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  • Reitan, Nina Kristine
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Fire Research Norway.
    Friquin, Kathinka L.
    RISE - Research Institutes of Sweden, Safety and Transport, Fire Research Norway.
    Fjellgaard Mikalsen, Ragni
    RISE - Research Institutes of Sweden, Safety and Transport, Fire Research Norway.
    Brannsikkerhet ved bruk av krysslaminert massivtre i bygninger: en litteraturstudie2019Report (Other academic)
    Abstract [en]

    This literature study presents recent research on fire safety in cross laminated timber (CLT) buildings. Results from large fire experiments and other studies in the period 2010 - 2018 are summarized, with focus on the following research questions:• How do constructions consisting of protected or exposed CLT contribute to the fire development in a room?• How can contribution to the fire development from detailing of CLT be avoided?There is an increasing desire to use wooden structures in tall buildings, as a substitute for more traditional construction materials. However, the use of combustible construc-tions in buildings in Norwegian Fire Class 3 (usually five floors or more) is not pre-accepted in the guideline to Regulations on technical requirements for construction works (TEK17), and fire safety must therefore be documented by analysis in such structures. When designing tall and complex timber buildings, it must be taken into account that a fire involving a timber construction may have more severe consequences than in buildings with constructions of steel or concrete, if the fire design of the construction and detail solutions is insufficient. Several studies show that fire exposed CLT, or CLT with insufficient protection, can cause a fire to develop faster, be more intense and last longer than a fire where the only fuel is the furniture and fixtures in the fire room. It is shown that the amount of fire exposed timber in a room may have impact on the extent and duration of a fire, but the knowledge has not yet been sufficient enough to be used in fire modeling, design and analysis.Research on charring rates, delamination and auto-extinction, all of which are factors that can have major impact on fire development and the fire resistance of the construction, takes place in Europe, Australia and North America. Although extensive research has been carried out, it is based on few large fire experiments, and the literature is still pointing to several knowledge gaps. However, the research projects have increased the knowledge of fire in timber buildings, and have contributed to the design of detail solutions, guidelines and development of models for function-based design. Revision of EN 1995-1-2 is under preparation and expected to apply from 2022. A knowledge base for the audit can be found in the network COST Action FP1404 Fire Safety Use of Bio-Based Building Products (COST FP1404) Working Group 2 (WG2). They have published several guidelines relevant for the fire design of CLT, including e.g. calculation methods for the prediction of charring rates and depths, determination of reduced CLT cross-section, design of CLT detailing and a suggested test method for evaluating adhesive performance.Based on the literature review, the following conclusions and recommendations are given for CLT constructions:

    The design phase must sufficiently consider protection of the construction and con-tribution of the construction to the fire energy, and to a greater extent include the assessment of detailing and ventilation conditions. It should be considered whether analytic fire engineering design also should be required for buildings in the Norwegian Fire Classes 1 and 2 where more than one CLT wall is exposed.

    • By protecting all CLT surfaces of the structure with cladding, the construction may retain the stability and the load bearing capacity during the required time of fire resistance.

    • In buildings with only one exposed CLT wall in each fire cell, it may also be appropriate to use solutions that satisfy the pre-accepted performances, but one must consider whether a somewhat longer and more intense heat radiation and flame exposure on the facade outside window openings will require measures beyond the pre-accepted performances given in the guideline to TEK17.

    • Rooms where two or more CLT walls in addition to the ceiling are exposed, are configurations that should be avoided.

    • The risk of delamination can be reduced by using heat-resistant glue.

    • There is generally a need for relevant documentation for fire-resistant solutions for joints between CLT walls and floors and service penetrations in CLT constructions.

    • Test methods for testing of joints and penetrations in CLT constructions should be standardized. For example, there exists no standardized test for corner joints. Tests of penetration seals for CLT constructions are scarce, although they can be tested according to EN 1366-3. However, CLT is not a standard supporting construction according to EN 1366-3, and this must be taken into consideration when the test results are evaluated. Joints in glulam constructions should also be tested because they are often used in conjunction with CLT elements.

