As long as the re-wiring is done correctly, and the Bruheat bucket doesn't draw more than 30 Amps at 220V, and your dryer receptacle is truly wired to a 220VAC/30 Amp breaker then you will be fine. The fact that it has a 220V 15A plug on it is encouraging, but I would check for a placard or in the manual to find out how much current it draws, since it is used, the plug could've been replaced before. But, you can always plug something that draws less current into a higher rated outlet...think about it like plugging a cell phone charger into the same receptacle as your microwave oven.
Draft 1: Lightly smoked Weizen
Draft 2: Belgian Wit
Draft 3: Rauchbier
Primary 1: German Scwarzbier
On Deck: Belgian Brown Ale, Pale Ale, Stout