US 4,277,942 A · Exhaust gas recirculation apparatus

Apparatus for recirculating a portion of the exhaust gases from an exhaust gas stream resulting from the combustion of an inlet fuel stream and an inlet air stream in a burner region, the apparatus comprising:

(a) wall means for separating the inlet air stream from the burner region and the exhaust gas stream;
(b) heat exchanger means associated with said wall means for extracting heat values from the exhaust gas stream to cool all the exhaust gases, said heat exchanger means also enclosing in part the burner region;
and
(c) ejector means formed in said wall means for admitting the inlet air stream into the burner region and for entraining and mixing a portion of the cooled exhaust gases from the cooled exhaust gas stream in the air being admitted, and air/cooled exhaust gas mixture being formed immediately prior to being admitted to the burner region,
the recirculated exhaust gases providing lower combustion temperatures and reduced NO.sub.x formation in the burner region.

2 more elements

Apparatus for recirculating a portion of the exhaust gases from an exhaust gas stream resulting from the combustion of an inlet fuel stream and an inlet air stream in a burner region, the apparatus comprising:

(a) wall means for separating the inlet air stream from the burner region and the exhaust gas stream;
and
(b) ejector means formed in said wall means for admitting the inlet air stream into the burner region and for entraining and mixing a portion of the exhaust gases from the exhaust gas stream in the air being admitted, said air/exhaust gas mixture being formed immediately prior to being admitted to the burner region,
the recirculated exhaust gases providing lower combustion temperatures and reduced NO.sub.x formation in the burner region, said wall means further including
(1) a first wall separating the inlet air stream from the exhaust gas stream and the burner region, and
(2) a second wall separating the exhaust gas stream from the burner region;
and
wherein said ejector means includes
(i) inlet nozzle means in flow communication with the inlet air stream,
(ii) outlet nozzle means in flow communication with the burner region, and
(iii) suction inlet means in flow communication with the exhaust gas stream and cooperating with said inlet nozzle means and said outlet nozzle means,
said inlet nozzle means being formed in said first wall, and said outlet nozzle means formed in said second wall, wherein said ejector means includes a plurality of ejectors, and said inlet nozzle means includes a plurality of individual inlet nozzles formed in said first wall, the axes of said inlet nozzles being directed toward the burner region.

9 more elements

Apparatus for recirculating a portion of the exhaust gases from an exhaust gas stream resulting from the combustion of an inlet fuel stream and an inlet air stream in a burner region, the apparatus comprising:

(a) wall means for separating the inlet air stream from the burner region and the exhaust gas stream;
and
(b) ejector means formed in said wall means for admitting the inlet air stream into the burner region and for entraining and mixing a portion of the exhaust gases from the exhaust gas stream in the air being admitted, said air/exhaust gas mixture being formed immediately prior to being admitted to the burner region,
the recirculated exhaust gases providing lower combustion temperatures and reduced NO.sub.x formation in the burner region, said wall means further including
(1) a first wall separating the inlet air stream from the exhaust gas stream and the burner region, and
(2) a second wall separating the exhaust gas stream from the burner region;
and
wherein said ejector means includes
(i) inlet nozzle means in flow communication with the inlet air stream,
(ii) outlet nozzle means in flow communication with the burner region, and
(iii) suction inlet means in flow communication with the exhaust gas stream and cooperating with said inlet nozzle means and said outlet nozzle means,
said inlet nozzle means being formed in said first wall, and said outlet nozzle means formed in said second wall, the burner region being cylindrical and fuel being admitted to the burner region at one axial end from the inlet fuel stream through fuel nozzle means, said wall means further including a third wall positioned to enclose the end of the burner region, the fuel nozzle means penetrating said third wall, said second wall partially enclosing the end of the burner region and being spaced from said third wall, said ejector means including an aperture in said second wall for exposing said third wall and said fuel nozzle means to the burner region, said outlet nozzle means including the annular gap formed between said second wall and said third wall at the edge of said aperture, and wherein said first wall also partially encloses the burner region end and is positioned between, and spaced from, said second wall and said third wall, said ejector means further including an aperture formed in said first wall for exposing said third wall to said second wall, said inlet nozzle means including the annular gap formed between said first wall and said third wall at the edge of said first wall aperture.