  • Johansson, Marie
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Gustafsson, Anders
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Olsson, Jörgen
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Ylmen, Peter
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Nord, Tomas
    Linköping University, Sweden.
    Dorn, Michael
    Linneaus University, Sweden.
    Fruhwald Hansson,, Eva
    Lund Universtiy, Sweden.
    Serrano, Erik
    Lund Universtiy, Sweden.
    Broman, Olof
    Luleå University of Technology, Sweden.
    Jansson, Gustav
    Luleå University of Technology, Sweden.
    Sandberg, Dick
    Luleå University of Technology, Sweden.
    Brännström, Mattias
    Renewinn, Sweden.
    Framtidens biobaserade byggande och boende: Slutrapport2019Report (Other academic)
    Abstract [en]

    The aim

    of the project "Biobased building and living for the future" was to create conditions for increased use of bio-based products and services in the construction sector in Sweden and Europe and to increase the competitiveness of the Swedish timber manufacturing industry. The project has shown ways to develop E-commerce, parts of the production where increased digitalization leads to increased capacity and quality, as well as solutions for development of floor systems, external walls and tall timber buildings. The project has shown development opportunities to increase the use of bio-based products that implemented will increase competitiveness.

    The project has been divided into eleven sub-projects to study the various aspects of external factors, market conditions and business models, process development and product development. Within each sub-project, several workshops have been carried out to jointly evaluate results and decide the next step in the sub-project. Through joint workshops, the partners have also been able to meet and share results across the sub-projects and spread knowledge and create networks within the industry. The last part is perceived as very valuable by both the companies and the academy / institute.

    For the joinery value chain, a current situation analysis has been carried out and shown how the development of E-commerce platforms must be combined with process development in order to have a large effect. The results will be utilized in the companies' strategy work ahead. For the timber building value chain, demonstrators have shown development opportunities for both process and product development. The next step for the companies is to evaluate the various solutions linked to their own production conditions.

  • Andersson, Mattias
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Oxfall, Henrik
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Nilsson, Camilla
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Mapping and Evaluation of some Restricted Chemical Substances in Recycled Plastics Originating from ELV and WEEE Collected in Europe2019Report (Other academic)
    Abstract [en]

    Recycling of plastics is a critical step toward the realisation of a sustainable society. Plastic is a fitting material to recycle, as it often can easily be melted and formed into new products. Plastic recycling is therefore an easy process with pure plastics, however, most of the plastics that are recycled today are not pure and contain additives and/or impurities. Some of these additives can be hazardous substances that could be harmful for both humans and the environment. It is therefore important that these hazardous substances are not recycled and transferred into new products. To ensure a safe use of plastics, these substances are today regulated in new products, but old products could still contain these substances (legacy chemicals). To comply with legislation it is therefore critical that these substances are removed during the recycling process. There are however many hazardous substances that are yet not regulated, which may also be present in products and therefore recycled material. 

    Waste Electronic and Electrical Equipment (WEEE) and End-of-Life Vehicles (ELV) are two of the materials streams that contains a high amount of legacy chemicals. These streams have been associated with spreading legacy chemicals after recycling. In several reports WEEE plastics have been identified as the source of brominated flame retardants (BRF) found in toys and everyday items. According to the EU regulation the use of certain BFRs is not permitted in new products or articles above a certain value. Recyclers and resellers of the recycled plastic often specified that the products should not be used in toys, medical equipment of food contact application, yet BFRs from WEEE can still be found in these products. This could mean that either producers that use recycled material in new products do not follow the recommendations from the recyclers, or that the recycled material does not fulfil the regulations. Another possibility for the findings of legacy chemicals in these items could be a meagre follow-up on imported plastics.

