Abstract: A cyclonic separating apparatus includes a chamber for separating dirt and dust from an airflow, an inlet to the chamber and a shroud. The shroud includes a wall having inner and outer surfaces and a multiplicity of through-holes forming an outlet from the chamber. Each through-hole has an axis. The inner surface of the wall has a serrated profile having a plurality of serrations arranged around at least a part of the circumference of the wall, each serration having a first face and a second face. At least one through-hole passes through the first face of at least one serration. By providing a plurality of serrations around the inner circumference of the wall, the airflow is forced to follow a longer path through each through-hole for when compared to conventional arrangements. This reduces the amount of dirt and dust which is able to pass through the shroud.

Abstract: A cyclonic separating apparatus includes a chamber for separating dirt and dust from an airflow, an inlet to the chamber and a shroud. The shroud includes a wall having a multiplicity of through-holes forming an outlet from the chamber, each of the through-holes having substantially rectangular cross-sections with width to height ratios in the range of 1.5:1 to 1:1.5. The rectangular cross section of the through-holes maximizes the available through-hole area in the shroud, produces a low pressure drop across the shroud and reduces the amount of material required for manufacture. Further, this ratio allows the cross-sectional area of the through-holes to be dimensioned to prevent larger particles of dirt and dust from passing through the through-holes in the shroud, while still providing the required structural integrity.

Abstract: There is provided cyclonic separating apparatus (100) comprising a chamber (112) for separating dirt and dust from an airflow, an inlet (110) to the chamber (112) and a shroud (200). The shroud (200) comprises a wall (200) having a multiplicity of through-holes (208) forming an outlet from the chamber (112), each through-hole (208) having a width and a height, wherein the through-holes (208) have substantially rectangular cross-sections with width to height ratios in the range of 1.5:1 to 1:1.5. The rectangular cross section of the through-holes (208) maximises the available through-hole (208) area in the shroud (200). This results in a low pressure drop across the shroud (200) and reduces the amount of material required for manufacture. Further, this ratio allows the cross-sectional area of the through-holes (208) to be dimensioned to prevent larger particles of dirt and dust from passing through the through-holes (208) in the shroud (200), whilst still providing the required structural integrity.

Abstract: A cyclonic separating apparatus includes a chamber for separating dirt and dust from an airflow, an inlet to the chamber and a shroud. The shroud includes a wall having inner and outer surfaces and a multiplicity of through-holes forming an outlet from the chamber. Each through-hole has an axis. The inner surface of the wall has a serrated profile having a plurality of serrations arranged around at least a part of the circumference of the wall, each serration having a first face and a second face. At least one through-hole passes through the first face of at least one serration. By providing a plurality of serrations around the inner circumference of the wall, the airflow is forced to follow a longer path through each through-hole for when compared to conventional arrangements. This reduces the amount of dirt and dust which is able to pass through the shroud.