Filter device with spirally flushing function

A filter device with a spirally flushing function, comprising a head, a filter flask main body, a filter element, a filter element casing, a flow divider and a filter element end cap

• wherein the head comprises a water inlet hole, a water outlet hole, and a flushing hole, the water inlet hole being connected with a water inlet passage, the water outlet hole being connected with a water outlet passage, and the flushing hole being connected with a flushing passage;
• the filter flask main body is connected with the head, and the filter element, the filter element casing, the flow divider and the filter element end cap are arranged inside the filter flask main body;
• the filter element casing is arranged outside the filter element, and the filter element casing has a plurality of filter element casing water inlets, wherein a first gap, forming as a part of the flushing passage, is configurated between the filter element casing and the filter flask main body, wherein a plurality of spirally rotating flushing guide ribs is provided on an interior surface of the filter element casing and a plurality of spirally rotating flow guide ribs is provided at a lower portion of an outer surface of the filter element casing;
• the flow divider is provided outside the filter element casing and covers a portion of an upper end of the filter element casing, wherein a second gap, forming as another part of the flushing passage, is configurated between the flow divider and the filter flask main body;
• the filter element end cap is fixed to the top of the filter element, and the filter element end cap provides a water outlet, which penetrates through the flow divider and is connected with the water outlet passage, wherein a third gap, forming as a part of the water inlet passage, is configurated between the filter element end cap and the flow divider;
• wherein raw water enters the water inlet passage from the water inlet hole, and enters into the filter element casing through the plurality of filter element casing water inlets and flows along the plurality of flushing guide ribs in a spiral manner, and then the raw water swirls and flows on the surface of the filter element and is divided by the filter element into filtered water and concentrated water;
• the filtered water enters into the water outlet passage from the filter element end cap and flows out from the water outlet hole;
• and the concentrated water enters into the flushing passage from a lower end of the filter element, and spirally flows along the plurality of flow guide ribs and out from the flushing hole.