Respiratory support system and blower for respiratory support system
A respiratory system including a dual outlet blower. One of a first and a second outlet of the blower provides a flow of gases to one of a pair of nasal outlets of a nasal interface and the other one of the first and second outlets provides a flow of gases to the other one of the pair of nasal outlets of the nasal interface. In an alternative embodiment, one of the first and second outlets provides a flow of gases to a nasal outlet of an oro-nasal interface and the other one of the first and second outlets provides a flow of gases to an oral outlet of the oro-nasal interface.
1. A dual axial outlet blower comprising:
an impeller comprising impeller blades, and
a housing comprising an impeller chamber in which the impeller rotates, an axial inlet, a first axial outlet and a second axial outlet,
wherein, with rotation of the impeller in a first direction of rotation, a first flow of gases from the first axial outlet is greater than a second flow of gases from the second axial outlet, and
with rotation of the impeller in a second direction of rotation, the second flow of gases from the second axial outlet is greater than the first flow of gases from the first axial outlet.
2. A blower as claimed in claim 1 , wherein: rotation of the impeller in the first direction of rotation generates a first flow of gases from the first axial outlet and a second flow of gases from the second axial outlet, rotation of the impeller in the second direction of rotation generates the first flow of gases or a third flow of gases from the second axial outlet and the second flow of gases or a fourth flow of gases from the first axial outlet, and the flow rate of the first flow of gases is greater than the flow rate of the second flow of gases, and the flow rate of the third flow of gases is greater than the flow rate of the fourth flow of gases; wherein the impeller blades are radially extending blades that are shaped to give a given flow rate for a given rotational speed regardless of rotational direction.
3. The dual axial outlet blower or claim 2 , wherein the impeller is symmetric.
4. The dual axial outlet blower of claim 1 , wherein the impeller is asymmetric.
5. The dual axial outlet blower of claim 4 , wherein the impeller blades are forwardly curved with respect to a rotational direction such that the impeller is preferentially rotated in one direction.
6. The dual axial outlet blower of claim 1 , wherein the dual axial outlet blower comprises a motor for driving rotation of the impeller, and the housing comprises a motor chamber for supporting the motor within the housing.
7. The dual axial outlet blower of claim 1 , wherein the impeller is a centrifugal impeller.
8. The dual axial outlet blower of claim 1 , wherein the first axial outlet is at a first side of the dual axial outlet blower and the second axial outlet is at a second side of the dual axial outlet blower.
9. The dual axial outlet blower of claim 1 , wherein the dual axial outlet blower further comprises a second impeller, and the housing further comprises a second impeller chamber in which the second impeller rotates, and
wherein the impeller and the second impeller are rotationally coupled to rotate together, the impeller generating the first flow of gases from the first axial outlet when the impeller and the second impeller rotate in the first direction of rotation, and the second impeller generating the second flow of gases from the second axial outlet when the impeller and the second impeller rotate in the second direction of rotation.
10. The dual axial outlet blower of claim 9 , wherein the dual axial outlet blower comprises a motor for driving rotation of the impeller and the second impeller, the motor comprising a rotor and a stator, wherein the impeller and the second impeller are rotationally coupled to the rotor.
11. The dual axial outlet blower of claim 10 , wherein the rotor is positioned axially between the impeller and the second impeller, and
wherein the housing comprises a motor chamber for the motor located axially between the impeller chamber and the second impeller chamber.
12. The dual axial outlet blower of claim 1 , wherein the housing comprises a first stator ring and a second stator ring, each stator ring comprising a plurality of volute paths, the first axial outlet comprising the plurality of volute paths of the first stator ring, and the second axial outlet comprising the plurality of volute paths of the second stator ring.
13. The dual axial outlet blower of claim 12 , wherein the dual axial outlet blower is without a volute chamber other than the plurality of volute paths of the stator rings.
14. The dual axial outlet blower of claim 13 , wherein each stator ring comprises a plurality of curved vanes, each said volute path separated from an adjacent volute path in each stator ring by a said curved vane.
15. The dual axial outlet blower of claim 14 , wherein the plurality of curved vanes are spaced circumferentially apart radially outside of or adjacent to or at a radial outer perimeter of the impeller.
16. The dual axial outlet blower of claim 13 , wherein each volute path has an increasing area perpendicular to an air flow direction at least part way through said volute path so that the speed of the air flow decreases along the said volute path to increase pressure of the flow.
17. The dual axial outlet blower of claim 16 , wherein the increasing area perpendicular to the air flow direction is provided by a circumferential or radial width that increases in dimension from an impeller chamber end of said volute path to an outlet end of said volute path.