Abstract The aim of this technologically oriented study was to develop an evaluation method for post-completion audits of investment projects in paper production lines. The development work was based on the constructive research approach. The objectives of the method were practical applicability, a comprehensive framework, and measures of project performance. The evaluation method developed here is based on an adapted Malcolm Baldrige self-assessment framework, which has been embedded with three evaluation perspectives: project Targets (T), Risk management (R), and company Strategy (S). The compositions of these perspectives i.e. TRS perspectives, serve as the fundamental basis for a value added project. The evaluation criteria have been designed to fulfil the requirements of the paper industry and demanding projects. Scoring guidelines are used as a basis for evaluation results. Furthermore, supportive evaluation tools were developed to improve the accuracy and comparability of evaluation results. Evaluation is conducted by a group which consists of qualified tutors, project experts and facilitators. The latter are used especially to increase objectivity. The method was tested with two cases studies which were applied in a greenfield paper machine project. The first case study focused on technology choices. The second case study was a full-scale study of the whole project scope. The evaluation results were relatively accurate, and feedback results were particularly positive. Usage of the TRS perspectives can produce information which benefits decision-making. The method is capable of measuring both technical facts and subjective opinions. Moreover, the method is applicable in practice and can improve the investment process in general.

The SAPPI Ngodwana mill is the largest integrated pulp and paper mill in Africa and is situated in the Elands River catchment in the Mpumalanga province. A need has arisen at the mill to reduce effluent volumes requiring discharge. The combined mill effluent is currently irrigated onto pastures and over the years percolation of attenuated effluent has resulted in elevated chloride levels in the Elands River. Elevated chloride levels in the river have in turn impacted on the tobacco farmers downstream of the mill. Reclamation of Kraft Liner Board effluent was identified as a means of reducing the hydraulic load onto the irrigation pastures and at the same time reduce the intake of fresh water into the mill. Two possible uses for the reclaimed effluent, namely washing of bleached or unbleached pulp, were identified. The major reclaimed water quality variables of concern for re-use are; biodegradable organic material, colour and suspended solids. Approximately 9 months of pilot-scale activated sludge treatment of the effluent demonstrates that sufficient organic material can be removed for re-use, as wash water. Removal of the organic material was not influenced by sludge age in the range 2 to 8 days. A high degree of colour removal was achieved, which is contrary to reports in the literature. Even with the high colour removal achieved, however, insufficient colour was removed to allow washing of bleached pulp. Pulp and paper effluents are often reported to result in filamentous bulking activated sludges. This was confirmed in the testwork. Severe sludge settleability problems were experienced throughout the pilot-scale testwork. Filamentous bulking was identified as the cause of poor sludge settleability and preventative or control strategies would have to be implemented on full-scale. / Dissertation (MEng)--University of Pretoria, 2010. / Chemical Engineering / unrestricted

Today paper is to find everywhere, and the production factories always need to increase the productivity if they want to stay competitive. Stora Enso Kvarnsveden has one of the biggest magazine paper machines in the world, which produces around 1900 meters of paper per minute. The production process is highly automatized, which reduces the number of operators that work on the machine. Still, process variations can cause brakes in the paper web and lead to loss of income, energy and paper production. It may also have a direct impact on the paper quality. This report is focusing the following question: How to keep the Paper Machine production process under controlled conditions? To make a data analysis fully relevant, we need to use the most important variables of the machine. By analyzing these data some unexpected behavior and variation of process values can be pointed out. The analyzing tool needs to be fast and portable, and therefore a software system has been developed. By comparing process data with reference data this software can make a powerful analysis. The created software is intended to be used either by operators or engineers. The most important results are collected in a file. In this text file, the comparison function gives the results which are stored in a CSV-format. Furthermore, an auto-update function allows the users to run it automatically. Graphical presentations are supporting the interpretation of the results.

