Vaal Triangle wastewater treatment plant first recipient of IE3 compliant DRN motors
A major wastewater treatment project in the Vaal Triangle has become the first recipient in South Africa of the new IE3 compliant DRN motors from SEW-EURODRIVE .
The initial order is for 10 complete units with gearboxes and motors ( six 45kW motors and four 55kW motors ), comments the head of projects , Rudi Swanepoel . These specific units will be used for aerator applications . “ With aerator and mixing applications , our projects and engineering teams have to double check all of the loads and bending moments . These loads are supplied to us by the client , based on their designs . We then have to ensure that the gearboxes that have been selected are suited to the application at hand ,” Swanepoel explains . “ Our calculation program has been designed specifically to determine if the gearbox selection is adequate , based on the loads and bending moments . This is particularly important when it comes to aerators and mixers . Thus , these are not off-the-shelf products , but have been selected specifically for the system in question .”
Vane-tastic flow meter
The Vane Technology Principle , a method of measuring and monitoring the flow of different media through piping , has been proven worldwide . Kobold flow meters / monitors work with this proven principle . Kobold , represented locally by Instrotech , has on offer a new rotating vane flow meter , the equipment of choice whenever traditional impeller technology is to be used for the measuring or monitoring of volumetric flow rates . The modular design of this type makes the system universal in use , inexpensive , and space-saving in operation .
The DFT rotating vane flow meter completely fulfils the requirements of industry for efficient and low-cost production methods . Due to the option of a polytetrafluoroethylene ( PTFE ) housing , users get a resistant and highly reliable measurement system for operating in aggressive media .
The wide measuring range of 0.2 – 2.0l / min . up to 3 – 60l / min . means that DFT rotating vane flow meters can be used for a wide variety of applications . With a maximum operating temperature of 80 ° C and a maximum pressure of 16 bar ( if the brass housing is used ), this device can be used for almost all process conditions . The heart of the Kobold impeller is a securely embedded ring magnet , which is hermetically sealed against the respective medium . It transfers the rotation of the impeller to a Hall sensor fixed to the housing with a space-saving attachment . This sensor in turn transforms the rotational movements into a frequency signal in proportion to the volumetric flow . The downstream Kobold electronic evaluation unit then transforms the signal into either a digital display or an analogue normalised signal , or it can be used to switch up to two limit contacts . LEDs show operational readiness and switching state of the limit value relay . Also , counter or dosage electronics can be used .
In combination with the Kobold electronic unit , this system provides extremely accurate measuring results , under difficult conditions .
Typical applications are in cooling water monitoring , general mechanical engineering , wastewater treatment , all heavy goods industries , and in the chemical industry . u
Kobold DFT rotating vane flow meter .
Instrotech
LR Civil
SEW-EURODRIVE also had to comply with stringent specifications in terms of these motors , due to the arduous conditions on site in the wastewater treatment plant . These included the addition of auxiliary instrumentation such as PT100s ( to measure temperature ) and thermistors ( a cut-out failsafe when the motor temperature reaches a set high point ). Other additional accessories included strip heaters for colder conditions , and rain canopies . European regulations introduced at the beginning of 2016 meant that all two- , four- , and six-pole asynchronous motors with a power rating of 7.5 – 375kW must meet the requirements of energy-efficiency class IE3 in the European Union ( EU ). In 2017 , IE3 is now mandatory for all asynchronous motors with a power rating of 0.75 – 375kW . “ SEW-EURODRIVE has always remained at the forefront of new technological and regulatory developments , and keeping the South African industry up to date is important to us and to our customers . The first successful order of these latest generation motors for the wastewater treatment industry is testament to this approach ,” Swanepoel concludes . u
Large-bore horizontal drilling comes to SA
Horizontal directional drilling ( HDD ) has been used quite extensively in the South African construction and civil engineering sectors , but only in small bore applications . Now , there is scope for large bore pipelines , bringing extensive benefits and cost savings .
According to LR Civil operations manager , Daniele Carnicelli , local engineers and contractors have been slow to pick up on the overseas success of HDD in large bore applications , where holes of over 500mm can be horizontally drilled for unobtrusive pipeline installation .
LR Civil , a member of the Raubex Group , has teamed up with geotechnical engineers , Geopractica , and HDD experts , TRG International , to apply this well-established technology to South African conditions .
“ We have already notched up one notable success by recently completing a one kilometre HDPE pipeline under a Port Alfred beach and into the ocean ,” says Carnicelli . “ This was for an outfall pipe for the new reverse osmosis desalination plant near the town .”
He says the hole was drilled horizontally at depths of between 20 and 30 metres , with a 150-tonne Maxi-Rig , without any threat to the pristine beach environment or disruption to the public .
“ HDD obviates the need to dig from surface to lay and bury large diameter pipes ; this means that many of the normal challenges of pipeline installation are sidestepped altogether ,” he says . “ Where a pipeline crosses a watercourse , for example , a water use licence may be required ; this is a process that could take up to 18 – 24 months and possibly delay a project significantly .”
Wherever a trench will intersect a gas , power , telecommunications , or water line , other permissions usually need to be secured . In the case of HDD , the drill path simply goes under this infrastructure and safely avoids it . u
Cost saving with unobtrusive pipeline installation . networking contributor tech news industry environment infrastructure municipalities
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