IMMERSION PIPE HEATER

PURPOSE:To restrict a noise level to a lower level and improve an efficiency of combustion by a method wherein an extreme end of a burner is mounted below a liquid surface of heated liquid and a catalyst reacting part is constituted at a downstream side of the burner. CONSTITUTION:A burner 7 is ignited, a combustion gas of high temperature flows in a combustion gas passage 6 toward a flowing-out port 4 so as to heat liquid 2 around a flow pipe 5. In the midway part of the combustion gas passage 6 is formed a catalyst reaction part 9. If a carrier 10 is made by a ceramic honeycomb structure 11, it has many communication holes 13 in it, so that the combustion gas may flow through the communication holes 13 and the gas is discharged out of the pipe 5. When the combustion gas passes through a catalyst reaction part 9, the combustion gas reacts rapidly with remaining combustion air to make a complete combustion, so that it is possible to prevent harmful carbon oxide from being discharged. There is no useless discharging of energy, so that it is possible to keep a high efficiency of combustion. In addition, the ceramic honeycomb 11 has an action to store high temperature and an efficiency of thermal condition is further improved. The combustion gas flow passage downstream side of the catalyst reaction part 9 is throttled to be narrow and noise caused by a phenomenon of resonance in the pipe 5 is restricted to a low level.