Die Zerkleinerung von Holzpellets und damit die Entstehung von Feinanteil während des pneumatischen Transports wird zusammen mit den auftretenden Druckverluste im Rahmen dieser Arbeit experimentell und numerisch untersucht. Zunächst erfolgt die Entwicklung eines empirischen Bruchmodells auf Basis von Einzelpartikelprallversuchen zur statistischen Beschreibung des Bruchverhaltens von Holzpellets in Abhängigkeit von Kenngrößen wie Partikellänge, Aufprallgeschwindigkeit und -Winkel. Die entwickelten Korrelationen werden in den hauseigenen DEM-Code des Lehrstuhls für Energieanlagen und Energieprozesstechnik der Ruhr-Universität Bochum implementiert. Gekoppelte DEM-CFD Simulationen geben detaillierte Einblicke in die Abhängigkeiten der Strömungsverhältnisse sowie des Bewegungsverhaltens und der mechanischen Belastungen der geförderten Partikel von Betriebsbedingungen und Leitungskomponenten. Die numerischen Ergebnisse stimmen qualitativ mit denen korrespondierender Experimente überein und zeigen die Erhöhung von Pelletbruch und Feinanteil durch zunehmende Förderluftströme bzw. abnehmende Pelletmassenströme und kleinere Krümmerradien. Das entwickelte Bruchmodel ermöglicht detaillierte Untersuchungen pneumatischer Fördervorgänge und die Auslegung schonender Betriebsbedingungen und Leitungskomponenten zur Reduzierung von Druckverlusten sowie Pelletbruch und Feinanteil. In the present thesis, the dependence of wood pellet degradation and fines formation during pneumatic conveying on operating conditions like air and product mass flow or shape of pipe components is investigated. Both the size reduction of the cylindrical pellets during pneumatic transport caused by mechanical impacts and the prevailing pressure losses are analysed experimentally and numerically. Single particle impact tests are performed for investigating the breakage behaviour of wood pellets including the effect of particle length, impact velocity and collision angle. Based on the empirical correlations derived, a numerical degradation model is developed and implemented into the in-house DEM code of the Department of Energy Plant and Technology of the Ruhr-University Bochum. Experimental and numerical investigations are conducted using coupled DEM-CFD simulations to obtain detailed insights into flow conditions, particle motion and the mechanical loads on the pellets during pneumatic conveying. Numerical results show good qualitative agreement with the experimentally determined degradation rates and prevailing pressure losses. The degradation model developed allows detailed investigation into wood pellet degradation and fines formation during pneumatic conveying and enables the design of pipe configurations and operating conditions to prevent particle size reduction and excessive pressure losses.
Over 100 woodworking techniques from joints to finishing With Woodwork Step by Step you can tackle every type of carpentry project with confidence- create a shelf, a coat rack or even a chair. In an age where household objects are mass produced, nothing beats working with wood to create a unique object you've built to last. This book makes woodwork simple, showing step-by-step how to master woodworking tools and techniques and gives woodwork plans that explain exactly how to get the perfect results. You'll be able to learn how do everything from preparing wood to planing and sanding and create anything from chopping boards to wine racks. A gallery of all the key woodworking equipment, materials and suitable woods means that you'll never be left puzzling over what to use to get started.This book assumes no knowledge and explains techniques in start-to-finish detail, so you can fast track through woodworking with accessible and easily achievable projects. Woodwork Step by Step is ideal for beginners at woodwork and DIY or old hands looking to dust off the cobwebs and start working in wood again (content previously published in The Woodwork Manual 9781405332064).
You know how the saying goes: turnabout is fair play. That means it's time for boyfriend to bend over. These four stories all feature women who might not wear the pants in the relationship, but who do take a turn wearing the cock. Whether it's the woman taking a turn receiving a blow job or otherwise taking charge in the bedroom, once you slide on a strap-on, power dynamics change. And that's just what these tales examine, with all the steamy consequences. Zara's husband David, one of the twin heads of a premier biotech company, may not quite be what he seems. His violent history, long suppressed with a neural implant, is re-emerging in strange ways, and he-or his twin brother-may be "Double Dealing" with their identities. It will take cleverness, courage, and the services of a world class hacker to untangle the web of deception around the brothers Gemini. Then, is it happily ever after for William and Jenny... and her husband, Alex? Will knows he's loved, but he's still the third wheel in a married couple's household. It's up to Jenny and Alex to prove to him that his place in their hearts has the "Permanency" he desires. Shammara might be the princess of a magical kingdom, but her royal duty to submit to her chosen suitor is a distasteful one, literally. So she does what any girl will do when her father, the king, is murdered and her future kingdom is overrun by her uncle's evil minions: she flees into the mountains with the aid of a loyal and besotted guardsman to become queen of a tribe of Amazons, turning the "Phallusy" of male magical superiority right on its head as she fights to reclaim her crow. Obviously. Finally, Captain James Wilmington survives the wreck of his ship and the loss of most of his crew, only to find himself rescued-and imprisoned-aboard a pirate corsair. Held at the mercy of the lady pirate Faisal, whose allure and charms ensnare him, Captain Wilmington soon finds himself transitioning from a captive hostage to "Your Most Humble and Obedient Servant.
The compelling story of one family's life among the rugged landscapes of the Coast Mountains, converting youthful ideals, raw land and a passion for the outdoors into a practical off-grid homestead. Rob Wood grew up in a village on the edge of the Yorkshire Moors, where he eventually developed an obsessive preoccupation with rock climbing. After studying architecture for five years at the Architectural Association School in London, England, and becoming an architect, he made his way to Montreal, then to Winnipeg and ended up in Calgary. During his time in Canada, Rob became a pioneer of ice climbing and posted numerous first ascents in the Rockies. Eventually, life in corporate Alberta proved unfulfilling and Rob realized that he needed to find a place where he could reconnect with nature, which brought him to the remote reaches of Canada's West Coast. Settling on Maurelle Island, he and his wife built an off-the-grid homestead and focused on alternative communities and developing a small house-design practice specializing in organic and wholesome building techniques. At Home in Nature is a gentle and philosophical memoir that focuses on living a life deeply rooted in the natural world, where citizens are connected to the planet and individuals work together to help, enhance and make the world a better - and sustainable - place.
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