Here is a responce from D&D
HI ! I am the head designer with D & D Marine. I hope I can answer all of your questions about our new skimmer. First we have been producing skimmers for over twenty years now, a very large part of our market has been in Europe. Our angular concentrator has always been part of our design, the way it works is this.
As a skimmer injects air into the reaction chamber and layer of stabilized foam is created. As this layer develops the air below it can no longer vent out the top of the skimmer, as this happens the air must still escape so it lifts the foam and pushes it out ahead of itself.
NOW, the details, Instead of using the old "upside down funnel design we use an angle. The reason is this, with the upside down funnel the only way to control how wet or dry the foam is is proximity to the overflow point at the top of the neck. With our angular concentrato top by raising or lowering the water level you actually change the surface area of the foam. The best way I can explain the advantage of this is to talk about cooking a pan cake. My goal is to cook a pan cake that I can put my fist under the center of and lift. If I cook one the size of a trash can lid and one the size of a lunch plate, I will have to cook the bigger heavier one much drier in order not to just punch my fist through it. The same is the case in changing the surface area of the foam. The larger the surface area the drier it must be before it can be lifted. In the reverse if we raise the water level and reduce the surface area we can get rapid (but wetter ) production. BTW> yep the top of the angle is sealed.
Sorry if my typing leaves a bit to be desired. I hope this helps
Oh, with regards to cleaning, with the top removed you can put your entire hand inside for cleaning. The entire core is also removeable. We have had units out in stores running on demo for two weeks and been able to clean them well enough to use for advertising photos !!!
Also the port design has been around a very long time, it will not clog on you. NOW I will say this you have huge control over how wet or dry the foam is, I am certain if you really try you can get it so dry that it possibly could clog but in twenty years I have never had this as a complaint. Best wishes D&D