Painelaitteen hitsauksen kehittäminen

Työ tehtiin Steris Finn Aqualle, joka oli ottanut tuotantoon uuden autoklaavimallin kevään 2007 aikana. Työn tavoitteena oli kehittää painelaitteen hitsausta vertailemalla kevytmekanisointi, mekanisointi ja robotisointiratkaisuja ja hankkia riittävät tiedot mahdollisen investointipaatoksen tueksi. Tarkastellut kevytmekanisointilaitteet koostuivat kuljetinkiskosta, kuljettimesta ja mahdollisesta railonseurantalaitteesta. Tarkasteltu mekanisointijärjestelmä oli asiakaskohtaisesti räätälöitävä kokonaisuus. Tarkasteltuun hitsausrobottijärjestelmään kuului kappaleenkäsittelylaite sekä etäohjelmointiohjelmisto. Työn teoriaosassa käsiteltiin painelaitelainsäädännön vaikutuksia tuotantoon, ruostumattoman ja haponkestävän teräksen ominaisuuksia hitsauksen kannalta, tuotannossa käytettäviä hitsausprosesseja, hitsauksen mekanisointia ja automatisointia sekä railonseurantaa. Työn käytännön osuudessa käytiin läpi painelaitevalmistuksen nykytila. Painelaitevalmistus jaettiin eri työvaiheisiin ja työvaiheet analysoitiin, millä varmistettiin, että kehitysresurssit suunnataan oikeisiin kohteisiin. Kehitysehdotuksena esitettiin joko railonseurannalla varustetun kevytmekanisointilaitteiston tai etäohjelmoitavan hitsausrobottijärjestelmän hankintaa. Kevytmekanisoinnilla on mahdollista saavuttaa samat edut kuin kalliimmillakin mekanisointilaitteilla ja kevytmekanisoinnin etuna on käyttöönoton helppous ja laitteiston edullisuus. Hitsausrobotin hankintaan liittyy epävarmuustekijöitä, joiden tarkempi selvittäminen on tarpeen, ennen hitsausrobotin hankintapaatosta. Suuremmilla tuotantomäärillä hitsausrobottisolu olisi ollut selkeästi parempi ratkaisu.

Customer consciousness in the production process of a steel factory

The purpose of this thesis is to examine the level of customer consciousness of the production process employees in a steel factory and to investigate the methods of internal marketing in order to propose development practices to enhance the customer consciousness of the case company employees. The significance of the level of customer consciousness is discussed and practices already implemented affecting the level of customer consciousness in the company are examined. The literature review gives an insight to the role of customer consciousness in the CRM philosophy of a manufacturing company and examines the means of internal marketing in enhancing customer consciousness. In the empirical part of the study, the level and significance of customer consciousness is determined by conducting individual and focus group interviews. The interviews are also used to examine the practices that could function in enhancing the customer consciousness of the employees. Development suggestions to improve the level of customer consciousness in the production process are given based on the results. The level of customer consciousness is at a poor level in the production process and influences above all on work motivation and job satisfaction, but possibly on customer satisfaction as well. The enhancement of customer consciousness in the production process should be done e.g. by ensuring the distribution of right knowledge coherently to all of the employees, gathering large customer reference database to exploit in work and in training, using visual illustration in presenting the customer information, training proactively and letting the employees to participate in the customer oriented development activities. Customer satisfaction focused reward system can be considered.

Identification of extractives and polysaccharides as foulants in membrane filtration of pulp and paper mill effluents

