  Radiation pressure-driven outflows from luminous accreting supermassive black
holes are an important part of active galactic nucleus (AGN) feedback. The
effective Eddington limit, based on absorption of radiation by dust, not
electron scattering, is revealed in the plane of AGN absorption column density
$N_{\mathrm{H}}$ as a function of Eddington fraction $\lambda_{\mathrm{Edd}} =
L_{\mathrm{bol}}/L_{\mathrm{Edd}}$, where a lack of objects is seen in the
region where the effective limit is exceeded. Here, we conduct radiation
simulation using the CLOUDY code to deduce the radiative force applied onto
dusty gas at the nucleus and compare to the gravitational force to reveal the
outflow region and its boundary with long-lived absorption clouds. We also
investigate how the outflow condition is affected by various AGN and dust
properties and distribution. As expected, the dust abundance has the largest
effect on the $N_{\mathrm{H}} - \lambda_{\mathrm{Edd}}$ diagram since the
higher the abundance, the more effective the radiative feedback, while the
impact of the inner radius of the dusty gas shell, the shell width and the AGN
spectral shape are relatively negligible. The presence of other central masses,
such as a nuclear star cluster, can also make the feedback less effective. The
AGN spectral energy distribution depends on the mass of the black hole and its
spin. Though the effects of the AGN SED on the diagram are relatively small,
the fraction of ionizing ultraviolet (UV) photons from the blackbody accretion
disc is affected more by black hole mass than spin, and can influence the
efficiency of radiation pressure.
