Animal slurry (liquid manure) is a significant source of air pollution. Because the biological and chemical processes that drive emission are sensitive to temperature, there is a need for simple tools that can be used to predict the temperature of stored animal slurry for both emissions inventories and research. In this contribution we describe a heat transfer model and an open-source software implementation that addresses these limitations. The model is a simple mechanistic representation of the slurry-environment system, and the software includes a default parameter set developed from a combination of theory and fitting to measurements made at three concrete tanks in Sweden, and evaluated using measurements from two additional tanks. This contribution describes the model and software program and presents examples. © 2023 The Author(s)
Gotland Slagteri AB jointly with pig producers experienced that several construction projects of pig facilities were delayed or hindered due to insufficient locally established advisory services, specifically with competence in construction of pig facilities and the associated growth process. In corporation with the unit of Agriculture and Horticulture at Research Institutes of Sweden (RISE) and the farm advisory service, Gård och Djurhälsan, a project was carried out with the aim to write a handbook about the construction and growth process. One of the objectives with the handbook was to serve as a manual in which a pig producer could get more information about a specific topic relevant in the process. The handbook is composed of shorter texts in addition to checklists, "step by step", templates, forms and calculation tools. The project group has had several, so-called dialogue meetings, where specific topics, relevant to the construction and growth process, have been discussed within the group or with the participation of experts. The purpose of these meetings has been to retrieve deeper knowledge of specific topics, e.g., pig production planning, bank and finances, disease control and organic production. All these dialogue meetings have resulted in various chapters in this handbook. Additionally, there are a stand-alone template about writing a work environment plan for construction sites, several calculation tools for the operational phases in pig production, a template for ventilation and heat demand in pig units, a construction investment calculation tool and a time planning tool, i.e., a Gantt chart. The guidance focuses on the administration of a construction project and the growth process related to it. This guide does not contain topics related to e.g., crop production, feed production or manure handling. Neither such administration as required during the actual operational phase of the pig facility, such as systematic work environment plan or systematic fire protection plan. Additionally, the project group went on a study tour to Bornholm, Denmark, to discuss pros and cons operating an abattoir or pig production on an island (Grisproduktion på Bornholm – reseberättelse från studieresa i projektet ”Utökad grisproduktion på Gotland”, RISE report 2021:114).
Vid konventionell simulering av pressgjutning idag modelleras en så kallad puck/tablett som motsvarar kolven i framskjutet läge. Då simuleringen inleds strömmar smältan på ett idealt sätt ut ur pucken/tabletten och in i gjutsystemet. Momentet i skottkammaren simuleras alltså inte och det är en förenkling som medvetet görs. Projektet fokuserar till större del på hur smältan beter sig innan 2:a fasen och söker parametrar som styr processen före 2:a fasen, som är relevanta för kvalitén och på slutkomponent. Praktiska försök utförs för att finna samband mellan simuleringsresultat och processparametrar som används fram till 2:a fasen. Virtuella försök utförs för att hitta generiska samband mellan komponentkvalité och processparametrar som styr pressgjutningen före 2:a fasen. I de virtuella försöken ses att andelen stelnat material ökar med ökad fördröjning och beror minst på fyllnadsgraden. Projektet har genom virtuella försök visat hur komponent kvalite påverkas av hur smältan beter sig innan 2:a fasen, dock så lyckas inte projektet med detta i de praktiska försöken.