1. A heat recovery device comprising a gas diverter valve, a gasliquid heat exchanger and a flow duct;
the gas diverter valve comprising a valve member movable between a bypass position and a heat exchange position;
the gasliquid heat exchanger comprising a plurality of gas flow passages, a gas inlet manifold and a gas outlet manifold in flow communication with said gas flow passages;
the flow duct comprising:
(a) a top sealing surface adapted to seal to a sealing surface of a gas flow conduit, the top sealing surface surrounding a top opening in the flow duct; and
(b) a duct wall extending between the heat exchanger and the top sealing surface and enclosing an interior of the flow duct, wherein the interior of the flow duct is in flow communication with the gas flow passages of the heat exchanger.
2. The heat recovery device of claim 1, wherein the flow duct further comprises:
(c) a bottom sealing surface along which the flow duct is secured to the heat exchanger, the bottom sealing surface surrounding a bottom opening in the flow duct through which the interior of the duct is in flow communication with the gas flow passages of the heat exchanger.
3. The heat recovery device of claim 1, wherein the gas diverter valve further comprises a planar support frame which defines a valve opening in which the valve member is received; and
wherein the flow duct further comprises a planar nesting ridge surrounding the top opening of duct, and wherein the support frame is received on top of the nesting ridge.
4. The heat recovery device of claim 3, wherein the top sealing surface comprises a top sealing flange which surrounds the nesting ridge and is separated therefrom by a shoulder, such that the nesting ridge is recessed relative to the top sealing flange.
5. The heat recovery device of claim 4, wherein a leading edge or a trailing edge of the valve member overlaps with an edge of the nesting ridge or the top sealing flange; and
wherein at least one of the valve member and the nesting ridge or top sealing flange is notched in an area of said overlap.
6. The heat recovery device of claim 1, further comprising a flow vane located proximate to a leading edge of the valve member when the valve is closed, wherein the flow vane has a smoothly contoured surface, and wherein the flow vane overlaps the leading edge or the trailing edge of the valve member when the valve is closed.
7. The heat recovery device of claim 1, wherein the gas diverter valve further comprises a planar support frame which defines a valve opening in which the valve member is received;
wherein one face of the support frame is secured to the top sealing surface of the duct and the opposite face of the support frame is adapted to seal to said sealing surface of said gas flow conduit; and
wherein the top sealing surface of the duct comprises a top sealing flange which extends inwardly from the duct wall.
8. The heat recovery device of claim 4, wherein the top sealing flange is formed separately from the remainder of the duct and is provided with an upstanding flange, and wherein the top of the duct is provided with an upstanding flange which is sealed to the upstanding flange of the top sealing flange.
9. The heat recovery device of claim 8, wherein the upstanding flanges are sealed together by crimping.
10. The heat recovery device according to claim 2, wherein the gasliquid heat exchanger further comprises a mounting plate having a gas inlet manifold opening and a gas outlet manifold opening, the openings of the mounting plate aligning with the respective gas inlet manifold and gas outlet manifold of the heat exchanger;
wherein the bottom sealing flange of the duct is secured to the mounting plate;
wherein an edge of the valve member engages an upstanding tab extending from the mounting plate into the interior of the duct, with the valve member in the heat exchange position;
wherein the upstanding tab engages and overlaps an edge of the valve member when the valve member is in the heat exchange position
wherein the upstanding tab is angled relative to the mounting plate by an angle of less than 90 degrees, such that the valve member engages the tab when rotated from the closed to the open position by less than 90 degrees; and
wherein the upstanding tab comprises a resilient member which biases the valve member toward the closed position when the valve member is engaged with the tab.
11. The heat recovery device according to claim 1, wherein the duct is constructed from first and second base portions, each having a bottom wall with an opening in alignment with one of the gas inlet manifold and the gas outlet manifold of the heat exchanger, wherein back-to-back walls of the base portions form a central dividing wall which extends upwardly from the bottom walls, and divides the duct into two portions throughout a portion of its height; and
wherein the duct further comprises an upper side wall portion extending between the base portions and the valve.
12. The heat recovery device according to claim 1, the gas diverter valve further comprises an arm having a first end and a second end, wherein the first end of the arm is rigidly attached to the valve member and the second end of the arm is pivotable about a pivot axis, such that the valve member is movable between the bypass position and the heat exchange position by pivoting the arm.
13. The heat recovery device of claim 12, wherein the valve member includes an angled end portion proximate to at least one of a leading edge and a trailing edge of the valve member, wherein the angled end portion extends from the valve member in a direction toward a surface which said leading or trailing edge of the valve member will engage when in the heat exchange position.
