Destruction Problems

[Thanos]

Don't mix Particle Physics with PhysX, they are completely different solvers.
Particle Physics is more of a grain simulator and can only use spherical collisions, while PhysX can use any shape (like voronoi fragment.. etc)

Your setup should be something like this.
BIrth object (box)
voronoi
PhysX Shape (you're just basically enabling PhysX there)
PhysX Switch (kinematic)  - you are making them non movable, but will be calculated by physX as collision object
Surface test (inside) - create new box to be used for this surface test, animate it how you want it, and whatever particle that is inside of it, will be activated...
_______________________...connect this surface test with new event, where you will only have...
PhysX Switch (dynamic) - this is where you activate particles that are inside the box
(I see many people place here another PhysX Shape... you don't need it... once activated, PhysX is automatically transferred into the new event... you only need PhysX switch to activate them)

Now, if you don't want default gravity and ground plane collision, just grab Tyflow icon, and turn that off in the PhysX options.

If you want particles to shoot outwards, you need some force to do it.
Maybe create a smaller box inside, and use surface force in the secind operator, and pick that box, and it will use box normals to shoot particles out.
Or maybe you can try adding force, and create spherical TyWind inside the box, and use that...

Keep in mind that some particles might now move, because they are stuck between non activated particles.
I sometimes animate scale a little bit down (from 100 to 90) to solve that...

Hope this helps.

Thanks for the help. I will try your setup and will return with the results in due time .