A switching device includes a rod, a rotating shaft, and a valve assembly including a cover and a plug member. The cover engaged with the valve body has a first block section, a second block section, a space, and a threaded hole communicates with the space. The plug member is rotatably provided in a chamber of the cover, changing an area of an opening of an inlet hole. The rotating shaft has a projection is adapted to drive the plug member to rotate. A rod body of the rod has a threaded section engaged with the threaded hole. When the projection abuts against the first block section, the plug member seals the inlet hole. When the projection abuts against the rod, the plug member changes the area to a first area. When the projection abuts against the second block section, the plug member changes the area to a second area.

A switching device includes a rod, a rotating shaft, and a valve assembly including a cover and a plug member. The cover engaged with the valve body has a first block section, a second block section, a space, and a threaded hole communicates with the space. The plug member is rotatably provided in a chamber of the cover, changing an area of an opening of an inlet hole. The rotating shaft has a projection is adapted to drive the plug member to rotate. A rod body of the rod has a threaded section engaged with the threaded hole. When the projection abuts against the first block section, the plug member seals the inlet hole. When the projection abuts against the rod, the plug member changes the area to a first area. When the projection abuts against the second block section, the plug member changes the area to a second area.

A method of operating a cooking zone (2) of a cooking appliance (1). The method includes determining an actual temperature value representative of an actual temperature of an item (6) to be heated; determining a power level (I) set on a user control device (3); and calculating a rectified power level (II) based on the actual temperature value, the actual power level (I) and a preset setpoint temperature. The rectified power level (II) is configured to remove differences between the actual temperature value and setpoint temperature and the rectified power level (II) is indicated on a user display (9, 4).

A method of operating a cooking zone (2) of a cooking appliance (1). The method includes determining an actual temperature value representative of an actual temperature of an item (6) to be heated; determining a power level (I) set on a user control device (3); and calculating a rectified power level (II) based on the actual temperature value, the actual power level (I) and a preset setpoint temperature. The rectified power level (II) is configured to remove differences between the actual temperature value and setpoint temperature and the rectified power level (II) is indicated on a user display (9, 4).

A liquid fuel portable heater (100) comprises: a combustion chamber (101) having a fuel inlet with a nebuliser (13); an electric pump (10) having an inlet (11) for suctioning said liquid fuel from a tank (6), and an outlet (12) connected to said nebuliser (13); a control unit (20) configured so that, when the heater (100) is turned on, said control unit (20) supplies the electric pump with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116). In addition, a method for controlling an electric power supply of a fuel electric pump (10) of a liquid fuel portable heater by means of an electric control unit (20) configured to control said electric power supply, comprising a step of electrically supplying said pump, once the heater is turned on, with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116).

A liquid fuel portable heater (100) comprises: a combustion chamber (101) having a fuel inlet with a nebuliser (13); an electric pump (10) having an inlet (11) for suctioning said liquid fuel from a tank (6), and an outlet (12) connected to said nebuliser (13); a control unit (20) configured so that, when the heater (100) is turned on, said control unit (20) supplies the electric pump with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116). In addition, a method for controlling an electric power supply of a fuel electric pump (10) of a liquid fuel portable heater by means of an electric control unit (20) configured to control said electric power supply, comprising a step of electrically supplying said pump, once the heater is turned on, with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116).

A switching device includes a rod, a rotating shaft, and a valve assembly including a cover and a plug member. The cover engaged with the valve body has a first block section, a second block section, a space, and a threaded hole communicates with the space. The plug member is rotatably provided in a chamber of the cover, changing an area of an opening of an inlet hole. The rotating shaft has a projection is adapted to drive the plug member to rotate. A rod body of the rod has a threaded section engaged with the threaded hole. When the projection abuts against the first block section, the plug member seals the inlet hole. When the projection abuts against the rod, the plug member changes the area to a first area. When the projection abuts against the second block section, the plug member changes the area to a second area.

The present disclosure includes: a casing with an open top; a combustion compartment including: a combustion chamber disposed inside the casing to generate a blue flame-shaped flame by burning vegetable oil; a combustion cover enclosing the combustion chamber therein, and having an inner wall spaced apart from an outer wall of the combustion chamber by a predetermined distance to form a predetermined cavity; and an air chamber disposed below the combustion cover with a lower end of the combustion chamber being positioned above, wherein the air chamber supplies outside air toward the combustion chamber during combustion of the vegetable oil; an oil tank that supplies the vegetable oil to the combustion chamber; and a control unit that controls whether or not to drive the air chamber, the flow and supply pressure of the outside air, and whether or not to supply the vegetable oil and a supply amount of the vegetable oil.

The present disclosure includes: a casing with an open top; a combustion compartment including: a combustion chamber disposed inside the casing to generate a blue flame-shaped flame by burning vegetable oil; a combustion cover enclosing the combustion chamber therein, and having an inner wall spaced apart from an outer wall of the combustion chamber by a predetermined distance to form a predetermined cavity; and an air chamber disposed below the combustion cover with a lower end of the combustion chamber being positioned above, wherein the air chamber supplies outside air toward the combustion chamber during combustion of the vegetable oil; an oil tank that supplies the vegetable oil to the combustion chamber; and a control unit that controls whether or not to drive the air chamber, the flow and supply pressure of the outside air, and whether or not to supply the vegetable oil and a supply amount of the vegetable oil.

According to various aspects, exemplary embodiments are disclosed of blow through direct fired heaters including evaporator coils and/or energy recovery ventilation.