They seem to be using a fast moving rotor with holes in the backside of the blades that extract the steam from the cavity and then condense it.

--- Links and related articles:

University: http://www.sfu-kras.ru/en/news/22304

Related paper: http://research.sfu-kras.ru/publications/publication/5140807... (doi: 10.1007/s11431-014-5631-0)

List of articles of the mentioned researcher (Kulagin) is at http://research.sfu-kras.ru/publications/author/24184408

(Nothing stands out on arXiv when searching for either desalination, cavitation or Siberian Federal University)