Catalytic burner, especially for a vehicle heater
A catalytic burner, especially for a vehicle heater, for the catalytically supported combustion of a fuel/combustion air mixture, includes a mixing chamber ( 24 ) and a combustion air feed device ( 36 ), for feeding combustion air to the mixing chamber ( 24 ) and a fuel feed device ( 28, 34 ), for feeding fuel to the mixing chamber ( 24 ), upstream of the mixing chamber ( 24 ). A catalyzer device ( 46 ) is provided with at least one catalyzer unit ( 48, 50, 52, 70 ), through which the fuel/combustion air mixture can flow. The fuel feed device ( 28, 34 ) includes an evaporator device ( 28 ) receiving liquid fuel from a fuel feed line ( 34 ) and releasing fuel vapor into the mixing chamber ( 24 ) or/and the at least one catalyzer unit ( 48, 50, 52, 70 ) includes a grid-like support with catalyst material on a surface of the a grid-like support.
1. A catalytic burner for the catalytically supported combustion of a fuel/combustion air mixture, the catalytic burner comprising:
a mixing chamber;
a combustion air feed device feeding combustion air to the mixing chamber;
a fuel feed device feeding fuel to the mixing chamber;
a catalyzer device downstream of the mixing chamber, the catalyzer device comprising at least one catalyzer unit, through which the fuel/combustion air mixture flows,
the fuel feed device comprising a porous evaporator device receiving liquid fuel from a fuel feed line and releasing fuel vapor into the mixing chamber;
a burner housing with a bottom wall and with a circumferential wall defining a combustion chamber downstream of the mixing chamber and containing the at least one catalyzer unit;
a projection provided at the bottom wall of the burner housing, the projection having a circumferential wall surrounded by the circumferential wall of the burner housing and extending from the bottom wall of the burner housing, the projection having a bottom wall arranged at a distal end of the projection in relation to the bottom wall of the burner housing, in the direction of a catalytic burner longitudinal axis, wherein the mixing chamber is provided in the interior of the projection, and at least one part of the porous evaporator device is carried at the bottom wall of the projection;
at least one part of the porous evaporator device provided at at least the bottom wall of the projection on a side of the at least the bottom wall of the projection facing away from the combustion chamber,
wherein one of the at least one catalyzer unit is arranged spaced apart from the circumferential wall of the projection.
2. A catalytic burner in accordance with claim 1 , wherein at least one of:
at least one flow opening is provided in an area of the circumferential wall of the projection, located adjacent to the bottom wall of the projection; and
at least one flow opening is provided in an area of the circumferential wall of the projection, located adjacent to the bottom wall of the burner housing.
3. A catalytic burner in accordance with claim 1 , wherein at least one and preferably each flow opening in the circumferential wall of the projection is covered by one of the at least one catalyzer unit.
4. A catalytic burner in accordance with claim 3 , wherein the at least one catalyzer unit is provided on an outer side of the circumferential wall of the projection, facing the combustion chamber.
5. A catalytic burner in accordance with claim 1 , wherein
at least one part of the porous evaporator device is provided on a side of the circumferential wall of the projection, facing the circumferential wall of the burner housing; and
at least one flow opening, leading to the mixing chamber, is provided in the circumferential wall of the burner housing, in an area of axial extension of the projection.
6. A catalytic burner in accordance with claim 1 , wherein a chamber is formed between the circumferential wall of the burner housing and the circumferential wall of the projection and is defined at least partially by the at least one catalyzer unit at an end area located at a distance from the bottom wall of the burner housing.
7. A catalytic burner in accordance with claim 1 , further comprising a flow diaphragm with at least one flow opening, the flow diaphragm being provided at the circumferential wall of the burner housing and at least one flow opening is covered by the at least one catalyzer unit.
8. A catalytic burner in accordance with claim 7 , wherein:
a chamber is formed axially between the projection and the flow diaphragm;
the chamber is divided by the catalyzer unit into a radially outer chamber area and a radially inner chamber area.
9. A catalytic burner in accordance with claim 1 , wherein the at least one catalyzer unit is formed in the upstream direction or in the downstream direction with an arc shape, conical shape or cylindrical shape.
10. A catalytic burner in accordance with claim 1 , further comprising an electrically excitable heating device associated with the porous evaporator device.
11. A catalytic burner in accordance with claim 1 , wherein
the at least one catalyzer unit comprises a grid support with catalyst material on a surface of the grid support.
12. A catalytic burner in accordance with claim 11 , wherein the grid support is deformed to obtain the installed shape of the at least one catalyzer unit.
13. A catalytic burner in accordance with claim 1 , wherein;
said one of said circumferential wall and said bottom wall of said projection have two diametrically opposite longer sides and two diametrically opposite shorter sides;
said side of said one of said circumferential wall and the bottom wall of said projection with said porous evaporator device is one of said longer sides of said one of said circumferential wall and said bottom wall of the projection.