Method for cleaning sand in a sand bed

A method for cleaning sand of a sand bed of a facility including a slow sand filter, infiltration basin and pools having sand beds in water treatment works and plants, the method comprising the steps of:

• providing a remote-controlled cleaning machine including a chassis having a front end and a rear end;
• first and second caterpillar track assemblies mounted on respective longitudinal sides of said chassis;
• first and second drive wheels for engaging said first and second caterpillar track assemblies, respectively;
• a motor mounted on said chassis;
• electromagnetic clutches connected to said drive wheels;
• said motor being connected to said drive wheels via said electro-magnetic clutches for driving said caterpillar track assemblies for propelling said machine over said sand bed;
• and, a submersible pump having a nozzle and a hydrocyclone connected to the submersible pump;
• traversing said sand bed;
• removing sand to be cleaned of sludge from the top surface of said sand bed with said submersible pump and said nozzle thereof;
• discharging said sand to be cleaned to said hydrocyclone to separate said sludge from said sand;
• discharging the separated sludge suspended in water to a waste disposal location of said facility through a hose connected to said hydrocyclone;
• and,
• returning the cleaned sand to said sand bed.