MechChem Africa September 2017

Mech Chem SEPTEMBER 2017 AFRICA

This month: From pump rental to sales: the solution-driven approach

Bioremediation in the oil refinery and petrochemical sector

Smarter cider production for efficient operation

Legendary engine support and an African vision

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Pump systems, pumps, valves and seals 8 From pump rental to sales: the solution-driven approach MechChem Africa visits the new expanded premises of Integrated Pump Rental (IPR) and Integrated Pumps Technology (IPT) and talks to IPR’s managing director, Lee Vine. 10 Pumping systems 101: What are pressure gauges actually telling us? 13 Why pump slurries with a peristaltic pump? 14 Locally manufactured API pumps for Europe’s refineries 15 High-flow models expand dewatering portfolio 16 Advantages of vertical turbine pumps for boiler use 19 Travaini: the all-technologies vacuum pump specialist Power generation, sustainable energy and energy management 20 Legendary engine support and an African vision MechChemAfrica visits Cummins Southern Africa and talks to Meshach Kwegyir-Aggrey; Racheal Njoroge; and MD,Thierry Pimi about its engines in Africa. 22 SA ranks 10 th for general RE investment conditions High-Tech Processing, a local brewery, beverage, alcoholic and soft drink plant solutions provider, chose Endress+Hauser to join with them to offer an international beverage manufacturer the most efficient and cost-saving operation possible. 33 Six new FMCW radar level transmitters 35 AI in the oil and gas sector Environmental, waste management and cleaning technologies 36 Bioremediation in the petrochemical sector GK-IT Environmental Services, a local leader in bioremediation and environmental products, offers risk-averting solutions, particularly for hydrocarbon-contaminated soils in the petrochemical and oil refinery sectors. Innovative engineering 42 Whereto for thermoelectrics? After several years of excitement, investment and growing interest in thermoelectrics and its potential in energy harvest- ing applications, Harry Zervos, principal analyst for IDTechEx in Florida, USA, calls for a clearer look at what’s hype and what’s reality. REGULARS 2 Comment: Grid parity now favours renewable investments 4 On the cover: BMG World revealed BMG held two open days on September 14 and 15 to showcase and unveil its expanded and refurbished BMGWorld facility in Droste Park, Johannesburg: the culmination of a supply chain re-engineering strategy, which began nearly 10 years ago. 6 SAIChE column: What kind of engineering graduates are required today? 38 Product and industry news 44 Back page: Virtual technology for blast training 25 Containerised power solution drives Mali mill 26 Dry-type transformers for modular sub-stations 29 Drive technology seeks to optimise energy requirements Petrochemical, oil and gas 30 Smarter cider production

P U B L I C A T I O N S CR O WN

Published monthly by Crown Publications cc Cnr Theunis and Sovereign Streets Bedford Gardens 2007 PO Box 140, Bedfordview, 2008 Tel: +27 11 622 4770 e-mail: mechchemafrica@crown.co.za www.mechchemafricamagazine.co.za Editors: Peter Middleton e-mail: peterm@crown.co.za Glynnis Koch e-mail: glynnisk@crown.co.za Advertising: Brenda Karathanasis e-mail: brendak@crown.co.za Design: Darryl James Publisher: Karen Grant Deputy publisher: Wilhelm du Plessis Circulation: Karen Smith The views expressed in this journal are not necessarily those of the publisher or the editors. P U B L I C A T I O N S CR O WN P U B L I C A T I O N S CR O WN 2015/02/10 01:17:09PM

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Front cover: BMG Lauren Holloway +27 11 620 7597 laurenhy@bmgworld.net www.bmgworld.net

September 2017 • MechChem Africa ¦ 1

Grid parity now favours renewable investments

T he UK media is currently reporting ‘ a huge boost for renewables as offshore windfarm costs fall to record lows’. In The Guardian , the Liberal Democrats and The Green Party are quoted as saying that ‘the results should sound the death knell for Hinkley Point C’, the nuclear plant to be built by France’s EDF and its Chinese partner, CGN, using Areva’s EPR technology. Wind turbine bid prices in the UK were expected to be at record low levels of somewhere between £70 and £80 per MWh, already below the agreed £92.50 bid for Hinkley Point C. In September 2017, however, two new windfarms – the Hornsea 2 project off the Yorkshire coast and the Moray offshore windfarm in Scotland – secured guaranteed prices for their power of £57.50/MWh from the UK government, well below the agreed nuclear bid price and half of the price being awarded to new offshore windfarms just two years ago. Denmark’s Dong Energy and Spain’s EDP were winning bidders at £57.50/MWh for Hornsea 2 and Moray offshorewindfarmprojects, respectively, while ahigher bidprice at £74.785/MWhwas accepted from Germany’s Innogy for a project off the Lincolnshire coast at TritonKnoll – this to reflect its one-year earlier delivery date in 2021/22. These bid prices translate intoR0.97 andR1.27 for wind and R1.57 for nuclear at a R17/£ exchange rate. Wind bid prices for our own REIPPP programme are even more dramatic: For onshore wind proj- ects, the average price that Eskom will pay IPPs has dropped from R1,51/kWh in Bid Window 1 to R0.62/kWh from preferred bidders for the latest Bid Window 4 projects. Similarly for PV, which started from a high of R3.65/kWh and was also down to an average of R0.62/kWh by the end of Bid Window 4. Following the results of the first Coal IPP Bid Window 1 in October last year, the CSIR’s Tobias Bischof-Niemz and Ruan Fourie of the CSIR’s Energy Centre decided to consolidate the achieved tariffs for electricity from IPPs. Their analysis is summarised in a presentation called Cost of new power generators in South Africa: Comparative analysis based on recent IPP announcements . A clear conclusion is that as a ‘consequence of renewables cost reduction for South Africa, solar PV and wind are 40% cheaper than new baseload coal today’ – R1.03/kWh for coal and between R0.56 and R0.62/kWh for wind and PV. Also, as part of the analysis, Bischof-Niemz and Fourie ‘levelised’ the high capacity factor Eskom new-build costs for Medupi and Kusile – R1.05 and R1.16 per kWh, respectively – and baseload nuclear

