Paineellisten rumpusuodinten kunnossapitostrategian kehittäminen ja implementointi

Tutkimuksen tavoitteena oli luoda UPM-Kymmene Oyj:n Kaukaan sellutehtaalle tuotannolliset näkökulmat huomioiva ja kunnossapitokustannukset optimoiva paineellisten rumpusuodinten kunnossapitostrategia. Paineelliset rumpusuotimet on sellutehtaan kuitulinjan keskeinen laiteryhmä, jonka vuosittaiset kunnossapitokustannukset ovat merkittävät. Tarkastelu työssä keskittyi paineellisen rumpusuotimen päätytiivistyksen kunnossapitostrategian kehittämiseen, koska päätytiivistys muodostaa laitteen vuosittaisista kustannuksista suurimman osan. Kunnossapitokustannusten optimointi suoritettiin strategisen johtamisen periaatteiden mukaisesti eri teknistaloudelliset näkökulmat huomioiden. Kunnossapidon toteutukselle määriteltiin tuotannon tavoitteet, jonka perusteella luotiin uusi kunnossapitostrategia. Työssä tehdyn tutkimuksen perusteella siirtymällä korjaavasta kunnossapidosta ehkäisevään kunnossapitoon, voidaan saavuttaa säästöjä kunnossapitokustannuksissa. Uuden strategian toteutumisen mahdollistamiseksi määriteltiin strategiset projektit, jotka käsittelivät muun muassa uusien tiivistemateriaalien käyttöönottoa, alajärjestelmien muutostöitä sekä toimintatapojen muutoksia. Strategian ja strategisten projektien toteutusta varten laadittiin kirjalliset dokumentit, joiden perusteella implementointi suoritetaan. Toimenpiteille määriteltiin vastuuhenkilöt ja toteutusajat, joiden mukaisesti eri organisaatiotasot toimivat. Strategia laadittiin seuraavalle kymmenelle vuodelle, mutta strategian toteutusta ja tuloksia on seurattava vuosittain. Muuttuvassa liiketoimintaympäristössä kunnossapidon optimitila ei ole staattinen, joten strategiaa on oltava valmis päivittämään. Aktiivisella ja suunnitelmallisella toiminnalla on mahdollista saavuttaa merkittäviä säästöjä tuotannon ja kunnossapidon näkökulmasta.

Pyörivien sähkökoneiden kotelointia koskevat standardit ja aksiaalivuokoneen jäähdytyksen kehittäminen

Tämä diplomityö on osa Lappeenrannan teknillisen yliopiston ja Visedo Oy:n yhteistyöprojektia. Työssä selvitetään pyörivien sähkökoneiden kotelointeja koskevia standardeja ja niiden vaikutukset koneiden suunnittelulle ja valmistukselle. Lisäksi työssä käsitellään aksiaalivuokoneen jäähdytykseen liittyviä ongelmia, kehitetään koneen nykyisiä jäähdytysratkaisuja ja ideoidaan käytettävissä olevia uusia jäähdytysmenetelmiä. Kehitysideoiden rajoitteena toimii koneelta vaadittu kotelointiluokka IP 64 – IP 68 sekä koneelle määritetty kestomagnetoitu aksiaalivuorakenne. Sähkökoneiden kotelointeja koskevien standardien asettamien vaatimusten määrittäminen tapahtui suurilta osin kirjallisuusselvityksenä. Standardien vaikutukset koneiden suunnittelulle ja valmistettavuudelle on selvitetty standardien kotelointien rakenteelle asettamien vaatimusten perusteella. Aksiaalivuokoneen jäähdytysongelmien selvittäminen, käytössä olevien jääh-dytysratkaisujen kehittäminen ja uusien menetelmien ideointi suoritettiin projektiluontoisesti yhdessä eri alojen asiantuntijoista koostuvan jäähdytystyöryhmän kanssa. Työn tuloksena laadittiin Visedo Oy:lle standardikäsikirja, jonka avulla Visedon sähkökoneiden tuoteperheeseen kuuluvien koneiden suunnitteluvaiheessa voidaan varmistaa koneiden standardienmukaisuus. Käsikirjassa on myös esitetty huomioita eri kotelointiluokkien asettamista vaatimuksista koneiden valmistukselle. Aksiaalivuokoneiden jäähdytykseen liittyen tavoitteena oli ratkaista aksiaalivuokoneisiin liittyviä jäähdytysongelmia. Työn tuloksena saa-tiin selville aksiaalivuokoneissa jäähdytyksen kehittämistä vaativat kohteet, laadittiin nykyisten jäähdytysratkaisujen parannusehdotuksia ja kehitettiin täysin uusia jäähdytysmenetelmiä.

