Chemical Technology April 2015

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Regular features 3 Comment

Design and materials of construction 24 HDK ® pyrogenic silica – Creating products by closing loops In chemical terms, pyrogenic silica consists of very pure amorphous silicon dioxide. Unlike precipitated silica, silica sol or silica gel, pyrogenic silica is produced by the reaction of chlorosilanes with hydrogen and oxygen in an oxyhydrogen flame at over 1 000 °C. by Dr Robert Johnston, Director Business Team HDK®, Wacker Silicones, Wacker Chemie AG, Germany Waste management 30 The development of an online biofouling monitor for cooling water systems The BOMM device offers a simple means of obtaining representative sessile samples from Eskom cooling water systems. by Kelley Reynolds-Clausen, Eskom Holdings SOC Ltd, Research, Testing and Demonstration, Johannesburg, South Africa 28 Focus on design and materials of construction

by Helen Clark, Administrator of the United Nations Development Programme

23 CESA Forum 35 Et cetera 36 SAIChE IChemE news/Sudoku 104/Solution to Sudoku 103 Cover story 4 Dewatering pontoons decrease costs and improve efficiencies Pontoon or skid-mounted pump setsoffer a flexibility not always possible with conventional dewatering solutions. Petrochemicals 6 WirelessHART automates cooling tower operations Wireless instrumentation and an asset management system reduce chemical, maintenance, lost production and repair costs. by Nikki Bishop and Jason Sprayberry, Emerson Process Management Pumps and valves 14 Energy-saving potential in high-vacuum brazing furnaces using diffusion pumps For many years, energy efficiency has been the number-one topic with manufacturers and users of vacuum furnaces for thermal treatment.The search for energy-saving possibilities concentrated mainly on the furnaces themselves and the optimisation of the heat-treatment processes. 10 Focus on petrochemicals

Transparency You Can See Average circulation (July – September 2014) Paid: 17

Free: 3 968 Total: 3 715

Chemical Technology is endorsed by The South African Institution of Chemical Engineers

34 Focus on waste management

and the Southern African Association of Energy Efficiency

by Uwe Zoellig and Hans-Werner Schweizer both of OerlikonLeybold Vacuum GmbH, Cologne, Germany

DISCLAIMER The views expressed in this journal are not neces- sarily those of the editor or the publisher. Generic images courtesy of www.shutterstock.com

18 Focus on pumps and valves

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