– R1.20 to R1.30 and R1.17 if using low-capex tech- nology such as Rosatom’s. We include an article about the Allianz Climate and EnergyMonitor 2017 in our Power generation, sustain- able energy and energy management feature for this issue, inwhich South Africa emerged 10 th among G20 countries for general renewable energy investment conditions and 12 th for its investment attractiveness. But while we have been steadily increasing our renewables capacity through the REIPPP programme and, consequently, we have a high presence of leading renewable energy businesses, our investment attrac- tiveness index has dropped from45 to41between the 2016 and 2017 reports. Also, our renewable investment needs ‘for creating a Paris Agreement-compatible and climate-resilient power infrastructure’ based on the combination of absolute 2017 investment needs, investment needs relative toelectricity consumption, and the vulnerabil- ity of electricity supply in2017, are the secondhighest of all G20 nations, with only India requiring more. The report’s ‘insight’ into SouthAfrica’s score sum- mary acknowledges that South Africa has a national strategy to tackle climate change ‘but the ambition level is relatively low and there is no existing plan to decarbonise the electricity sector’. Andon theREIPPPprogramme, it says: ‘the current auctioning system is insufficient to create a level- playing field for renewables compared to fossil-fuel electricity infrastructure’. The World Economic Forum’s Renewable Infrastructure Investment Handbook: A Guide for Institutional Investors , published in December 2016, cites twodevelopmentsmaking investing in renewable energy more attractive. First, renewable infrastructure now exhibits size- able investment potential –anadditional US$1-trillion in annual renewable infrastructure investment is needed by 2030. Second, renewable energy technology, especially solar and wind, has made exponential gains in ef- ficiency in recent years, enough to achieve economic competitiveness and, inan increasingnumber of cases, grid parity. ‘By 2020, solar photovoltaic is projected to have a lower LCOE (levelised cost of energy) than coal or natural gas-fired generation throughout the world,’ the Forum report states. Grid parity is no longer an excuse to block the advancement of renewables; renewable energy in- vestment now makes financial sense. With investors lining up to develop independent plants, why are we so reluctant to open up the market? q

Peter Middleton

MechChem Africa is endorsed by:

2 ¦ MechChem Africa • September 2017

BMG World revealed BMG, part of Invicta Holdings Limited, held two open days on September 14 and 15 to showcase and unveil its expanded and refurbished BMG World facility in Droste Park, Johannesburg. “The reveal of BMGWorld is the culmination of a consolidation and supply chain re-engineering strategy, which began nearly ten years ago,” says managing director, Gavin Pelser.

T he BMG World facility in Johan- nesburg consolidates the company’s efforts towards being a leading distribution and engineering facil- ity in Africa. “The company’s R400-million investment to upgrade the existing Droste Park facilities in Johannesburg transforms the facility into a leading-edge distribution centre and centralises functional and support operations onto a single site,” says Pelser. “Through this rationalisation initiative, BMG strives to achieve cost optimisation and to improve regionalised branch office systems, thereby enhancing customer service capabil- ity,” he says, adding further: “The BMGWorld facility reflects thecompany’s ability tosupply world class integrated engineering solutions throughout Africa.” BMG marked the official opening of the recently upgraded ‘BMGWorld’ distribution and engineering facility in Johannesburg by hosting a two-day event, which included site tours, product exhibits and working demonstrations showing how BMG inte- grates its vast product range and extensive technical services into tangible operational efficiencies. Thenewfacilities containover 308000m 3 of warehousing and more than 300 000

line items of product. This enables BMG to continue to provide high levels of operating efficiencies and todeliver services in linewith continued growthof the business. Customers now have greater than ever accessibility to BMG’s products, through more than 130 BMG branches and a wide distribution net- work in South Africa and across borders into Swaziland, Zambia, Botswana, Mozambique, Namibia, Tanzania and Ghana. BMG’s pledge to service excellence is achieved by constantly assessing market requirements and by expanding the com- pany’s solutions’ services, product ranges and branch networks to meet demand. The company has concluded a number of acqui- sitions and secured the exclusive supply, service and distribution agreements with some of the world’s most respected manu- facturers of quality branded engineering components. The range now encompasses bearings, seals and gaskets, power transmission com- ponents, drives, motors and materials han- dling components. Also in BMG’s extensive product portfolio are hydraulics from BMG Hydraulics and pneumatic systems, fasten- ers and tools, as well as valves, filtration and lubrication systems.

Reliability engineering BMG’s technical resources centre focuses on keeping plant in full productive output by ensuring mechanical reliability of plant and machinery. The technical resources team partnerseachcustomertoensuredependable solutions – fromthe initial design concept and specification all theway through tomanufac- turing, quality control, commissioning and support of equipment in use. BMGWorld is also home to field services. A team of mobile technicians provides spe- cialist skills, complementing the company’s workshop maintenance capability, to ensure highest-possible levels of plant reliability. Specialist services include installation, ad- justment and maintenance of components, shaft and pulley alignment, balancing, oil sampling and analysis and critical equipment inspections and lubrication schedules. BMG also offers technical supervision and on-site quality checks. Maintenance training and fault diagnosis also form an important part of BMG’s field services. BMG’s value-enhancing services

BMGWorld is also home to field services, a team of mobile technicians that provides specialist onsite servicing skills.

