Agreed, It's a pretty standard de-hulling (or macerating), cleaning and bleaching (and/or grinding) process.
The Rasper would tend to suggest Sugar Beet Root processing - tearing and macerating, with the settling tanks used for flocculation or raw sugar juice or the first stage of molasses extraction. You said earlier, however that it has nothing to do with sugar processing.
The auger and bolter would tend to suggest post-1780 a-la Oliver Evans, flat belts were used until the 1930s (proven technology and useful for bucket elevators before air ejectors were adopted). The sketch would tend to suggest around the 1830 to 1900 mark though.
Grinders were used for simplicity/cheapness but you can't beat stone or roller-grinding for flour. However I don't think flour/meal was intended here, unless in a lower grade (if army, that could well be the case), it looks more like pulp/waste processing. Again if beets were involved I would say its for producing feed/fodder for animals.
Hmm...... :nut:
That's my tuppenceworth, 'm going to go and lie in a dark room now, this is bothering me.....
Alec.