Reduction of specific energy consumption of a thermomechanical pulping plant

Kuumahiertoprosessi on erittäin energiaintensiivinen prosessi, jonka energianominaiskulutus (EOK) on yleisesti 2–3.5 MWh/bdt. Noin 93 % energiasta kuluu jauhatuksessa jakautuen niin, että kaksi kolmasosaa kuluu päälinjan ja yksi kolmasosa rejektijauhatuksessa. Siksi myös tämän työn tavoite asetettiin vähentämään energian kulutusta juuri pää- ja rejektijauhatuksessa. Päälinjan jauhatuksessa tutkimuskohteiksi valittiin terityksen, tehojaon ja tuotantotason vaikutus EOK:een. Rejektijauhatuksen tehostamiseen pyrittiin yrittämällä vähentää rejektivirtaamaa painelajittelun keinoin. Koska TMP3 laitoksen jauhatuskapasiteettia on nostettu 25 %, tavoite oli nostaa päälinjan lajittelun kapasiteettia saman verran. Toisena tavoitteena oli pienentää rejektisuhdetta pää- ja rejektilajittelussa ja siten vähentää energiankulutusta rejektijauhatuksessa. Näitä tavoitteita lähestyttiin vaihtamalla päälinjan lajittimiin TamScreen-roottorit ja rejektilajittimiin Metso ProFoil-roottorit ja optimoimalla kuitufraktiot sihtirumpu- ja prosessiparametrimuutoksin. Syöttävällä terätyypillä pystyttiin vähentämään EOK:ta 100 kWh/bdt, mutta korkeampi jauhatusintensiteetti johti myös alempiin lujuusominaisuuksiin, korkeampaan ilmanläpäisyyn ja korkeampaan opasiteettiin. Myös tehojaolla voitiin vaikuttaa EOK:een. Kun ensimmäisen vaiheen jauhinta kuormitettiin enemmän, saavutettiin korkeimmillaan 70 kWh/bdt EOK-vähennys. Tuotantotason mittaamisongelmat heikensivät tuotantotasokoeajojen tuloksia siinä määrin, että näiden tulosten perusteella ei voida päätellä, onko EOK tuotantotasoriippuvainen vai ei. Päälinjan lajittelun kapasiteettia pystyttiin nostamaan TS-roottorilla vain 18 % jääden hieman tavoitetasosta. Rejektilajittelussa pystyttiin vähentämään rejektimäärää huomattavasti Metso ProFoil-roottorilla sekä sihtirumpu- ja prosessiparametrimuutoksin. Lajittamokehityksellä saavutettu EOK-vähennys arvioitiin massarejektisuhteen pienentymisen ja rejektijauhatuksessa käytetyn EOK:n avulla olevan noin 130 kWh/bdt. Yhteenvetona voidaan todeta, että tavoite 300 kWh/bdt EOK-vähennyksestä voidaan saavuttaa työssä käytetyillä tavoilla, mikäli niiden täysi potentiaali hyödynnetään tuotannossa.

Operational characteristics of four metering systems for agricultural fertilizers and amendments

The use of fertilizers and solid amendments in agriculture generates special interest for their effect on crop productivity, as well as for their environmental impact. The efficient use of these products demands knowing their physical and mechanical properties, the storing conditions effect and the operational characteristics of the metering systems used in the fertilizing equipment. In this context, the present study was developed with the purpose of evaluating the operational characteristics of different fertilizing metering systems and to determine the adequate metering system-product operational parameters, using powder lime, powder gypsum, granular 10-30-10 (N-P-K), and granular urea. Operational differences were established among four types of commercial fertilizer metering systems, including wire auger, star-shaped feed wheel, feed screw and ridged traction wheel. The study found that the unloading rate depends directly on the fertilizer metering system's rotating speed and is affected by particle size, repose angle, bulk density and moisture content of the applied product. The wire auger and star-shaped feed wheel metering systems were adequate for the distribution of powder products and the feed screw for granulated fertilizers. Furthermore, theoretical and experimental characteristic equations were established, defining curves for calibration and handling of the products plus the rotating speed range in which a better distributing behavior was achieved.

