Injection nozzle 7 and electrode rods 8 and 9 (ignitor) are surrounded by double-cylinder flame stabilizer 10. Toroidal blocking plate 13 closes between inner and outer cylinders 11 and 12 of the stabilizer at its distal end whose proximal end is connected with line 15 for introducing combustion air 14 to between the cylinders. Inflow holes 16 are formed throughout the inner cylinder at its proximal end. Peripheral fins 17 are formed peripherally on the inner cylinder radially inwardly through cutting and bending-up at positions shifted from the inflow holes toward the distal end of the inner cylinder such that combustion air is introduced from circumferentially to form swirling flow inside the inner cylinder. End fins 18 are formed on the blocking plate in fuel injection direction through cutting and bending-up such that combustion air is discharged circumferentially to form swirling flow around flame 21.

Provided is an injector (30) having a plurality of injector modules (44) that include a spray cup having a chamber and a plurality of radial air passages for directing air radially into the chamber, and a pressure swirl atomizer attached to the spray cup and having a fluid passage for directing fluid axially into chamber and an air passage for directing air axially into the chamber. By providing radial and axial air flow and axial fuel flow into the chamber, the fuel may be mixed to prevent local hot spots that lead to high NOx emissions, and a stable flame may be maintained without autoignition and flashback. The axial air flow also prevents recirculation zones from forming at a base of the spray cup, provides improved atomization and enhanced combustion.

An evaporator assembly (10), in particular for a fuel-operated vehicle heater (12), comprising a pot-like evaporator reception (14), an evaporator body (16) inserted into the pot-like evaporator reception (14), a plate-like designed hold-down element (18), which is fixed to the evaporator reception (14) and fixes the evaporator body (16) in the evaporator reception (14), and wherein the plate-like designed hold-down element (18) has at least one retaining claw (22), which has an upper part (26) on an upper side (24) of the plate-like designed hold-down element (18) and a lower part (30) on a lower side (28) of the plate-like designed hold-down element (18), wherein the upper part (26) and the lower part (30) point away from the plate-like designed hold-down element (18).

An evaporator assembly (10), in particular for a fuel-operated vehicle heater (12), comprising a pot-like evaporator reception (14), an evaporator body (16) inserted into the pot-like evaporator reception (14), a plate-like designed hold-down element (18), which is fixed to the evaporator reception (14) and fixes the evaporator body (16) in the evaporator reception (14), and wherein the plate-like designed hold-down element (18) has at least one retaining claw (22), which has an upper part (26) on an upper side (24) of the plate-like designed hold-down element (18) and a lower part (30) on a lower side (28) of the plate-like designed hold-down element (18), wherein the upper part (26) and the lower part (30) point away from the plate-like designed hold-down element (18).

A vehicle heater includes a heater housing (12) elongated in a direction of a housing longitudinal axis (L). A housing circumferential wall (34) defines a combustion air flow space (40). A combustion chamber assembly unit (14) is carried on the heater housing and has a combustion chamber (20) receiving combustion air from the combustion air flow space. A combustion air blower (42), with a combustion air blower housing (44), is carried on the heater housing. A combustion air inlet opening (56), in the combustion air blower housing, provides the inlet for combustion air into the combustion air blower. A combustion air connection unit (64), carried on the heater housing, has a combustion air passage duct (74) open outwardly in a first duct opening area (76) for receiving combustion air. The combustion air passage duct is open towards the combustion air inlet opening in a second duct opening area (78).

An atomizing burner and corresponding method for turning an atomizing burner from an ON state to an OFF state. The burner has independently controllable flows of atomizing air, combustion air, and fuel flow, the burner in the ON state having flow values of burner parameters including flow of atomizing air, flow of combustion air, and fuel flow. The method includes: changing, in response to an OFF instruction, flow of at least one of the flow of atomizing air, combustion air and/or fuel to a lower non-zero value; first discontinuing, after a first period of time since the changing, flow of fuel and flow of atomizing air; maintaining, for a second period of time since the first period of time, flow of combustion air; second discontinuing, after the maintaining, flow of combustion air; wherein the maintaining prevents buildup of excess heat inside the burner during the transition to the OFF state.

An atomizing burner and corresponding method for turning an atomizing burner from an ON state to an OFF state. The burner has independently controllable flows of atomizing air, combustion air, and fuel flow, the burner in the ON state having flow values of burner parameters including flow of atomizing air, flow of combustion air, and fuel flow. The method includes: changing, in response to an OFF instruction, flow of at least one of the flow of atomizing air, combustion air and/or fuel to a lower non-zero value; first discontinuing, after a first period of time since the changing, flow of fuel and flow of atomizing air; maintaining, for a second period of time since the first period of time, flow of combustion air; second discontinuing, after the maintaining, flow of combustion air; wherein the maintaining prevents buildup of excess heat inside the burner during the transition to the OFF state.

An atomizing burner and corresponding method for turning an atomizing burner from an ON state to an OFF state. The burner has independently controllable flows of atomizing air, combustion air, and fuel flow, the burner in the ON state having flow values of burner parameters including flow of atomizing air, flow of combustion air, and fuel flow. The method includes: changing, in response to an OFF instruction, flow of at least one of the flow of atomizing air, combustion air and/or fuel to a lower non-zero value; first discontinuing, after a first period of time since the changing, flow of fuel and flow of atomizing air; maintaining, for a second period of time since the first period of time, flow of combustion air; second discontinuing, after the maintaining, flow of combustion air; wherein the maintaining prevents buildup of excess heat inside the burner during the transition to the OFF state.

An air swirler arrangement comprises a coaxial arrangement of an inner and an outer air swirler passage. Each air swirler passage comprises a radial flow swirler. Air swirler arrangement comprises a coaxial arrangement of first, second and third members. Second member has radially extending upstream portion spaced axially from first member and a convergent portion. Third member has a radially extending upstream portion spaced axially from the upstream portion of second member and a radially inner surface having convergent and divergent downstream portions and a radially outer surface having a divergent downstream portion. First, second and third members the vanes of the radial flow swirlers is a monolithic structure. Plurality of circumferentially spaced passages are provided within the third member and each passage has an inlet in the surface and an outlet arranged to direct fluid onto the divergent portion of the surface or the surface of the third member.

An air swirler arrangement comprises a coaxial arrangement of an inner and an outer air swirler passage. Each air swirler passage comprises a radial flow swirler. Air swirler arrangement comprises a coaxial arrangement of first, second and third members. Second member has radially extending upstream portion spaced axially from first member and a convergent portion. Third member has a radially extending upstream portion spaced axially from the upstream portion of second member and a radially inner surface having convergent and divergent downstream portions and a radially outer surface having a divergent downstream portion. First, second and third members the vanes of the radial flow swirlers is a monolithic structure. Plurality of circumferentially spaced passages are provided within the third member and each passage has an inlet in the surface and an outlet arranged to direct fluid onto the divergent portion of the surface or the surface of the third member.