A mixer for a continuous flow reactor and methods for forming the mixer and the operation thereof. The mixer allows for segmentation of a primary reactant flow through a plurality of ports into many smaller flows that are injected as jets into a secondary reactant flow in channels of the mixer. The channel has a constant width dimension to enhance even flow distribution and local turbulence of the primary and secondary reactant flows. The constant width dimension of the channel and the size and number of the ports of the mixer can be configured to ensure the primary reactant flow injected into the channel directly impinges on a surface of the channel that is opposite the injection point at normal operating conditions.