Recent Patents on Mechanical Engineering - Volume 1, Issue 3, 2008

Magnetorheological elastomer (MRE) is a new branch of MR materials, which are smart materials whose rheological properties can be controlled by the application of an external magnetic field. MREs are solid, rubber-like materials whose modulus can be adjusted by applying magnetic field. In this article, the current research and patents on the material fabrication, modeling and testing, and applications will be reviewed and discussed. As the articles review, recent interesting in applications focused on three main areas. The first one is on the sound and vibration control, especially on the vehicle applications, including dynamic vibration absorber and isolator. The second one is on the controllable stiffness change and deformation, such as roll in papermaking machine and releasable fastener system. The third one is on the sensors and actuators. In summary, MREs have made significant advances and will have promising applications.

This paper reviews some industrial applications where a central role is played by the interaction between a surface and an impacting drop or spray. In particular, attention is focused on patents describing methods to optimize the application by controlling the drop deposition. This can be achieved, for instance, by using additives that change the fluid rheology, or by modifying artificially the state of the surface. The industrial applications considered here span across the whole range of engineering disciplines, from the distribution of agrochemicals to the fabrication of microlenses, and should be intended as examples of the potential as well as of the multidisciplinarity of this topic.

Pulverized coal combustion is widely used for electricity generation around the world. The oxides of nitrogen are among the important polluting species, emitted from coal combustion, having large scale adverse impacts on the environment and life. There can be different routes of the formation of NOx from coal combustion and their emission from electric utilities depends on several boiler operating parameters as well. Among the different options of reducing the NOx formation and emission from power station boilers, the introduction of low NOx burner is one of the less expensive alternatives, which can also be readily retrofitted in the existing plants. The present review has focused on the different design decisions in the burner technology for reducing the formation of NOx. Important patents in the field as well as several commercial designs of the burners have been analyzed. A discussion has also been incorporated on some of the current innovations for further reduction of NOx in order to achieve stringent regulations in the near future.

Advances in high power technology are demanding size reduction of thermal systems resulting in constrained spaces for increased heat transfer. This has led to thermal management problems in emerging systems which have defied solution by conventional cooling methods. Due to recent developments in nanotechnology, a new class of heat transfer fluids called nanofluids was discovered. A nanofluid is a solid-liquid mixture produced by dispersing metallic nanoparticles in a liquid to enhance the heat transfer performance. Experiments have shown that nanofluids have substantial higher thermal conductivities compared to the base fluids. This application of nanometer-sized particles in liquids holds huge prospects for confronting cooling problems in thermal systems. This paper summarizes the explanations that have been presented for the enhanced thermal conductivity of nanofluids, the methods of preparation as well as recent and important patents on nanofluids heat transfer. It also identifies areas for further research. This review indicates that exploitation of nanofluids could lead to development of coolants that can be applied in thermal systems leading to remarkable impact in many sectors especially energy and transportation. Also, the principles of nanoparticles in biofluids can be applied to drug delivery in body tissues thus providing new medical treatment methods.

The first patent for a plate heat exchanger was granted in 1878 to Albretch Dracke, a German inventor. The commercial embodiment of these equipments has become available in 1923. However, the plate heat exchanger development race began in the 1930's and these gasketed plate and frame heat exchangers were mainly used as pasteurizers (e.g. for milk and beer). Industrial plate heat exchangers were introduced in the 1950's and initially they were converted dairy models. Brazed plate heat exchangers were developed in the late 1970's. However, copper brazed units did not start selling until the early 80's. Nickel brazing came to market around ten years later, since copper presents compatibility problems with some streams (e.g. ammonia). All-welded and semi-welded (laser weld) plate heat exchangers were developed during the 1980's and early 90's. Shell and plate heat exchangers were recently introduced in the market and can withstand relatively high pressures and temperatures, as the shell and tube does. The fusion bonded plate heat exchangers (100% stainless steel) are a technology from the 21st century, these equipments being more durable than brazed plate heat exchangers. The plates are the most important elements from the different plate heat exchangers mentioned above. This paper initially introduces the gasketed plate and frame heat exchanger and common chevron-type plates. Resorting to computer fluid dynamics techniques, the complex 3D flow in cross-corrugated chevron-type plate heat exchanger passages is visualized. Recent patents related with the plates from different plate heat exchangers are then outlined.

Suspension system is one of the most important systems in a modern vehicle. It significantly contributes to the vehicle's availability and safety, keeps vehicle occupants comfortable and also protects the vehicle from damage and wear. Due to its importance in the vehicle structure, a massive amount of effort has been spent on enhancing the performances of suspension system, such as stability, controllability, and other capabilities. This paper briefly reviews recent innovations and some representative patents (since 2000) in this area and outlines the features and advantages of these inventions. The future trends of research in the suspension system design are also discussed.

This work investigates a fully-developed laminar flow of a complex channel with a period of 2d. Because of the character of symmetry, the study will focus on an L-shaped region. The governing equations are the Poisson equations. The analysis is solved by an eigenfunction expansion and the point-match method. The local velocity, the maximum velocity, the average velocity and the f. Re of the channel are discussed in the present paper. Furthermore, the results of present research are compared and discussed with the relevant references and it shows that the results will be helpful toward the proposals in the channel flow systems of recent patents.

Based on the state-of-the-art of Arecibo 305m diameter telescope, an innovative design was proposed by the author ten years ago to build the next generation large radio telescope. In the design, a cable supporting system with 6 long reach cables is utilized to move the feed in space, which works in the same way as parallel cable-driven robots. In order to achieve the desired position precision of the feed, a fine-tuning Stewart platform is added to the cable supporting system. Due to the long reach of the cable and high feed position precision, cable curve needs to be carefully accounted for. Because of the low stiffness of the cable supporting system, the interaction between the cable supporting system and the Stewart platform is also a problem to solve. A series of key technology researches have been done, and both 5m and 50m demonstrate models are built to validate the proposed design. At the same time, several relevant patents have been issued. This paper intends to make an introduction and discussion about this. /P>

This short review article gives an overview of the use of several novel, metallurgical temperature sensors. These include the Feroplug, the Sigmaplug, the Templug and PETIT. Metallographic methods that utilise carbide segregation and the thickness of metal oxide scales that accumulate on steam boiler pipes are also introduced. Besides reviewing the various metallurgical sensors, emphasis has been placed on the Sigmaplug, which is a new, potentially patentable technique. A new application i.e. monitoring of temperature fluctuation and overheating/underheating, for an ‘old’ patented technique, the Feroplug, is also discussed in this article. New results on the Sigmaplug, some of which have not been published before, on this potentially patentable technique are presented in this article. Additionally, the latest results by the present group of authors on the use of metallurgy-related phenomena in stainless steels for temperature measurement are introduced. The Feroplug is an ‘old’ patented technique that was originally designed for the measurement of long-term average temperatures. Recently, attempts have been made to assess the possibility of using this technique for temperature fluctuation and overheating/underheating monitoring. Results on this topic are introduced.

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