Regional sales manager, Willem Strydom, talks about SEW-EURODRIVE’s agricultural offering and the company’s growing success, most notably in the poultry industry.
The Agricultural sector has kept SEW-EURODRIVE very busy this past year, says Willem Strydom, regional sales manager at SEW-EURODRIVE. “We have products and solutions tailored for cattle and poultry feed processors, abattoirs and, on the chemical side, for manufacturers of pesticides and fertilisers,” he says.
During 2021, sales to the poultry industry have been particularly buoyant. “On the feed side, we have implemented several successful new plants in partnership with feed-mill OEMs in Pretoria and Johannesburg,” he says.
Feed mills, he continues, are fairly similar in shape and size, with a few minor differences between poultry and beef. The process starts with milling and mixing. Screw conveyors driven by SEW geared motors feed measured quantities of ingredients into a hammer or roller mill, which crushers the dry ingredients – corn, wheat and other grains with some medication.
“The ingredients are then mixed using small paddle mixers driven by our geared motors or, for batch applications mixing 2.0 tons or more, using entry level industrial gearboxes (IGs) of about 55 kW, which can cope with the relatively high torque requirements.
“At the final stage of manufacture, a binder such as molasses is added to the mix before the feed is extruded into pellets. Because of the low speed and high torque requirements, our IGs are typically used here too, to drive the extruder,” notes Strydom.
Describing the control required, he says that on a single paddle mixer, the control is fairly easy, since only the speed and torque has to be controlled. This is done using SEW-EURODRIVE’s single variable speed drives (VSD).
“The biggest mixer drive we have supplied was for a dual drive mixer with two paddles. We supplied two 75 kW SEW IE3 motors connected to two industrial gearboxes weighing 750 kg each. Size wise, this is similar to the mixer-drives used for aeration in the wastewater treatment industry,” Strydom explains.
With respect to control for dual paddle mixers, however, the synchronisation of the rotation also has to be precisely controlled to prevent contact between the two paddles. “These turn in opposite directions and each paddle is controlled by its own VSD, while an upper level PLC controller keeps the two paddles synchronised for optimised mixing.
“With respect to speed, plants tend to have two or three different product mixes, which each require a different mixing speed and torque for thorough blending. By using VSDs, we are able to pre-programme the blending requirements to make product switchovers easier,” Strydom explains.
“Demand is still growing in this area and we are currently involved with a project requiring 13 geared motors and two industrial gear units for a poultry feed mill in the North West province,” adds Strydom.
A second area of success for SEW-EURODRIVE’s agricultural offering has been on the abattoir side of the poultry industry. “In a poultry abattoir, the chickens are suspended on an overhead conveyor system called an air line. Slaughtered chickens are fully processed while continuously moving through all the processing stages on this line, including plucking, washing and chilling.
Recently, there was a project where the chain conveyor used was a staggering 2.2 kilometres in length. To drive this conveyor, 36 gearmotors were needed, and they were divided into sections in order to manage the load and chain tension variations,” he says.
To prevent these long chain conveyors from snapping, 6 or 7 hydraulic or pneumatic tensioners are used to take up slack or to reduce the tension, which varies considerably due to loading and unloading variations and temperature differences between, for example, the chiller and the unloading sections, and the loading and washing sections.
“To drive the chain conveyor and to control its tension and speed, we use an SEW geared motor with our MOVidrive frequency inverter, . The master VSD picks up the position from the proximity sensors on the tensioners. It then calculates the motor speeds required in each sector and adjusts them to restore the tensioner to its neutral position,” Strydom explains. Following the initial success in overcoming the chain snapping problems, SEW-EURODRIVE designed five more of these systems during the 2021 year.
From a design perspective, SEW-EURODRIVE’s Maxolution Department is on hand to assist in the design of any agricultural processing lines and the selection of the most efficient and effective drive solutions and control strategies for these applications. “Our Maxolution designs for abattoirs are particularly successful because they involve all of the mechanical, electronic, programming and onsite systems integration work,” says Strydom.
Across the agricultural sector, he says that energy efficiency has become increasingly important, which is leading farmers and serviced providers to look more closely at sophisticated modern drive solutions. “As a precursor to investing in expensive to run backup systems, the sector is on a big energy efficiency drive, so as to minimise consumption, reduce energy costs and backup investment needs,” Strydom concludes.
