This is a model for a Venturi pump I designed to pump toxic gasses without them flowing through the blower/diaphragm pump. It is quite easy to print with any material and needs no post processing besides tearing off the support of the vacuum inlet pipe.

I have a full report about the part in my blog: http://fenneclabs.net/index.php/2019/01/22/3d-printed-venturi-pump/