The expanded BMGWorld facility houses an advanced manufacturing centre and engineering workshop where complete drive trains can be assembled.

4 ¦ MechChem Africa • September 2017

⎪ Cover story ⎪

On September 14 and 15, 2017, BMG marked the official opening of the recently upgraded ‘BMG World’ distribution and engineering facility in Johannesburg.

provide measurable production efficiencies, whichmeancompetitiveadvantageandprofit maximisation in all industries. Functional operations at BMG World BMG World’s product warehouse and dis- tribution centre houses the entire product range, a highly advanced manufacturing centreand thegeneral engineeringworkshop. There are also specialist assembly and repair workshops for drives, conveyors, hydraulics and pneumatics, as well as electric motors, electronics, gaskets, lubrication systems and filtration. BMG has invested in the latest materials handling equipment, including high bay reach trucks, to optimise volumetric efficiency. Special machinery at the new facility includes eight dock levellers that will handle approxi- mately 120 containers a month. BMG is committed to providing 24-hour customertechnicalsupportforproductionef- ficiencyand reliability throughoutAfrica. This is enhancedby advanced technical anddesign support across all functional disciplines. q

BMGWorld’s assembly workshop also offers conveyor belt splicing services for all the leading conveyor belt manufacturers. Combined with constant training and modern evaluation techniques, conveyor operators can be assured that their belts will be spliced correctly to maintain the belt warranty.

As well rotary shaft seals, O-rings, hydraulic, pneumatic and mechanical seals, custom manufactured seals and gaskets are made to requirements in a wide variety of materials in BMG World’s strategically located CNC specialist machinery workshop. A full range of sealants and adhesives from global brand leaders is also available.

The new distribution facilities contain over 308 000 m 3 of warehousing and more than 300 000 line items of product.

A regenerative load test rig allows 30 000 Nm/200 kW drive trains to be tested while drawing less than 15% of the motor power from the municipal grid.

September 2017 • MechChem Africa ¦ 5

In the current ‘#FeesMustFall’ climate we’ve decided to open up a discussion around issues related to higher education in South Africa. Here is an opinion piece by Wolf Bernhardt, honorary senior lecturer at the University of KwaZulu-Natal, who has been a member of SAIChE for over 20 years. Please note that this is the opinion of the author and not necessarily of the Institution. What kind of engineering graduates are required today?

O btaining a degree, which is pre- sumed to be a requirement for becoming a professional, is a very expensive process. In terms of return on investment, the graduates entering theprofessional worldneed to contributeval- ue commensurate with the salary they earn. Many senior executives who approve the recruiting of new graduates, express disap- pointment in the value these new graduates bring to their organisations. After years of mentoring and contribution of significant resources, the graduate frequentlymoves on to ‘greener pastures’. Educators keep asking what kind of skills their students need to acquire to be valuable in the working world. Worldwide there has been a restructuring of engineering curri- cula around ‘graduate attributes’ in terms of

professional practice? Indeed, what kind of challenges do professionals need to resolve andwhat competencies are required todo so? Some of the following points highlight the realities of life today: 1. We work in a technologically complex world where many sophisticated tools, software programmes and machines per- form difficult, multistep functions. 2. Issues that require professional inter- vention are multidimensional, impacted by economic, societal, ethical, techno- logical, political, environmental and other pressures. 3. Change takes place at a rapid rate andpro- fessionals need to understand the change taking place and how it is likely to affect their organisation. 4. Decisions must frequently be made

measurable criteria studentsmustmeet tobe awarded their degrees. Just someof the graduate attributes – also called exit level outcomes – articulated in the Engineering Council of South Africa (ECSA) document E-02-PE are as follows: • Problem solving. • Application of scientific and engineering knowledge. • Engineering design. • Investigations, experiments and data analysis. • Engineering methods, skills and tools – including Information Technology. • Professionalandtechnicalcommunication. But does the definition of ‘graduate attri- butes’, and the assessment of their achieve- ment, go far enough to define which people can deliver the type of work required for

SAIChE IChemE’s national AGM The SAIChE IChemE AGMwas held on the 20 April 2017 in Johannesburg. The then president, Dawie van Vuuren, welcomed attendees, relayed apologies and the minutes from 2017 were approved. Van Vuuren thanked the council members, the executive committee and the secretariat of SAIChE IChemE for their contribution to the Institution as well as for their effort towards helping compile the annual report. This reportwas presented to the attendees at the AGM. The Silver Medal Awards for 2016’s top graduating Chemical Engineering students from South African Universities were: H Marais of UP; S Ditlhobolo of UJ; A M Da Camara of NWU; TD Pons from UCT; S Madhi of WITS; S Pillai of UKZN; WC Ruwona from CPUT and I Sielinou Ngankam of TUT. The meeting ended with associate pro- fessorCraigSheridanacceptingtheposition as new president.

even more with her command of the facts when answering questions after the talk. As usual, therewas a congenial atmosphere with old regulars to the meeting mingling with some fresh faces. The newly constituted SAIChE IChemE Gauteng committee members are: Chair, Carl Sandrock; Vice Chair, Danielle Bearman; Secretary, Doctor Tshikotshi; and Treasurer, Linda Jewell; Public Relations, Zita Harber and Qasim Fakir; Catering, John Bewsey; IChemE Contact, Nirvanna Ramparsad; and members without port- folios include Shaan Oosthuizen, Michael Daramola and Celo Mausse. q Megan Hardwick, Leigh Pearce and Danielle Bearman at the Gauteng branch AGM.

