Fluid inlet device, use, and method or retrofitting

A fluid inlet device suitable for introducing a mixture of liquid and gas into a vessel, which fluid inlet device comprises a guide member having a surface on which surface a liquid film is present during normal operation, and having a main direction of gas flow along the surface; and wherein the guide member is provided with a liquid catcher channel extending from an upstream position with respect to the guide member to a downstream position, and wherein a virtual line along the guide member between the upstream position and the downstream position deviates from the main direction of gas flow; the use of the fluid inlet device for introducing a mixture of liquid and gas into a gas-liquid contacting vessel; and a method of retrofitting a fluid inlet device.