14. The heat recovery device of claim 12, wherein said valve member has an upper curved surface which, when the heat recovery device is joined to said gas flow conduit, protrudes into the gas flow conduit and causes a reduction in a cross-sectional area of the conduit in the vicinity of the valve member.
15. The heat recovery device of claim 1, wherein the interior of the flow duct is provided with an upstanding dividing wall which separates an inlet side of the flow duct from an outlet side of the flow duct, and which extends throughout substantially the entire height of the flow duct, wherein the dividing wall substantially prevents bypass flow in the heat exchange position;
wherein the valve member pivots about a pivot axis which is located proximate to either a leading edge or a trailing edge of the valve member; and
wherein the pivot axis is proximate to the dividing wall.
16. The heat recovery device of claim 1, wherein the flow duct further comprises a bottom opening through which the interior of the flow duct is in flow communication with the gas flow passages of the heat exchanger;
wherein the valve member pivots about a pivot axis which is located proximate to either a leading edge or a trailing edge of the valve member; and
wherein the pivot axis of the valve member is located in close proximity to the bottom opening.
17. In combination, a heat recovery device and a gas flow conduit, wherein the heat recovery device comprises a gas diverter valve, a gasliquid heat exchanger and a flow duct;
the gas diverter valve comprising a valve member movable between a bypass position and a heat exchange position;
the gasliquid heat exchanger comprising a plurality of gas flow passages, a gas inlet manifold and a gas outlet manifold in flow communication with said gas flow passages;
the flow duct comprising:
(a) a top sealing surface sealed to a sealing surface of the gas flow conduit, the top sealing surface surrounding a top opening in the flow duct;
(b) a duct wall extending between the heat exchanger and the top sealing surface and enclosing an interior of the flow duct, wherein the interior of the flow duct is in flow communication with the gas flow passages of the heat exchanger.
18. The combination of claim 17, wherein the conduit is flattened in the vicinity of the connection to the top sealing surface of the flow duct, such that the conduit is wider than the valve member, and wherein an interior surface of the conduit is provided with extensions which extend inwardly toward the valve member and which minimize bypass flow around the sides of the valve member in the heat exchange position.
19. The combination of claim 17, wherein a cross-sectional area of said conduit is increased proximate to an inlet side of the flow duct and reduced proximate to an outlet side of the flow duct.
20. A heat recovery device, comprising:
(a) a gasliquid heat exchanger comprising a plurality of gas flow passages, a gas inlet manifold, and a gas outlet manifold in flow communication with said gas flow passages;
(b) a gas flow duct comprising:
(i) a hollow interior chamber;
(ii) a first open end and a second open end spaced apart from one another along a bypass gas flow direction, wherein a bypass gas flow passage is defined through the hollow interior chamber between the first and second ends, along said bypass gas flow direction; and
(iii) at least one opening through which flow communication is provided between the interior chamber and the gas inlet and outlet manifolds of the heat exchanger, wherein said at least one opening is located between the first and second ends of the gas flow duct;
(c) a gas diverter valve comprising a first valve member and a second valve member, both of which are located within the hollow interior chamber of the gas flow duct, wherein each of the first and second valve members is pivotable about a pivot axis between a closed position in which flow communication between the hollow interior chamber and one of the manifolds of the heat exchanger is substantially prevented by the valve member, and an open position in which flow communication between the hollow interior chamber and one of the manifolds of the heat exchanger is permitted;
wherein, with both of the valve members in said closed position, the valve members substantially block said at least one opening so as to substantially prevent flow communication between the hollow interior chamber and the gas inlet and outlet manifolds of the heat exchanger.
21. The heat recovery device of claim 20, wherein the second valve member is located downstream of the first valve member along said bypass gas flow direction, and is spaced apart from the first valve member, wherein the first valve member substantially prevents flow communication between the hollow interior chamber and the gas inlet manifold of the heat exchanger in its closed position, and wherein the second valve member substantially prevents flow communication between the hollow interior chamber and the gas outlet manifold of the heat exchanger in its closed position.
22. The heat recovery device of claim 20, wherein each of the valve members comprises a flap having a leading edge and a trailing edge spaced apart along said bypass gas flow direction, and wherein the pivot axis of each said valve member is proximate to the leading or trailing edge thereof, and is transverse to the bypass gas flow direction.
23. The heat recovery device of claim 20, wherein the pivot axes of both the first and second valve members are proximate to said at least one opening, and wherein the first and second valve members remain substantially entirely within the hollow interior chamber during pivoting of the valve members from their closed positions to their open positions.
24. The heat recovery device of claim 20, wherein the pivot axis of the first valve member is proximate to the trailing edge of the first valve member, and the pivot axis of the second valve member is proximate to the leading edge of the second valve member.
