Rss http://www.mersen.com/ Latest news from mersen.com en Rss http://www.mersen.com/typo3conf/ext/tt_news/ext_icon.gif http://www.mersen.com/ 18 16 Latest news from mersen.com TYPO3 - get.content.right http://blogs.law.harvard.edu/tech/rss Thu, 12 Jan 2012 12:29:00 +0100 Cooling devices for power electronics http://www.mersen.com/en/focus/article/cooling-devices-for-power-electronics.html The three principal cooling technologies–air-based, water-based and diphasic–cater for different... Download the article The three principal cooling technologies–air-based, water-based and diphasic–cater for different industrial applications. This article is devoted to Mersen’s expertise in the water cooling devices used to protect power electronics. The development of power converters is currently racing ahead owing to the growth in demand for energy. Cost reductions and the growing need for compact and efficient solutions are key factors for the development of new converters. The progress achieved in recent years in power electronics also requires the use of increasingly efficient components at the heart of these converters. In this edition, we take an in-depth look at cooling devices, the core elements providing thermal protection for converters. The goal of a cooling system is to allow the heat generated by an electrical or electronic system through its use to be dissipated to stop components from overheating and to prevent their premature deterioration. The key task of a cooling device is thus to maximize the efficiency of heat dissipation. This is particularly crucial in power electronics where the heat generated by the electronic components that needs to be dissipated is very high indeed. This dissipation of heat depends on a number of key factors:
  • the thermal conductivity of the materials used,
  • the size of the exchange surface between the item for cooling and the cooling device,
  • the cooling device’s thermal exchange coefficient.
The manufacturing technology used by Mersen satisfies these requirements by harnessing the Group’s unique brazing and tooling expertise. 1 – Brazing: this consists in joining two metal parts together.
The aluminum vacuum brazing technology employed by Mersen is well-known for the reliability and robustness it affords systems. This very high-temperature process ensures the cohesiveness of two or more metal parts, by allowing molecules to agglomerate directly without the addition of any filler material. This very clean technology that delivers proven robustness helps to optimize heat exchanges, thereby boosting the dissipation of the heat given off by the electronic components, while preventing the risks of corrosion or leakage, which are very critical indeed when water is used in close proximity to electric circuits. 2 – Tooling: this consists in creating the internal hydraulic circuits within the cooling device. The precision of Mersen’s tooling produces highly sophisticated circuits, and this sophistication is instrumental in maximizing heat exchanges and the dissipation of heat. Thanks to its ability to design solutions geared to meeting the constraints specific to each industrial challenge and its aluminum vacuum brazing technology and high-speed tooling, Mersen has become a key player in cooling systems for electronic components and helps its customers to minimize their costs. Mersen works with Siemens and Thalès, as well as on applications in the energy, transportation and aerospace sectors.   Example of an aluminum cooling device for three IGBT power components
Mersen cooling devices for green energy projects in the North Sea Mersen has signed a contract with Siemens Energy to supply thousands of cooling devices to protect the converters used for the transmission via sub-aquatic cables of the electricity generated by offshore wind farms in the North Sea and their connection to onshore power grids. Harnessing HVDC technology for high-voltage power transmission, the systems developed by Siemens Energy can be used for extremely high power transmission over very long distances and provide a trusted method to connect asynchronous grids or grids of different frequencies, while reducing losses. These systems are also equipped with a new generation of voltage-sourced converters (VSCs), well-known for their flexibility and suitability where only limited space is available. Mersen’s cooling devices were chosen because they satisfy the requirement of flawless reliability for this advanced technology equipment, which is used in highly exacting environments and conditions.
 
