Method and device for mixing gaseous chemical auxiliary agent and fiber suspension

A method and apparatus for admixing a large volume of gas (at least about 10% in volume) with a fiber suspension having a concentration of 8-25%. It is especially suitable for the mixing of ozone-containing gas with pulp. The pulp enters through the inlet of the mixer. After the gas enters the mixture, the pulp and gas are fluidized to achieve homogenization. The flow of pulp through the mixer can be controlled by a throttle valve so that the mixer can The fluctuation of the inlet and outlet and the pressure drop are minimal, and the uniformly mixed gas and pulp mixture is discharged from the outlet of the mixer. The initial stage of mixing is the pre-mixing zone. The gas and pulp are fluidized at the flocculation level. The gas is evenly distributed throughout the pulp and then into a homogenized zone where the fiber suspension is at the fiber or flocculation micelle level. Fluidization takes place, in which the gas comes in contact with each fiber or flocculation micelle and finally reaches the maintenance zone where the fluidization level remains sufficiently high without bubbling and separating the gas from the pulp.