Air precleaner and method for separating heavier-than-air particulate debris from debris laden air
View Patent ↗A method and an air precleaner for separating heavier-than-air particulate debris from debris laden air to provide a clean airflow are disclosed. A flow path extends through the precleaner from an inlet to an outlet. Debris laden air is drawn into the inlet by a vacuum in communication with the outlet of the precleaner. A vortex flow of the debris laden air is formed in the flow path and flows through a first stage, ejective based precleaner and a second stage, scavenger based precleaner. Each stage centrifugally separates and removes particles of debris from the vortex flow. Efficient operation under extreme conditions with significant improvement in air filter life, is made possible by the air precleaner and method.
1. An air precleaner for separating heavier-than-air particulate debris from debris laden air to provide a clean air flow, the precleaner comprising:
a flow path extending through the precleaner from an inlet to an outlet;
airflow management structure positioned to direct debris laden air drawn into the precleaner inlet into a vortex flow in the flow path in response to the application of a vacuum to the outlet which is communicated through the flow path to the inlet;
a first stage precleaner in the flow path to centrifugally separate and remove particles of debris from the vortex flow and the flow path, the first stage precleaner including a particle accelerator rotatably mounted in the first stage precleaner and rotatably driven by the vortex flow in the flow path to increase the rotational velocity of the vortex flow and encourage removal of debris therefrom; and
a second stage precleaner in the flow path downstream from the first stage precleaner to receive the vortex flow from the first stage precleaner and to centrifugally separate and remove from the vortex flow and the flow path particles of debris remaining in the vortex flow.
2. The air precleaner according to claim 1 , wherein the second stage precleaner includes a catch tray for collecting centrifugally separated debris from the vortex flow, the catch tray being located in a separator chamber for the vortex flow in the second stage precleaner.
3. The air precleaner according to claim 2 , further comprising a scavenger port in the catch tray through which collected debris in the catch tray can be exhausted.
4. The air precleaner according to claim 3 , further comprising a vacuum source connected to the scavenger port.
5. The air precleaner according to claim 4 , wherein the vacuum source employs exhaust gas flow from an internal combustion engine to develop a vacuum to scavenge collected debris.
6. The air precleaner according to claim 1 , further comprising a prescreen that removes large debris from debris laden air entering the precleaner.
7. The air precleaner according to claim 1 , wherein the airflow management structure includes a plurality of vanes.
8. The air precleaner according to claim 1 , wherein the first stage precleaner further includes a circular separator chamber having an inner wall with an ejection duct therein to remove centrifugally separated debris and air from the vortex flow moving through the separator chamber.
9. The air precleaner according to claim 8 , wherein an end of the circular separator chamber has a toroidal dome for smooth airflow transition of the vortex flow moving through the circular separator chamber in a cyclonic pattern past the ejection duct toward the toroidal dome where it is folded over by the toroidal dome for whirlpooling back in a direction away from the toroidal dome inwardly of and through the vortex flow moving toward the toroidal dome.
10. The air precleaner according to claim 9 , wherein the particle accelerator includes a central hub having an outer configuration which forms a smooth transition from an arch of the toroidal dome to an outer end of the central hub.
11. The air precleaner according to claim 9 , wherein the inner wall of the separator chamber, as seen in a cross section thereof taken along a longitudinal axis of the air precleaner slopes inwardly in the direction of the toroidal dome to decrease the cross sectional area of the vortex flow moving through the separator chamber.
12. The air precleaner according to claim 11 , wherein the shape of the separator chamber provides a linear reduction in cross sectional area of the flow path for the vortex flow moving through the separator chamber thereby increasing the velocity of the vortex flow in the separator chamber and keeping debris and the air circulating around the inner wall of the separator chamber for ejection through the ejection duct.
13. The air precleaner according to claim 1 , wherein the particle accelerator includes a central hub and a plurality of curved appendages that are arc back from the central hub in a swept back attitude relative to the direction of the vortex flow.
