A pump efficiency test rig, designed and built by researchers based at the Flow Process Research Centre, was recently used to test the characteristics of sewage sludge and paper pulp waste fluids in Stockholm.

The centre, which is based in the Civil Engineering and Survey Department at the Cape Town campus, is tasked with researching problems that relate to the flow of industrial fluids.

The researchers have expertise in making precise measurements of the viscous characteristics (called rheology) of complex fluids, and then relating these characteristics to the flow of industrial fluids and pumping systems.

The test rig, which was shipped to Stockholm earlier this year, was used by the researchers to test the characteristics of these fibrous suspensions.

The team, Prof Rainer Haldenwang, Dr Veruscha Fester and Mr Richard du Toit recently returned from Stockholm, where they spent several weeks conducting tests.

Prof Haldenwang said: “It took us only two days to assemble the rig and to do the water tests, showing that the rig is truly portable, despite its physical size.”

He said the portability of the test rig and ease of reassembly stems directly from Mr du Toit’s unique modular design of the test loop and its support structures.

“Without him it would have taken much longer,” said Prof Haldenwang.

The team’s host and project partner in Stockholm, Dr Richard Holm, who works for Innventia, a paper pulp research institute, was also impressed that the facility was operational in such a short time.

A research facility at Hammarby Sjöstadverk in Stockholm, operated by the Swedish Environmental Research Institute and the Royal Institute of Technology, supplied centrifuged sludge.

Two types of sludge (lysed and unlysed) from another water treatment plant, were also tested to determine their viscous properties. In total, eight sludges and three concentrations of fibre suspensions were tested over a period of three weeks.

Prof Haldenwang said one significant achievement was finding the characteristic pump curve for fibre suspensions in laminar flow, which is a huge point of debate in this area of research and rarely obtained experimentally.

The project sponsors, which include the Swedish International Development Cooperation Agency and Tillväxtverket, a Swedish Agency for Economic and Regional Growth, were impressed by the amount of test work completed.

They were also pleased to witness the efficient pumping of very viscous slurries by centrifugal pumps at a much lower pumping power than is often the case in industry. The sponsors indicated that they would like to see the results implemented in industry.

Prof Haldenwang said the results of the tests are invaluable for further research.

He said they are now planning to conduct an audit of the type of pumps and energy usage in local sewage treatment plants, and to demonstrate how knowledge of the viscous properties of sludge can be used to monitor and control pumps for optimum use of energy.

By Candes Keating

Written by CPUT News
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29 of CPUT’s academically deserving students studying Civil Engineering, Building Surveying and Architectural Technology are the latest recipients of bursaries, each valued at R60 000.

The Construction Education and Training Authority (CETA), who support training, education and skills development in the construction industry is the donor of the funds, which total a whopping R1.74 million.

This is the latest agreement between CPUT and the various Sector Education Training Authorities (SETAs) brokered by the Advancement Department. Major donations in the form of bursaries, research and Work Integrated Learning opportunities have also been received from BANKSETA, (Banking and Micro-Finance SETA) AgriSETA, (Agricultural SETA), CATHSSETA, (Culture, Arts, Tourism, Hospitality and Sports SETA), CHIETA (Chemical Industries Education and Training Authority) and the Wholesale and Retail SETA (W&R SETA).

CETA may fund the students until they finish their courses, but are committing for one year at this stage. A continuation of donor funds will depend on the students’ performance and the availability of resources within CETA.

Female-focussed: A minimum of 40% of the CETA bursary recipients are women.

Coby Greef, Provincial Coordinator of CETA says he’s delighted to see so many female faces amongst the bursary recipients. The CETA has stipulated that a minimum of 40% of beneficiaries of the bursaries must be women.

“CETA is committed to providing a conducive environment for learning and artisan development, with a special focus on youth, women and our military veterans,” says Greef. ‘We’re working closely with institutions of higher learning to ensure quality learning to equip professionals and artisans with the necessary skills needed to build our nation.”

Written by Janyce Weintrob
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The motor vehicle manufacturing industry is one of the largest consumers of innovative textile materials.  

Cars contain enough textiles to cover the floor of a small apartment and textiles are in everything from car seats, seat belts, carpets, airbags and roof liners.

In total an average car may contain in the region of 40 m2 of textiles while other components like door panels, brakes and dashboards are made from composites which is a combination of textile fibre and resins (glue). The use of textiles continues to the car’s engine, the air and oil filters and even tyres.

Textiles are perfect for these components because they are versatile, cost effective, light weight and promote fuel efficiency. Natural fibres like cotton, hemp, flax, silk and wool are more readily available and a lot easier to process than the metals used in car manufacturing, thus making them essential in keeping manufacturing costs low.

“Textiles can be manipulated into various shapes with ease and the fibres used in them are light weight which makes for a lighter, more fuel-efficient vehicle. Also, by reducing emissions these textiles contribute to a healthier environment,” says Dr Asis Patnaik from CPUT’s Clothing and Textile Department.

Many of the innovations in car manufacturing can be traced to Formula One racing, where the more conventional use for textiles, in clothing, is also incorporated. The door panels in luxury vehicle are made from carbon fibre composites, which were first used in Formula One cars. The suits worn the by the drivers are also made from material that protects them from the high temperatures and pressures they are subjected to when racing.

“Textiles have a diverse range of applications in automotive, aerospace, manufacturing, building, medical, hygiene, packaging, civil engineering, protective clothing, agriculture and sports. It is a unique and exciting area, where many inter-disciplinary fields are working together in developing a better world,” adds Patnaik.

Written by Abigail Calata

Vice-Chancellor Prof Chris Nhlapo recently opened the new Navarre Residence at Wellington Campus, which is a 212-bed extension to the original residence, “with careful attention to the needs of the modern student crafted into the design”

In his opening speech, Nhlapo said: “It is then with a real sense of accomplishment that I stand here today to see the fruits of that hard labour completed. As the course offerings at the Wellington campus became more popular, the university quickly outgrew the traditional residences which had adequately serviced our student community for decades.”

Navarre Residence was built in 1927 and, much like now, “was constructed to provide additional student accommodation”. “Decades later, we still face a critical student housing crisis. But in Wellington, it was not as easy as simply building something bigger… We were restricted with the options available, and the heritage value of many buildings meant wholesale building works were not always possible,” remarked Nhlapho.

He added that, however, after years of due diligence, the funding and approval for the reconstruction of Navarre was finally approved and “14 months ago, we broke ground”.

In the rooms, the University has accommodation for single and double sleeper options, with the ablution and kitchen areas giving “a familial sense which elevates the living experience from simple dormitory life to one where you feel at home in your space”.

“We have also been mindful of using environmentally friendly building techniques like a cutting-edge roofing system, natural ventilation, and sun-screening options, all very useful if we consider the temperatures here in Wellington,” Nhlapo continued.

“I think you will agree that the result is a well-considered building which is sensitive to its environment and the needs of the students who will pass through these corridors for years to come. I am very proud of what we have created, and I hope the students who will be lucky enough to be placed here will appreciate and enjoy it.”

The Vice-Chancellor thanked his Infrastructure Development and Facilities Management colleagues for managing the project from start to finish. “Thank you also to our stellar consultant teams from Colab Concepts, Talani Quantity Surveying, JG Afrika Civil Engineering and PMC Consulting.”

Written by Aphiwe Boyce