
{"publication_number": "US-9789431-B2", "abstract": "a cleaning device for a dust filter has a flow duct extending between an entry opening and an exit opening . an annular chamber surrounds the flow duct . gas - inlet connectors are provided for inflow of pressurized gas into the annular chamber . nozzle gaps delimited by nozzle - gap walls open toward the flow duct . the annular chamber has an upper annular shell and a lower annular shell interconnected pressure - tightly in a connection region . the gas - inlet connectors are molded on the upper annular shell . the lower annular shell is predominantly flat , extends horizontally or downwardly toward the nozzle gaps , and forms the lower nozzle - gap wall . in order to meet highest demands in terms of hygiene , in the connection region the angle at which the annular shells mutually abut in the annular chamber is at least 90 \u00b0. gaps and constrictions are thus avoided .", "application_number": "US-201615215602-A", "description": "the basic construction and the basic operating mode of the compressed - air cleaning device which operates according to the coand { hacek over ( a )