letters of patent of special high efficency heat transfer plate for detachable plate heat exchanger
letters patent of detachable wide channel plate heat exchanger
letters patent of detachable ceramic multi-tube dust collector
letters patent of removable deformed casing heat exchanger
letters patent of removable full automatic and unmanned comparment heat exchang station
letters patent of air cooler shutter blade punching cut die
letters patent of vertical floating head heat exchanger
letters patent of unequal cross-sectional flow area plate heat exchager