Depends on how the purifier works. If it produces an aerosol then this may be entering the smoke detector and being thought to be smoke as it has the same effect on the sensor. If it works through ionisation of the air then the air entering the detector will cause a deflection in the sensing unit as it has a charge, again simulating smoke and hence triggering the alarm.

Edited by user 15 November 2016 23:43:05(UTC)  | Reason: Spelling and additional words