The search for new renewable materials has intensified in recent years. Pulp and paper mill process streams contain a number of potential compounds which could be used in biofuel production and as raw materials in the chemical, food and pharmaceutical industries. Prior to utilization, these compounds require separation from other compounds present in the process stream. One feasible separation technique is membrane filtration but to some extent, fouling still limits its implementation in pulp and paper mill applications. To mitigate fouling and its effects, foulants and their fouling mechanisms need to be well understood. This thesis evaluates fouling in filtration of pulp and paper mill process streams by means of polysaccharide model substance filtrations and by development of a procedure to analyze and identify potential foulants, i.e. wood extractives and carbohydrates, from fouled membranes. The model solution filtration results demonstrate that each polysaccharide has its own fouling mechanism, which also depends on the membrane characteristics. Polysaccharides may foul the membranes by adsorption and/or by gel/cake layer formation on the membrane surface. Moreover, the polysaccharides interact, which makes fouling evaluation of certain compound groups very challenging. Novel methods to identify wood extractive and polysaccharide foulants are developed in this thesis. The results show that it is possible to extract and identify wood extractives from membranes fouled in filtration of pulp and paper millstreams. The most effective solvent was found to be acetone:water (9:1 v/v) because it extracted both lipophilic extractives and lignans at high amounts from the fouled membranes and it was also non-destructive for the membrane materials. One hour of extraction was enough to extract wood extractives at high amounts for membrane samples with an area of 0.008 m2. If only qualitative knowledge of wood extractives is needed a simplified extraction procedure can be used. Adsorption was the main fouling mechanism in extractives-induced fouling and dissolved fatty and resin acids were mostly the reason for the fouling; colloidal fouling was negligible. Both process water and membrane characteristics affected extractives-induced fouling. In general, the more hydrophilic regenerated cellulose (RC) membrane fouled less that the more hydrophobic polyethersulfone (PES) and polyamide (PA) membranes independent of the process water used. Monosaccharide and uronic acid units could also be identified from the fouled synthetic polymeric membranes. It was impossible to analyze all monosaccharide units from the RC membrane because the analysis result obtained contained degraded membrane material. One of the fouling mechanisms of carbohydrates was adsorption. Carbohydrates were not potential adsorptive foulants to the sameextent as wood extractives because their amount in the fouled membranes was found to be significantly lower than the amount of wood extractives.

Química e colorimetria da madeira de Eucalyptus grandis W. Mill ex Maiden termorretificada

A termorretificação visa melhorar as características para agregar valor à madeira através da aplicação de calor. O objetivo foi avaliar as alterações químicas e colorimétricas da madeira termorretificada de Eucalyptus grandis submetida a 170, 200 e 230 ºC por 3, 5 e 7 h. Os teores de extrativos, lignina, holocelulose, composição elementar e os parâmetros colorimétricos foram determinados. Os teores de extrativos aumentaram nos tratamentos a 170 °C e diminuíram a partir de 200 °C, enquanto o teor de lignina total aumentou e o de holocelulose diminuiu a partir de 200 °C. O teor de carbono aumentou e o de oxigênio diminuiu a 230 °C por 5 e 7 h. A termorretificação reduziu a claridade, matriz vermelho (a*) e matriz amarelo (b*) da madeira de eucalipto em todos os tratamentos.

EFFECTS OF HARVESTING ON LEAF PRODUCTION AND REPRODUCTIVE PERFORMANCE OF Copernicia prunifera (Mill.) H.E. Moore1

ABSTRACT This work aimed to evaluate the consequences of the monthly extraction of immature leaves in survival, leaf production and reproductive performance ofCopernicia prunifera H. E. Moore palm, popularly known as carnaúba. One hundred sixty reproductive adult palms were monitored for 17 months in four extractive communities located at the coast of the state of Piauí. As a result, it was observed that leaves, flowers, fruits and seeds production were reduced in the palm submitted to 50% or 75% monthly extraction. Higher levels of extraction were followed by smaller levels in seed germination. No deaths were observed even in the group subjected to 75% monthly leaves exploration. In order not to produce damage to palm trees development it is suggested that leaf extraction rate should not exceed 25% monthly as well as pausing of extractive activity preferentially during fruit maturation.

Stochastic variability of output levels in a pulp mill

Quite often, in the construction of a pulp mill involves establishing the size of tanks which will accommodate the material from the various processes in which case estimating the right tank size a priori would be vital. Hence, simulation of the whole production process would be worthwhile. Therefore, there is need to develop mathematical models that would mimic the behavior of the output from the various production units of the pulp mill to work as simulators. Markov chain models, Autoregressive moving average (ARMA) model, Mean reversion models with ensemble interaction together with Markov regime switching models are proposed for that purpose.

