The invention relates to an apparatus for introduction of droplets into a reactor, comprising a holder for at least one dropletizer unit, where the dropletizer unit has a feed for a liquid to be dropletized and a dropletizer plate and the dropletizer plate has holes through which a liquid to be dropletized is introduced into the reactor, where the holder for the at least one dropletizer unit can be pushed into the reactor or pulled out of the reactor through an opening in the shell of the reactor. At least one rail is accommodated within the reactor and is used to guide the holder for the at least one dropletizer unit along it.