MY18 Multi-stage Hammer Mill
Mechanical Drive - 31% Less Power
We designed a mill that can handle drops in engine RPM without significantly effecting capacity or kill, which enabled us to harness the efficiency and simplicity of the mechanical drive without being tethered by fluctuations in engine rpm. Our drive is driven off the harvester’s engine with minimal moving parts, incorporating only shafts, belts and gearboxes. This is to maintain a lower power draw and fit to class 7-10 harvesters. We use precision machined custom bearing spindles and a custom, German made spiral bevel gearbox.
The War on Wear
We have attacked wear on multiple angles this year with
We created the Aero-IMPACT 2.0 system that efficiently creates high air flow for maximum capture of weed seeds, minimum disruption of the harvester sieve and minimise infeed blockages. Uniquely able to maintain high air flow under highly loaded conditions even at reduced rpm. We have optimised the residence time that material is in the mill, to improve capacity, reduce wear and reduce over processing. We have also improved the aerodynamics of our impact elements which has meant less turbulence and therefore less wasted energy.
The diagram above shows the movement of straw, chaff, grain and air in the harvester. The baffle-beater gap let's air escape unrestricted, too much air escaping above baffle = risk losing seeds. Seed Terminator's huge air flow means less air escaping above baffle = no cleaning shoe air restriction and maximum capture of weed seeds.
As you can see in the video material is sucked into Multi-Stage Hammer Mill even with the side covers off.
South Australian Grains Industry Trust funded research conducted by Trengove Consulting in 2017 found ryegrass weed seed kill was 93% at 2250 rpm and increased to 98% or greater at normal operating speeds (2500–3000 rpm). Results also showed than 99% control of several other species including wild radish, brome grass,wild oat, bifora, bedstraw and tares and increasing chaff flow rate (harvest rate) did not reduce control of these species
96% Kill Performance
The Weed Science Research Group, a part of the University of Adelaide confirmed that Seed Terminator could consistently reduce germination of Annual Ryegrass by 96% compared to a control sample.
Associate Professor Chris Preston, Geoff Philips, Dr Nick Berry, Associate Professor Gurjeet Gill, PhD Candidate David Brunton, Graduate engineer Keagan Grant
[ August 2018 ]
After a few late nights fitting up the Seed Terminator, Nick spent two weeks operating the harvester, trying different Seed Terminator configurations, different harvesters setups, measuring grain loss, living and breathing harvest. There are a huge number of design changes for the MY2018 Seed Terminators. If it is one thing we have learnt, it is that what works in theory and what works in the field can be miles apart. There is nothing like proof in the paddock; being able to test the machine in Canada prior to our Aussie harvest is a great opportunity to get a jump start on 2018 lessons. Header (nee Combine) Uptime is a big focus for us, the most important thing we can do is not interrupt your harvest operation. We have already implemented a few tweaks to the design based on the early results in the field.
We are gathering information on how to operate our new blockage sensors and a bushel of knowledge (excuse the pun) on how to drive the machine. One of the things we had to deal with in the early Canadian harvest was an abundance of green weeds at harvest, mostly Kochia; driving to conditions the Seed Terminator 'ate her greens' without a fuss. Others include high harvest moisture (15-18% Canola, 20% Wheat, 18% Peas), cold temperatures (haven't had a day above 20 degrees yet), moist conditions including harvesting during drizzling rain and working through tough canola straw, so far she hasn't missed a beat!
AeroIMPACT 2.0 = Capacity, capacity, capacity
Early reports confirm the new AeroIMPACT 2.0 technology is able to replicate the increased capacity we saw in the lab, in the paddock; bring on Harvest 2018!
A Kangaroo Island purpose built facility will provide direct access to farmland, harvest machinery and collection of crop materials, while combining science, engineering, feedback in a confidential space enabling us to create next generation technology.
"The indications so far are that the major cause of wear is any soil that reaches the mill. When harvesting crops with the front right on the ground or if the ground is undulating, soil can enter the harvester fronts. For high silica soil types wear rates are highest. Outer screens are the first component to wear (because of maximum material speed). The middle and inner screens last proportionally longer (reduced tip speeds) than outer screens. Rotor and flails are similar to middle screen life. We have learnt that there is another compromise that needs our focus; cutting height to capture weeds and wear rates because of soil entering the front." Nick Berry
First set of tests in January 2018 show that 15-20% power reduction is looking very achievable within our current design framework.
[ October 2017 ]
The South Australian Grains Industry Trust is using one of the three test stands to trial the Seed Terminator against a range of crops including Wheat, Canola, Lentils, Beans, Chaff laced with Ryegrass, Broom Grass, Turnip, Prickly Lettuce, Medic, Tares, Wild Radish, Bifora, Bedstraw, Marshmallow and Wild Oats. Early results show Seed Terminator is over performing.
