I have been replacing the insulation in my crawlspace and its ‘blown in’ kind of insulation called ‘Insulfluf’ made from powdered recycled paper and boric acid to make it fire retardant.
I found that while I could physically put a lot of it into bags with a dustpan, there was always going to be little left overs that wanted vacuuming, but I would always fill up my vacuum cleaner back in seconds. So to give me more vacuuming capacity, and to put a large drum vacuum into my shop I experimented with cyclonic bin vacuums a bit before settling on this. Its really simple design and was made out of cheap things.