Water is a scarce and unevenly distributed national resource and it is, therefore, important to reduce water consumption in paper mills. Closure of water systems for reuse, however, directly and indirectly results in an increase in the numbers and types of microorganisms resulting in poor runnability, lower production rates and increased safety hazards. The aim of this study was to investigate the microbiology of paper-mill water systems in South Africa to aid in closure of water systems whilst controlling microbial fouling. Different environmental parameters monitored at paper mills were reviewed together with microbial enumeration techniques employed by industry and characterisation and identification methods to study bacteria. Various environmental and process parameters could play an important role in the number and type of microorganisms in a paper-mill water system. The highest correlation between an environmental parameter and biological activity was found for oxidation-reduction potential and the numbers of culturable aerobic bacteria. Other environmental parameters that significantly influenced microbial numbers were temperature, dissolved oxygen, dissolved solids, chemical oxygen demand, nitrogen, phosphorous, specific water consumption, pulp furnish, biocide class and retention time. The characterisation and identification of problematic bacteria in paper mills could enable better control since the correct biocides could be applied to minimise microbiologically associated problems. Prevalent bacteria that were isolated from the water systems of 14 paper machines were typed into 35 distinct groups using ERIC-PCR and PCR-RFLP and identified with sequence analysis. Eleven of the 35 types were identified to species level, 20 types were identified to genus level and the remaining four types were identified to family level. It was found that the majority of bacteria belonged to the genera Acinetobacter and Pseudomonas that contain well-known slime-forming bacterial species. Traditional methods employed to investigate bacteria in industrial water systems often do not accurately represent the composition and diversity of bacterial communities. DGGE analysis could provide a powerful tool for monitoring bacterial diversity, since it is able to discriminate between identical sizes of PCR-amplified DNA fragments that differ in their sequence content. The use of DGGE to monitor changes in microbial populations could improve control of microbial fouling, but more analyses would be needed to validate the results of the present study. / Dissertation (MSc (Microbiology))--University of Pretoria, 2008. / Microbiology and Plant Pathology / unrestricted

Deposits can be formed in the paper machine due to sticky materials from wood and recycled paper. These deposits get stuck on process equipment and cause the product quality to deteriorate and the efficiency of the paper machine is reduced. The purpose of this thesis is to increase the understanding about deposits among machine operators, and to suggest methods that can be used to reduce the amount of deposits formed in Bravikens paper machines. To fulfill the purpose of the thesis a pre-study, a literature review and interviews with machine operators and production staff, were carried out. These methods led to the planning and creation of an education about deposits for machine operators. The education about deposits for machine operators consisted of an interactive lecture to introduce the subject of deposits and a subsequent discussion. This approach was chosen to give the machine operators the opportunity to discuss their work situation on the paper machines related to their new knowledge about deposits. The education was carried out with hopes of finding new ways to manage the formation of deposits in the paper machines. According to the evaluation of the education, all machine operators considered the purpose of the education to be fulfilled. Bravikens t hermomechanical pulp, TMP, system should be developed to reduce the amount of sticky material reaching the paper machine from TMP. More analysis of the whitewater system is needed to determine which method of development that could be implemented to reduce costs and increase functionality of the paper machine. In order to develop the methods of handling deposits, Braviken should continue their work with competence development among the employees. Enhanced competence increases awareness of the problem among machine operators and it facilitates communication between employees who are working to reduce deposit formation. Improved communication also facilitates learning and contributes to the overall competence development at Braviken paper mill. / Avsättningar kan bildas i pappersmaskinen på grund av klibbigt material från veden och returpappret. Dessa avsättningar fastnar på processutrustning och medför att slutproduktens kvalité försämras samt att pappersmaskinens verkningsgrad reduceras. Syftet med detta examensarbete är att öka förståelsen om avsättningar bland maskinoperatörer samt ge förslag på metoder som kan användas för att reducera mängden avsättningar på Bravikens pappersmaskiner. För att uppfylla syftet med examensarbetet har en förstudie, en litteraturstudie och intervjuer med maskinoperatörer och personal från Bravikens produktionssektioner, genomförts. Dessa metoder låg till grund för planering och skapande av en utbildning om avsättningar för maskinoperatörer. En utbildning med maskinoperatörer genomfördes för att uppfylla syftet med examensarbetet. Utbildningen innehöll en interaktiv föreläsning för att introducera ämnet avsättningar och ett diskussionsavsnitt. Detta upplägg valdes för att ge maskinoperatörerna möjlighet att diskutera deras arbetssituation på pappersmaskinen relaterat till deras nya kunskaper om avsättningar. Utbildningen genomfördes i hopp om att hitta nya sätt att hantera avsättningsbildningen. Utvärderingen av utbildningen visade att alla deltagande maskinoperatörer ansåg att syftet med utbildningen uppnåddes. För att utveckla Bravikens hanterande av avsättningar bör Bravikens anläggning för att tillverka termomekanisk pappersmassa, TMP, utvecklas för att minska mängden klibbigt material som tar sig vidare till pappersmaskinen, PM. Mer analyser på bakvatten bör också utföras för att avgöra vilken utvecklingsmetod som är möjlig att införa med avseende på kostnad och funktion. Arbetet med att utveckla avsättningshanteringen bör också fortsätta genom kompetensutveckling för de anställda på Braviken. Detta ökar medvetenheten om problematiken bland maskinoperatörerna och förbättrar kommunikationen mellan de olika personalgrupper som arbetar för att minska avsättningsbildningen. Den förbättrade kommunikationen i sin tur underlättar även lärande och bidrar till kompetensutveckling på Bravikens pappersbruk.

