To eliminate harm of water by driving a diaphragm by nitrogen gas pressure as a power source to activate a pumping action.
Diaphragms 114A, 114B are driven by nitrogen gas pressure as a power source to activate a pumping action, in a diaphragm type circulation pump 11. Compressed nitrogen gas flowing into through the inlet 111 passes through gas passages alternately changed over by a slide valve and alternately enters air chambers 115A, 115B at the inside of diaphragms 114A, 114B symmetrically disposed in the right and left sides to actuate respective diaphragms 114A, 114B. Since the compressed nitrogen gas itself does not contain water content at all, there is no such an inconvenience as the slide valve 113 is frozed. Accordingly, the slide valve or the like in the driving structure part of the diaphragm is not frozed to prevent the pumping motion from deteriorating or going wrong.
ONISHI AKIMITSU
TAKEHARA NAOTO
INUI KAZUYUKI
