Devices for simulating pulmonary activities and/or pulmonary functions are known, in principle, in modern technology. Such lung simulators, which can provide especially a sinusoidal motion of air, i.e., a motion similar to that seen in a human being, in the form of inhalation and exhalation, are used, for example, in breathing simulators, which are used especially for a function test and/or approval test of respirators, for example, closed-circuit devices. In respirators, which are configured as such a closed-circuit device, especially as a closed-circuit device that is independent from the ambient air, the consumed air is not released into the surrounding area, as, for example, in respirators operating with compressed air, but is reprocessed in the respirator. For example, especially oxygen is added and carbon dioxide is adsorbed during such a processing. To make it possible to carry out a function and/or approval test in case of a closed-circuit device, an exhaled air must therefore be simulated. In particular, the temperature of the air must be regulated to about 37° C. and the relative humidity of the air must be set at about 90% to 100%. Conditioning modules are frequently used to achieve this.
Regulating the temperature of and humidifying a gas, especially air, is known, in principle. For example, gases can thus be passed through a plurality of thin tubes made of a membrane material, which are surrounded by water, whose temperature is regulated, for humidifying gases for fuel cells. Humidity is transported through the membrane into the gas in the tubes. It is, however, disadvantageous here that a high flow resistance develops for the gas due to the use of the thin tubes. Further, it is known that water with a regulated temperature can be injected into an air stream. Such devices are used, for example, in medical devices for ventilating patients. It is, however, disadvantageous here that the temperature regulation and humidification of only a small volume flow of gas can be achieved. Larger volume flows can be handled only by the use of a plurality of these devices. Another possibility, often used in conditioning modules, is to pass the water over a tank containing water with a regulated temperature. Heating and humidification of the gas takes place due to flowing over the surface of the water and the rise in humidity due to the take-up of water vapor from the liquid by the flowing gas taking place in the process. An increase in the amount of conditioned volume flow can only be achieved by enlarging the entire device in this case as well.
In an approval test for respirators, there are specifications, especially legal ones, concerning, for example, a maximum gas volume of the test set-up used and/or a maximum flow resistance of the device. Providing larger volume flows, which are likewise often necessary according to the specifications, solely by a corresponding scale-up of the device used thus has limitations, at least in this field of use.