Patent ID: 8359785

Claim:
A fan type noxious insect control apparatus comprising: an inlet port; an outlet port; and an axial flow fan; and a chemical carrier carrying a noxious insect control active ingredient; wherein: air is drawn through the inlet port by driving the axial flow fan and passed through the chemical carrier carrying the noxious insect control active ingredient to form air containing the noxious insect control active ingredient, the air being run out through the outlet port to diffuse the noxious insect control active ingredient into an ambient atmosphere; the inlet port is upstream of the axial flow fan and is open along an axial direction of the axial flow fan; the outlet port is downstream of the axial flow fan and is open along a radial direction of the axial flow fan; the apparatus further comprises an annular wall for guiding an air flow of the axial flow fan, and an air flow passage communicating between a delivery section of the axial flow fan and the outlet port; the annular wall has an inner peripheral surface opposing blade tips of the axial flow fan; the inner peripheral surface is generally circular in cross section perpendicular to an axis thereof and has an air guide section opposing the blade tips of the axial flow fan across a clearance; the air flow passage is configured so as to convert air flowing out of the axial flow fan in the axial direction thereof to air flowing in the radial direction thereof; the air flow passage has an outer peripheral guide surface and an inner peripheral guide surface radially opposed to the outer peripheral guide surface, the inner peripheral guide surface extending from a vicinity of a boss of the axial flow fan to the outlet port; and at least one of the outer peripheral guide surface and the inner peripheral guide surface of the air flow passage is of a generally arced shape in a radial section thereof such that air flows smoothly and without turbulence.