Abstract: A flow system, preferably a micro fluidic system, having a base part (4) with at least one flow path formed therein and a lid part (5) being attached to the base part (4) in such a manner that it covers the flow path(s). The flow path(s) comprise(s) a flow restrictor (1) and a flow channel comprising an inlet section positioned immediately upstream relatively to the flow restrictor (1). At least the inlet section of the flow channel has a cross section defining at least two distinct depths of the flow channel. This may be achieved by defining a centre section (3) and at least one peripheral section (2), the centre section (3) having a depth and a width which are substantially larger than the depth(s) and width(s) of the peripheral section(s) (2). If air bubbles are formed in the system this design of the inlet section will allow a flow of liquid to enter the shallower parts of the flow channel, while the air bubbles are confined to the deeper parts of the flow channel.

Abstract: The present invention relates to apparatus for delivering a controlled or restricted flow of liquid and limiting bubble fragmentation at the inlet. This is achieved in flow restrictor with a flow channel having over most of its length a substantially constant, minimum hydraulic diameter D=4A/W wherein A is the minimum local cross-sectional area of the channel and W is the minimum local wetting perimeter of the channel, by smoothly widening the channel at its inlet such that: at distances z from the inlet face with 0<z<z1, the channel has a hydraulic diameter Dz?k*D wherein k?1.3; at distances z from the inlet face with z1<z<z2, the channel has a hydraulic diameter Dz with k*D?Dz?D; and at distances z from the inlet face with z2<z, the channel has a hydraulic diameter Dz with Dz?1.02D, except possibly for a similar widening of the channel at the outlet.

Abstract: The present invention relates to apparatus for delivering a controlled or restricted flow of liquid and limiting bubble fragmentation at the inlet. This is achieved in flow restrictor with a flow channel having over most of its length a substantially constant, minimum hydraulic diameter D=4A/W wherein A is the minimum local cross-sectional area of the channel and W is the minimum local wetting perimeter of the channel, by smoothly widening the channel at its inlet such that: at distances z from the inlet face with 0<z<z1, the channel has a hydraulic diameter Dz?k*D wherein k?1.3; at distances z from the inlet face with z1<z<z2, the channel has a hydraulic diameter Dz with k*D?Dz?D; and at distances z from the inlet face with z2<z, the channel has a hydraulic diameter Dz with Dz?1.02D, except possibly for a similar widening of the channel at the outlet.