Patent ID: 7455769

Claim:
A filter device for purification and/or for at least partial dealkalization of raw water, comprising: a raw water inlet and a pure water outlet, a filter line A having one flow channel segment and a first filtration segment, and a blending line B having an adjustable distribution valve and a second filtration segment, wherein the filter line A and blending line B are connected to raw water inlet by a separation device that divides the raw water inlet into two partial flows of the filter line A and the blending line B, wherein the adjustable distribution valve is separate from the separation device and located in blending line B downstream from the separation device, and wherein the filter line A and blending line B are connected to a pure water outlet by a connection device, wherein both filtration segments are arranged in an inner container, wherein flow characteristics of components of the blending line B, defined by the pressure loss function Δp B ({dot over (V)} B ), is adapted utilizing the adjustable distribution valve and the second filtration segment, to a flow characteristic of components of the filter line A, defined by the pressure loss function Δp A ({dot over (V)} A ), in such a manner, that for at least one blended portion X with X={dot over (V)} B /({dot over (V)} A +V B ), for volume flows of a first volume flow range between {dot over (V)} 1 =10 l/h to {dot over (V)} 2 =120 l/h, for at least a second volume flow range having a range of at least 5 l/h within the first volume flow range, a blend condition:  V . B ⁢ 1 - X X - V . A  V . A ≤ 0.15 = G is satisfied, whereby G represents a threshold value of the blended condition, Δp A ({dot over (V)} A ) the pressure loss in the filter line A and Δp B ({dot over (V)} B ) a pressure loss in the blending line B, in dependence of the volume flows {dot over (V)} A , {dot over (V)} B in liters per minute of water in the lines A and B.