July 2017 Image above is of one of the three test stands: Pitot tube with hot wire anemometer to measure the air flow, torque transducer to measure torque, dustpan and broom to measure kill!
During 2017 harvest there were many learnings and on balance, it was a successful one and a massive leap forward from 2016. The Seed Terminator's beat the living daylights out of billions of weed seeds across the country; 32 machines running successfully across 4 Australian states. Our Farmer Research Partners not only made a real difference to the sustainability of their farms, but they have played a huge part in developing our technology to assist the whole industry.
Our upgraded drive system worked really well, farmers noted that they didn’t notice power draw in canola and barley if the conditions were good. Long green canola straw presented an issue in some areas, if at times too much straw ended up in the mill hoppers. Harvester setup has a role in this, for example an internal chopper on a CASE machine throws straw better than an internal beater. We were able to implement a blockage sensor on one machine which proved quite effective. As the season progressed and the crops dried out, blockage issues disappeared. In the wheat and lupins, engine load was increased over barley and canola. Cutting wheat low to the ground to collect weeds requires a lot of power to thresh. Additionally, wheat produces a lot of chaff on the sieve and can contain a lot of short straw for the mill to process. 35 tonne/hour of wheat produces around 10 tonne/hour of chaff. Lupin pods on the other hand are just tough to process! Our farmers did note that the material coming out of the mill was highly pulverised and volunteer and weed seeds exiting the mill were like flour. This amount of pulverising ensures that there are no escapees in tougher conditions when the moisture is up, or the seeds are smaller, however it comes at a cost of additional load. Lesson 1 from harvest was that there is an opportunity to reduce the amount of pulverisation and the load on harvester.
In the middle stages of harvest, we started to notice that some machines had more mill wear than expected, particularly in sandy soil types. Low cut heights and undulating ground can result in sand entering the harvester and into the mill. Also rain can splash sand onto the lower part of the plant. This effect is so profound that we found nearby farmers cutting the 7-10cm height have twice as much wear as 15-20cm height. Clearly there is another compromise between cut height (and collection of seeds) and mill wear. On some machines, sand also gets sucked through the harvester fan, particularly machines with tracks.
"I have been asked, if the sand is entering the harvester then why isn’t my harvester wearing out? And the answer is all around tip speed. Nothing on the harvester has any where near the tip speed of the rotor which is around 330 km/h. At these speeds sand acts like a sandblaster, biting into the steel."
Lesson 2 from harvest was we need a resistant wear package for sandy regions. At harvest we managed to trial 3 different surface treating options with some good success but a lot to work on.
The harvest finished up and the team went straight to work on reducing power and increasing wear life. A lot of brain storming, some fundamental modelling, and lots (and lots) of prototype testing. In addition to these goals we have continued to develop our drive system. One season of testing is not enough to test long term reliability, so we are using accelerated life testing of components in the off season.
2016 was Seed Terminator's maiden year, the idea of the Multi-stage Hammer Mill was concieved by Dr Nick Berry in June 2016, designed in July 2016 and manufactured in August 2016. A concept that uses the long-held knowledge that hammer mills kill seeds and then splitting that process over three stages to achieve the capacity needed to process the chaff stream of a modern combine harvester. September 2016 saw the promising results of pouring chaff through the mill on a stationery test stand and samples analysed by the Weed Science Research Group, a part of the University of Adelaide confirmed that the Seed Terminator could consistently reduce germination (i.e. seed kill) compared to a control sample by 90% when operated at 2,700rpm.
The Drive System concept was developed to fit across different makes, keeping it as simple as possible with minimal moving parts. CGS Engineers and Nylastex Tooling proceeded to build 9 prototypes on three makes across 4 states in a matter of weeks. The nine prototype trial units were installed on Case (7120, 8010, 8120, 9240), New Holland (CR 8090, CR 9090) and John Deere (9760 STS, 2 x S680). The prototypes were trialed in four states (Western Australia, South Australia, New South Wales and Victoria) across a variety of crops (Wheat, Barley, Canola, Lupins, Oats, Lentils, Faba Beans), soil types and key rainfall zones in the 2016 Harvest.
The season was fortunately a long one as it was a challenging harvest, we were able to try 3 completely different drive systems. The perseverance from all involved was exceptional and enabled us to learn a huge amount and prepare for a massive year of research and development in 2017. The outcome of 2016 harvest was purely we needed a robust drive system. The mill seemed to perform well with a few tweaks needed.