Who Knew Cut Grass Would Be So Tricky To Move!

Like all publications, here at Hackaday we are besieged by corporate public relations people touting press releases. So-and-so inc. have a new product, isn’t it exciting! But we know you, our readers, we know you like hacks, and with the best will in the world, the vast majority of such things have nothing of the hack about them. Just occasionally though a corporate offering does contain a hack, and today we have a fascinating one from Charm Industrial, who are doing their best to make hydrogen from biomass. They were finding cut grass to be an extremely difficult material to handle, and their account of how they managed to feed it from a hopper into their machinery makes for interesting reading.

You might expect grass to flow from a conical hopper like an ungainly liquid, but in fact it readily clogs and forms bridges, blocking the outlet. Changing the design of the hopper made little difference, so they tried an auger. The auger simply compressed the blockage harder, resulting in the counter-intuitive strategy of running the auger in reverse. But even that didn’t work, leaving the area round the auger clear but the rest of the grass as a solid clump. Rotating plows were tried with multiple different profiles followed, but finally they settled upon a vibrating bin activator. It’s a crash course in materials handling, and though the Hackaday bench is likely to avoid having to handle cut grass except when emptying the lawnmower, it’s still worth a look.

We may have done very little with handling cut grass, but we’ve certainly taken a look at creating it.