Torch head of blowtorch

A torch head of a blowtorch comprising:

• a head body portion;
• a nozzle system, wherein the nozzle system has a rear end and a front end opposite the rear end, wherein the rear end is inserted into the head body portion and the front end protrudes out of the head body portion respectively, wherein the nozzle system includes a suction seat, an inner tube, and an outer tube, wherein the suction seat includes a first outer channel extending along a longitudinal direction of the nozzle system from a first end adjacent to the rear end to a second end adjacent to the front end, wherein the suction seat includes at least one side channel extending from an outer periphery thereof along a radial direction of the nozzle system, wherein the at least one side channel is not opened to and communicated with the first outer channel, wherein the inner and the outer tubes are connected to the second end of the suction seat which is adjacent to the front end, wherein the outer tube circumferentially surrounds the inner tube, wherein the inner tube is hollow and defines an inner channel, wherein the outer tube is hollow and defines a second outer channel, wherein the first outer channel is opened to and communicated with the second outer channel, wherein the inner channel has a first end adjacent to the suction seat opened to and communicated with the at least one side channel, and wherein the inner channel has a second end opposite the first end opened to and communicated with the second outer channel, wherein the first and the second outer channels are passages for mixtures of air and fuel, wherein when the torch head produces a flame, the mixtures of air and fuel in the second outer channel are ignited, and so a negative pressure condition is created in the nozzle system, which cause air outside the torch head to be able to be sucked into the at last one side channel, and wherein the air sucked is able to be delivered to the second outer channel through the inner channel, thereby improving combustion efficiency and heating temperatures, preventing the mixtures of the air and fuel in the second outer channel from flowing in reverse direction toward the rear end, and inhibiting the flame from burning backward to the rear end, and preventing a gas explosion in the torch head;
• and
• an ignition system disposed in the head body portion protrudes into the second outer channel.