14. The air precleaner according to claim 13 , wherein a curved area of the appendages extends into a passageway which forms a portion of the flow path downstream of the separator chamber, the curved area being cupped in the direction of the airflow vortex in the passageway for rotationally powering the particle accelerator at a speed greater than the rotational speed of the vortex flow upstream of the particle accelerator.
15. An air precleaner system for separating heavier-than-air particulate debris from debris laden air to provide a clean airflow to the intake of an internal combustion engine, the system comprising:
a flow path extending through the precleaner system from an inlet to an outlet in communication with the intake of an internal combustion engine;
airflow management structure positioned to direct debris laden air drawn into the precleaner through the inlet into a vortex flow in the flow path in response to the application of a vacuum to the outlet by the engine intake, which vacuum is communicated through the flow path to the inlet;
a first stage precleaner in the flow path to centrifugally separate and remove particles of debris from the vortex flow and the flow path, the first stage precleaner including a particle accelerator rotatably mounted in the first stage precleaner and rotatably driven by the vortex flow in the flow path to increase the rotational velocity of the vortex flow and encourage removal of debris therefrom; and
a second stage precleaner in the flow path downstream from the first stage precleaner to receive the vortex flow from the first stage precleaner and to centrifugally separate and remove from the vortex flow particles of debris remaining in the vortex flow,
wherein the second stage precleaner includes a catch tray for collecting centrifugally separated debris from the vortex flow, a scavenger port in the catch tray through which collected debris in the catch tray can be exhausted, and a vacuum source connected to the scavenger port, the vacuum source employing exhaust gas flow from the internal combustion engine to develop a vacuum to scavenge collected debris.
16. A method of separating heavier-than-air particulate debris from debris laden air to provide a clean air flow, the method comprising:
drawing debris laden air into an inlet of an air cleaning system by application of a vacuum to an outlet of the air cleaning system which is in communication with the inlet by way of a flow path extending through the system between the inlet and the outlet;
directing debris laden air drawn into the inlet of the air cleaning system into a vortex flow in the flow path;
centrifugally separating and removing particles of debris from the vortex flow and the flow path in a separator chamber of a first stage precleaner of the system, wherein the centrifugal separating and removing is facilitated by transferring energy from the vortex flow in the flow path downstream of the separator chamber to increase the rotational velocity of the vortex flow in the separator chamber;
directing the vortex flow in the flow path downstream of the first stage precleaner through a second stage precleaner to centrifugally separate and remove remaining particles of debris from the vortex flow in the flow path.
17. The method according to claim 16 , including collecting the particles of debris separated and removed at the second stage precleaner and scavenging the collected debris from the air cleaning system by means of a vacuum developed from the exhaust gas flow of an internal combustion engine.
18. An air precleaner for separating heavier-than-air particulate debris from debris laden air to provide a clean air flow, the precleaner comprising:
a flow path extending through the precleaner from an inlet to an outlet;
airflow management structure positioned to direct debris laden air drawn into the precleaner into a vortex flow in the flow path in response to the application of a vacuum to the outlet which is communicated through the flow path to the inlet;
an ejective based precleaner stage in the flow path to centrifugally separate and remove particles of debris from the vortex flow and eject the debris from the air precleaner;
a scavenger based precleaner stage in the flow path downstream from the ejective based precleaner stage to receive the vortex flow from the ejective based precleaner stage and to centrifugally separate and remove from the vortex flow particles of debris remaining in the vortex flow.
19. The air precleaner according to claim 18 , wherein the scavenger based precleaner stage includes a catch tray for collecting centrifugally separated debris from the vortex flow and a scavenger port through which collected debris in the catch tray can be exhausted.
20. The air precleaner according to claim 19 , further comprising a vacuum source connected to the scavenger port, the vacuum source developing a vacuum employing exhaust gas flow from an internal combustion engine to scavenge debris collected in the catch tray.