We would like to thank everyone for attending the AGM, and encourage our members toparticipate in their local branch activities. Gauteng Branch AGM The 2017 Gauteng branch AGM was held directly after the national AGMat the same venue. This arrangement worked very well and allowed interestedmembers to attend both events. The affairs of the AGM were handled swiftly, with our financials in good order anda strong committeeholding regu- lar events. The speaker,Mariette Liefferink, held the audience in rapt attention for the 30minutes she spokeon thewater situation in South Africa, but impressed everyone

Dawie van Vuuren welcomes the 2017 National president, Craig Sheridan.

6 ¦ MechChem Africa • September 2017

⎪ SAIChE news ⎪

Therearemanytoolsavailablethatwillgive answerstotechnologicalproblems,butthe professional needs the ability to check if the proposed solutions are realistic. • Lateral thinking – when confronted with a problem that is unfamiliar to the person, the temptation is to go back to the text- books and get the relevant knowledge/ information. But it is often necessary to get a wider perspective before engaging in this specialised task. One way to train oneself to think laterally is to talk to col- leagues about the problem before trying to solve it on their own. This also relates to overcoming the ‘not invented here’ syndrome andawillingness toaccept solu- tions from external sources for problems in the organisation. • Negotiation skills – a lot of work in the professionalsphereinvolvesastutenegoti- ating skills that enable theperson toobtain what he does not have fromsomeonewho has it, at an affordable price. • Criticalthinking–thisinvolvesthecapacity tocarefullyanalyseproposedsolutionsand interrogate the assumptions underlying thesesolutions,aswellasdeterminingtheir likelihood of providing feasible answers. • The ability to access relevant and appro- priate information – we are blessed with anabundanceof published informationvia the Internet and other electronic media. Theprofessional needs the capacity tofind information that is relevant andapplicable to the problems in hand. You may argue that the above attributes can only be acquired through extensive exposure to and having practice in resolving real life situations encountered in professional prac- tice, which take years to develop. What the educator needs to ask is: “Can I, who have the responsibility to prepare the aspiring professional tomake positive contri- butions in this complex environment, shorten this periodof development, so that the gradu- ate can start becoming part of a functioning team as soon as he joins this team?” A way to stimulate this kind of develop- ment is to set tasks that require students to exercise all the attributes described. Assignments rooted in the real world would require students to do extensive research to craft feasible solutions. To stimulate lateral thinking, theaimsof theassignmentsmust not be over-specified. The students themselves must choose appropriatemethodologies. For this, creativity and critical thinking are re- quired. Insisting that studentswork in groups gives thempractice innegotiationwhere they decide which aspects of the assignments are done by which members of the group. Careful definition of the criteria on which the assignments will be assessed will require the students to pay close attention to detail.

quickly, otherwise opportunities are lost to competitors. 5. Clients expect guaranteed results, so the solutions or services provided by profes- sionals need to fully satisfy clients’ needs. This requires that the professional under- stands in detail what the client wants. 6. Because of the speed of communication, clients expect instant service. 7. The professional world is characterisedby pressurefromvariousquarters–superiors requiring specified tasks, subordinates asking for information, the professional needing to access reliable and appropri- ate data and techniques, checking up on service providers. In this environment, burnout canoftenoccur, with severe, long- term consequences. 8. The amount of information available on any subject is vast. To function effectively in this world, it is necessary to prepare the student aspiring to become a confident professional to gain at least an adequate level of performance in all the spheresmentioned above. The traditional university curricula, which devoted 70 to 90% of the learning activities to technologi- cal competence, understandably fail to meet these rigorous demands. As an educator, I am askingmyselfwhat contribution I canmake to achieve this lofty ideal. Maybe a starting point is to try and define what kind of person – rather than what skills sets – one would like to see developed during theyearsatuniversity.Theword ‘attribute’ad- equately describes the characteristics I would look for when considering employing a candi- date for a position as a professional engineer. The following are attributes that, in my opinion, are essential for functioning ad- equately in a professional work environment: • Logical thinking – the ability to define causes and predict results in a variety of situations. • Self-discipline and self-motivation, which are necessary to pace oneself according to the tasks required in relation to their deadlines. • Attention todetail – it is necessary to think practically and anticipatewhat conditions need to be in place for the successful implementation of an idea. This includes the ability to identify errors in calculations or data collected. • Judgement – the ability to make sound business decisions based on the available information. • Creativity – professionals need the ca- pacity to think of new ways of tackling problems instead of merely copying what other people have done before. • Analytical skills – these include the capac- ity to check the results of calculations to ensure that these results are plausible.

SAIChE IChemE SAIChE Board members: President: C Sheridan Imm. Past President D van Vuuren Honorary Treasurer L van Dyk + Vice President: Honorary Secretary: EMObwaka Vice President: D Lokhat Council member: JJ Scholtz Council member: AB Hlatshwayo Council member: K Harding Council Member: M Low Council member: BK Ferreira Council Member: HMazema Council Member: MChetty Council Member: A de Bondt Council Member: MMabaso Council Member NN Coni Member (co-opted): MD Heydenrych Chair Gauteng: C Sandrock Chair KZN: D Lokhat Chair Western Cape: HMazema Contact details SAIChE PO Box 2125, North Riding, 2162 South Africa For the educator, the challenge is to set assignments that are sufficiently challeng- ing and can only be successfully executed by students who have a clear understanding of the problem and who exercise the attributes that professionals use every day. Having said this, it is acknowledged that it is virtually impossible to simulate a work environment with all its distractions and demands at a university. Industrial work experience while the students are studying would help in the development process. Acknowledgement The author wishes to acknowledge the valu- able feedback givenandadditional comments made by Iain Kerr, a colleague in the School of Chemical Engineering, UKZN, on the draft version of this article. Wewould like toknowwhat your thoughts are, so please email the editors of ‘MechChem Africa’ at mechchemafrica@crown.co.za. q

