Chemical Technology October 2016

Chemical Technology • October 2016

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

DIN EN ISO 12944.

Back to basics

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

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

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.

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