Process for disinfecting hot water supply systems

Apparatus for ozone treatment of hot water for the purpose of disinfection of the water in a hot water supply system of a building, comprising:

• a heat transfer means for heating the water;
• a treatment tank for forming treated water;
• a feeding pile supplying hot water from the heat transfer means to the treatment tank, the feeding pipe having a reducing valve to decrease a higher operational pressure of the supply system to a lower pressure of the treatment tank;
• a device for generation of an ozone-containing gas with a second feeding pipe to the treatment tank;
• and
• a gas take off for the remaining gas coming out thereof;
• at least one drain for supplying the treated water from the treatment tank to an end user;
• and
• a pump, which is disposed at the drain, and which serves to increase the pressure of the treated water to the higher operational pressure of the water supply system.

A method for the ozone treatment of hot water, for the purpose of disinfection of the water, of a hot water supply system of a building, which system comprises a feeding pipe which supplies hot water from a heat transfer means to an ozone treatment device, and a distribution system which leads to users, wherein the method comprises the steps of:

• heating water to approximately 50 degrees Celsius;
• feeding the hot water from the heat transfer means, under a reduction of pressure, into a treatment tank having the ozone treatment device;
• lowering the pressure in the treatment tank to a range of 3.times.10.sup.4 to 7.times.10.sup.4 Pa, wherein the pressure is less than an operating pressure of the hot water supply system;
• introducing an ozone-containing gas continuously into the water in the treatment tank, wherein this ozone-containing gas passes through the water in the form of bubbles;
• dissolving ozone in the water, and the gas undergoing transition into a gas phase in an upper section of the tank;
• drawing off the gas from the tank;
• and
• conducting the treated water, under an increase of pressure to the operating pressure of the hot water supply system, to the distribution system of the building, wherein the operating pressure of the hot water supply system is in the range of 3.times.10.sup.5 Pa to 7.times.10.sup.5 Pa.