    In this study the Research Institutes of Sweden (RISE) has, on behalf of the Swedish Environmental Protection Agency (Naturvårdsverket), investigated the content of legacy chemicals in recycled plastics that have been processed in a recycling facility. The plastics originated from WEEE and ELV and have been gathered from recyclers across Europe. A number of different legacy chemicals were investigated, both inorganic (Cd, Pb, Hg) and organic substances (flame retardants and plasticisers). To simulate a real case scenario and to get better measurement accuracy, all samples were injection moulded. The analysis of the samples was performed using X-ray fluorescence spectrometry (XRF), Inductively coupled plasma (ICP) and Gas chromatography with a Mass spectrometer (GC-MS). All the processing and analysis (except for SCCP/MCCP)) were done by RISE which gives good control over the analysis process, which are important when interpreting the results. In total 54 samples of PE, PP, ABS and PS, were gathered and tested. It was found that all but two samples contained legacy chemicals below the regulated values. The two samples that did not meet the legal limit had a HBCDD content above 100 ppm. All the tested materials contained detectable amounts of bromine, and 15 samples contained detectable amounts of regulated BFRs. None of the detected regulated BRFs were above 186 ppm.  Most of the materials also contained detectable amounts of cadmium and lead.

  • Antonsson, Ulf
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Nordling, Bengt
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Demker, Ingvar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sjöqvist, Mia
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Funktionsprovning av tätskiktsystem förvåtutrymmen 20192019Report (Refereed)
    Abstract [en]

    Functional testing of waterproofing systems for use behind ceramic tiling based on flexible sheets 2019

    Functional testing

    The result is worse than before.

    Six (32%) of the nineteen tested waterproofing systems passed the function test without leakage. Thirteen (68%) tests resulted in leakage.

    This result is worse than that obtained in the previous project in 2016, (1) when eight (40%) of twenty tested waterproofing systems passed the functional test without leakage. There has therefore been some deterioration in the as constructed systems.

    The result, however, is better than in the project performed in 2014 (2) when only three (15%) of twenty tested waterproofing systems passed without leakage.

    In this project, several leakages are localised around the penetrations of large and small drainpipes. This is an increase compared to previous studies. We have seen on several occasions that pipe collars have had poor quality. This has been noticed by that the polymer material used for sealing around the tube has lost its water tightness ability during the test. It is most probable that the material has a residual deformation (from setting) that causes the material to lose its ability to seal around the tube. We have also noted that the pipe collars have delaminated i.e. the layers in the collars have been divided into their individual constituents during the test.

    Leakages have also been caused by connections to gullies, inside corners, outside corners and in joints of foils.

    Fortunately, none of the investigative systems showed leakage that was so extensive that one could describe it as total damage.

    Water vapour resistance and mass per unit area

    Thirteen tested waterproofing on flexible sheet systems show a result between 2,5 and 4,5 million s/m, which is a high or very-high water vapour resistance. Six flexible sheet systems have a result below 2,5 million s/m.

    In the determination of water vapour resistance and mass per unit area, we can clearly see that some manufacturers have made changes in or replaced their flexible sheet with a new one, compared with the previous investigation (1).

    We further note that 10 out of 14 flexible sheets have a lower water vapor resistance than in the previous investigation (1). It is also notable that the PVC sealing layer has a low water vapor resistance.

    Indication of long-term properties

    In order to obtain an indication of the amount added antioxidants that improves the long-term properties of the materials, the DSC analysis of flexible sheets have been performed. In the same way as in the previous project, 2016, (1) it seems that the flexible sheets to be more stabilized for long-term use compared to the previous study in 2014, (2). However, for all analysed materials, to make a reliable service life prediction of the material, an accelerated ageing at moderate temperature is recommended.

  • Johansson, Pernilla
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Bok, Gunilla
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Missfärgade fasader på svenska flerbostadshus2017Report (Other academic)
    Abstract [en]

    The study contains a field study in which several facades of buildings were studied, as well as a survey where real estate managers have shared their experiences.

    On 28% of the total of 268 facades studied in the field study, discoloration was found to such an extent that it was judged to affect the aesthetic impression. Both mould fungi and algae could be identified in the samples taken on discoloured facades. Most of the facade materials studied consisted of rendering or sheet metal. On buildings with façade of sheet metal, the north side was more susceptible to discoloration than other parts of the buildings. No impact on the point of the compass could be observed on buildings with other facade materials. No regional difference in the extent of discoloration could be found in the study. The survey confirms these observations.

