Home

Festo is combining measurement, control and regulation technology with pneumatic actuators and valve terminal blocks, along with its Aquatronics training capability, to supply customised automation solutions for water and wastewater treatment. MechTech talks to Durban-based industry segment specialist for water & wastewater at Festo, Strini Perumal.

Festo SA water wastewater Strini Perumal“Globally we have been automating water treatment plants for many years, and for the past few years we have been growing our water offering in the southern and South African market,” begins Perumal. “A key focus for us is providing complete turnkey solutions for municipalities, water utilities and industrial treatment plants,” he adds.

“South Africa has many manual system, where operators need to open and closer valves using wheels and levers. Festo provides fully automated systems, which offer much better control of water or wastewater treatment processes and deliver better and more consistent water quality. Equally important, though, is maintenance and these systems have built-in diagnostics and are designed for easy plug-and-play maintenance,” he tells MechTech.

“In partnership with water infrastructure contractors, we provide turnkey installation packages for water service providers with all media valves, pneumatic actuators, controls and up to the SCADA and software for the main control room – and we are able to optimise an automation solution regardless of the plant’s size or location,” Perumal assures.

Festo water automated skidsDescribing the needs of a typical municipal treatment plant for potable water, he says that water is generally pumped into the plant from a river into a raw water reservoir. From there it is first chemically treated (pre-chlorination) to minimise algae growth, before being aerated for the removal of dissolved solids.

The water is then treated with clarifying agents or flocculants, which cause tiny dispersed particles called colloids to coagulate onto larger ones. “The treated water is then slowly mixed before being passed into a clarifier tank, where the heavier particles sink forming a sludge at the bottom of the tank, while the clear water is tapped off over a weir at the top.

The clear water then passes into filter beds, typically gravity-fed sand beds that remove the remaining fine solid particles. “Between cycles, though, these beds are cleaned, via a backwash process,” Perumal point out. The filtered water is again dosed to remove any remaining bacteria and then transferred to storage reservoirs as potable water.

“At every stage of this process, valves are used to control the process flow. Valve actuators open and close these valves. This used to be done manually, but we are now able to automate every part of the process, from level control to dosing management and back purging,” Perumal explains.

There are two technologies available for automating valve actuation, electrical or pneumatic actuation. “Based on extensive research by Festo, we have found pneumatic actuation to be far more economical than electrical. Pneumatic systems need a compressor, air driers and filtration units, which have to be piped through to the valves and actuators, while electrical systems only need power. But electrical systems are more expensive and they need specialised technicians to manage them. They also need more complicated programming, since they are continuously variable devices,” he says, adding that, “pneumatic valve actuators are much easier to manage. All they need is two air lines into each valve.”

Perumal argues that cost comparisons need to be evaluated over time. “While pneumatic actuation systems are often believed to use a lot of compressed air, this is not really the case. Once a valve has been opened, it stays open, without consuming additional air, so very little is actually consumed. We use compressed air storage tanks across the plant, and once these have reached system pressure, the supply compressor can shut down.

“But the air that is used needs to be properly cleaned and dried. In the past, we have found that operators haven’t been properly draining and cleaning out their filters. This causes condensation to accumulate in the airlines, which eventually damages the actuators,” he explains.

“In response, we have automated the draining of the filters on the compressors. This enables operators to realise even better long-term cost savings. Instead of having to send a technician to drain the filters, we have automatic dump valves on timers that will ensure that these filters are adequately drained,” he adds.

Festo has an agreement with compressor suppliers to incorporate these dryers as part of an integrated compressor solution. “Also, with these compressors, we offer maintenance contracts to service compressors during our warranty periods,” he says.

On a component level, Festo offers an extensive range of valves and actuators with unique features to improve product life. “On butterfly valves, for example, the rubber seats can leak. A traditional valve, which is often controlling the flow of dirty or chemically dosed water, fluid can leak though the valve stem and into the actuator itself, eventually causing damage and shortening the valve life.

“Festo has a safety relief system on its actuators to automatically purge any leakage, safeguarding the actuator and prolonging its life,” Perumal says, adding that these particular valves can operate for between 20 add 50 million cycles. “Festo also provides service kits for all of its actuators and service agreements can be also be adopted to further improve reliability.”