Wear of rotary plows operating in a tropical clay loam soil

The wear resistance of rotary plows operating in a clay loam soil was studied. The degree of damage caused to the soil and the amount of mass lost by the tools were determined in order to establish correlations between the physical properties of the soil and the wear mechanisms acting on the tribosystem. Field tests were carried out in 12 plots and a randomized experimental design with 4 levels, 3 replicas per level and 2 passes per plot was applied. The levels relate to the tillage implements employed: rotary tiller, rotary power harrow, small motorized rotary tiller and control (unaltered soil). The highest mass losses were measured in rotary tiller and rotary power harrow's tools, while the small motorized rotary tiller's tools showed generally lower levels of damage. It was determined that the effective contact time between tool and soil, the rotating speed and the sudden impact forces are the most significant factors affecting the wear resistance in field operations. Thirty days after tillage operation the soil samples were taken from each plot at a mean depth of 100 mm in order to determine bulk density, gravimetric moisture content and percentage of aggregates smaller than 5 mm. No significant differences among the values of these properties were found in the experiments. The wear mechanisms acting on the tools' surface are complex and include 2-body and 3-body abrasion as well as the presence of sudden impact forces.

Spraying systems and traveling speed in the deposit and spectrum of droplets in cotton plant

ABSTRACT Tractor traveling speed can influence the quality of spraying depending on the application technology used. This study aimed to evaluate the droplet spectrum, the deposition and uniformity of spray distribution with different spraying systems and traveling speeds of a self-propelled sprayer in two phenological stages of the cotton plant (B9 and F13). The experimental design was randomized blocks and treatments were three spraying techniques: common flat spray tips; tilted flat jet with air induction, at 120 L ha-1; and rotary atomizer disk, 20 L ha-1, combined with four traveling speeds: 12, 15, 18 and 25 km h-1, with four replications. Spraying deposition was evaluated for both leaf surfaces from the cotton plant apex and base (stage B9) and middle part of the plant (stage F13) with a cupric marker. A laser particle analyzer also assessed the droplet spectrum. The centrifugal power spray system produces more homogeneous droplet spectrum and increased penetration of droplets into the canopy in both phenological stages. Variation on the operating conditions necessary for increased traveling speed negatively influences the pattern of spraying deposits.

The Finnish Paper Workers' Union at a crossroads: Labor union representativeness in a changing environment, 1980-2008