    The survey shows that many property managers consider that discolouration generally constitutes a problem in their property portfolio, due to costs for maintenance or cleaning, complaints from residents or a reduced general impression of the property portfolio. Although some managers did not consider it to be a general problem, some specific façade types in the property stock may be discoloured and cause problems. Most property managers considered that a façade should not receive an unacceptable discoloration until after at least 10 years. Their experience was that several buildings received such growth already within 10 years after construction of the building.

    Respondents of the survey were asked to evaluate discolouration of some example facades, by looking at pictures. It was found that the extent of a discolouration to be regarded as unacceptable varies between different people and different types of buildings. In the survey, real estate owners' experiences of different remediation methods of discoloured facades were surveyed, and it was found that the experiences differ. The property managers believe that a cleaned facade should last at least 5 years before the extent of discoloration becomes unacceptable.

    Results from the study will be used as questions and hypotheses in future studies, e.g. to investigate the effectiveness of remediation agents and to develop tools and guidelines for preventing new discoloration.

  • Sandberg, Karin
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Pousette, Anna
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Norén, Joakim
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Sandberg, Marcus
    Luleå Technical University, Sweden.
    Olofsson, Thomas
    Luleå Technical University, Sweden.
    Mukkavaara, Jani
    Luleå Technical University, Sweden.
    Hållbarhetsutvärdering av byggnader - Case Ripan i Kiruna2018Report (Other academic)
    Abstract [en]

    Sustainability includes several parameters, and these can be measured and valued in many different ways. This study focuses on balancing the various parts to achieve sustainability by minimizing energy for heating and energy to produce the materials used in the building as well as minimizing cost for material investment and cost for heating using optimization techniques. This is balanced together with the environmental impact. This report describes an initial study for sustainability optimization of a smaller building. The goal is to develop a comprehensive approach to provide a broader basis of decisions for new construction.

    The calculation included the building envelope (exterior walls, roof and floors), interior walls and stabilizing elements for different frames of wood (timber frame and CLT).

    The result from the Ripan Case shows that the timber frame design has the lowest embodied energy and operating energy, and lowest cost for investment and heating during the operating phase. The environmental impact of the timber frame design was also low.

  • Andersson, Jan-Erik
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Nordman, Roger
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Vikberg, Tommy
    Luleå Technical University, Sweden.
    Energy mapping in the sawmill industry with focus on drying kilns2013Conference paper (Other academic)
    Abstract [en]

    The forest industry stands for approximately 11 % of Sweden’s total export. However, the forest industry is energy intensive. In 2008, sawmill industry alone consumed almost 8,7 TWh of energy, corresponding to 5 % of the Swedish industries total energy consumption. Out of their total consumption, 2200 GWh was electric power, 194 GWh heating oil , 4229 GWh bio-fuel, 574 GWh district heating, and other fuels such as diesel 1503 GWh [1].The project ”EESI- Energy Efficiency in the Sawmill Industry” was started in the spring of 2010 with the aim of demonstrating the possibilities to reduce the energy consumption in the sawmill industry with 20 % by 2020. 16 sawmill corporations and 14 equipment suppliers has joined the project which is carried out in two phases of which the first phase was carried out during 2010 and 2011. EESI has now reached half time and the first energy-saving implementations have been completed at the participating sawmills.This paper presents the energy-mapping, measurements and modelling performed by the participating sawmills during the first phase of the project [2, 3]. The average energy consumption per sawn cubic metre of boards varied between approximately 300 to 500 kWh/m3. Out of this, the electricity consumption was on average 85 kWh/m3, bio-fuel 290 kWh/m3 and diesel 1.8 l/m3.However, the main concern from sawmills regarding energy consumption was the wood drying process. The striking results from the preliminary measurements were the large variation in energy consumption even with similar drying kilns. This was especially apparent for the heat consumption in kiln dryers which could vary as much as 50 % for the same dimension of spruce planks.The results from the first phase of the project resulted in a large number of actions in order to reduce the energy consumption which are now being implemented or have already been completed. Examples of those actions are: simplified management system adapted to sawmills, weighing of packages for more accurate wood drying, reduced speed or intermittent operation of the air circulating fans in batch kilns and moisture content measurements of bio-fuel.References[1] Statistiska centralbyrån (SCB), 2013, Industrins årliga energianvändning 2011, Slutliga uppgifter, EN23SM1301, ISSN 1654-367X. (In Swedish). [2] Andersson, J-E., Lycken, A., Nordman, R., Olsson, M., Räftegård, O., and Wamming, T. State of the art – Energianvändning i den svenska sågverksindustrin. SP Rapport 2011:42, ISBN 978-91-86622-72-5. (In Swedish).[3] Andersson, J-E., Räftegård, O., Lycken, A., Olsson, M., Wamming, T., and Nordman, R. Sammanställning av energimätningar från EESI fas 1. SP Rapport 2011:41, ISBN 978-91-86622-71-8. (In Swedish).

