Recirculating combustion apparatus jet pump

Claim 2

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defining with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the Coanda nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an acute angle less than 30* to the forward boundary at the nozzle outlet, and the rear boundry terminates in a guiding surface directed at a small acute angle to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 3

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defining with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the Coanda nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an angle between 15* and 20* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at a small acute angle to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 4

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defining with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the Coanda nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an angle between 15* and 20* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at a small acute angle to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 5

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defininG with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the Coanda nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an acute angle less than 30* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at an angle less than 10* to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 6

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defininG with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the Coanda nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an acute angle less than 30* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at an angle less than 10* to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 7

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defining with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an angle between 15* and 20* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at an angle less than 10* to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.

Claim 8

A combustion apparatus comprising, in combination, an innermost wall defining a combustion zone having upstream and downstream ends, an inner wall defining an annular air passage with the innermost wall, an outer wall defining with the inner wall an annular recirculation passage from the downstream to the upstream end of the combustion zone and defining a discharge passage from the combustion zone, and an outermost wall defining a dilution air passage with the outer wall to conduct air into the discharge passage; the downstream end of the inner wall being curved inwardly to form a forward boundary for a Coanda nozzle, and the downstream end of the innermost wall being curved outwardly to define a rear boundary for the Coanda nozzle, the nozzle encircling the downstream end of the combustion zone between the said curved ends adapted to discharge into the recirculation passage and entrain combustion products discharged from the combustion zone into the recirculation passage; comprising a structure in which the forward boundary of the nozzle is substantially radial, the rear boundary of the nozzle converges toward the forward boundary to define a converging air entrance to the nozzle such that a surface equidistant from the said boundaries is directed at an angle between 15* and 20* to the forward boundary at the nozzle outlet, and the rear boundary terminates in a guiding surface directed at an angle less than 10* to a perpendicular to the adjacent forward boundary of the nozzle outlet, the guiding surface having a width greater than the width of the nozzle outlet; and a supplementary outlet means from the said air passage into the recirculation passage by-passing the Coanda nozzle.