Do you have an electrical schematic of the power and control circuits?
Is it necessary for it to run on both 400V/50Hz and 460V/60Hz, or will it remain at 460V/60 Hz?
There are several ways to go about it, and balancing the best vs. least expensive ways becomes the question.
1. Plug it into 460V, and see what happens.
Not recommended, because at least one, and probably more components are likely to fail, possibly including catching on fire.
2. Use a transformer to step up 400V to 460V.
12 KVA may do, but 15 KVA gives more thermal headroom and motor startup surge capacity.
This takes care of heater and control voltage, but a 50 Hz, 3 phase motor operated at 60 Hz will run 20% faster (60Hz/50Hz) than rated speed.
Whether you can get away with it depends on the specific blower/motor combo. Possibly, if the motor doesn't now operate at close to full load amps AND the blower design allows it (or the blower isn't coupled directly to the motor shaft, and can be brought down to design speed by changing the sheave ratio). Depending on design, the power required by a centrifugal blower increases by up to the square of speed increase. Another possibility is to add a variable frequency drive to operate the motor at design voltage/frequency/speed.
3. Modify machine to operate on 460V.
Replace motor and heater to 460V equivalents. Replace control transformer from 400V to 460V primary.