The purpose of this thesis is, in collaboration with the Swedish company Innventia, to explore the possibilities of using paper machines to create fabric-like nonwoven materials. As part of a relatively new research-area, it serves as some of the ground knowledge that is needed to drive this field forward. The research of this thesis is born from the increasing need for more environmental friendly textiles, and to find new uses for the paper production facilities and companies that are currently experiencing a decline in paper production. The materials used in the research were produced with the Finnish handsheet former and the StratEx sheet-maker made by Innventia. The research consists of the following tests: Tissue Softness Analysis, (TSA), tensile strength and bending stiffness. The tests are done with different combinations of lyocell, PLA, softwood and dissolving pulp in the tested sheets. It is also tested if the lyocell can be a meaningful substitution for PLA in combination with softwood pulp and dissolving pulp when creating the fabric-like materials. In conclusion of this research it can be said that, compared to benchmarking samples like bedding sheets, table cloths and cotton shirts, the sheets created and tested are competitive alternatives to existing materials when it comes to softness. It also became clear that the tensile strength has to be increased to make fabric-like nonwoven materials applicable on the same level as existing textiles. Even so, it is still evident that there is a potentiality in the use of paper machines in the development and creation of new fabric-like materials.

This master thesis deals with the technical diagnostics, focusing mainly on vibration diagnostics. This problematice is described in the first part of this work on a theoretical level. The next part describes the paper machine, diagnostic system and the measuring points are classified into databases. The practical part of this work consists of a proposal for the methodology of vibration diagnostics for a paper machine, the procedure for measuring and evaluating the measured values. Part of the work is also a practical example of the measurement of the central cylinder, on which the procedure is tested, and the compilation of new limit values.

Press felts are highly critical components of the paper machine. A degraded press felt could lead to paper web breaks, which requires the paper machine to be restarted. Moreover, a degraded felt influences the quality of the paper, leading to paper disposal. Condition monitoring aims at minimising the risk of paper web breaks, unsatisfactory paper quality and other types of production loss while maximising the useful life of the press felts. However, installing a new condition monitoring system is expensive and the installation can be difficult to fit into the scheduled maintenance stops. This thesis investigates the possibility of using existing monitoring systems instead of installing a new one. Four possible approaches of monitoring the degradation of the press felts have been explored. The identified approaches of press felt monitoring were tested by using data acquired through existing monitoring systems of the paper machine PM2 at BillerudKo-rsnäs in Karlsborg, located in the north of Sweden. The first approach is based upon process parameters. This approach could, however, not be properly investigated due to a malfunctioning sensor. The second approach revolves around the natural frequencies of the felt and the frequency changes as the felt degrades. The remaining two approaches originates from the hypothesis that felt degradation could lead to impacts as the possibly uneven felt passes the rollers. One approach is to detect these possible impacts by using the time domain feature kurtosis. The other approach is to monitor the harmonics these impacts could lead to. Neither the natural frequency nor the kurtosis approach was deemed promising, partly based on the results of the analysed data but also due to intrinsic deficiencies of these approaches. The approach based on felt harmonics did, however, exhibit indications that it might be a feasible monitoring technique. The felt harmonics approach should be further investigated. Furthermore, a python program that can synchronise data from different sources was developed. This program enables degradation features to be extracted using machine learning algorithms. However, due to the lack of vibration data and labels of the current felt condition, machine learning was not applied. / Pressfiltar är ytterst kritiska komponenter i pappersmaskinen. En nedsliten pressfilt kan orsaka pappersbanbrott vilket innebär att pappersmaskinen måste startas om. En nedsliten filt kan också påverka papperskvaliteten vilket resulterar i att papper måste kasseras. Tillståndsövervakning är ett steg närmare att kunna optimera användandet av pressfiltarna, det vill säga maximera livstiden samtidigt som risken för oplanerade stopp minimeras. Att installera ett nytt tillståndsövervakningssystem kan dock vara dyrt och installationen kan vara svår att rymmas i de planerade underhållsstoppen. Detta masterarbete utreder möjligheten att använda existerande övervakningssytem istället för att installera ett nytt. Fyra möjliga angreppssätt för tillståndsövervakning av pressfilten utforskades. De identifierade övervakningsteknikerna testades genom att använda data från existerande övervakningssystem på pappersmaskinen PM2 hos BillerudKorsnäs i Karlsborg utanför Kalix. Det första angreppssättet baseras på processparametrar. Detta angreppssätt kunde dock ej utvärderas på grund av en defekt sensor. Det andra angreppssättet kretsar kring filtens egenfrekvenser och dessas förändring när filten slits ut. Återstående två angreppssätt har sitt ursprung i hypotesen att en försämrad filt kan ge upphov till slag när den eventuellt ojämna filten passerar valsarna. Ett angreppssätt är att detektera dessa eventuella vibrationer genom tidsdomänfunktionen kurtosis. Det andra angreppssättet som använts är att övervaka de övertoner som slagen kan leda till. Varken angreppssättet baserat på egenfrekvens eller det baserat på kurtosis bedömdes lovande. Detta delvis baserat på resultaten från analyserad data men också på grund av de inneboende bristerna för dessa två angreppssätt. Det angreppssätt som baseras på filtens övertoner visade däremot indikationer på att det kan utgöra en möjlig övervakningsteknik och detta angreppssätt bör därför utforskas vidare. Vidare utvecklades ett pythonprogram som kan synkronisera data från olika källor. Programmet möjliggör applicering av maskininlärningsalgoritmer. På grund av brist på vibrationsdata och klassificering av nuvarande filttillstånd applicerades dock inte maskininlärning. / NonStopp

