(I'm not saying it isn't true, just that I assume by the way you've stated this you're a developer that's rarely left alone to get anything done, and I can't see how that's beneficial to your employer.)
During the day I may solve up to a dozen small problems, which might be a small customization of the font-end for a big client, debugging a random bug or two on the spot, querying the database for some new sales stat, and so on. If something comes in to our bug-tracker that I think I can resolve within 30 minutes, I do it immediately. The rest of the time I work on the long term (no deadline) projects to improve the system as a whole. Sure those projects suffer a bit but our clients are always very impressed when we can fix his bug, make his customisation change or implement his new report, literally just minutes after he requested it.
your manager can either stop it by charging your time back to the requestor ( I would suggest you track the requests -send emails sayi g Bob you wanted a new sales report, it's third on list and expect it 9am)
or he can explicitly Market you to the business - what I previously did. And it is a powerful weapon for your manager. The higher ups feel well treated and the department gets all it's interrupts funnelled thru one person, who in your case seems good at it and happy to do it
but I strongly suggest you track the work, and push the marketing value of what you do.