  • Vikberg, Tommy
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Sehlstedt-Persson, Margot
    Luleå Technical University, Sweden.
    Tryckfall över värmebatteri i virkestork: resultat av tre års mätningar. Slutrapport.2019Report (Other academic)
    Abstract [sv]

    Möjligheterna att utföra behovsstyrt underhåll på virkestorkar istället för enligt ett underhållschema vore önskvärt. En av underhållsåtgärderna som är svåra att schemalägga i tiden är rengöring av värmebatterierna eftersom graden av nedsmutsning i stor del beror på råvaran, utomhusklimatet och sågutrustningen. I detta projekt mättes det statiska tryckfallet över värmebatteriet i 1:a-zon i en två zons kanaltork. Mätningen pågick under tre års tid och målet var att få till stånd en mätning som indikerar när det är dags att rengöra värmebatteriet. Projektets slutsatser är:

    • Det är möjligt att mäta graden av spånpålimning på värmebatterierna genom att mäta tryckfallet över värmebatteriet.
    • Tryckfallsmätning kan tjäna som indikator för när det är lämpligt att rengöra värmebatteriet.
  • Sehlstedt-Persson, Margot
    et al.
    Luleå Technical University, Sweden.
    Vikberg, Tommy
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Utveckling av industriell virkestorkning: Slutrapport2019Report (Other academic)
    Abstract [sv]

    Projektet har behandlat ett antal delstudier kopplat till virkestorkning inom följande områden : ADAPTIVITET, FUKT­DYNAMIK och TORKNINGSKVALITET. Projektet har bidragit till att steg har tagits mot målet att uppnå en mer självstyrande och automatiserad torkningsprocess, en mer optimerad och energieffektiv torkningsprocess samt bättre och jämnare torkningskvalitet som samman­taget minskar torkkostnader genom att:

    ADAPTIVITET identifiera olika mättekniska- och återkopplade signaler som kan användas i simulatorer och styrsystem: ”ΔT” principens möjlighet att adaptivt förlänga dragtider i en FB-kanal, termograferingens diagnostiska möjlighet att få en momentan överblick över rumslig fukt­kvots­spridning i en torkande virkeslast samt difftrycksmätningens potential att signalera rengöringsbehov för att undvika försämrad lufthastighet och värmeöverföring i en kanal.

    FUKTDYNAMIK öka förståelsen för virkets fuktdynamik genom att i tomografstudier visa på möjligheten att optimera diffusionsdriven jämviktskonditionering vid olika fuktkvotsnivåer och på så sätt effektivisera tid och energianvändning i torkar. Fuktförändringar under pågående kondi­tio­nering har aldrig tidigare studerats i tomograf.

    i tomografstudier visa hur övergången mellan kapillär och diffusionsfas genom  ΔT tydligt kan identifieras

    genom CT-studier ge ökad förståelse och förbättrat underlag för fuktdynamisk modellering i kapillär och diffusionsfas.

