Electricity + Control May 2019

DRIVES, MOTORS + SWITCHGEAR

Driving the conveyors in new Mpumalanga coal mine

A greenfield coal mine in the Mpumalanga coalfields region has standardised on drives from SEW-EURODRIVE for its entire con- veyor-belt system. This entailed a 27-unit order that was assem- bled at the original equipment manufacturer’s Nelspruit facility and transported directly to site early this year. The order consisted of a complete drive package in the form of a simple ‘bolt-on’ solution for the conveyor-belt system. This included the drives, gearboxes, base plates, guards and, in one instance, an ancillary cooler. The project was facilitated by the Projects Department of SEW-EURODRIVE, under the direction of Project Sales Represent- atives Brett Weinmann and Bruce Farthing. This specialist in-house

department focuses on providing clients with complete solutions. Weinmann explains that the long-term aim of the Projects De- partment is to establish relationships with project houses in particu- lar, which put their designs out to competitive tender. Thereafter it is the responsibility of Farthing, a qualified mechanical engineer, to develop a solution best suited for the specific application and that is presented to the client for approval. “Our team is dynamic,” says Weinmann. “We strive to offer the best solution together with best customer service and technical back-up. We don’t simply supply products, but look at the applica- tion holistically.” The order for the new mine’s conveyor-belt system had to be customised and an important part of the service was ensuring the required specifications were met and keeping to the delivery date. “We like to be on-site during this critical phase of any project, to ensure that everything is according to specification and installed correctly. For example, we double-check the oil levels and the align- ment of the units and are also present at the first cold start-up,” Weinmann notes. Critical to the success of this project was the close working re- lationship with the project house, which allowed SEW-EURODRIVE an extended lead time. “This enables us to iron out all the technical specifications in advance and benefits our sub-suppliers as well,” Farthing says. SEW-EURODRIVE has subsequently received orders for anoth- er three cross-border projects with the same client, assisting in expanding its footprint in the African mining industry. Enquiries: SEW-EURODRIVE. Visit: www.SEWEurodriveSA The WEG VSD can also be used to set sleep and wake modes in the pump operation. This facilitates significant cost savings as pumping can then be done on a demand-driven basis. Where there are multiple pumps in use at the same pump sta- tion,WEG Pump Genius software and theWEG CFW11 VSD can be used to alternate motor usage automatically in order to ensure that each motor/pump combination has equal operation time. This pre- vents one pump being subjected to excessive wear and regulates the wear across all the pumps – resulting in the lower total cost of ownership for the installation. WEG VSDs support optimisation of water usage in the agribusi- ness which in turn supports effective land use. Enquiries: ZestWEG Group Africa.Tel. +27 (0)11 723 6000 or email: marketing@zestweg.com

The 27-unit drive package for the conveyor system was assembled at the OEM’s Nelspruit facility before being transported to the installation site.

Cost savings in water collection and pumping systems

WEG Variable Speed Drives (VSDs) offer the agricultural sector a way to reduce operating costs on automated water collection systems with a reduction in motor energy consumption when the motor speed is reduced. In addition, the VSDs allow for monitoring of all functionalities of a pumping operation, including special functions that contribute to saving operating costs and will optimise, control and protect the entire irrigation system. The drives can send commands automatically to the electric motor to facilitate control of the pumping installation and enable greater effectiveness when irrigating. TheWEG CFW 700 frequency inverter or VSD provides accurate speed variation for the electric motor, ensuring it operates accord- ing to the pressure needs of the irrigation system. With the neces- sary field telemetry, it can also take different land inclinations into account. Another important benefit is the drive’s ability to detect low pressure – indicating leakage in a pipeline. With this early warning from the VSD, users do not need to install specialised leak detec- tion equipment and can take remedial action as soon as required. Where water is being pumped from a river to the dam for fur- ther irrigation, use of the WEG VSD allows optimum control of the water level. It will prevent overflow situations and dry pumping can be set up without the addition of flow sensors.

The WEG CFW 11 VSD used in the Pump Genius configuration for an agricultural installation.

Electricity + Control

MAY 2019

11