In this research particle trajectory in a bidirectional vortex flow has been numerically predicted and the results experimentally validated. Scale analyses of forces show their order of magnitudes and give a criterion to recognize the order of magnitude of exerting forces on the particle. The particle has been assumed to be a rigid sphere. Initial velocity, diameter, density, and position of entering particle are assumed to be known. If the particle length scale is considered not to be comparable with the chamber length and if particle number density is low, then influence of particle on the flow field is negligible and a one-way solution is applicable. The governing equation is converted to a set of nonlinear, coupled, second-order ODE and solved by a numerical scheme. Results show that higher density, larger diameter, and higher initial axial velocity tend to move the particles further in the axial direction. Also, the maximum axial movement of the particle occurs when the initial radial velocity is zero and there is an optimum entrance position that provides a maximum traveling trajectory for particles. Increasing initial z-direction velocity component and density will result in increasing traveling trajectory.