Device for the combustion of fluid combustible materials

In a device for the combustin of fluid materials, in particular particulate solid fuels suspended in a fluid, such as coal particles suspended in water, comprising:

• a fuel atomization nozzle,
• a combustion chamber, and
• means for supplying combustion air to said device,
• the improvement wherein said fuel atomization nozzle is located in a precombustion chamber having a mouth which opens into said combustion chamber,
• means for directing a minor part of said combustion air into said precombustion chamber, and
• means for directing a major part of said combustion air to the region of said mouth of said precombustion chamber opening into said combustion chamber, said fuel atomization nozzle having means defining two annular nozzle orifices coaxially located at one end of an approximately cylindrical hollow nozzle housing,
• an approximately cylindrical, hollow insert piece located within said housing,
• an axially aligned central shaft located within said insert piece,
• an impingement plate on the free end of said central shaft,
• the inner surface of said nozzle housing defining an outer first flow channel of annular cross-section for a first fluid medium,
• means defining an inner, second flow channel inside said outer, first flow channel and surrounding said shaft, said inner, second flow channel being of annular cross-section and being provided for a second fluid medium,
• means defining an annular groove at the end of said outer first flow channel in the region of the free end of said insert piece, said annular groove opening outwards at an angle to the longitudinal axis of said nozzle housing, and acting in use as a vibration generator, and communicating directly with said first annular nozzle orifice,
• a second insert piece being located between said insert piece and said shaft,
• means defining a first annular space between the inner surface of said insert piece and the outer surface of said second insert piece, and
• means defining at least one passage communicating between said first annular space and said inner, second flow channel surrounding said shaft.