Modular pressure swing adsorption apparatus with clearance-type valve seals

A rotary module for implementing a high frequency pressure swing adsorption process includes a stator having a number of function compartments opening into the stator valve faces, a rotor rotatably coupled to the stator and including a number of apertures opening into the rotor valve faces, and a self-regulating clearance-type valve seal positioned between the valve faces of the stator and rotor so as to regulate the rate of gas flow between the stator and the rotor. Each valve seal includes a sealing face disposed adjacent a respective one of the rotor valve faces and is pivotable relative to the respective rotor valve face for varying the gas flow rate in accordance with the clearance distance between the sealing face and the respective rotor valve face. Each valve seal also includes a passage which communicates with one of the function compartments for varying the clearance distance in response to a pressure differential between the passage and an approaching aperture. In this way, the valve seal maintains a smooth pressure transition profile as the flow paths are switched between the function compartments. As a result, equilibrium is maintained between the adsorbent material and the mass transfer front of the gas, and the efficiency of the gas separation process is enhanced.