There is no simple answer. Depends on things like the 24 volt DC power supply efficiency. If you have lets say 24 volts at 5.5 amps you have about 132 watts. With a mains supply capable of 230 volts at 16 amps that would be about 3680 watts. So in a perfect world about 27 motors. Again, that is not real. Nothing is taking into account losses.
If it's 230 VAC single phase, power factor is about 0.6 for a rectified bridge design. Assuming some power loss in the converter, you have about half the input power available at the output which is maybe 1800 Watts. That would be about 13 load units of 24V/5.5A each, if the converter is reasonably efficient.
This is for a automation project and I am new with automation. The motors will be used in conveyor modules that will move carts at top of them. Every conveyor has 9 axels, each axel drives by a DC motor (the one mentioned above) . The main reason we want to use these motors are for at they are very cheep! 53$ each. Each motor will be driven by PLC via I/O. Any suggestions? Can anyone refer to some reading about these subjects (how to chose motors, converters and ..)?