I have one of those big generic (mine is Axminster branded) 635mm dual drum things. 15amp of whatever.
I'm a heathen so use it for thicknessing!
(I have a thicknesser or two, but the sander gets around the tear out issues on figured wood)
I find the best way to scrap belts is by taking too much off in a pass. Second is probably too low a feed rate in conjunction with removal amount.
You would assume that if you're taking a heavy cut a slow feed would be good but this isn't always the case. Scorching and gumming can occur.
Like I say, I use mine heavily. It's got 80g avomax in it. Maybe even 60g.
If I take gentle cuts I can get a belt to last an hour or somthing. I can manage less than 10mins if I do it wrong.
Again, I'm not trying to finish on it, and u have the second drum lifted.
On the last passes I'll take a very fine cut (finally feeding the part through a number of times without changing roller height) and then use a da sander.
If I was doing stacks of parts, I'd set it up with fine paper for sanding, but I reckon it would take a while to learn not to wreck this.
I've had zero luck with cleaning paper. Generally gums up, then the gummed stuff scortches black. Then comes off taking the grit with it.
Once too much grit is gone, I change the paper.
I really like the machine. I had real issues before thicknessing parts after template routing. I'd try and flatten wood prior and then it would move again after cutting.
Now I route it first, and take to final size weeks later on the sander. I get way way less bother like this