Oxygen pumping/separation devices

Pressure-swing parametric pumping would seem to have many applications for separation of from very small to quite large gas streams. One area of promise is the production of oxygen from air. Union Carbide is currently marketing a small device for producing up to about six liters per minute of 90+ percent oxygen for medical use in homes. This device actually contains... 

Electrochemical pumps and compressors that is, devices for dosage, separation, compression or removal of oxygen (or hydrogen), according to Faraday s law. The set-up devoted to separate oxygen from air has been also referred to as either the ion transport membrane (ITM) or solid electrolyte oxygen separation (SEOS) [6]. 

If two such electrodes are separated by a thin layer of only zirconia, the application of a potential will lead to the pumping of oxygen from the cathode to the anode. This device can be used as an amperometric sensor for oxygen if a diffusion barrier restricts the flux of oxygen to the cathode. Note that similar devices are also often used as potentiometric sensors according to the Nernst equation (i.e., the lambda-probe in cars with catalytic converters). In this case one side of the cell has to act as a reference, e.g., by using ambient air. 

The second advantage is the use of positive feedbacks that are arisen in the system at the recirculation mode of action due to saturation of filtered water with oxygen of air and effective removal of products of microbial metabolism, as described in Sections 8.5 and 8.6. The scheme of combined filtration-flotation device that operates continuously, under recirculating conditions (rotating wheel), is shown in Figure 8.14. In this device, the processes of filtration, bioflltration, bubble aeration (exchange absorption), and bubble-film extraction are realized in a common reaction space, separated by the unit case 1. The centrifugal pump 2 is used to ensure the circulation of treated... 

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