    TORKNINGSKVALITET förbättra torkningskvalitet genom bättre målfuktkvotsträff och mindre fuktkvotsspridning genom de ovan nämnda adaptiva metodernas potential.

    visa att en kombination av torkning med efterföljande hyvling och behandling med mögel­hämmare kan åstadkomma en produktgrupp av splintvedsbrädor av furu, contorta och gran med god och likvärdig mögelbeständighet.

    Studierna som avrapporteras övergripande i denna rapport har utförts inom delprojekt 3 inom ramen för projektet ”TiiN, TräInnovation i Norr”.

    Samtliga delstudier avrapporteras separat i följande TCN- rapporter.

    TCN-rapport: Temperaturdifferens ”ΔT” mellan virkesyta och luft under pågående torkning som möjlig styrparameter i virkestorkning. Mätningar i labb och industriskala. Margot Sehlstedt-Persson, LTU, Tommy Vikberg, RISE, Gerhard Scheepers, RISE.

     

    TCN-rapport: Värmekameramätningar i virkestorkar. Gerhard Scheepers, RISE.

     

    TCN-rapport: Mögeltest av torkade furu, gran och contorta bräder: Sammanfattning av “Mould susceptibility of dried boards of Contorta pine, Scots pine and Norway spruce A comparative study” Faksawat Poohphajai, februari 2018. Margot Sehlstedt-Persson, LTU.

     

    TCN-rapport: Konditionering av virke vid olika fuktkvoter – studier i tomograf. Margot Sehlstedt-Persson, Lars Hansson, José Couceiro samtliga LTU, Tommy Vikberg RISE.

     

    TCN-rapport: Tryckfall över värmebatteri i virkestork - resultat av tre års mätningar. Tommy Vikberg, RISE och Margot Sehlstedt-Persson, LTU. 

  • Sehlstedt-Persson, Margot
    et al.
    Luleå Technical University, Sweden.
    Vikberg, Tommy
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Scheepers, Gerhard
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Temperaturdifferens ”ΔT” mellan virkesyta och luft under pågående torkning som möjlig styrparameter i virkestorkning.: Mätningar i labb och industriskala.2019Report (Other academic)
    Abstract [sv]

    Målsättningen med denna studie har varit att utvärdera frågeställningen om tempe­ratur­differensen mellan lufttemperatur och virkesyta (ΔT), kan användas adaptivt i en FB kanal för att detektera övergång från torkning i kapillär till diffusionsfas. Man eftersträvar att så mycket kapillärt vatten som möjligt ska avgå i zon 1 innan virket går in i zon 2 för att inte fuktkvoten ska bli för hög i uttagsänden.

    Inledningsvis utfördes ett antal grundläggande försök i labbmiljö följt av en mer omfattande mätning i industriskala vid J-G Anderssons i Linneryd. Vid Linneryds­försöket gjorde även termografimätningar. Slutligen gjordes ett långtidsförsök vid Norra Timbers anläggning i Kåge med beröringsfri IR-sensor för mätning av yttemperatur på långsidorna av passerande virkestaplar.

    Slutsatser av grundläggande försök i CT-lab

    Utvärderingen av försök på enbitsnivå pekar mot att ΔT signalen har god potential att kunna användas för att detektera när fibermättnad nås i virket. I kanaler med stora virkeslaster med varierande fuktinnehåll måste dock yttemperaturmätningar göras på medelvärden av större ytor. Nästa steg var industriella mätningar i kanal där dock ingen kontinuerlig fukt­kvots­bestäm­ning var möjlig att göra.