Siemens converter
With permission from Siemens * High Voltage Direct Current Mersen in cooling technologies Mersen has three sites in Europe, North America and Asia, which have the three principal cooling technologies covered. All these facilities can recommend the right solution from Mersen’s range of cooling systems to meet customers’ specific requirements in their respective region with a view to maximizing their cost efficiency and technical performance. That said, each of them has specializations deriving from their history. Based in La Mure, the French facility boasts particular expertise in designing solutions and vacuum brazing technology, which it harnesses to deliver water cooling solutions. It also possesses a unit manufacturing heat pipe cooling devices. The Toronto facility in North America largely focuses on manufacturing technical air cooling devices by drawing on a unique, patented technology. Lastly, the Shanghai plant in China has capacity dedicated to air and water cooling technologies and is supported by the expertise of the other two facilities.]]> Markets Financial Thu, 12 Jan 2012 12:29:00 +0100 Mersen and the protection of power Electronics http://www.mersen.com/en/focus/article/mersen-and-the-protection-of-power-electronics.html Almost 15% of the energy produced today is converted. Conversion is handled by the power... Download the article Almost 15% of the energy produced today is converted. Conversion is handled by the power semiconductors used in converters. Mersen’s activities encompass two functions of the power electronics market:
  • Efficiency of the manufacturing process for power semiconductors with ultrapure Graphite machined parts,
  • Safety and reliability of power converters.
This article focuses on the second of these functions. Power converters Power converters are currently experiencing strong development due to the ever-increasing demand of energy. Lowering their cost, growing demands to reduce their overall size and better efficiency are key requirements for new power converters developments. Power semiconductor components are critical in achieving these new requirements. The benefits provided by these components are subject to certain constraints. For example, they operate at extremely high frequency, the heat they generate has to be dissipated … and they need to be protected against catastrophic failure when miss applied. Mersen helps to overcome these constraints with a range of adapted products. Role of power converters Power converters are used to alter the form of a source’s electrical energy to make it compatible with its required use. Put another way, they are used for the following applications:
  • Power conversion: generation of alternating current from a direct current source, or vice versa, for example, energy storage and renewable energy applications,
  • Power regulation: delivery of a constant charge from a variable source, forexample power quality applications.
There are four types of power converters catering to different types of equipment and power sources, including rectifiers (AC to DC), inverters (DC to AC), choppers (DC to DC) and cycloconverters (AC to AC). Power converters provide more flexible use of the energy and improve its management,transmission and distribution. Several examples of the uses of power converters are:
  • in photovoltaic and wind energy systems, where power converters transform the source current and voltage waveforms before the energy is transferred to the grid,
  • in rail transportation, where power converters manage and supply energy to the train motors and collect the energy generated at braking,
  • in variable speed drives for controlling electric motors in industrial or commercial facilities,
  • in network interconnections for the modulation of voltage and frequency of the grid.

Mersen's key role in power converters Mersen already helps to overcome the constraints described above using two efficient and reliable categories of product: Fast acting fuses and other electrical protection devices (switches and fail-safe surge protection devices) protecting against catastrophic failure, a field in which Mersen is the world leader ; Cooling devices providing the thermal protection of components while enabling the heat to dissipate.

Mersen expands its range to keep pace with technological advances The substantial progress achieved in recent years in terms of commutation frequency of the power semiconductor components, voltage application and current density has led to changes in the materials and assembly techniques used for power converters. To keep pace with the latest technological advances, Mersen recently signed a preliminary agreement to buy Eldre, one of the world’s leading suppliers of laminated and insulated busbar. The laminated busbars play a key role in power converters. They provide connection between the various components, limit the parasitic inductance, ease the assembly and integration, leading to an improvement of the overall power converter reliability, performance and efficiency while minimizing assembly costs. This acquisition will help to strengthen Mersen’s position as a leading global player in power electronics.

