Multi-bed downflow reactor

A multi-bed downflow reactor for the catalytic conversion of a liquid and/or a gas comprising a chamber arranged between adjacent catalyst beds, which chamber comprises

• a) at least one device situated substantially annularly along the inner wall of said reactor comprising a series of openings for injecting an additional liquid and/or gas for controlling the temperature in the reactor,
• b) a collecting tray for receiving liquid,
• c) a centrally arranged compartment for receiving gas situated on said tray comprising side walls extending upwardly from the tray and containing substantially annular openings or series of openings for receiving gas, a roof interconnecting the side walls, and a swirl device to impart a swirling motion to gas passing therethrough to the mixing zone of element d)
• d) a mixing zone for mixing liquid and gas,
• e) a distribution tray substantially parallel to said collecting tray comprising passages allowing liquid and gas to pass downwardly over an adjacent catalyst bed, whereby the collecting tray is arranged downstream of the device(s) for injecting the additional liquid and/or gas and comprises guiding channels directing liquid downwardly into a central part of the mixing zone, wherein the compartment is arranged upon the collecting tray and comprises at least one passage allowing gas to pass downwardly, and wherein the mixing zone is arranged between the collecting tray and the distribution tray;
• and
• f) a centrally located pre-distribution tray located substantially parallel to said distribution tray wherein the distance between the collecting tray and pre-distribution tray and the distance between the pre-distribution tray and distribution tray ranges from a ratio of 1 to 3.