Tel: +27 11 704 5915 Fax: +27 86 672 9430 email: saiche@mweb.co.za saiche@icheme.org website: www.saiche.co.za

September 2017 • MechChem Africa ¦ 7

MechChemAfrica visits the new expanded premises of Integrated Pump Rental (IPR) and Integrated Pumps Technology (IPT) and talks to IPR’s managing director, Lee Vine. From pump rental to sales: the solution-driven approach

W ith 13 years previous experi- ence in the pumping industry – as an applications engineer on the dewatering side; head of a mining and minerals pumping division; and as a rental division manager – Lee Vine has beenwith IPR since its inception in 2015. “With all my experience on mines I saw a need for a solution for silted-up lined ponds. This sparked an idea for my own dredge, which we started to design as soon I joined IPR,” Vine reveals. The end result is IPR’s proprietary Slurry Sucker, which has achieved instant success as arentalsolution.“OurSlurrySuckermeetsthe need to clean lined process ponds, removing the accumulated slurry deposits from the pond floor,” Vine says. Notably, theSlurrySucker systemdoesnot require submersible pumpswith cutter heads to agitate the settled sludge, which tend to damage the liner. “We pump water through the dredge head to disturb the sludge, and we immediately pump the slurryup andout of thepond. Thismeans thatwe can cleanapond while it is online, since the disturbance is con- tained in the region immediately surrounding thedredgeheadandall of thedisplaced slurry

is evacuated immediately,” he explains. Describing the components of the system, Vine says that two 18 kWdewatering pumps located in front and at the back of a floating pontoon are used to drawwater from the top surface of the pond. This water is pumped through front and back jetting bars to agitate the slurry on the pond floor. “A submersible slurry pump suspended underneath the pontoon is then used to evacuate the disturbed area, pumping the slurry throughfloating hoses out of thepond,” Vine tells MechChem Africa . “To move the Slurry Sucker across the pond, we use a transferring rope systemwith winches, which pull the system fromone side to the other. After each pass the height of the suspended slurry pump is automatically dropped a further 100 to 200 mm, and once the ‘cut’ is completed, the tensioningwinches are moved across a further two metres and a new cut line is started,” he says, adding, “this design suits ponds of 5.0 to 6.0 m deep that are, typically, 150 by 150 m in area.” Vine says that, at many of the process cir- cuits onourmines, due to lackofmaintenance and/or incidents such as thickener break- down, “I have seen the accumulated silt from

process water ponds being fed back into the processing stream, with costly consequences. Our Slurry Sucker rental solution is ideal for preventing that from happening, safely and reliably, without having to shut down the processing plant or having to invest in new equipment,” he points out. “And for bigger ponds, or where the pond is caked with dry thick slurries with too little surfacewater,wecancleanthepondusingour hydro-mining solution called Slurry Blaster. This involves taking cleanwater fromanother pond or source and then blasting the slurry material towards the slurry to create enough suspension topumpoff the slurry. But this has to be done offline,” says Vine. “Both of these rental options are 100% turnkey solutions. We do not simply hire out equipment and deliver to site. Following a technical onsite consultation, we supply all of the equipment and accessories needed to clean the pond in question, then we install it and oversee the entire cleaning process, which can take months. We then leave with our equipment after the job is done,” he assures. IPR took responsibility for the Sykes brand in 2016 with immediate rental success. “We have only been the exclusive Sykes agents for a little over a year and we have already filled our rental fleet with Sykes solutions. When people rent our equipment and seehoweffec- tive and reliable it is, they find it much easier to justify a purchase,” he suggests. Vine cites a recent success in the coal industry involving Sykes CP150s. “Following a rental period from November 2016 to February2017, our clientswere so impressed that they bought eight units identical to those on rental. These pumps are from the 6-inch Sykes Contractors Pump (CP) range. They have a shut off head of around 70 m and on the right sideof the curveflows of up to120 ℓ / sec can be delivered,” he says. Also included in the Sykes rental offering fromIPRare theXH(extra-highhead), theHH (high-head), the MH (medium-head) and the SW (sewage) ranges. “The CP range is very versatile. It gives a good balance between flow and head, but we can offer a best-fit pump for every conceivable pit dewatering Diesel-powered pit dewatering from Sykes

Designed to clean lined process ponds, the Slurry Sucker system does not require submersible pumps with cutter heads to agitate the settled sludge and, due to the design and engineering of the dredge head, it is able to operate while the pond is online.

8 ¦ MechChem Africa • September 2017

⎪ Pump systems, pipes, valves and seals ⎪

application, with heads of up to 210 m from the XH range and pump flows, at nominal heads of over 500 m. “The Sykes CP150 can empty the 2.5-mil- lion litre Olympic Swimming pool in four hours, while the MH300, built for high flow and long pipe runs, cando in it inone hour and 20 minutes,” Vine notes. The key advantage of Sykes pumps is that the impellers, wear plates andall the internals of the wet end are make in stainless steel as standard. “InSouthAfrica, we are seeing a rise inacidminedrainageandthepHlevelsofmine wastewater are continuously falling. Stainless steel internals are increasingly necessary to combat corrosion in this tough environment. “Also, Sykes pumps have an excellent and highly reliable Venturi-based self-priming system with no moving parts. This system allows the pumps to prime, run in snore con- ditions, run dry and automatically reprime, without any damage to the pump,” Vine tells MechChem Africa . Where electrical power is readily available, IPR has a full range of drainage solutions available: Grindex dewatering pumps from 1.0 kWto90 kW; Grindex sludge pumps from 2.0 to 10 kW; as well as the Faggiolati range of submersible electricwastewater, transfer, sewage and chemical pumps in the 5.7 kW to 270 kW power range. “With full stainless steel pumps available, Faggiolati pumps offer robust solutions for arduous and corrosive conditions found on mines, construction sites and water treatment plants,” Vine says, adding that Faggiolati pumps are also start- ing to be used in the food industry for pastes and food pulp. “But we are not a simple supplier of pump rental units,” he reiterates. “We supply full solutions that include all of the accessories necessary to get the pumps working quickly andeffectively. If a control panel is needed, we have portable units ready for immediate in- stallation andwe supply hoses, hose flotation devices and all of the connectors and fittings needed – everything from the problem to the discharge point,” he points out. “We pride ourselves on our service suc- cess. We focus fully on our clients and their problems andapplications. Client satisfaction is our number one priority. Second is quality. Drainage sludge and wastewater solutions