    Slutsatser av industrimätningar i Linneryd

    Mätningar av virkets yttemperatur, lokalt torkklimat, lufthastighet, fuktkvot och ΔT i prover placerade i olika positioner i en virkesstapel med 22x100 mm granbräder under torkning i en 2 zons FB kanal, visar överensstämmande resultat.  Nivåerna på ΔT i nedblåsningsschaktet visar tydligt om proven var kvar i kapillärfas eller inte. Höga nivåer på ΔT som i centrala de­lar­na av paketen i höjdled  innebär att proverna fortfa­rande var i kapillärfas. Låga nivåer på  ΔT, som på kanterna av mittpaketet, innebär att kapillär­fasen har passerats. I positioner där slutfuktkvot blev  betydligt högre än målfuktkvot (centrum i toppaket) var ΔT nivån hög i ned­blås­ningsschaktet. Detta virke skulle med fördel ha haft längre tid i zon 1. Virket på kan­terna var redo för övergång till zon 2. I praktiken görs dock naturligtvis drag­ningar för en hel stapel i taget.

     

    Termografibilderna ger en ögonblicksbild av torkningsläget i en virkelast och har potential att vara ett komplement till befintliga mätmetoder. Industrimätningarna visar att det är möjligt att ta bra värmebilder i nedblåsningsschaktet i en FB kanal. Att ha en permanent värmekamera i nedblåsningsschaktet ställer dock krav på kylning av kameran som inte klarar höga tempe­raturer.

    Slutsatser från långtidsförsök vid Norra Timbers anläggning i Kåge

    Två pyrometrar riktade att mäta yttemperatur på de två översta paketen på passerande vagnar installerades i en gångdörr vid nedblåsningsschaktet i en FB kanal. Beräknat ΔT tycks kunna utgöra värdefull processdata för att styra torkens dragningstid.

    Yttemperaturmätningar med pyrometer är en relativt robust metod som fungerar bra i en virkestork. Ingen rengöring behövdes under de fyra månaderna som mätningen pågick.

  • Sehlstedt-Persson, Margot
    et al.
    Luleå Technical University, Sweden.
    Hansson, Lars
    Luleå Technical University, Sweden.
    Couceiro, José
    Luleå Technical University, Sweden.
    Vikberg, Tommy
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Konditionering av virke vid olika fuktkvoter: studier i tomograf2019Report (Other academic)
    Abstract [sv]

    Fuktförändringar i virke under pågående konditionering har aldrig tidigare studerats i tomograf.

    Resultat av denna labbstudie av diffusionsbaserad, icke-kondenserande jämviktskonditionering vid olika fuktkvotsnivåer sammanfattas enligt följande: (Notera att torkningsspänningar inte utvärde­rats i denna studie utan enbart fuktförändringar.)

    • Studien styrker industriella erfarenheter att konditionering ”tar bättre” på virke nedtorkat till lägre fuktkvot jämfört än om fuktkvoterna är högre.
    • Försöken ger en god fingervisning om hur länge konditionering bör pågå för en viss önskad medel­fuktkvotshöjning i ett industriellt vanligt förekommande klimat 70 °C och psykrometer­skillnad 2° vilket motsvarar en jämviktsfuktkvot på 16,8%. Vill man ex höja medelfuktkvoten från 10 – 12% visar resultaten att 4 timmars konditionering är tillräckligt för furuvirket. Att i samma klimat höja medel­fuktkvoten 2% vid högre startfuktkvoter (mellan 14–23%) har inte i något fall varit möjligt för vare sig gran eller furu under de 8 timmar som konditionering pågick. Det är också viktigt att påpeka att konditioneringsklimatet i dessa labbförsök har uppnått börvärden mycket snabbt (figur 3) vilket inte är fallet vid stora virkeslaster i industriskala där basningskapacitet och blåsdjup påverkar tid till uppnådda börvärden.
    • Vad gäller fuktkvotsskillnad nära ytorna ses generellt en utplaning av fuktförändringar i samtliga försök efter 3–4 timmar.
    • Fuktkvotsnivån spelar roll för den inledande fuktkvotsförändringen inom tvärsnittet: ju torrare virke desto snabbare förändring.
    • När konditioneringen startar är fuktvandringen i splintved effektivare än i kärnved vilket sannolikt förklaras av splintvedens högre diffusivitet.
    • Vad gäller eventuella skillnad mellan träslag är det inte möjligt att dra några slutsatser.
    • Metodstudien visar att upplösningen i tomografen är tillräcklig för att kunna utvärdera fuktkvotsförändringar nära virkesytorna i ca 3 mm tjocka skal.
  • Brännvall, Elisabet
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Kulander, Ida
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Consequences in a softwood kraft pulp mill of initial high alkali concentration in the impregnation stage2019In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 34, no 1, p. 28-35Article in journal (Refereed)
    Abstract [en]

