Electricity and Control March 2016

ROUND UP

PLANT MAINTENANCE, TEST + MEASUREMENT

Efficient flow measurement using heating jackets

An Endress+Hauser client in the Power industry has presented a challenge, measuring the flow of sulphur into the SO ³ plant, the sul- phur has to remain in a liquid form at 135°C to prevent it from cool- ing, hardening, blocking the tubes and ultimately obstructing the process. Coal has been the mainstay of electricity generation and plays an important role.The coal is finely ground before beingmixed with warm air and burned in huge boilers. The generated steam passes through a turbine making it rotate to generate electricity,

which is then fed into the national grid. Waste produced in the form of pulverised fuel ash is removed from the boiler gases by electrostatic precipitators before the gases pass up the chimneys. In the order to reduce harmful emissions, sulphur trioxide SO ³ is injected into the precipitation inlet flow to change the resistiv- ity of the existing particles and enhance the performance of the electrostatic precipitators. Too much SO ³ will create a higher acid dewpoint and increased probability of cold-end corrosion and acid emission. If there is too little, the electrostatic precipitator’s performance will suffer and release increased particulate emissions to the atmosphere. Measuring the flow of sulphur into the SO ³ plant is therefore integral to the process, as is retaining the optimum tempera- ture. The sulphur flows at extremely high temperatures and the pipelines need to be trace-heated to maintain the fluid properties of the sulphur. Promass 83F is more than up to the challenge with a process temperature capability of 350°C, performing at pressures up to 350 bar. In order for the application to work effectively, the sulphur has to remain in a liquid form at 135°C to prevent it from cooling, hardening, blocking the tubes and ultimately obstruct- ing the process. However, if the temperature exceeds 150°C, the viscosity raises and the sulphur does not flow easily. Maintaining

the optimum temperature is therefore vital to achieving maximum effectiveness of the process. Heating jackets were recom- mended as they can be placed over the Promass meter in order to maintain the optimum temperature for sulphur flow.

Enquiries: Frans van den Berg. Tel: +27(0)11 262 8000 or email info@za.endress.com

Electrical equipment protection during outages

Legrand’s power solutions ensure protec- tion of electrical equipment and continuity of service during planned and unexpected power outages. “Thesemodular systems include certified low emission (CLE) cast resin transformers, busbar trunkings, enclosures for power

electricity costs and can reduce electricity consumption by up to 20% during off-peak activity. The absence of flammable insulation liquids, the use of self-extinguishingmateri- als exempt of toxic gas emissions, reduced noise levels and low electromagnetic emis- sions, ensure enhanced environmental protection in all installations. Legrand’s standard distribution transformers have rated power between 100 and 3 150 kVA, primary rated voltage up to 36 kV and sec- ondary rated voltage up to 433 V. Special transformers have rated power up to 20 000 kVA, primary rated voltage up to 36 kVA and secondary rated voltage on request. For climate conditions these transform- ers can withstand severe conditions - E2 - environmental class, C2 - climatic class, F1-fire-behaviour class. Enquiries: Tel. +27(0)11 444 7971 or email legrand.south-africa@legrand.co.za

switchgear and controlgear assemblies, as well as uninterruptible power supply (UPS) units,” states Marc Naidoo, projects and technical coordinator, Legrand SA . “An important advantage of selecting Legrand components for efficient, safe and flex- ible power distribution, is the immediate integration between the company’s busbar trunking systems, cast resin transformers and XL³ cabinets.” “All Legrand power solutions systems encompass the latest tech- nology for energy efficiency, quality power supply, optimum safety and enhanced aesthetics.” Legrand’s environmentally friend- ly, dry type cast resin transformers, transfer electrical power between two different voltage systems at the same frequency, with low environ- mental impact. These HV/LV trans- formers offer significant savings on

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