A cornerstone of lowering costs is the simplicity and maintainability of pneumatic systems over electrical equivalents. “We believe that pneumatics offers better solutions for South Africa in terms of long term operational and maintenance costs, largely due to the system’s simplicity.

“Conventionally, where a pneumatic valve was connected to an actuator, each valve would have its air supply and electrical power and control cabling routed back via a thick conduit though junction boxes to a centralised filter bank and back to the main control room. Now, we can use valve terminal block technology in decentralised Festo panels to significantly reduce the complexity and amount of piping and cabling,” Perumal says.

“From a decentralised panel, which includes its own filter unit, we can control a number of nearby valves. And between the panel and the valve actuators, we need only connect one pneumatic pipe and an electrical feedback cable.

“Communication between each distributed panel and the centralised SCADA control system is achieved via a Fieldbus connectivity such as Profibus, Ethernet or DeviceNet or any other single cable protocol. This system also enables self-diagnostics. If a coil, valve or actuator fails to reach the position required, this is immediately diagnosed and an alarm signal is sent to the main SCADA to direct the operator to the problem point. So faultfinding is easy and much more immediate, significantly reducing downtime,” he tells MechTech.

Valve terminal blocks consist of all the solenoids, pneumatic valves and input/output signal sensor – ultrasonic level sensors, temperatures probes, valve position sensors, etc. The sensors are all wired into the valve terminal block in the distributed panel, from where ‘intelligent signals’ are sent to the central controller. And the distributed panels are IP65 protects from dust, moisture and sunlight.

“Panels are easy to access. LEDs are used to detect problems and, to replace a single valve-slice of a terminal block, all you need to do is to isolate the main pressure into the panel, remove two screws on the faulty terminal and replace it with a new one,” says Perumal.

Festo is currently involved with a rural project that involves remote monitoring and control. “At a water treatment plant in northern KwaZulu-Natal, we are installing an automated plant and SCADA system that will allow the water treatment plant and the pump station to be managed from one central point. Using the CPX-MPA valve terminal block, which has its own built-in PLC and wireless communication system, operators have full control functionality and faultfinding capability from the remote control and monitoring office.

In addition, for small rural treatment plants using borehole water, for example, Festo has a solution for containerised water treatment. “These systems have all the required water treatment processes packaged into a transportable container. This removes the need for any civil construction onsite, making it an ideal rural solution, particularly if coupled with remote control and monitoring,” suggests Perumal.

“We are a complete solutions provider in the automatic water treatment space,” he concludes. “This is a differentiator for us. We even offer the operator training courses at several different level through the globally developed Aquatronics courses.”

Latest News

Engineering firms implicated in fraudulent Transnet deals

Published: 21 July 2017

The revelations brought by the #GuptaLeaks emails continue on a weekly basis, with the latest covering the fraud perpetrated by some of the world’s biggest companies. At least seven organisations...

Read more

Eskom’s finances make headlines – again

Published: 20 July 2017

Power utility Eskom is once again making headlines in South Africa. Following recent media reports that Eskom has only got R20 billion in its coffers, the utility publicly responded that...

Read more

Coega continues development

Published: 19 July 2017

The Coega Special Economic Zone (SEZ) continues to be developed, with a number of projects coming on line, as well as further investments on the part of the Coega Development...

Read more

Key skills for HVAC engineers

Published: 18 July 2017

Without the integration of heating, ventilation, and air conditioning (HVAC) products and systems in a building, it is extremely difficult to keep a work environment safe and healthy. HVAC, which...

Read more

Nelson Mandela Metropolitan University to offer engineering degrees

Published: 17 July 2017

The Nelson Mandela Metropolitan University has announced that they will be phasing out its National Diploma in engineering programmes, replacing them with new three-year Bachelor of Engineering Technology degrees. The...

Read more

World first hardwood cross-laminated timber building unveiled

Published: 16 July 2017

Construction techniques have advanced significantly since humans started building their houses out of wood, but wood is still used for the architectural enhancements it offers. Many different types of wood...

