based on the principles of statistical product quality control. The tasks include measuring samples and evaluating the results in the Excel program and with QI Macros tool. Second edition. E-book available only for students of the University of Maribor, Faculty of Mechanical Engineering

Dimensional Measurements

Praktikum Meritve dimenzij je študijski pripomoček za izvajanje laboratorijskih vaj pri predmetu Tehniške meritve. Vaje so namenjene spoznavanju preprostih tehnik merjenja dimenzij v proizvodnem strojništvu. Obsegajo samostojno izvajanje različnih primerov meritev s poudarkom na iskanju rešitev za doseganje čim manjših pogreškov in čim boljše merilne zanesljivosti.Publikacija je dostopna le študentom Univerze v Mariboru, Fakultete za strojništvo.Dimension measurement practicum is a study tool for performing laboratory exercises in the subject Engineering measurement. Exercises are intended to learn simple techniques for measuring dimensions in manufacturing engineering. It includes the implementation of various examples of measurements with an emphasis on finding solutions to achieve the lowest possible errors and the best possible measurement reliability.The publication is available only to students of the University of Maribor, Faculty of Mechanica

Utjecaj magnetskog polja na redoks potencijal redukcijskih i oksidacijskih spojeva

Redox potentials of two reducing (sodium dithionite and glucose) and two oxidizing (hydrogen peroxide and sodium hypochlorite) agents were monitored at various concentrations and at different temperatures for 30-75 minutes after the exposure of their water solutions (glucose and hypochlorite solutions oncesodium dithionite and hydrogen peroxide solutions one, two and/or three-times) to the static magnetic field of flux density of 0.9 V s M-2 . The aim of the investigation was to suggest improvements, i.e., intensification and stability, of the reduction-oxidation ability of selected agents applicable in textile fibre processing, primarily bleaching and vat dyeing. Results of the experiments show that magnetic treatment (of solutions) raises both the reducing ability of glucose and the oxidation ability of hydrogen peroxide and sodium hypochlorite, promising some technological and economical benefits for the textile industry as well as forother fields of chemistry.Redoks potencijali vodenih otopina dvaju redukcijskih (natrijev ditionat i glukoza) i dvaju oksidacijskih (vodikov peroksid i natrijev hipoklorit) spojeva mjereni su pri različitim koncentracijama i različitim temperaturama 30–75 minuta poslije izlaganja otopina statičnom magnetskom polju gustoće toka 0,9 V s m–2. Otopine su polju izlagane ili samo jednom (glukoza i natrijev hipoklorit) ili jednom, dvaput i triput (natrijev ditionat i vodikov peroksid). Cilj je istraživanja predložiti poboljšanje redukcijske, odnosno oksidacijske sposobnosti odabranih spojeva koji se koriste u obradi tekstilnih vlakana, prvenstveno za izbjeljivanje i bojenje. Rezultati eksperimenata pokazuju da se magnetskom obradom otopina povećavaju redukcijska sposobnost glukoze i oksidacijska sposobnost vodikova peroksida i natrijeva hipoklorita, što bi moglo biti tehnološki i ekonomski korisno tekstilnoj industriji, a zanimljivo ostalim granama kemije

Influence of magnetic field on the aragonite precipitation

Many laboratory investigations of magnetic water treatment (MWT) for scale control explained the formation of less compact scales by raised portion of aragonite, which is needle-like and less adhesive than rhombohedral calcite crystals, while our experiment was conducted with tap water, which contains Mg+2 and Fe+2 ions in concentrations exceeding thresholds for calcite inhibition, common for major tap waters. MWT efficiency was evaluated by amounts of scale precipitated in boilers and pipes during three-weeks run of two parallel experimental lines-one with and another without magnetic treatment. All scales were identified by X-ray diffractometer to be aragonite,but in the case of magnetic treatment, scales occurred in much smaller amounts: the scale on heating copper-pipe spiral was 2.5-times thinnerdue to MWT and in zinc-coated steel pipe occurred as very thin powder-like coating, while in the line without the treatment abundant hard lining was formed. The scalesć morphology was observed by scanning electron microscope: the husks from both lines consisted of parallel distributed needles, but these crystals were about four times thinner in the case of MWT. The present work demonstrates that hard scale deposits can form even under conditions where aragonite precipitates predominantly, and that MWT can also affect the crystallization of this polymorph in a manner conducive to scaling control

