A pressure change adsorption type oxygen enricher including an adsorption bedpacked with an adsorbent capable of selectively adsorbing nitrogen rather thanoxygen a compressor for feeding air to the adsorption bed a flow channel switchingvalve for repeating with a given timing the adsorption operation of feeding theair from the compressor to the adsorption bed and taking out enriched oxygen andthe desorption operation of depressurizing the adsorption bed to regeneratethe adsorbent and flow rate measuring means for measuring the flow rate of supplyof produced enriched oxygen. The oxygen enricher is characterized by havingpulsation detecting means for detection of any pulsation of supply oxygen andfurther having control means for control of the rate of air fed from the compressoron the basis of detection results. Thus, an apparatus satisfying the requirementof secondary features, such as compactness, low power consumption and noiselessness,is realized by paying attention to the fluctuation of product flow rate causedby suppression of the rate of oxygen produced and carrying out the feedback controlof production rate by a flow rate sensor alone.