This thesis consists of four articles and an introductory section. The main research questions in all the articles refer to the changes in the representativeness of the Finnish Paper Workers' Union. Representativeness stands for the entire entity of external, internal, legal and reputational factors that enable the labor union to represent its members and achieve its goals. This concept is based on an extensive reading of quantitative and qualitative industrial relations literature, which includes works based on Marxist labor-capital relations (such as Hyman's industrial relations studies), and more recent union density studies as well as gender- and ethnic diversity-based 'union revitalization' studies. Müller-Jentsch's German studies of industrial relations have been of particular importance as well as Streeck's industrial unionism and technology studies. The concept of representativeness is an attempt to combine the insights of these diverse strands of literature and bring the scientific discussion of labor unions back to the core of a union's function: representing its members. As such, it can be seen as a theoretical innovation. The concept helps to acknowledge both the heterogeneity of the membership and the totality of a labor union organization. The concept of representativeness aims to move beyond notions of 'power'. External representativeness can be expressed through the position of the labor union in the industrial relations system and the economy. Internal representativeness focuses on the aspects of labor unions that relate to the function of the union as an association with members, such as internal democracy. Legal representativeness lies in the formal legal position of the union – its rights and instruments. This includes collective bargaining legislation, co-decision rules and industrial conflict legislation. Reputational representativeness is related to how the union is seen by other actors and the general public, and can be approximated using data on strike activity. All these aspects of representativeness are path-dependent, and show the results of previous struggles over issues. The concept of representativeness goes beyond notions of labor union power and symbolizes an attempt to bring back the focus of industrial relations studies to the union's basic function of representing its members. The first article shows in detail the industrial conflict of the Finnish paper industry in 2005. The intended focus was the issue of gender in the negotiations over a new collective agreement, but the focal point of the industrial conflict was the issue of outsourcing and how this should be organized. Also, the issue of continuous shifts as an issue of working time was very important. The drawn-out conflict can be seen as a struggle over principles, and under pressure the labor union had to concede ground on the aforementioned issues. The article concludes that in this specific conflict, the union represented its' female members to a lesser extent, because the other issues took such priority. Furthermore, because of the substantive concessions. the union lost some of its internal representativeness, and the stubbornness of the union may have even harmed the reputation of the union. This article also includes an early version of the representativeness framework, through which this conflict is analyzed. The second article discusses wage developments, union density and collective bargaining within the context of representativeness. It is shown that the union has been able to secure substantial benefits for its members, regardless of declining employment. Collective agreements have often been based on centralized incomes policies, but the paper sector has not always joined these. Attention is furthermore paid to the changing competition of the General Assembly, with a surprisingly strong position of the Left Alliance still. In an attempt to replicate analysis of union density measures, an analysis of sectoral union density shows that similar factors as in aggregate data influence this measure, though – due to methodological issues – the results may not be robust. On this issue, it can be said that the method of analysis for aggregate union density is not suitable for sectoral union density analysis. The increasingly conflict-ridden industrial relations predicted have not actually materialized. The article concludes by asking whether the aim of ever-increasing wages is a sustainable one in the light of the pressures of globalization, though wage costs are a relatively small part of total costs. The third article discusses the history and use of outsourcing in the Finnish paper industry. It is shown using Hyman's framework of constituencies that over time, the perspective of the union changed from 'members of the Paper Workers' Union' to a more specific view of who is a core member of the union. Within the context of the industrial unionism that the union claims to practice, this is an important change. The article shows that the union more and more caters for a core group, while auxiliary personnel is less important to the union's identity and constituencies, which means that the union's internal representativeness has decreased. Maintenance workers are an exception; the union and employers have developed a rotating system that increases the efficient allocation of these employees. The core reason of the exceptional status of maintenance personnel is their high level of non-transferable skills. In the end it is debatable whether the compromise on outsourcing solves the challenges facing the industry. The fourth article shows diverging discourses within the union with regard to union-employer partnership for competitiveness improvements and instruments of local union representatives. In the collective agreement of 2008, the provision regulating wage effects of significant changes in the organization or content of work was thoroughly changed, though this mainly reflected decisions by the Labor Court on the pre-2008 version of the provision. This change laid bare the deep rift between the Social Democratic and Left Alliance (ex-Communist) factions of the union. The article argues that through the changed legal meaning of the provision, the union was able to transform concession bargaining into a basis for partnership. The internal discontent about this issue is nonetheless substantial and a threat to the unity of the union, both locally and at the union level. On the basis of the results of the articles, other factors influencing representativeness, such as technology and EU law and an overview of the main changes in the Finnish paper industry, it is concluded that, especially in recent years, the Finnish Paper Workers' Union has lost some of its representativeness. In particular, the loss of the efficiency of strikes is noted, the compromise on outsourcing which may have alienated a substantial part of the union's membership, and the change in the collective agreement of 2008 have caused this decline. In the latter case, the internal disunion on that issue shows the constraints of the union's internal democracy. Furthermore, the failure of the union to join the TEAM industrial union (by democratic means), the internal conflicts and a narrow focus on its own sector may also hurt the union in the future, as the paper industry in Finland is going through a structural change. None of these changes in representativeness would have been so drastic without the considerable pressure of globalization - in particular changing markets, changing technology and a loss of domestic investments to foreign investments, which in the end have benefited the corporations more than the Finnish employees of these corporations. Taken together, the union risks becoming socially irrelevant in time, though it will remain formally very strong on the basis of its institutional setting and financial situation.

