A gas appliance, gas guide conduit and sealing device and method for avoiding gas back-feed or return flow

摘要

The present invention relates to a sealing device (100) in order to avoid a return flow, in particular of a gas heater with a fan for conveying of combustion air, a gas - / air - mixture and / or an exhaust gas, a gas guide conduit, a a gas appliance as well as a method for avoiding a return flow of a gas in a gas flow channel of a device.It is an object of the invention, a compact and which can be produced with little effort to provide sealing device (100), which provides a double sealing function and which is doubly secured against a failure.The a gas appliance are characterized, the gas guide conduit and the sealing device (100) as a result of the fact that two cooperating sealing units are provided, wherein one of the sealing units as a sealing unit (10) of a siphon with a valve seat (11) and the other sealing unit is designed as a valve-like the sealing unit (20) with a sealing surface (21) is provided, wherein the sealing surface (21) of the valve-like the sealing unit (20) for sealing at least partially in a liquid (40) of the siphon-type the sealing unit (10) engages.The method is characterized in that a sealing of the flow channel is carried out by means of two cooperating sealing units, wherein the sealing of an interaction of a siphon-type the sealing unit (10) with a valve-like the sealing unit (20) comprises, in such a way that, during the simultaneous sealing of the two valve units the valve-type the sealing unit in a liquid of the siphon-type the sealing unit (10) is at least partially submerged.