]]> Markets Group Financial Mon, 21 Nov 2011 17:08:00 +0100 Manufacturing artificial graphite http://www.mersen.com/en/focus/article/manufacturing-artificial-graphite.html Mersen’s history began with a series of innovations associated with the manufacture of synthetic... Mersen’s history began with a series of innovations associated with the manufacture of synthetic graphite. This article explains how Mersen manufactures this unique material and how its exceptional properties are used in many different applications in the industries of the present and the future and help fuel the Group’s expansion. The remarkable properties of graphite
The various uses of graphite derive directly from its exceptional physical properties. Graphite is characterized by its resilience to very high temperatures and to corrosion, its thermal and electrical conductivity, its mechanical resilience, its self-lubricating properties, its suitability for machining and the length of its service life. All these qualities make it a vital material for a whole host of industrial applications. Before we take a closer look at them, we will first recap on the history and secrets of manufacturing synthetic graphite. Brief history
Carbon and graphite exists in various different forms. Natural graphite is mined, whereas artificial graphite is produced through the graphitization of amorphous carbon, a process discovered and patented in 1893 by Charles Street, an engineer working at Le Carbone, the forerunner of the Group, which represented its first major innovation. Secrets of manufacturing graphite
Raw materials Three basic ingredients:
  • cokes, obtained through carbonization (above 1,000°C) of tar produced by distilling oil and coal,
  • artificial graphite, which derives from the recycling of graphite materials
  • carbon black or natural graphite, and additional ingredients: a derivative of oil and carbon used to bind the particles together.
Manufacture (see figure 1)
After inspections to check their quality, the principal ingredients are ground up. The coke, graphite and solid binder are then loaded into a mixer that heats them up. The rise in temperature melts the binder and ultimately moistens the grains, before the gradual reduction in temperature serves to enhance the viscosity of the mix until it solidifies. After further grinding, the mix is placed in a rubber mold to be compressed or
shaped and it may be extruded into a die. The volatile materials are then eliminated through baking. This extremely lengthy stage (1 to 2 months) takes place at a temperature of 800°C to 1,000°C. Next comes the graphitization phase, which consists in heat-treating the blocks in an electric kiln at 3,000°C for one to three weeks. At a very high temperature, the carbon atoms realign themselves into hexagonal crystalline structures, which thus form artificial graphite. The substance’s properties change. It becomes a good conductor and its resilience to oxidization improves. The blocks are cut to the final dimensions and then undergo a series of tests(density, resilience, resistance to flexion, hardness, expansion coefficient, etc.) to safeguard its quality. The first phase lasts for around four months in all. Various additional purification and impregnation steps enhance the graphite’s qualities and give it additional benefits for a number of industrial processes. Remarkable properties in highly demanding industrial environments
Based on the properties deriving from the manufacturing methods and productionstages, graphite (see box) may be used in various applications, such as:
  • the manufacture of silicon, a critical component in the manufacture of solar panels,
  • the manufacture of LEDs and semiconductors,
  • highly corrosive environments, making it ideally suited for the fine chemicals and pharmaceuticals industries,
  • extremely high-temperature environments (kiln linings, glass-making, etc.),
  • mechanical structures: friction components, seamless joints, lubricating products,
  • electrical applications, notably including motor brushes,
  • rail industry, with collection strips.
Various types of artificial graphite
There are various types of artificial graphite, and their diverse range of properties facilitates their use in a vast array of industrial applications.
  • High-quality isostatic graphite (compressed in an isostatic press) is used for solar energy applications, as well as LEDs and semiconductors, electrical discharge machining, glass industry and chemicals. Mersen is the world’s co-leader of isostatic graphite.
  • Extruded graphite is used as electrodes in furnaces for the production of recycled steel.
  • Specialty extruded graphite is used in kiln equipment, heat exchangers, molds, crucibles, pods, etc.
  • Molded graphite is used to manufacture electrodes for electrical discharge machining, molds for continuous casting or sintering, etc.
Next issue of Focus Mersen
In a forthcoming edition of Focus Mersen, we will show how the extremely high degree of purity of Mersen’s isostatic graphite and its technological innovations producing components in record-breaking dimensions can provide solutions to the new challenges facing the solar energy and electronics sectors. Download Focus Nr.12 in pdf ]]> Markets Tue, 06 Sep 2011 10:38:00 +0200 Mersen launches its new website http://www.mersen.com/en/focus/article/mersen-launches-its-new-website.html To celebrate its new identity, a year after it's name change from Carbone Lorraine to Mersen, the... This new design offers an improved site map to  ease navigation and help our current and future clients and partners undersand the Group. This site has been particularly upgraded with new international pages to give information (data sheets, brochures, contacts…) in many languages and countries where the Group is present. Links to dedicated international pages: - Australia - Austria - Benelux - Brazil - Canada (English and French) - China - France - Germany - India - Italy - Japan - Korea - Latin America - Morocco - Nordic countries (Denmark, Sweden, Finland) - Russia - South Africa - Southeast Asia (Singapore, Thailand, Vietnam, Indonesia, Philippines, Malaysia) - Spain - Taiwan - Turkey - United Kingdom - United States]]> Group Mon, 13 Jun 2011 11:00:00 +0200 With TPMOV® technology, Mersen harnesses innovation to enhance the safety of electrical equipment http://www.mersen.com/en/focus/article/with-tpmovR-technology-mersen-harnesses-innovation-to-enhance-the-safety-of-electrical-equipment.html Surge protection devices (or SPDs) perform an important safety function in electrical systems.... Surge protection devices (or SPDs) perform an important safety function in electrical systems. Specifically, they protect electrical equipment against transient overvoltages. They are commonly fitted in electrical distribution boards, control systems, and power supplies for industrial and communication applications. And they are increasingly used to help solve power quality problems. Mersen sells a key SPD component, based on new TPMOV® technology, developed by Mersen R&D teams.

