Technology Update

Software for cleaner cement manufacture:

An engineering consultancy is using engineering simulation software to improve the sustainability of making cement. Cement manufacturing is a complicated, resource intensive process in which limestone and other materials are crushed and milled, preheated to separate gases from solids and then heated in a kiln at temperatures up to 14500 C. The preheating of raw materials and maintaining temperatures use a large volume of fossil fuels. Increasing costs and negative environmental impacts are making cement manufacturers to explore the use of alternative fuels. German Consultancy Aix process has been musing computational fluid dynamics software from Ansys to explore possible process improvements and avoid physical testing. Alternative fuels being considered, such as, scrap tires, paper waste and plastic waste have different physical characteristics and combustion processes which can disrupt the cement making process. Engineers at Aixprocess have used fluid dynamics to simulate the effects of these fuels on combustion rates and outputs, heat and mass transfer processes and chemical reactions within cement kilns. Martin Weng, Co-founder of Aix process, said: We have been able to analyze the effects o replacing 40% of the traditional fuels used in an existing cement factory with alternative fuels used in an existing cement factory with alternative fuels. Specifically, we worked on determining the process modification needed maintain high kiln temperature and to stay within operating critical parameters. We have learned that to use these new fuels, we must compensate with increased oxygen pressure and an intensified materials blending process. Real-world testing to reach this same conclusion would have taken much longer and been far expensive Based on their simulations engineers have a high degree of confidence that cement manufacturers can successfully replace traditional fossil fuels with alternative secondary fuels leading to both economic and environmental benefits. They plan to use Ansys software to analyze and optimize other aspects of the cement making industry, including chemical reactions within kilns and the separation processes used to isolate gases and solids during the preheating phase. Because cement manufacturing is a complex process characterized by heterogeneous flows, high temperatures distinct phases and precise material concentrations – it is an ideal application for engineering simulation software.

Soft polymers put robotic fish in the swim:

Researchers from ,the Massachusetts institute of Technology have built a school of swimming robo fish to be used to maneuver into areas where traditional underwater autonomous vehicles cannot go. Mechanical engineers reckon the sleek robotic fish could be used to inspect submerged structures such as boats and oil pipes, to patrol ports and to detect pollutants. Given the fish’s robustness, it would be ideal as a long term sensing and exploration unit. Several could be deployed and even if only small percentage makes it back there would not be a terrible capital loss due to their cost. The robotic fish, each less than 30 cm long are powered by a single motor and are made of fewer than 10 components, including flexible compliant body that houses all the parts and protects them from the environment. The motor, in the fish’s midsection, initiates a wave that travels along the fish’s flexible body, propelling it forwards. The robo fish bodies are continuous flexible and made from soft polymers. This say the researchers makes them more maneuverable and better able to mimic the swimming motion of real fish, which propel themselves by contracting muscles on either side of their bodies generating a wave that travels from head to tail. Most swimming techniques can be copied by exploiting natural vibrations of soft structures. Other researchers including a team at the University of Essex have developed robotic using traditional assembly of rigid components to replicate the motions of fish, but the MIT team is the only one using controlled vibrations of flexible bodies to mimic biological locomotion. With these polymers, you can specify stiffness in different sections, rather than building a robot with discrete sections. This philosophy can be used for more than just fish – for example, in robotic prosthetic limbs. The team’s first prototypes, 12.5 cm long mimic the carangiform swimming technique use by bass and trout. Most of the movement takes place in the tail end of the body. Fish with this type of motion are generally fast swimmers with moderate maneuverability. Later versions of the robo fish about 20 cm long swim like tuna, which are adapted for even higher speeds and long distances. In tuna, motion is concentrated in the tail and in the region where the tail attaches to the body, and the amplitude of body motions in this region is greater than in carangiform fish.