We have presented results of the experimental study on measuring maximal ti
me tau(max) of stay of Al particles in the reverse current zone (RCZ) of th
e combustion chamber with sudden expansion (CCS). We have discovered the in
fluence on tau(max) of such parameters, as degree of sudden expansion r*, d
imension d(m), and shape of particles, velocity U-0 and main stream turbule
nce epsilon(0).