    Impregnation with high initial concentration is fast and efficient, leading to a homogeneous delignification in the subsequent cook, resulting in improved screened pulp yield. To obtain high initial alkali concentration, the white liquor flow needs to be significantly increased. The moisture content of the wood chips and the alkali concentration of the white liquor limit the initial alkali concentration of the impregnation liquor that can be reached. It is therefore of interest to evaluate the possibility to implement high alkali impregnation (HAI) industrially and the consequences this would have on the mill system. The effect of HAI on mass and energy balances in a kraft pulp mill has been studied using mill model simulations. The sensitivity to disturbances in important parameters for process control has been compared to impregnation scenarios used industrially. It was shown that high initial alkali concentration can be achieved on industrial scale by increased white liquor flow. HAI has a positive effect on recovery flows and reduces the need for make-up chemicals. The HAI concept is less sensitive to variations in process parameters, such as chip moisture and white liquor concentration, thus diminishing the risk of alkali depletion in chip cores. © 2019 Brännvall and Kulander.

  • Han, Shaobo
    et al.
    Linköping University, Sweden.
    Alvi, Naveed Ul Hassan
    Linköping University, Sweden.
    Granlöf, Lars
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Granberg, Hjalmar
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Berggren, Magnus
    Linköping University, Sweden.
    Fabiano, Simone
    Linköping University, Sweden.
    Crispin, Xavier
    Linköping University, Sweden.
    A Multiparameter Pressure–Temperature–Humidity Sensor Based on Mixed Ionic–Electronic Cellulose Aerogels2019In: Advanced Science, ISSN 2198-3844, article id 1802128Article in journal (Refereed)
    Abstract [en]

    Pressure (P), temperature (T), and humidity (H) are physical key parameters of great relevance for various applications such as in distributed diagnostics, robotics, electronic skins, functional clothing, and many other Internet-of-Things (IoT) solutions. Previous studies on monitoring and recording these three parameters have focused on the integration of three individual single-parameter sensors into an electronic circuit, also comprising dedicated sense amplifiers, signal processing, and communication interfaces. To limit complexity in, e.g., multifunctional IoT systems, and thus reducing the manufacturing costs of such sensing/communication outposts, it is desirable to achieve one single-sensor device that simultaneously or consecutively measures P–T–H without cross-talks in the sensing functionality. Herein, a novel organic mixed ion–electron conducting aerogel is reported, which can sense P–T–H with minimal cross-talk between the measured parameters. The exclusive read-out of the three individual parameters is performed electronically in one single device configuration and is enabled by the use of a novel strategy that combines electronic and ionic Seebeck effect along with mixed ion–electron conduction in an elastic aerogel. The findings promise for multipurpose IoT technology with reduced complexity and production costs, features that are highly anticipated in distributed diagnostics, monitoring, safety, and security applications. © 2019 The Authors.

  • Olsson, Thomas
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Franke, Ulrik
    RISE - Research Institutes of Sweden, ICT, SICS.
    Introduction to Service Level Agreements2019Report (Other academic)
    Abstract [en]

    Modern industrial production environments are rapidly transforming.Concepts such as smart industry and Industry 4.0 encompass many expectations onhow digital technology can improve industrial plants. Some strands are betteralgorithms for robotics, better situational awareness through ubiquitous RFID,fewer production interruptions through smarter predictive maintenance, and moreagile production lines enabling greater customization of products. Many of theseideas depend on reliable access to IT services such computing power and dataavailability. If these falters, the benefits will not materialize. Therefore,it is crucial to study the Service Level Agreements (SLAs) that are used toregulate such services.

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