Gas diffuser with peripheral flow effect e.g. for air filter in protected work area has pairs of facing surfaces creating lateral flow faster than main flow

摘要

The gas diffuser (1), producing a main flow (71) at a given speed, is made with at least two pairs of facing surfaces (14) through which part of the flow is diffused. The surfaces extend mainly in the same direction as the main flow and are designed to create a lateral flow (72) at the periphery of the main flow with a speed higher than that of the main flow. At least some of the surfaces (14) form a downstream diffusion wall of constant porosity, made from perforated metal or textile material and having at least one fold (13) lying parallel to the direction of the main flow.