Electricity + Control November 2017

round up PLANT MAINTENANCE, TEST + MEASUREMENT

High-pressure gas flow control

series) – are a more compact and much cheaper alternative to flow meters, which are combined with valves that are controlled pneu- matically or using a servomotor. For controlling process pressure, Vary-P valves are often also applied in conjunction with Bronkhorst pressure meters. The Vary-P valve comprises a flow control sec- tion, along with a mechanism that keeps the differential pressure over this valve at a constant approx. 6 bar. As a result, the pressure at the inlet and outlet of the mass flow or pressure controller may vary without affecting the control performance. For gas flow control up to 200 bar, Bronkhorst has recently de- veloped a new, directly driven control valve; i.e. without a Vary-P mechanism. This development makes mass flow controllers fitted with this valve (F-220 series) even more compact, offering even faster control. Industrial versions (IP65 rating) of all mass flow con- trollers can also be supplied. High-pressure mass flow controllers are often used to control gas flow in chemical processes, both in research and in production environments. Mecosa is the sole agent for BRONKHORST HIGH- TECH B.V. in South Africa.

Vary-P control valves were already introduced by Bronkhorst in 1985 for controlling high-pressure gas flow with high pressure differences of up to 400 bar (later on extended to 700 bar). The control valves – usually integrated in a mass flow controller (F-230

Enquiries: +27 (0) 11 257 6100 or email measure@mecosa.co.za

Is modernisation a must for South African mines?

He explained that large scale youth unem- ployment is a real challenge but South Africa is fortunate to have an abundance of young people who are intrinsically more ‘tech-sav- vy’ and need to be incorporated to help solve the problems facing the mining industry. Van der Woude showed that already much is being done through a coalition of willing partners called ‘Mining Precinct’. A donation of R150 M from the DST (Depart- ment of Science and Technology) is going towards R&D. The Chamber of Mines has donated R35 M; the DTI (Department of Trade and Industry) has donated R8 M; and Mining Companies – R1 billion. Unions be- lieve modernisation is inevitable and want to be involved in the process. He pointed out that the extraction of gold and that of platinum have been picked to be the first mining processes to be modern- ised as this type of mining faces the most difficult challenges in the world but also offers marvellous opportunities. Through modernisation the longevity of the mines will be increased, people will be removed from dangerous zones and finally there will be no more drill and blast but contin- uous operation 24/7. This solution needs to be developed in South Africa for South African mines. He emphasised that there is no ‘off the shelf’ solution for South Afri-

On 18 October Siemens hosted a Min- ing Technology Day in Sandton. The key- note address was given by Sietse van der Woude, Head of Modernisation and Safety, Chamber of Mines. Van der Woude start- ed his address by saying that mining is re- sponsible for 457 698 direct jobs; makes up 40% of South Africa’s exports and contributes R304 billion to the GDP mak- ing it the backbone of the South African economy. However, the current state of deep-level mining, with its associated in- creased costs and reduced productivity, is unsustainable. If the mining industry does nothing and continues on its current path using current methods this could lead to 200 000 job losses in the next ten years. Alternatively, modernising the South Afri- can mining environment could unlock the equivalent potential of eleven large gold mines and eight platinum mines. Van der Woude emphasised that mod- ernisation needs to be people-centric in South African mining because 15 million of the country’s population are unemployed. People-centric modernisation must be developed with and for the people under- standing that due to the poor quality of ed- ucation in South Africa people need to be upskilled and technology ‘de-skilled’ which means making equipment user friendly.

can conditions. Roland Ehrl, Executive Vice President Minerals, Siemens, echoed this sentiment when he said of the Siemens solution for mines: “Digitalisation is not a ‘one size fits all’ solution but needs to be developed with the customer.” Enquiries: Keshin Govender.Tel. +27 (0) 11 652 2000 or email Keshin.govender@ siemens.com or visit www.twitter.com/ siemens_press

Michael Avery (classic FM) and Sietse van der Woude (Chamber of Mines).

Roland Ehrl, Executive Vice President

Minerals, Siemens.

Electricity + Control

NOVEMBER 2017

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