Sykes diesel powered dewatering pumps are also now part of the rental offering from IPR. These include the XH (extra-high head), the HH (high head), the MH (medium head); the CP (Contractors Pump); and the SW (sewage) ranges.

Grindex Maxi L pumps being used to check the depth of the clean water dam. IPR has Grindex dewatering pumps from 1.0 kW to 90 kW and Grindex sludge pumps from 2.0 to 10 kW available for rental.

As a rental company, high-reliability is critical, so we develop and offer dewatering, slurry and sludge solutions usingonlyqualitybrands and components. This combination makes our offering difficult to better,” Vine believes. “The approach spills over to the sales side of our business, through IPT. We offer the

same high levels of service and support and the same high-quality product range to our customers. “Also, by adopting a rental solutions in ad- vanceofmaking apurchase, customers canbe certain that theirmoneywill bewisely spent,” Vine concludes. q

September 2017 • MechChem Africa ¦ 9

Pumping systems 101

What are pressure gauges actually telling us? Harry Rosen discusses the very important role of pressure gauges: why they must to be accurate; the need to measure absolute pressure on the suction side, and how to determine what is happening to a pump from the suction and discharge pressure gauge readings.

I n our pump training courses, trainers frequently harp on about the impor- tance of installing pressure gauges on the pumps at factories or plants. One trainer compares pumps without gauges to driving a motor vehicle without an instru- ment panel – you have no idea how fast you are going, what revs the motor is doing, or whether the engine is running hot. Pressure gauges are inexpensive, generally easy to install if pressure tappings exist, and they are critical to understanding the operation of your pumps.

Now that all the pumps in our plant have pressure gauges, on both the suction and discharge sides, what do we do with this in- formation? Howwill it help us to operate our pumps more efficiently and reliably? Onceagain, aswithmost questions related to pumping systems, the answers are not simple. Some of the uncertainties are: • Are the gauges accurate? • Is the suction gauge correct for the application? • How do we interpret the discharge pres- sure reading?

and compare this with the reading off the installed gauge. In principle, one needs to be able to trust the reading off the gauge. What does the suction pressure actually mean? The suction pressure, together with the discharge pressure, is required to calculate the total dynamic head of the pump. In most applications it will be significantly lower than the discharge pressure of the pump and so the accuracy of the measurement is not that important. As an example, a typical cooling water pump has 20 kPa suction pressure and 600 kPa discharge pressure – do we really need to measure the suction pressure ac- curately? Even a 50% error in the suction pressure reading (10kPa)will lead to less than 2%error in calculating thepumphead. Sowhy then is it so important to ensure our suction pressure gauges are accurate? Themostimportantfunctionofthesuction gauge is not to calculate the pump head, but to identifyNet Positive SuctionHead (NPSH) problems that could lead to the pump cavitat- ing. We do not want cavitation in our pumps, as it tends to destroy their impellers, casings, bearings and mechanical seals within a very short period of time. To prevent pumps from cavitating, we need to ensure that the NPSH required by the pump, which is easily read off the pump curve, is lower than the NPSH available in the system. How do we find the NPSH available in the system? We read it off the suction pres- sure gauge. However, we know that NPSH is measured in absolute pressure so the suction pressure gauge must be capable of measuring this. To illustrate the above, assume our pump has an NPSHr of 5.0 m (as read off the pump curve). There is an installed gauge just before the suction of the pump and we will look at two different operating conditions with two different types of gauges. Let us assume we are at sea level where the atmospheric pressure is 101 kPa. Table 1 below shows two scenarios. We know that available NPSH must be higher than the NPSH required by the pump to ensure the pump does not cavitate. It is clear from the example in Table 1 that going

The general state of gauges on our pumps

I have been in numerous plants where the gauges installed on pumps are in a very sorry state. Blocked pressure tappings,

gauges filled with water, broken dials, and out of date ormissing calibration certificates are just some of the obvious signs of dysfunctional instrument that cannot give an accu- rate reading. Blockages in the read-

ing pipe and isolation valves not fully open exacerbate the problem. Evenbrandnew looking gauges with clear displays may not be reading accurately. Pressure gauges need to be recalibrated on a regular basis, at least once a year. This should be done by removing the gauge and sending it off for recalibration, but a pragmatic alternative is to install a calibrated gauge and take a snap shot reading while the pump is operating,

Figure 1: A compound pressure gauge showing the onset of cavitation only starting at gauge pressures below -40 kPa (-0.4 bar). A standard pressure gauge would still be showing 0 kPa and would be useless in this application.

Gauge Pressure

Absolute pressure

No Type of gauge

Is the pump cavitating?

Normal pressure gauge Compound pressure gauge Normal pressure gauge Compound pressure gauge

0 kPa

0-101 kPa

We don’t know

1

-32 kPa 69 kPa (7.0 m) No. We have a margin of 2.0 m

available between NPSHa and NPSHr

0 kPa

0-101 kPa

We don’t know

2

-62 kPa 39 kPa (4.0 m) YES. NPSHa in the system is less than that required by the pump

Table 1: Two scenarios for determining whether a pump is cavitating due to insufficient NPSH.