The MOV in TMPOV®

The metal oxide varistor, or MOV, is a key component in the electrical protection devices that are used in lightning conductor and surge protection systems. The word “varistor” stands for “variable resistor”, because this component displays a non-linear resistance characteristic: when the voltage in an electrical circuit exceeds a certain threshold, the resistance of the varistor drops sharply to direct excess current outside the circuit and thus protect all electrical and electronic equipment downline of the surge protection device against damage from the voltage surge.



In performing its intended function under repeated power surges, a classic varistor will gradually deteriorate (figure 2), eventually giving rise to serious malfunction, possibly involving fire or explosion, in extreme cases. So this component must necessarily be disconnected and replaced before component deterioration risks damaging the systems that the device is supposed to protect.

Some ten years back, Mersen began work on a technology that would remedy this very important failing in ordinary MOV devices. The result was TPMOV® technology, for “thermally protected metal oxide varistor”. A TPMOV® takes the form of a cartridge containing a metal oxide varistor, a heat sensor in direct contact with the varistor surface, and a spring-loaded shield in insulating material (figure 3). If the varistor heats under transient overvoltage conditions, with high fault current, the heat sensor trips, causing the screen to be pushed into place by the spring to isolate the varistor from the circuit well before thermal runaway can take place (figure 4).
The device also includes a remote status indication system for reporting when replacement is needed. This is especially important in critical control circuits.

TPMOV® diagrams



Mersen’s patented TPMOV® technology was initially designed for use in SPDs. Under industrial-scale manufacture it soon became a standard in electric protection. Using this technology, Mersen covers 80% of SPD applications in North America.

Successful market take-up of TPMOV® technology spawned development of new product lines that continue to expand, addressing new markets such as power electronics and electrical power distribution. TPMOV® technology is especially suitable in applications such as solar power, which are sensitive to power surges and power quality.

What’s next…
Mersen will be continuing development of products and applications based on TPMOV® technology, enhancing functionality along with voltage and power characteristics to meet market demand, especially in surge protection for DC power distribution.

Download Focus Nr.11 in pdf ]]> Markets Mon, 30 May 2011 18:39:00 +0200 Direct-current motors are still serving well http://fileadmin/user_upload/pdf/Resume___Article_AC_GB.pdf Mersen partners with other major actors of the electric motors and drives business to write an... Markets Fri, 15 Jul 2011 14:06:00 +0200 2010 dividend (attributed in 2011) http://www.mersen.com/en/focus/article/2010-dividend-attributed-in-2011.html A dividend of €0.75 per share was approved by shareholders at the Annual General Meeting of May 19,... A dividend of €0.75 per share was approved by shareholders at the Annual General Meeting of May 19, 2011. This dividend can be paid in cash or new shares.

This leads to a total payout of €14.9 million, representing 38% of net income attributable to Mersen’s shareholders and 35% of net income from continuing operations, in line with the dividend policy adopted by the Group over the pas few years.

This dividend can be paid in cash or new shares.

Record date: May 25 2011

Ex-date: May 26, 2011

Issue price: 35,93€

Coupon code: FR0011046143

Option period: from May 26 to June 22, 2011

Payment in cash and listing of new shares: July 7, 2011]]> Financial Wed, 19 May 2010 18:55:00 +0200 Mersen, exclusive sponsor of HEI’s sailing club http://www.mersen.com/en/focus/article/mersen-exclusive-sponsor-of-heis-sailing-club.html Mersen has joined forces with HEI (hei.fr), the prestigious engineering school based in Lille, to... Mersen has joined forces with HEI (hei.fr), the prestigious engineering school based in Lille, to promote the school’s sailing club for the duration of the 2011 season.
 As the sports association’s exclusive sponsor, Mersen will accompany HEI’s sailing club and its crew of 12 engineering students throughout the year for training and especially the big annual events, including the Edhec race, the biggest student regatta in Europe with 150 schools competing (9-16 March in Lorient), and the SPI West France, the largest spinnaker sailing event in Europe with 500 crews and 20,000 spectators (21-25 April in La Trinité-sur-mer).

Mersen’s sponsorship of HEI’s sailing team is a way to ensure name recognition with a targeted public, while supporting a sport that embodies the Group’s values.