Ultrafiltration of pulp mill bleaching effluents

Main objective of this research was to find suitable polymeric ultrafiltration membranes with high retentions, good capacities and low fouling tendencies for the E2- and EP-effluent ultrafiltration. Purpose was to treat alkaline bleaching effluents with ultrafiltration in a way that permeates of the filtrations could be recycled back to process and the consumption of fresh water in the pulp mill could be reduced significantly. In the theoretical part of this work the challenges set by the pulp and paper indus-try processes for membranes were examined. An overview of the membrane tech-nology in the pulp industry was also provided. In addition process conditions in the chemical pulp bleaching and properties of bleaching effluents were discussed in literature study. In experimental part the E2- and EP-stage bleaching effluents from Stora Enso Imatra kraft pulp mill were ultrafiltered with CR250- and CR200-filters. Suitable membranes for ultrafiltration were chosen after screening experiments. Concentra-tion experiment was made for the E2-effluent in order to estimate water saving potential. The E2-effluent was finally ultrafiltered in the pulp mill in order to test the feasibility of ultrafiltration in a real industrial environment. Good membrane for the EP-effluent ultrafiltration based on the EP-screening ex-periments was polyethersulfone membrane UP020 with cut-off value of 20 000 Da. Polysulfone membrane UFX05 with cut-off value of 5 000 Da was promising membrane for the ultrafiltration of the E2-effluent. Based on the concentration filtration of the E2-effluent with UFX05 membrane the water saving potential could be 2.2 m3/Adt for the industrial scale ultrafiltration process. Retention re-sults, such as average COD retention of 60 %, from the trial filtration at the pulp mill with UFX05 membrane were modest compared to the screening experiments, where average COD retention was 75 %. Therefore tighter ultrafiltration mem-branes should be tested for the ultrafiltration of the E2-effluent. The UP020 mem-brane seemed to be suitable for the ultrafiltration of the EP-effluent however con-centration and pilot scale ultrafiltration experiments are needed to verify this.

Tal af John Stuart Mill

14 x 23 cm

Surface transformation hardening of carbon steel with high power fiber laser

This study investigated the surface hardening of steels via experimental tests using a multi-kilowatt fiber laser as the laser source. The influence of laser power and laser power density on the hardening effect was investigated. The microhardness analysis of various laser hardened steels was done. A thermodynamic model was developed to evaluate the thermal process of the surface treatment of a wide thin steel plate with a Gaussian laser beam. The effect of laser linear oscillation hardening (LLOS) of steel was examined. An as-rolled ferritic-pearlitic steel and a tempered martensitic steel with 0.37 wt% C content were hardened under various laser power levels and laser power densities. The optimum power density that produced the maximum hardness was found to be dependent on the laser power. The effect of laser power density on the produced hardness was revealed. The surface hardness, hardened depth and required laser power density were compared between the samples. Fiber laser was briefly compared with high power diode laser in hardening medium-carbon steel. Microhardness (HV0.01) test was done on seven different laser hardened steels, including rolled steel, quenched and tempered steel, soft annealed alloyed steel and conventionally through-hardened steel consisting of different carbon and alloy contents. The surface hardness and hardened depth were compared among the samples. The effect of grain size on surface hardness of ferritic-pearlitic steel and pearlitic-cementite steel was evaluated. In-grain indentation was done to measure the hardness of pearlitic and cementite structures. The macrohardness of the base material was found to be related to the microhardness of the softer phase structure. The measured microhardness values were compared with the conventional macrohardness (HV5) results. A thermodynamic model was developed to calculate the temperature cycle, Ac1 and Ac3 boundaries, homogenization time and cooling rate. The equations were numerically solved with an error of less than 10-8. The temperature distributions for various thicknesses were compared under different laser traverse speed. The lag of the was verified by experiments done on six different steels. The calculated thermal cycle and hardened depth were compared with measured data. Correction coefficients were applied to the model for AISI 4340 steel. AISI 4340 steel was hardened by laser linear oscillation hardening (LLOS). Equations were derived to calculate the overlapped width of adjacent tracks and the number of overlapped scans in the center of the scanned track. The effect of oscillation frequency on the hardened depth was investigated by microscopic evaluation and hardness measurement. The homogeneity of hardness and hardened depth with different processing parameters were investigated. The hardness profiles were compared with the results obtained with conventional single-track hardening. LLOS was proved to be well suitable for surface hardening in a relatively large rectangular area with considerable depth of hardening. Compared with conventional single-track scanning, LLOS produced notably smaller hardened depths while at 40 and 100 Hz LLOS resulted in higher hardness within a depth of about 0.6 mm.

