FuelCell Energy Granted U.S. Patent Titled ‘System for fast draining of an airfan heat exchanger and methods of using the same’
https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=4638&f=G&l=50&d=PTXT&p=93&S1=20210615&OS=20210615&RS=20210615