9 more elements

Apparatus for recirculating a portion of the exhaust gases from an exhaust gas stream resulting from the combustion of an inlet fuel stream and an inlet air stream in a burner region, the burner region being cylindrical and the fuel streams being admitted axially to the burner region through a fuel nozzle means, the apparatus comprising wall means for separating the inlet air stream from the burner region and the exhaust gas stream;

and ejector means formed in said wall means for admitting the inlet air stream into the burner region and for entraining and mixing a portion of the exhaust gases from the exhaust gas stream in the air being admitted, said air/exhaust gas mixture being formed immediately prior to being admitted to the burner region, the recirculated exhaust gases providing lower combustion temperatures and reduced NO.sub.x formation in the burner region, said wall means including a first wall separating the inlet air stream from the exhaust gas stream and the burner region, and a second wall separating the exhaust gas stream from the burner region;
and said ejector means including inlet nozzle means in flow communication with the inlet air stream, outlet nozzle means in flow communication with the burner region, and suction inlet means in flow communication with the exhaust gas stream and cooperating with said inlet nozzle means and said outlet nozzle means, said inlet nozzle means being formed in said first wall, and said outlet nozzle means formed in said second wall, said ejector means also including a plurality of ejectors, said inlet nozzle means including a plurality of individual inlet nozzles formed in said first wall, the axes of said inlet nozzles being directed toward the burner region, and said outlet nozzle means including a plurality of individual outlet nozzles formed in said second wall, each of said outlet nozzles being positioned co-axially with a respective inlet nozzle for receiving inlet air flow from said respective inlet nozzle, the interaction between the flow of inlet air from each of said inlet nozzles to the respective one of said outlet nozzles causing a portion of the exhaust gas stream to flow through said suction inlet means and becoming mixed with the inlet air stream in said outlet nozzles, the cross-sectional flow area of each of said outlet nozzles being greater than that of the respective one of said inlet nozzles, the axes of said plurality of outlet nozzles being coplanar and spaced around the periphery of the burner region, each outlet nozzle being directed inwardly toward said fuel nozzle means and eccentrically oriented for admitting the inlet air/exhaust gas mixture tangentially into the burner region for inducing swirling in the burner region and providing enhanced mixing of the fuel and inlet air/exhaust gas mixture.

Apparatus for recirculating a portion of the exhaust gases from an exhaust gas stream resulting from the combustion of an inlet fuel stream and an inlet air stream in a burner region, the burner region being cylindrical and the inlet fuel stream being admitted at one axial and through fuel nozzle means, the apparatus comprising wall means for separating the inlet air stream from the burner region and the exhaust gas stream;

and ejector means formed in said wall means for admitting the inlet air stream into the burner region and for entraining and mixing a portion of the exhaust gases from the exhaust gas stream in the air being admitted, said air/exhaust gas mixture being formed immediately prior to being admitted to the burner region, the recirculated exhaust gases providing lower combustion temperatures and reduced NO.sub.x formation in the burner region, said wall means including a first wall separating the inlet air stream from the exhaust gas stream and the burner region, and a second wall separating the exhaust gas stream from the burner region;
and said ejector means including inlet nozzle means in flow communication with the inlet air stream;
outlet nozzle means in flow communication with the burner region, and suction inlet means in flow communication with the exhaust gas stream and cooperating with said inlet nozzle means and said outlet nozzle means, said inlet nozzle means being formed in said first wall, and said outlet nozzle means formed in said second wall, said wall means further including a third wall positioned to enclose the end of the burner region, the fuel nozzle means penetrating said third wall, said second wall partially enclosing the end of the burner region and being spaced from said third wall, said ejector means including an aperture in said second wall for exposing said third wall and said third wall and said fuel nozzle means to the burner region, said outlet nozzle means including the annular gap formed between said second wall and said third wall at the edge of said aperture, and wherein said first wall partially encloses the burner region end and is positioned between, and spaced from, said second wall and said third wall, said ejector means further including an aperture formed in said first wall for exposing said third wall to said second wall, said inlet nozzle means including the annular gap formed between said first wall and said third wall at the edge of said first wall aperture, said ejector means further including a flow distribution means cooperating with said inlet nozzle means, said suction inlet means, and said outlet nozzle means.

Exhaust gas recirculation apparatus

Life of this patent

Exhaust gas recirculation apparatus

Life of this patent

Abstract

Claims22