Mixer

Patent metadata

Field	Value
Publication number	US-2018252412-A1
Application number	US-201815907953-A
Country	US
Kind code	A1
Filing date	Feb 28, 2018
Priority date	Mar 2, 2017
Publication date	Sep 6, 2018
Grant date	—

Abstract

A mixer having a housing, a duct within the housing, a first and a second injector arranged to inject a fluid at a centre zone of the duct, a third and a fourth injector arranged to inject the fluid at a wall zone of the duct. The first/third injectors are at a distance D1=v/2f1 or odd integer multiples of it from the second/fourth injectors in the absence of an acoustic node between them, or at a distance D1=λconv=v/f1 or full wave length integer multiples of it in the presence of an acoustic node between them. Advantageously f1 is greater than f2.

First claim

1 . A mixer comprising:
a housing; a duct within the housing; a first injector and a second injector arranged to inject a fluid at a centre zone of the duct; a third injector and a fourth injector arranged to inject the fluid at a wall zone of the duct, wherein: the first injector is at a distance D 1 =v/2f 1 or odd integer multiples of it from the second injector in an absence of an acoustic node between the second injector and the first injector, or at a distance D 1 =λ conv =v/f 1 or full wave length integer multiples of it in a presence of an acoustic node between the second injector and the first injector; and the third injector is at a distance D 2 =v/2f 2 or odd integer multiples of it from the fourth injector in an absence of an acoustic node between the third injector and the first injector, or at a distance D 2 =v/f 2 from the first injector in a presence of an acoustic node between the third injector and the first injector; wherein: f 1 is an oscillating frequency to be damped at the wall zone of the duct; f 2 is an oscillating frequency to be damped at the centre zone of the duct; and v is a fluid flow speed through the duct, wherein f 1 is greater than f 2 .

2 . The mixer of claim 1 , wherein both f 1 and f 2 are lower than 150 Hz.

3 . The mixer of claim 1 , wherein the first injector and/or the second injector and/or the third injector and/or the fourth injector comprise:
a plurality of rows of nozzles close to one another.

4 . The mixer of claim 2 , wherein nozzles of different rows of nozzles of a same injector have different penetration.

5 . The mixer of claim 2 , wherein the nozzles of a same row of nozzles have different penetration.

6 . A gas turbine comprising:
a compressor; a first combustion chamber; a second combustion chamber arranged to be fed with a fluid coming from the first combustion chamber; and a turbine, wherein between the first combustion chamber and the second combustion chamber a mixer is provided, which mixer includes: a housing; a duct within the housing; a first injector and a second injector arranged to inject a fluid at a centre zone of the duct; a third injector and a fourth injector arranged to inject the fluid at a wall zone of the duct, wherein: the first injector is at a distance D 1 =v/2f 1 or odd integer multiples of it from the second injector in an absence of an acoustic node between the second injector and the first injector, or at a distance D 1 =λ conv =v/f 1 or full wave length integer multiples of it in a presence of an acoustic node between the second injector and the first injector; and the third injector is at a distance D 2 =v/2f 2 or odd integer multiples of it from the fourth injector in an absence of an acoustic node between the third injector and the first injector, or at a distance D 2 =v/f 2 from the first injector in a presence of an acoustic node between the third injector and the first injector; wherein: f 1 is an oscillating frequency to be damped at the wall zone of the duct; f 2 is an oscillating frequency to be damped at the centre zone of the duct; and v is a fluid flow speed through the duct, wherein f 1 is greater than f 2 .

Assignees

• Ansaldo Energia Switzerland AG

Inventors

• Bothien Mirko Ruben
• Scarpato Alessandro

Classifications

• F23R3/346 Primary

  for staged combustion · CPC title

• F23R3/283

  Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances · CPC title

• F23R2900/03341

  Sequential combustion chambers or burners · CPC title

• F23R2900/00014

  Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators · CPC title

• F23R3/00 Primary

  Continuous combustion chambers using liquid or gaseous fuel · CPC title