Rough diagram of FBD from inlet to exhaust

Kindly help me to know the how inlet comes (steam) and where it goes. Mainly about HEPA

Fbd iinlet take fresh air from enviornment it passes throuth series of filter
Pannel,bag filter and then HEPA.Then this hot inlet air pass through product trolley and remove moisture from product.Then after passing from bag filter or SS filter it again goes to enviormment through exhaust duct.