What was found
DURING TAKEOFF ROLL DETECTED FAINT SMELL (SIMILAR TO SMELL OF COOLANT FLUID) AT ~90KTS, CONTINUED TAKEOFF WITHOUT FURTHER INCIDENT (NOISE ABATEMENT DEPARTURE, BLEEDS TRANSFERRED TO ENGINES), AT ~13,000FT HEARD A WHIRRING SOUND COMING FROM COCKPIT GASPERS, OBSERVED SMOKE COMING FROM CO-PILOT GASPER NEAR/BELOW AUDIO PANEL. DONNED O2 MASKS AND COMPLIED WITH QRC/QRH PROCEDURES FOR SMOKE IN COCKPIT. DECLARED EMERGENCY, REQUESTED TO RETURN TO TEB WITHOUT FURTHER INCIDENT. SMOKE APPEARED TO STOP AFTER A FEW MINUTES BUT CONTINUED TO HEAR INTERMITTENT WHIRRING SOUNDS FROM COCKPIT GASPERS. REMOVED THE AIR CYCLE MACHINE AND FOUND ACM TURBIN SEIZED. REMOVED AND REPLACED ACM IAW CL-350S MM 21-52·13.0PS CHECK GOOD. NO SMOKE OR SMELL WAS DETECTED