Read more

New fluorspar mine to be built

Published: 15 July 2017

Fluorspar development company Sephako Fluoride (SepFluor) has announced a R1.7bn investment into a mine north east of Pretoria. Nokeng Fluorspar Mine, which comprises a mine and concentrator, will produce 180...

Read more

4th annual Mozambique Gas Summit to be held

Published: 14 July 2017

The Mozambique Gas Summit & Exhibition, taking place in October, will cover the latest developments in the country’s gas industry. The event, which is being organised by the CWC Group...

Read more

South Africa joins Free Trade Area

Published: 13 July 2017

South Africa has become a signatory to the Tripartite Free Trade Area (TFTA). Launched in June 2015, the TFTA represents an integrated market of 26 countries with a combined population...

Read more

Africa Architecture Awards extends entry deadline

Published: 12 July 2017

The inaugural Africa Architecture Awards have received over 300 registered entries. As a result, the competition has extended its entry deadline, allowing more architects from across the continent the opportunity...

Read more

Numsa applies for strike certificate

Published: 11 July 2017

Wage talks in the engineering sector have reached an impasse, and the National Union of Metalworkers of South Africa (Numsa) has now applied for a strike certificate. The decision on...

Read more

Nigeria pilots pay-as-you-go solar power

Published: 10 July 2017

Nigeria is pioneering a new solar electricity service, the first in the world of its kind. The Y’ello Box, a solar electricity system which provides electricity 24 hours a day...

Read more

Italian polymer preparation plant launched locally

Published: 09 July 2017

Packaged Metering & Pumping Solutions (PMPS) has announced that it will be introducing an Italian OBL Polisol automatic polymer preparation plant to the South African market. Used in water and...

Read more

Kganyago: Hands off our Reserve Bank

Published: 08 July 2017

Following Public Protector Busisiwe Mkhwebane’s politically-charged recommendation that the Reserve Bank’s mandate should be changed, the institution’s Governor, Lesetja Kganyago publicly defended its independence. The Reserve Bank has filed a...

Read more

Metal and engineering producers suffering as SA deindustrialises

Published: 07 July 2017

According to Roberta Noise, Junior Economist at the Steel and Engineering Industries Federation of Southern Africa (SEIFSA), metals and engineering producers are under severe pressure. The Producer Price Inflation (PPI)...

Read more

Easigas launches optimisation and management service

Published: 06 July 2017

Easigas has added an energy optimisation and management service to its offering. The supplier of liquid petroleum gas (LPG), which has sought to promote quality and safety while improving operational...

Read more

Custom-made corrosion protection packaging

Published: 05 July 2017

Corrosion protection specialist Cortec Corporation has announced that it will be producing custom-made CorrTainer boxes at its manufacturing facility in Wisconsin, in the US. These boxes incorporate Vapor phase Corrosion...

Read more

Drought affects Gamtoos River Valley farms

Published: 04 July 2017

As South Africa’s drought continues, citrus, vegetable and dairy farmers in the Gamtoos River Valley are predicting low food yields as a result of their water allocation being reduced by...

Read more

Steel demand, production increasing

Published: 03 July 2017

Steel demand in emerging and developing economies‚ excluding China‚ is expected to grow by 4% this year according to forecasts by the World Steel Association. This demand is expected to...

Read more

Consulting engineers earning more, but payments still a challenge

Published: 02 July 2017

According to the latest Consulting Engineers South Africa (CESA) Bi-annual Economic and Capacity Survey (BECS), consulting engineers saw higher earnings, an improvement in industry confidence, and progress in transformation during...

Read more

Bobcat Equipment focuses on rental growth in SA

Published: 01 July 2017

Bobcat Equipment South Africa is aiming to grow its rental and aftermarket segments substantially. The company, part of the Goscor Group, has over 100 machines rented in the Johannesburg area...

Read more

The future of African cities under discussion

Published: 30 June 2017

Researchers predict that in 2030, Lagos, Cairo and Kinshasa will each have to cater for over 20 million people, while Luanda, Dar es Salaam and Johannesburg will have crossed the...

Read more

Base built for Graskop Gorge lift

Published: 29 June 2017

April this year saw the Grasko Gorge Lift Company breaking ground on its 51-metre glass elevator, part of the construction of the R40 million Graskop Gorge Adventure Centre. When completed...

