Chemical Technology October 2016

COVER STORY

GEMÜ valves — Made to last longer, even in the howling winds

GEMÜ is one of the world’s leading manufacturers of valves, measurement and control systems. Since 1964, this globally focused, independent family-owned enterprise has established itself in important industrial sectors thanks to its innovative products and customised solutions for process media control.

A broad-based modular system and adapted au- tomation components mean that predefined standard products and customised solutions can be combined to make over 400 000 product versions. GEMÜ specialises in the manufacture of high-quality valves, measurement and control systems. The coating on the valve bodies in its series of concentric, soft-seated GEMÜ 480 Victoria ® butterfly valves has recently been modified. In line with the new standard, a 250 µm epoxy coating is being used. The screws and bolts for fixing the actuators are manufactured from stainless steel. As a result of this and other measures, such as optimised workpiece pre-treatment before the coating process itself, all product configurations now comply with the requirements of the C5M, medium-durability classification as stipulated in A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. The wind wheel of the Greek engineer, Heron of Alexandria, in the first century is the earliest known instance of using a wind-driven wheel to power a machine. Centuries ago, windmills were most often used to mill grain, pump water, or both. Further developments led to the design of a wind DIN EN ISO 12944. Back to basics

turbine, which is a windmill-like structure specifically de- veloped to generate electricity. The first of these were built by the end of the nineteenth century, though the modern wind power industry began in 1979 with the serial produc- tion of wind turbines by Danish manufacturers. These early turbines were small by today’s standards, with capacities of 20-30 kW each. Since then, commercial turbines have increased greatly in size, with the Enercon E-126 capable of delivering up to 7 MW, while wind turbine production has expanded into many countries. Extracting energy from the wind Worldwide, many thousands of wind turbines are now operating, with an estimated total nameplate capacity of 194 400MW. Europe accounted for 48%of the total in 2009. A wind turbine installation consists of the necessary systems needed to capture the wind’s energy, point the turbine into the wind, convert mechanical rotation into electrical power, and other systems to start, stop, and control the turbine. In addition to aerodynamic design of the blades, design of a complete wind power systemmust also address design of the hub, controls, generator, supporting structure and foundation. Further design questions arise when integrat- ing wind turbines into electrical power grids. As of 2015, Denmark generates 40% of its electricity from wind, and at

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Chemical Technology • October 2016