Centrifuge after sonication
No, if you use only centrifugation to separate proteins from other parts of the (bacterial) cell, you need very high centrifugal forces. The actual speed (in rpm) you need to separate soluble proteins from the rest of the cell is mostly dependent on the rotor of the centrifuge, because both together determine the acceleration you get, which should be 
in the order of at least 10,000 - 100,000 g.

If you do not have a (working) ultracentrifuge available, you could try to precipitate your proteins from the lysate, which would allow you to use a normal centrifuge to collect it. However, this won't be an option if your protein can't be properly re-folded and you need it functional.