SUPPLYING DEVICE OF OXYGEN ENRICHED GAS FOR COMBUSTION

PURPOSE:To enable to obtain gas stably by a structure wherein a means to produce the pressure difference between the primary side and the secondary side of selective gas permeable membrane is provided in each membrane cell and, in addition, means to take the fresh air in a piping system are provided in the piping system to supply oxygen enriched gas to a combustion device. CONSTITUTION:Air intake ports 52 are provided in order to change the state of oxygen enriched gas during a course passing through conduits 51 and 58 (not shown). A filter is employed at the air intake port 52. The intake rate of the gas is controlled by a valve 53. The intake port 52 and its control valve 53 may be arranged at any position as far as the position is in the rear stage of membrane cells 1. When the port 52 is arranged between the vacuum pump 55 and the membrane cells 1, the pressure of the pump is resulted to be changed and accordingly the amount of change in oxygen concentration is larger. On the other hand, when the port 52 is arranged in the rear stage of the pump, solely the dilution of oxygen enriched air is resulted and accordingly the amount of change in oxygen concentration is smaller. Consequently, port 52 may be preferably arranged at a plurality of positions in both cases just mentioned above, when necessary.