A mixer unit comprising a mixing chamber is disclosed. In one example, the mixing chamber comprises a de-agglomerator with a de-agglomeration shaft with de-agglomeration paddles, and a mixer with a mixer shaft with two or more mixing paddles that are arranged for mixing and impelling particles and powders in an upstream direction towards the de-agglomerator, whereby the de-agglomeration shaft is arranged above, and in parallel with said mixer shaft, so that all particles will be impelled towards the de-agglomerator, each time particles are lifted. A first portion of the mixing chamber may also have an inner profile adjacent and curved about an upper part of the de-agglomerator and is arranged to guide particles and powders impelled by the mixing paddles over the de-agglomeration shaft and into a liquid spray.