Orientadores: Reginaldo Guirardello, Maria Teresa Moreira Rodrigues, Ignacio E. Grossmann / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T14:00:07Z (GMT). No. of bitstreams: 1 Drummond_DanielaMedeirosDevienne_D.pdf: 2651709 bytes, checksum: 8eda6bf1eb834515f79e1109e462fc7b (MD5) Previous issue date: 2008 / Resumo: A seção de prensagem é uma importante parte da máquina de papel, afetando as propriedades do produto, bem como interferindo no custo final de fabricação. O setor de prensagem é responsável pela retirada da água da folha, através de ação mecânica no NIP (zona de contato entre por dois rolos). Baixa eficiência deste setor acarreta inconveniente como à elevação do número de quebras da folha, pela diminuição da resistência à tração; aumento no consumo de vapor na seção secadora da máquina, e em muitos casos, a redução da produtividade devido à redução da velocidade da máquina. A eficiência da prensagem é muito importante: primeiro, uma grande quantidade de água deve ser removida da folha nas prensas para se obter economia na secagem; em segundo lugar, a maior eficiência na remoção de água produz uma folha mais seca e, portanto, mais resistente e menos sujeita a quebras. Na entrada das prensas, o conteúdo seco da folha varia entre 18 a 26 % e na saída varia entre 44 até 50 %. Nos últimos anos, observou-se uma evolução bastante rápida dos conceitos de prensas, buscando uma adequação das exigências tais como economia no processo operacional, aumentando a remoção de água neste setor e ao mesmo tempo mantendo ou melhorando as características da folha de papel; e ainda novas demandas de eficiências exigidas nas máquinas. A redução de 1% de umidade da folha provoca uma redução do consumo de vapor na ordem de 4 a 5%. Este trabalho apresenta o desenvolvimento de um modelo matemático para otimização do setor de prensagem de uma máquina de papel através do seqüenciamento de produção de bobinas. O modelo foi desenvolvido em MILNP, o software utilizado para a modelagem foi o GAMS e o solver utilizado foi CPLEX10. Obtivemos uma redução média 46% nas trocas de feltros, juntamente com um aumento de 5% na remoção de água e 12% na produção de bobinas / Abstract: The process of paper manufacture is essentially the removal mechanics of a fiber suspension, starting in the formation where relatively low level of force mechanics is used to remove the free water between staple fibers. The biggest force mechanics used for continuous removal of this water is in the section of presses, where the located one between them in such a way involves the compression of the leaf for water withdrawal of the interior of staple fibers how much. The more compressed the leaf, greater the amount of water is removed. The pressing is made with the leaf in contact with one or two felts in NIP (zone of contact between two rolls). The press sector is an important part of the machine, affecting the properties of the paper, as the smoothness and the density, as well as intervening with the final cost of manufacture. Low efficiency of this sector causes inconvenience as to the rise of the number of in additions the leaf, for the reduction of the tensile strength; increase in the vapor consumption in the drying section, and in many cases, the reduction of the productivity due to reduction of the speed of the machine. The reduction of 1% of humidity of the web the reduction of the steam consumption in the order of 4 5%. This work has as objective the development of a mathematical model for optimization of the press section of a machine of paper through the sequence of production of reels. The model was developed in MILNP, the software used for the modeling was the used GAMS and solver was CPLEX10. We got an average reduction 46% in the replacement of felts, together with an increase of 5% in the removal of water and 12% in the production of reels / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

The thesis deals with a description and a strength analysis of selected parts of a modified supporting structure of a press part of a paper machine. The construction is designed to simplify a replacement of felt belts during a service shutdown of the machine. The first part of the thesis is devoted to a brief description of the paper machine with a more detailed focus on the press part. The next part of the thesis includes a project of adjustment to the original design of the supporting structure. The last part deals with a strength control of construction nodes of the adjusted project. A strength calculation is further divided into a calculation using the finite element method and an analytical calculation. Results of both previous calculation methods are compared at the end of the thesis.