25. The heat recovery device of claim 20, wherein said at least one opening and the pivot axes are located in a base of the gas flow duct, the base having a planar flange through which the gas flow duct is attached to the heat exchanger.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for selecting packets comprising:
initiating a first packet selection process at a first time slot;
initiating a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy;
selecting a first packet at a third time slot in response to the first packet selection process; and
selecting a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein each of the first packet selection process and the second packet selection process comprises two or more subprocesses executed to select the first packet and the second packet respectively, and
wherein at least one of the subprocesses in the first packet selection process is different from the subprocesses in the second packet selection process.
2. The method of claim 1, wherein the first and second packets are selected based on an arrival time of the first and second packets at a corresponding egress queue and a departure time of a previous packet at the corresponding egress queue from a data flow associated with the first and second packets respectively.
3. The method of claim 1, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed in one time slot.
4. The method of claim 3, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed at a different level of the scheduling hierarchy.
5. The method of claim 1, wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process.
6. The method of claim 5, wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria.
7. A method for selecting packets comprising:
initiating a first packet selection process at a first time slot;
initiating a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy;
selecting a first packet at a third time slot in response to the first packet selection process; and
selecting a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein each of the first packet selection process and the second packet selection process comprises two or more subprocesses executed to select the first packet and the second packet respectively,
wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process,
wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria, and
wherein the selection criteria is one selected in a group comprising an arrival time and a contracted rate.
8. A computer readable medium having stored thereon sequences of instructions which are executable by a system, and which, when executed by the system, cause the system to:
initiate a first packet selection process at a first time slot;
initiate a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy;
select a first packet at a third time slot in response to the first packet selection process; and
select a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein each of the first packet selection process and the second packet selection process comprises two or more subprocesses executed to select the first packet and the second packet respectively, and
wherein at least one of the subprocesses in the first packet selection process is different from the subprocesses in the second packet selection process.
9. The computer readable medium of claim 8, wherein the first and second packets are selected based on an arrival time of the first and second packets at a corresponding egress queue and a departure time of a previous packet at the corresponding egress queue from a data flow associated with the first and second packets respectively.
10. The computer readable medium of claim 8, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed in one time slot.
11. The computer readable medium of claim 10, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed at a different level of the scheduling hierarchy.
12. The computer readable medium of claim 8, wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process.
13. The computer readable medium of claim 12, wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria.
14. A computer readable medium having stored thereon sequences of instructions which are executable by a system, and which, when executed by the system, cause the system to:
initiate a first packet selection process at a first time slot;
initiate a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy;
select a first packet at a third tine slot in response to the first packet selection process; and
select a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process,
wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria, and
wherein the selection criteria is one selected in a group comprising an arrival time and a contacted rate.
15. A system, comprising:
a switch fabric; and
an egress coupled with the switch fabric to
initiate a first packet selection process at a first time slot,
initiate a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy,
select a first packet at a third time slot in response to the first packet selection process, and
select a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein each of the first packet selection process and the second packet selection process comprises two or more subprocesses executed to select the first packet and the second packet respectively, and
wherein at least one of the subprocesses in the first packet selection process is different from the subprocesses in the second packet selection process.
16. The system of claim 15, wherein the first and second packets are selected based on an arrival time of the first and second packets at a corresponding egress queue and a departure time of a previous packet at the corresponding egress queue from a data flow associated with the first and second packets respectively.
17. The system of claim 15, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed in one time slot.
18. The system of claim 17, wherein each of the two or more subprocesses in the first packet selection process and in the second packet selection process is executed at a different level of the scheduling hierarchy.
19. The system of claim 15, wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process.
20. The system of claim 19, wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria.
21. A system, comprising:
a switch fabric; and
an egress coupled with the switch fabric to
initiate a first packet selection process at a first time slot,
initiate a second packet selection process at a second time slot immediately following the first time slot such that execution of the second packet selection process overlaps execution of the first packet selection process at different levels of a scheduling hierarchy,
select a first packet at a third time slot in response to the first packet selection process, and
select a second packet at a fourth time slot in response to the second packet selection process, the fourth time slot immediately following the third time slot,
wherein each of the first packet selection process and the second packet selection process comprises two or more subprocesses executed to select the first packet and the second packet respectively,
wherein when a subprocess is selected by the first packet selection process, it is locked and cannot be selected by the second packet selection process,
wherein the subprocess is selected from one or more subprocesses at a same level of the scheduling hierarchy by sorting the one or more subprocesses at that level based on a selection criteria, and
wherein the selection criteria is one selected in a group comprising an arrival time and a contracted rate.