You can follow the team’s progress on the sailing club’s dedicated website: http://heicce.free.fr (in French)]]> Human capital Tue, 20 Apr 2010 12:26:00 +0200 Seawater desalination, a growth market for Mersen http://www.mersen.com/en/focus/article/n10-seawater-desalination-a-growth-market-for-mersen.html In the previous issue of Mersen Focus we talked about the challenges of seawater desalination and... In the previous issue of Mersen Focus we talked about the challenges of seawater desalination and the main technologies used. This market holds valuable opportunity for Mersen, which offers a full range of equipment covering the key stages in the desalination process. Pretreatment in reverse-osmosis desalination process There are different types of reverse-osmosis desalination processes. In one of them, before the seawater goes through the process as such (see Mersen Focus n°9), it must first undergo preliminary treatment. This ensures optimum performance and service life for the desalination units, and is especially important for operation of the membranes.

Seawater composition varies considerably, and can include organic matter, algae and hydrocarbons. The pretreatment stage performs three main functions:
  • It substantially reduces the amount of suspended solids and thereby the turbidity (i.e. cloudy appearance) of the water.
  • It eradicates algae and hydrocarbons.
  • It reduces the tendency of the water to cause clogging.
To remove particles from the water, coagulation / flocculation treatment can be applied which consists in stirring the water in order to let suspended particles coalesce into heavier flakes, which can be readily removed by settling. Mersen makes stirrers specially designed for optimum mechanical performance and minimum energy consumption (see figure opposite). Prior to entering the reverse osmosis module, the settled water then goes through a sand bed filtration unit to remove residual suspended solids. For this stage in the process, Mersen supplies the filters (dual media filters), which take the form of rubber-lined carbon steel tanks big enough to handle thousands of cubic meters per day. Because of its industrial capacity to supply very large filters, weighing up to 60 tons, and meeting drastic manufacturing specifications, Mersen was selected in January 2010 to equip the largest reverse osmosis seawater desalination plant in the southern hemisphere. Mersen today is one of very few suppliers capable of making more than 70 filters in a year. This equipment is manufactured by Mersen’s Chinese production facility.



Thermal desalination

Mersen also supplies the heat exchangers that perform condensation filtration for the thermal desalination, or distillation, process (see Focus Mersen n°9 ).

focus-10-seawater-desalination-a-growth-market-for-mersen
]]> Markets Wed, 25 May 2011 15:27:00 +0200 Mersen signs the French Diversity Charter http://www.mersen.com/en/focus/article/mersen-signs-the-french-diversity-charter.html By signing up to the French Diversity Charter, Mersen has undertaken to promote a pluralistic... By signing up to the French Diversity Charter, Mersen has undertaken to promote a pluralistic approach and to combat all forms of discrimination. initiative is part of a whole series of measures that the Group has implemented over the past few years to promote diversity. As a priority avenue of improvement, it has been incorporated in the strategic plan since 2008. These measures are predicated on five pillars: 1. Raise awareness of non-discrimination and diversity issues among top management and staff involved in recruitment, training and career development and to educate them in these matters.
2. Respect and promote the application of all aspects of the principle of non-discrimination at every stage of the human resources management, in particular in the recruitment, training, promotion and career development of employees.
3. Endeavor to reflect, the diversity of the French society particularly in its cultural and ethnic dimension at every level of our workforce.
4. Make all our employees aware of our commitment to non-discrimination and diversity, and keep them informed of the practical results of this commitment.
5. Make the development and implementation of the diversity policy a subject of a dialogue with the employees’ representatives. We firmly believe that diversity represents an economic driver for our Group. By putting it at the heart of our strategy, it becomes an advantage bolstering our creativity and competitiveness. In very concrete terms, the program was significantly strengthened in 2010 with the launch of a Mersen Diversity Program. This program calls for specific action plans in three areas:
  • Cultural diversity through efforts to promote the diversification of managerial teams,
  • Gender diversity (aim of going from 18% of female managers at present to 20%),
  • Generational diversity, management of senior employees (notably keep employees aged 55 and over at 15% of the workforce in France).
Mersen is an international Group, with an industrial and commercial presence right around the world. Capitalizing on this cultural wealth will help to secure our development. Accordingly, all the Group’s sites are encouraged to address and promote all these aspects of Diversity. Link to the site: www.charte-diversite.com]]> Human capital Wed, 25 May 2011 18:37:00 +0200