Tank venting filter having a constriction in the air inlet area

A tank venting filter comprising:

• a housing defining a longitudinal filter axis that is vertically oriented in operation and defines a top end and a bottom end of the housing;
• the housing comprising an air inlet at the bottom end;
• the housing comprising an air outlet at the top end, wherein the air outlet is configured to be connected to a tank;
• the housing comprising an elongated tubular constriction above the air inlet;
• a filter element disposed in the housing and fluidically arranged between the air inlet and the air outlet;
• a downpipe extending axially between the filter element and the bottom end of the housing;
• wherein the air inlet forms the elongated tubular constriction where it enters the bottom end of the housing into an interior of the housing, the tubular constriction extending into the interior of the housing and into a radial interior of the downpipe, the tubular constriction spaced radially inwardly way from the downpipe such that a second annular gap is formed between a radial inner side of the downpipe and the tubular constriction, the tubular constriction including the following openings:
• at least one air passage cutout opening into the second annular gap in the radial interior of the downpipe, at least one air passage cutout for airflow entering the tank venting filter;
• at least one water passage cutout opening arranged at a bottom end of the second annular gap and arranged axially below the at least one air passage cutout, the at least one water passage cutout returning water or liquids from the tank venting filter into the air inlet;
• wherein a water drain passage is formed between an interior of the downpipe and the bottom end of the housing, the water drain passage arranged to drain water into the at least one water passage cutout of the tubular constriction;
• an annular plate is secured on the radial exterior of the downpipe, the annular plate extending radially outwardly from the downpipe towards a radial inner side of the housing;
• wherein an annular sedimentation chamber in the housing surrounds the downpipe between the annular plate and the bottom of the filter element;
• wherein a flow passage is formed between the annular plate and radial interior of the housing, the flow passage in communication with the at least one air passage cutout of the tubular constriction and opening into the annular sedimentation chamber.