1998 Ford Escort Fan belt

I was travelling with my 1998 ford escort wagon, when the fanbelt of my car cut into pieces the mechanic bought another one which fit but it was not the orginal model of it, since then everytime I on the air conditioner the fan belt makes strange and loud noise. Another technician told me to look for the original belt, that the noise is cause by the fan belt.I dont have the original fanbelt number, and every shop I go to, all the ask is the model number of the belt. Please can u provide same for me. Thanks.