Abstract: A device for mixing air and water in a water purifier comprises a water inlet pipe (3), which is connected to a water source and extends into a water purifier tank (2), and an air inlet pipe (6) extending coaxially inside the water pipe. One end of the air pipe is positioned outside the tank and the other end is positioned inside the water pipe to form an annular gap (8) between the end (7) of the air pipe and the inner wall of the water pipe. The water pipe has a mixing portion (9, 13) extending from the annular gap (8) to the mouth of the water pipe in the tank. In the mixing portion there is at least one ring (10-12) arranged on the inside of the water pipe and being hit by an annular water jet formed as the water passes through the gap (8), thereby forcing the water to mix with the air.

Abstract: A water-purifying apparatus, for reducing the radon content of radon-contaminated water, includes a reactor tank for treating the radon-contaminated water, a radon-releasing structure arranged in the upper part of the reactor tank to receive water from a first pump adapted to supply water from a source of water containing radon-contaminated water, the water from the radon-releasing structure accumulating in the reactor tank, an inlet duct extending between the first pump and the radon-releasing structure, an outlet duct from the reactor tank, the outlet duct being connected to a water consumption system, and a radon-gas outlet from the reactor tank. In a mixing structure, water from the first pump is mixed with water from the reactor tank with the aid of a second pump in order to produce such a water flow in the radon-releasing structure as results in effective radon release.