PCV Blower Fan 1998 S40

[Boys Car]

Please help me understand. My sons 1998 2.0Ltr S40 has a blower fan inline with the PCV and connects back to the Air intake tube, post filter and prior sensor. It started making screeming noises and thus needed replacement. After being quoted nearly what I paid for the car, for a new fan, I opted for a 2nd hand unit. I quickly found out these are as rare as rocking horse shoes. I am informed it was only used on one model? I did manage to pick up a new unit and vacumm operated valve in good condition. My question is when the fan operates it blows toward the pcv from the air intake tube. Is this right? Is the fan blowing the correct way? I cannot find any mention of it in my repair manual and would like to put my mind at rest. Can someone please give me some information or reason and the concept behind this method.