The preventation of surface precipitation on heat exchangers using a magnetic water-treatment device

V nalogi predstavljamo metodo za nadzor vodnega kamna na temelju magnetne obdelave vode(MOV) v prenosnikih toplote. Podali smo teoretičen pregled tvorbe kotlovca pri industrijskih prenosnikih toplote s poudarkom na obarjanju kalcijevega karbonata(CaCO3) in kalcijevega sulfata(CaSO4) ter osnovne izračune za uspešno uporabo naprav MOV pri preprečevanju nastajanja vodnega kamna.Magnetic water treatment(MWT), a water-conditioning method for scale control in heat exchangers(HEs), is discussed. The theoretical possibilities of scale formation in industrial processes, with the emphasis on the precipitation of CaCo3 and CaSo4 as the main scale components, are reviewed. Some preliminary calculations for a theoretical understanding of the scale problem in HEs and its prevention using MWTs are contributed

Modified scale crystallization in magnetic water treatment

Magnetna obdelava vode (MOV) je alternativna metoda priprave napajalnih vod za nadzor vodnega kamna in prav tako postaja pomembna pri izboljšavah drugih tekočin, ki vsebujejo vodo. Govor je o učinkih naprav MOV, med njimi o spremenjenem kristaljenju vodnega kamna in spremenjeni stabilnosti vodnih disperzij s poudarkom na spremenjeni hidrataciji ionov in trdnih površin zaradi magnetne protonske resonance kot enega izmed možnih mehanizmov. Nadalje je predlagana pojasnitev pospešenega obarjanja aragonita.Magnetic water treatment (MWT) is an alternative method of supplied-water conditioning for scale control and is also important in the amelioration of other water-based fluids. The effects of MWT devices, such as the modified crystalization of the scale-forming components and modified stability of the dispersion are discussed with the emphasis on the modified hydration of ions and solid surfaces due to magnetic proton resonance as one of the possible mechanisms. In addition, a possible explanation for the accelerated aragonite precipitation is proposed

A simulation of the cluster-formation process in a dispersion of fine particles under the influence of an external magnetic field

Naprave za magnetno obdelavo vode (MOV) so učinkovita, gospodarna in dobra ekološka rešitev za preprečevanje izločanja vodnega kamna. Na podlagi laboratorijskih preskusov so ugotovili, da je učinkovitost MOV odvisna od sestave obdelovanega disperznega sistema in obratovalnih razmer naprave. Na temelju teorije Derjagin-Landau in Verway-Overbeek (DLVO) in statistične metode Monte Carlo Metropolis smo razvili teoretični model nastajanja gruč dispergiranih delcev pod vplivom zunanjega magnetnega polja. Nadalje smo po načelu "odprtega vira" na podlagi omenjenega modela razvili računalniški program za simulacijo in grafično predstavitev nastajanja gruč pod vplivom zunanjega magnetnega polja. Rezultate izračunov smo analizirali z metodo delitve in metodo stopenjske porazdelitve.Magnetic water-treatment (MWT) devices for scale control can be used with good economic and ecological benefits. From experimental results under well-controlled laboratory conditions we have established that the effects of MWT devices are very dependent on the composition of the treated dispersion system and their working conditions. To investigate the effects of magnetic field on the process of cluster formation in a fine-particle dispersion under the influence of the external magnetic field of a MWT device a theoretical model based on the Derjagin-Landau and Verway-Overbeek (DVLO) theory and the statistical Monte Carlo Metropolis method was used. The open-source computer programs for the simulation and the graphical presentation of clustering under the influence of an external magnetic field were developed. The results were analysed by cluster analysis, based on the partitioning and hierarhical methods