Device for filtering a liquid and method for disinfecting such a device

A device for filtering drinking water, which device is connectable to a main system via a main cock, which device comprises:

• a ) separate first and second pipes respectively connected to the main cock;
• b) the first pipe being connected to an inflow opening of a first filter element via a first three-way cock and a third pipe;
• c) the first filter element being having an outflow opening connectable to an output system via a fourth pipe, a second three-way cock and a fifth pipe;
• d) the second pipe being connected to an inflow opening of a second filter element via a third three-way cock and a sixth pipe,
• e) the second filter element having an outflow opening connectable to the output system via a seventh pipe, a fourth three-way cock and an eighth pipe;
• f) the first three-way cock and the third three-way cock being mutually connected by a ninth pipe;
• g) the second three-way cock and the fourth three-way cock being mutually connected by a tenth pipe permitting direct and complete flow of water between the second and the fourth three-way cocks;
• h) each of the first and second filter elements being provided with first and second connections, respectively, for discharging concentrate from the respective filter element to a drain;
• i) first and second further pipes, respectively, being connected to the respective first and second filter element connections and including pipe closing devices;
• and,
• j) the first and second further pipes being connected to a still further pipe for discharge of concentrate into the drain.

A water filtration system comprising:

• a) a spaced pair of filters:
• b) water supply conduits connected to inlets of the filters and connectable to a common water supply source for delivery of water from said water supply source to the filters;
• c) outlet conduits connected to outlets from the filters for delivering filtered water to a common outlet for delivering filtered water to an end use location;
• d) four three-way valves each in a different one of the supply and outlet conduits;
• e) the valves having a first set of backwash positions wherein the inlet of one of the filters is connected to a drain, and the inlet of the other filter is connected to said water supply source;
• f) the valves having a second set of backwash positions wherein the inlet of said one filter is connected to said supply source and the inlet of said other filter is connected to said drain;
• g) the outlets of both filters being connected together by a conduit when the valves are in each of the first and second sets of backwash positions whereby the one filter may be backwashed by filtered water from the other filter when the valves are in the first set of positions and said other filter may be backwashed by filtered water from said one filter when the valves are in the second set of positions;
• and
• h) a further conduit coupled to the conduit connecting the outlets of the filters together, there being a heating element and a pump arranged along the further conduit.