A Steel Company Entering the Market Area of St. Petersburg

Tutkimuksen tavoitteena on selvittää tarkoituksenmukaisin etabloitumismenetelmä teräsyhtiön kansainvälistymisessä Pietarin markkinoille. Vaikka kansainvälistymistä onkin tutkittu paljon, kyseisen kontekstin erityispiirteisiin on aiemmissa tutkimuksissa kiinnitetty vain vähän huomiota. Kansainvälistymisteorioista työhön valittiin John Dunningin eklektinen paradigma sekä Uppsala-malli. Etabloitumismenetelmän valintaa puolestaan tarkastellaan eri vaihtoehtojen kautta, jotka kattavat viennin, suorat ulkomaan investoinnit, sopimusjärjestelyt sekä yhteisyrityksen. Valintaa selitetään taustalla vaikuttavien tekijöiden sekä kansainvälistymisprosessin kautta. Kohteena olevan markkina-alueen potentiaalin, ongelmien sekä yrityksen kilpailuetujen arvioinnin jälkeen ehdotetaan optimaalista ratkaisua. Omat haasteensa operaatiomuodon valintaan luovat potentiaalinen mutta haastava kohdemarkkina-alue sekä yrityksen sisäiset tekijät. Kontekstiin parhaiten sopivaksi etabloitumismenetelmäksi esitetään aloittamista välittömällä viennillä asiakkaiden etsimiseksi ja suhteiden luomiseksi. Kun asiakkuuksia alueella on riittävästi, myyntikonttorin perustaminen Pietarin lähelle nähdään tarkoituksenmukaisena paikallisen läsnäolon lisäämiseksi. Empiirinen data kattaa kahdeksan asiantuntijahaastattelua, jotka yhdessä muun lähdeaineiston kanssa rakentavat perustan empiirisille tuloksille. Tutkimuksen tulokset tarjoavat yritykselle perustellun ratkaisuehdotuksen siitä, kuinka Pietarin markkinoille tulisi etabloitua.

Risk management measures for REACH registered intermediate substances in pulp mill

Tämän työn tavoitteena on antaa kuvaus riskinhallintamenetelmistä viidelle välituotekemikaalille, joita käytetään Stora Enson Imatran tehtailla. Välituotekemikaalit ovat mustalipeä, viherlipeä, valkolipeä, natriumbisulfiitti ja natriumsulfiitti. Nämä kemikaalit ovat jo rekisteröityjä ECHA:an ja rekisteröintiin liittyen ECHA:an on toimitettava myös kuvaus riskinhallintamenetelmistä. Työn alussa kuvaillaan työn kannalta olennaiset säädökset ja viranomaiset, jotka valvovat kemikaalien käyttöä ja valmistusta Euroopan Unionin alueella. Tämän jälkeen kerrotaan yleisesti välituotekemikaalien rekisteröintikriteereistä. Työn loppuosa käsittää kuvauksen riskinhallintamenetelmistä jokaiselle kemikaalille. Riskinhallintamenetelmät sisältävät eristyksen teknisin keinoin, menettelytapa- ja valvontatekniikat, johtamistavat ja henkilökunnan koulutuksen ja välituotekemikaalien kuljetuksen. Myös jokaisen kemikaalin ominaisuudet on kuvattu ja lyhyt prosessikuvaus kemikaalien valmistuksesta ja käytöstä on esitetty helpottamaan ymmärtämistä.

Tertiary Treatment and Re-use of Kraft Pulp Mill Effluent

The efficient use of materials and natural recourses, for ecological and economic reasons, has become more and more important in all industries. In the forest industries this means higher levels of closure in the material circulations of the mills. One possibility to reduce wastewater discharge is to re-use part of the 2nd clarifier effluent as process water. The main target of this thesis was to evaluate the technical suitability of several mechanical and chemical tertiary treatment methods for water re-use. Some of the tested methods seemed to have high potential for the removal of some specific constituents from the wastewater. Tertiary treatment is needed because higher levels of closure may cause problems with increasing amounts of non-process elements in different points of kraft pulp process. The aspect of sustainable development was taken into account by evaluating positive and negative environmental effects of the treatment processes. Environmental benefits can be gained by using some of the tertiary treatment methods tested. These methods should still be researched more for system optimization.