Mädätys- ja kompostointilaitoshankkeen teknis-taloudellinen vertailu Lakeuden Ympäristöhuollossa

Työssä selvitettiin teknis-taloudellisen vaihtoehto Lakeuden Ympäristöhuollon keräämän biojätteen ja Seinäjoen lähialueella syntyvän hevosenlannan käsittelyyn. Nykyisin Lakeuden Ympäristöhuolto Oy:n keräämä biojäte kuljetetaan paikallisen jätehuoltoyhti-ön biokaasulaitokseen ja hevosenlantaa ei alueelta vielä kerätä olleenkaan. Työn lähtö-kohtana oli vertailla mahdollisesti rakennettavan oman biokaasulaitoksen ja rumpu-kompostointilaitoksen kannattavuutta toisiinsa. Kannattavuuden laskennassa käytettiin annuiteettimenetelmää. Työn kirjallisuusosiossa kerrotaan eloperäisten jätteiden ominaisuuksista mädätyksen ja kompostoinnin kannalta, mädätys- ja kompostointiprosessista, mädätys- ja kompostoin-titekniikoista sekä menetelmien eduista sekä haitoista. Työssä perehdyttiin myös mädä-tyksen ja kompostoinnin lopputuotteiden hyödyntämiseen. Vaihtoehtojen vaertailussa kumpikaan hankkeista ei ollut taloudellisesti kannattava. Vaikka prosesseihin saataisiin nykyään kerättävän biojätteen määrän lisäksi 2000 tonnia hevosenlantaa, se ei tee hankkeista kannattavia. Edes herkkyystarkastelussa laskettu korkeampi hevosenlannan porttimaksun määrä ei vaikuttanut kannattavuuteen. Lakeuden Ympäristöhuollon näin ollen on viisainta olla investoimatta kumpaakaan hankkeeseen.

AMB system for high-speed motors using automatic commissioning

The general trend towards increasing e ciency and energy density drives the industry to high-speed technologies. Active Magnetic Bearings (AMBs) are one of the technologies that allow contactless support of a rotating body. Theoretically, there are no limitations on the rotational speed. The absence of friction, low maintenance cost, micrometer precision, and programmable sti ness have made AMBs a viable choice for highdemanding applications. Along with the advances in power electronics, such as signi cantly improved reliability and cost, AMB systems have gained a wide adoption in the industry. The AMB system is a complex, open-loop unstable system with multiple inputs and outputs. For normal operation, such a system requires a feedback control. To meet the high demands for performance and robustness, model-based control techniques should be applied. These techniques require an accurate plant model description and uncertainty estimations. The advanced control methods require more e ort at the commissioning stage. In this work, a methodology is developed for an automatic commissioning of a subcritical, rigid gas blower machine. The commissioning process includes open-loop tuning of separate parts such as sensors and actuators. The next step is to apply a system identi cation procedure to obtain a model for the controller synthesis. Finally, a robust model-based controller is synthesized and experimentally evaluated in the full operating range of the system. The commissioning procedure is developed by applying only the system components available and a priori knowledge without any additional hardware. Thus, the work provides an intelligent system with a self-diagnostics feature and an automatic commissioning.

Silloitushitsauksen robotisointi

Tämän diplomityön tavoitteena oli tutkia ja selvittää kuormakoneen takarunkorakenteen silloitushitsauksen robotisointia. Työ päätettiin rajata koskemaan vain tiettyä moduulia takarungosta. Työssä kartoitettiin tarvittava laitteisto, selvitettiin runkomoduulin silloitusajat sekä arvioitiin investoinnin kannattavuutta. Silloituksen suorittavan järjestelmän vaatimuksena oli, että sen tulee asettaa osat paikoilleen hitsauskiinnittimeen ja tehdä tarvittavat silloitushitsaukset automaattisesti. Sopivaksi laitteistoksi osoittautui taloudellisuuden ja toiminnallisuuden näkökulmasta yhdestä kappaleenkäsittely- sekä hitsausrobotista muodostuva järjestelmä. Kappaleenkäsittelijän ohjauksessa käytetään konenäköä sekä osien paikannuksessa että laadunvarmistuksessa. Robotit liikkuvat yhteisellä lineaariradalla, jonka rinnalla on kappaleenkäsittelylaitteistoja hitsauskiinnittimineen. Robotisoinnin käyttöönotolla yhden takarungon moduulien kokoonpanoon ja silloitukseen käytettävä aika pienenee alle puoleen manuaaliseen työhön verrattuna. Näin saavutetaan merkittäviä kustannussäästöjä. Lisäksi hitsauskiinnittimet voivat olla verrattain yksinkertaisia manuaalityöhön verrattuna, jolloin myös säästetään työkaluinvestoinneissa. Robotisointiprojektin jatkotoimenpiteitä ovat laajamittaiset tuotantosimulaatiot layoutin, laitteiston sekä työkiertojen tarkaksi määrittämiseksi. Lisäksi itse tuotetta on muokattava paremmin robottisilloitukseen sopivaksi.

