No F lounge. Only SEN lounge. Nice, not big, has few beds in "quiet area".
Airport Dusseldorf - Nordrhein-Westfalen
Location Terminal A, gallery, opposite Transfer Center
Opening hours 5:30 am - 9:15 pm
Lounge features
Non smoking lounge
Restrooms
Showers
Office units
Miles & More printer
Wireless network
TV
Local magazines and newspapers
International magazines and newspapers
German magazines and newspapers
For future reference, this also helps:
http://www.lufthansa.com/ru/en/Homepage (help/contact)