Uv disinfector for optically dense fluids

A mixer for mixing fluid, the mixer comprising:

• a cylindrical body;
• an inlet pipe for transporting fluid into the cylindrical body;
• an outlet pipe for transporting fluid out of the cylindrical body;
• a central support shaft;
• and
• a plurality of mixing discs rigidly attached to the central support shaft via a central mounting hole;
• wherein each of the plurality of mixing discs comprises an array of holes on one side of the mixing disc;
• and
• wherein the mixing discs are arranged such that pressurised fluid entering the inlet pipe is forced through the array of holes of each of the plurality of mixing discs to provide chaotic mixing of the fluid before reaching the outlet pipe.

A method for disinfection of optically dense fluid, the method comprising:

• directing fluid to a chamber, the chamber being defined between a metal tube and a quartz tube that surrounds a UV lamp;
• irradiating the fluid with UV light from the UV lamp;
• directing the fluid from the chamber to a valve arrangement, the valve arrangement configured to direct fluid to spaces behind and in front of a cleaning sleeve surrounding the quartz tube in the chamber;
• and
• scrubbing the quartz tube with the cleaning sleeve, wherein scrubbing comprises:
• opening a first valve of the valve arrangement to direct fluid to the space behind the cleaning sleeve to move the cleaning sleeve forwards;
• and
• closing the first valve and opening a second valve of the valve arrangement to direct fluid to the space in front of the cleaning sleeve to move the cleaning sleeve backwards.