Multiple scales analysis of nonlinear oscillations of a portal frame foundation for several machines

An analytical study of the nonlinear vibrations of a multiple machines portal frame foundation is presented. Two unbalanced rotating machines are considered, none of them resonant with the lower natural frequencies of the supporting structure. Their combined frequencies is set in such a way as to excite, due to nonlinear behavior of the frame, either the first anti-symmetrical mode (sway) or the first symmetrical mode. The physical and geometrical characteristics of the frame are chosen to tune the natural frequencies of these two modes into a 1:2 internal resonance. The problem is reduced to a two degrees of freedom model and its nonlinear equations of motions are derived via a Lagrangian approach. Asymptotic perturbation solutions of these equations are obtained via the Multiple Scales Method.

Analysis of emergency braking performance with particular consideration of temperature effects on brakes

During vehicle deceleration due to braking there is friction between the lining surface and the brake drum or disc. In this process the kinetic energy of vehicle is turned into thermal energy that raises temperature of the components. The heating of the brake system in the course of braking is a great problem, because besides damaging the system, it may also affect the wheel and tire, which can cause accidents. In search of the best configuration that considers the true conditions of use, without passing the safety limits, models and formulations are presented with respect to the brake system, considering different braking conditions and kinds of brakes. Some modeling was analyzed using well-known methods. The flat plate model considering energy conservation was applied to a bus, using for this a computer program. The vehicle is simulated to undergo an emergency braking, considering the change of temperature on the lining-drum. The results include deceleration, braking efficiency, wheel resistance, normal reaction on the tires and the coefficient of adhesion. Some of the results were compared with dynamometer tests made by FRAS-LE and others were compared with track tests made by Mercedes-Benz. The convergence between the results and the tests is sufficient to validate the mathematical model. The computer program makes it possible to simulate the brake system performance in the vehicle. It assists the designer during the development phase and reduces track tests.

Numerical and experimental investigation of thermal louvers for space applications

Thermal louvers, using movable or rotating shutters over a radiating surface, have gained a wide acceptance as highly efficient devices for controlling the temperature of a spacecraft. This paper presents a detailed analysis of the performance of a rectangular thermal louver with movable blades. The radiative capacity of the louver, determined by its effective emittance, is calculated for different values of the blades opening angle. Experimental results obtained with a prototype of a spacecraft thermal louver show good agreement with the theoretical values.

Differential susceptibility of biotypes of conyza sumatrensis to Chlorimuron-ethyl herbicide

Horseweed (Conyza spp.) is an annual weed, infesting soybean crops in southern Brazil, with chlorimuron-ethyl being one of the most commonly used herbicides for its control. However, in recent soybean harvests, an unsatisfactory control of this weed using this herbicide was observed, generating suspicion regarding the selection of resistant biotypes. The objective of this study was to evaluate the susceptibility of horseweed biotypes to the herbicide chlorimuron-ethyl. Two experiments were conducted in a greenhouse; in the first one, the biotypes were selected selected, and the second experiment was arranged in a 5 x 5 factorial in a completely randomized design with four replications. The treatments used in the preparation of the dose response curves were doses of the herbicide chlorimuron-ethyl (0.0, 1.56, 3.13, 6.25, 12.5, and 25 g ha-1), applied on the five horseweed biotypes at the 3-4 leaf growth stage. The variables evaluated were visual control percentage and shoot dry weight, compared to the control without herbicide application, and plant acetolactate accumulation. It was concluded that there is a differential susceptibility among the biotypes at doses of less than 20 g ha-1 (dose response curves), which indicates low-level resistance. The practical consequences are the indications of chlorimuron-ethyl application at the maximum doses recomended and that the practice of rotating mechanisms of action must be used in the chemical weed management of these areas.