10 ¦ MechChem Africa • September 2017

⎪ Pump systems, pipes, valves and seals ⎪

Figure 2: A pump curve showing different measured operating points, and their effect on the pump efficiency and reliability. to the trouble of fitting a standard pressure gauge on the suction of the pump is a waste of time, as it does not show us when there is a problem. Either a compound pressure gauge – that can go negative – or an absolute pressure gauge must be used. What does the discharge pressure actually mean? Now that we have ensured the gauges are the correct type, and re- cently calibrated sowe are confident of their accuracy, what exactly are we measuring? We have seen how to use the suction pressure gauge to check on NPSHa and whether the pump is cavitating. But what about the discharge pressure? For the same pump above, we measure a discharge pressure of 550 kPa. Is the pumpOK? Is it running efficiently and reliably?What happens if the pressure rises to 650 kPa or drops to 400 kPa? Does that mean there is a problem? Unfortunatelywe are used to standalone instrumentation in the field, which tells us all we need to know, based on the single value being read. A vibration sensor reads 3.5 mm/s, and we know that anything less than 6.0 mm/s is OK and, if it is above 10 mm/s, then we should immediately do something. Monitoring the temperature of bearings or the cooling water to the mechanical seals quickly identifies a problem when the temperature rises above a preset alarm level. There is however no ruleof thumb that states that if thedischarge pressure of a pump is less than a certain value, then everything is OK. Some pumps have a discharge pressure of 8 000 kPa, which for a 10-stage mine dewatering pump is normal. Some pumps have discharge pressures of 80 kPa, a high flow axial flow pump as an ex- ample. The problemwith measuring the pump’s discharge pressure is that the reading on its own is insufficient. We need to relate it back to the specific pump curve – and for that we not only need the discharge pressure, but also the suction pressure. It is the total dynamic head developed by the pump that is im- portant, because this will tell us where the pump is operating on its performance curve, and how far away it is from the Best Efficiency Point (BEP). The pump could be running far to the right of BEP, and suffering from cavitation. Or the pump could be running far left of BEP, in an area of high recirculation leading to lower efficiency, in- creased wear on the impeller and casing, and reduced bearing and mechanical seal life. Measuring suction and discharge pressure is only the first step towards improving theoperationof thepump. Inmynext Pumps 101 column, I will discuss what to do with this information. q

September 2017 • MechChem Africa ¦ 11

⎪ Pump systems, pipes, valves and seals ⎪

Verder Pumps South Africa stocks a variety of peristaltic pumps specifically designed to be used in mining. In this article, the advantages of adopting peristaltic technology for pumping mine slurries are outlined. Why pump slurries with a peristaltic pump?

F irst among the reasons for a switch to using peristaltic hose pumps is that they use lesswater. Hose pumps can circulate slurrywithSGs of 1.6 to 1.8, which corresponds to 60 to 80% solids content. The traditional centrifugal pump loses efficiency when the slurry SG reaches 1.3 (30% solids) or higher. With this limitation, slurry pumps have significantly higher process water demands. On a plant processing 75 t of ore per hour at 65% solids content, every time a hose pump replaces a process slurry pump, it saves over 1100-million litres ofwater per year, because at the same duty, the hose pump requires less than 25% of the process water required by the slurry pump. A second compelling reason to switch to peristaltic pumps is power use. On the same 75 t/h plant, with the thickener underflow duty at full flow, a Verder VF125 hose pump absorbsaround35kW,whereasaslurrypump needs over 70 kW: a saving of over 50%. This directly translates into reduced electrical requirements. Power rationing is a concern for many establishedmines. Onnewdevelopments the infrastructure costs to import power can be considerable and can also cause significant delays and generate considerablenon-mining environmental opposition. There is also a sig- nificant economic case! In the above example, the hose pump reduced annual operating power demand by over 210 MWh. Peristaltic pumps also increase downline efficiency and reduce overall plant size. Pulp density is critical to optimum plant perfor- mance and an increased solid content can reduce the number of post thickening filter stages, saving on the initial capital cost and

reducing the footprint of mineral pro- cessing operations. They also reduce the overall en- vironmental impact of a mine. Many mineral recovery processes use cya- nide-based leaching techniques, es- pecially where gold is the key mineral. Cyanide has many adverse environmental consequences, including polluting the land surroundingtheplant,contaminatingaquifers and decimating life in watercourses. A traditional dosing solution is generally adopted for leaching, usingprogressing cavity pumpswith integral seals that require regular replacement. The sealson thesepumps repre- sent a real leakage risk. Peristaltic pumps are seal-less and consequently, posemuch lower contamination risks. Peristaltic pumps also have a very gentle pumping action, which is ideal for bio-oxida- tion techniques. This gentle actionminimises damagetofragilecellculturesinbio-oxidation reaction techniques. One such requirement, theBiox (R) process, uses a live culture to free gold fromsulphide ores, reducing cyanide us- age and improving process yields. The peristaltic pump’s low shear pumping action alsomaintains particle size, minimising the use of flocculent and other process re- agents. Conventional high shear technologies such as progressive cavity or screw pumps significantly increase reagent usage increas- ing operating costs and raising post process- ing costs due to flotation reagent carryover. Similarly, residual reagent can increase the waste remediation cost or increase the envi- ronmental damage fromtailings dams or their resultant groundwater pollution. From a reliability perspective, peristaltic pumps use results in lower maintenance