Read more

Group Five loses 5 board members

Published: 28 June 2017

JSE-listed construction company Group Five has lost five board members in a mass resignation. The board members announced their resignations following a breakdown in talks with its biggest shareholder, Allan...

Read more

Strikes headed for engineering sector

Published: 27 June 2017

The South African Federation of Trade Unions (SAFTU) has issued a statement saying it fully supports the National Union of Metalworkers of South Africa (NUMSA), in its negotiations for a...

Read more

productONE and 1Worx at Manufacturing Indaba 2017

Published: 22 June 2017

productONE and its subsidiary company, 1Worx, will be exhibiting at Sub-Saharan Africa's leading manufacturing event, Manufacturing Indaba.

Read more

SA economy unlikely to meet growth targets

Published: 26 June 2017

Ratings agency Moody’s Investors Service has followed its downgrade of South Africa’s credit rating with a similar demotion for Eskom, citing a negative outlook for the company. Moody's downgraded the...

Read more

Global Wind Day celebrated in SA

Published: 25 June 2017

June 15, 2017 marked the 10th anniversary of the first Global Wind Day, celebrating the potential of wind power. This year, South African companies joined the hundreds of events held...

Read more

Coal power on its way out

Published: 24 June 2017

Investment into renewable energy is overtaking that of coal in Botswana, delegates at the recent Botswana Resource Sector Conference heard. According to Jonathan Berman, MD of Fieldstone Africa, the energy...

Read more

Shopping centres move into the digital age

Published: 23 June 2017

Technology is revolutionising the way we do things, and one sector that is increasingly investing in new technologies is retail. According to the South African Council of Shopping Centres (SACSC)...

Read more

Magazines

African Fusion

AfricanFusionAfrican Fusion, the official publication of the Southern African Institute of Welding (SAIW), aims to provide up-to-date insight into welding technology and the welding industry.

Capital Equipment News

Capital Equipment News is dedicated to the application of equipment and modes of transport that are used in the mining, construction, quarrying, and transport industries.

Construction World

ConstructionWorldConstruction World was first published in 1982 and has grown to become a leader in its field, offering a unique mix of editorial coverage to satisfy the diverse needs of its readers.

Electricity + Control

ElectricityandControlE + C publishes innovative, technical articles that provide solutions to engineering challenges in measurement, automation, control, and energy management.

Lighting in Design

LightingandDesignLighting in Design is a glossy, upmarket publication aimed at lighting professionals. It is the only B2B magazine in SA that is dedicated solely to the subject of lighting.

MechChem Africa

MechChemJanuary2017cover MechChem Africa supports African engineering and technical managers across the full spectrum of chemical and mechanical disciplines.

Modern Mining

ModernMiningEstablished in 2005, Modern Mining is one of SA's leading monthly mining magazines, noted for the quality and accuracy of its writing and the breadth of its coverage.

Modern Quarrying

ModernQuarryingModern Quarrying is firmly entrenched as a leading industry-specific magazine. It focuses on promoting the science and practice of quarrying and processing in southern Africa.

Sparks Electrical News

SparksElectricalNewsReadable and informative, Sparks Electrical News is the newspaper for those involved in installing and maintaining electrical supplies and equipment.

Contact Crown

Web Manager: Karen Smith
Email: admin(@)crown.co.za

Phone: +27 11 622 4770
Fax: +27 11 615 6108

Crown House
2 Theunis Street
Cnr Sovereign Street
Bedford Gardens
Bedfordview 2007
P.O. Box 140
Bedfordview 2008

linkedin facebook twitter google plus youtube tv rss

sign up newsletter

 
Full Name*
Invalid Input

Company Name*
Invalid Input

Your Email*
Invalid Input

Phone*
Invalid Input

Postal Address 1*
Invalid Input

Postal Address 2*
Invalid Input

Postal Code*
Invalid Input

Street Address 1
Invalid Input

Street Address 2
Invalid Input

Postal Code
Invalid Input

Town / City*
Invalid Input

Country*
Invalid Input

Magazine

Invalid Input

Invalid Input