Verderflex hose pumps for mines can pump slurries with higher SGs, more efficiently, safely and reliably because of the peristaltic principles they employ. costs, less downtime and minimal spares stock holding. Slurries are often acidic and/or highly abrasive.Consequentially,conventionalslurry pumps use impellers made from increas- ingly expensive and non-standard materials with service lives that are measured in days. Abrasion-resistant peristaltic pump hoses lower themaintenance costs associatedwith wear and corrosion. Longer service intervals and easy in situ servicing also reduce pump downtime. On a peristaltic pump, only the rubber hose is in contact with the pumped liquid and as the ul- timate rubber lined pump, service life is mea- sured in months, reducing pump downtime and, since the hose can easily be changed in situ , maintenancehours are similarly reduced. Corrosion-resistant hoses also eliminate the need for costly special metal impellers. To pump highly acidic slurries, hoses are made from several standard elastomers, each proven in the mining environment to withstand process chemicals and avoiding the use of expensive exotic metal impellers. Verder has been supplying pumps to the mining sector in South Africa for the past 15 years and is a brand synonymous with qual- ity and durability. By using Verder Peristaltic pumps for slurryapplications, productioncost and downtime can be significantly reduced, providingamore cost-effectiveandprofitable processing. q

September 2017 • MechChem Africa ¦ 13

KSB Pumps and Valves South Africa has engineered, manufactured and supplied sizeable contracts for advanced magnetic drive API pumps to refineries in Russia and Germany, where they are being used to pump potentially hazardous ‘goudron’ and ‘mazout’ products and Isobutane HF. KSB Pumps and Valves product manager, Jan van Vuuren explains. Locally manufactured API pumps for Europe’s refineries

L ocally developed KSB RPHmdp mag- drive pumps were selected for use in a refinery in Russia for their ability to completely separate the drive-ends from the wet-ends of the pumps, which are in contact with the dangerous materials being circulated. Instead, RPHmdp pumps use separate magnetic drives to power the impellors, which negates the need for the traditionallyusedAPI Plan53sealing solution on the pumps. The magnetic drive pumps require sig- nificantly less maintenance and are a safer option than the Plan 53 pumps, which are complicated and require pressure regulated seals on either end of the pump to prevent hazardous liquids from leaking, which could havedisastrousconsequences.Plan53pumps also require constantmanagement andmain- tenance to ensure that they are 100% sealed and operational at all times. Strict requirements KSBPumps andValves productmanager, Jan van Vuuren, says the 18 locally developed RPHmdp pumps supplied for the project do not require a shaft sealing solution and there- foredonot neednearly asmuchmaintenance nor supervision as the old type. “In the case of the Russian Samara Transneft Refinery project, the deal was awarded to KSB Russia on merit, based on the advanced nature of the pumps, quality of

support and maintain the pumps within a mission-critical environment. The pumps also needed to be specially manufactured to withstand extreme operating temperatures of between -70 ˚C and 380 ˚C, as well as to withstand pressures of up to 40 bar – as per API requirements. “This was vetted by our Russian counter- parts who conducted an in-depth inspection of our manufacturing facility in Germiston to ensure production of the highest quality would be met and that API standards were in place. In addition, KSB Russia’s represen- tative, Vladimir Dragonman, also needed to be satisfied that the South African operation would be able to provide full back-up and support for the pumps whenever required. Needless to say, we far surpassedhis expecta- tions and he went back to Russia more eager than ever to continue with the deal,” says Van Vuuren. Another key reason why the refinery, one of the largest of its type in the world, chose RPHmdppumpsisduetoitsgoodtrackrecord at a number of petrochemical companies throughout the world – including Sasol – where they are successfully used in place of the old Plan 53 pumps. In Russia and globally, KSB has also sold hundreds of standard-type RPH pumps to the petrochemical industry and these have proved to be well supported throughout their lifespan by the company. Working with Monel ThelocalmanufacturingfacilityofKSBPumps and Valves has also developed a specialised pump for the pumping of the highly danger- ous Isobutane with HF (hydrofluoric acid) on

behalf of another of the world’s refineries, PCK Schwedt. Thischemicalisregardedasoneoftherisk- iest materials on earth to pump and called for special engineering tomanufacturemagnetic drive RPHmdp pumps out of Monel, which is able towithstand the acidity of IsobutaneHF. “Monel is super tough and is so difficult to work with that few people anywhere in the world are prepared to even try. It is tough to drill, difficult to machine and takes hours to perform the simplest machining. However, here in South Africa and in our manufactur- ing facilities in Germany, we are able to work with it and have successfully manufactured the pump as specified. “When finished it will cost twice the price of a standardmagnetic drive pump as a result of the difficult manufacturing process, but this pales into insignificance if onewere to try and manufacture the pump according to the traditionally usedAPI Plan53, which requires double seals, pressure balanced valves and a number of other technical requirements to prevent thedangerous chemical from leaking. “By comparison, the RPHmpd pump only exposes the wet-end of the pump to the chemical and the drive-end is completely separated. This makes it safer and much more cost-effective thanPlan53pumps,” Van Vuuren argues. The popularity of magnetic drive pumps has been spurred by stricter requirements from TÜV and other verification agencies for seal-less pumps to be used in chemical and petrochemical plants where potentially hazardous materials are being handled. In addition, the pumps are easily serviced, do not need constant supervision and have wet- ends that are fully interchangeable with the company’s standard RPH pumps, making for commonality of spares and maintenance. “With European standards calling for seal-less pumps and the movement towards simplicity, reliability and durability in the petrochemical and other industries, we are confident that the KSB RPHmdp will become the de facto pump wherever potentially haz- ardousmaterials are required to be pumped,” concludes Van Vuuren. q

constructionand the long-term ability of our global group to

Locally engineered and manufactured, API RPHmdp mag-drive pumps from KSB Pumps and Valves South Africa are finding favour across the globe in the petrochemical industry.

14 ¦ MechChem Africa • September 2017