JPS6055735B2 - Forced supply and exhaust combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forced air supply/exhaust type combustion apparatus in which a fan motor is used to forcibly supply and exhaust air into a combustion section, and is particularly intended to prevent overheating of the fan motor.

In a forced air supply/exhaust type combustion device, the fan motor is generally installed on the exhaust side of the combustion section in order to keep the combustion section under negative pressure and prevent the leakage of toxic gases. However, there was a problem in that it was exposed to a high-temperature atmosphere, leading to thermal failure.

Conventionally, this problem was solved by mixing air into the exhaust gas to lower the exhaust gas temperature, but such exhaust temperature lowering means created a new problem of dew condensation.

The present invention eliminates these conventional drawbacks, and embodiments thereof will be described below with reference to the accompanying drawings.

The figure shows a forced air supply/exhaust type gas instantaneous water heater; in other words, air flowing in through an air supply path 1 and gas from a gas path 2 are mixed in a mixer 3 and then reach a burner 4. It is ignited by pilot burner 5.

Thereafter, the combustion gas from the burner 4 undergoes heat exchange in a heat exchanger 6, and is discharged through an exhaust path 7. and,
A fan motor 8 is connected midway through the exhaust path 7.

The fan motor 8 has a centrifugal fan 10 housed in a casing 9 mounted on a shaft 12 of a motor 11, and the shaft 12 has one end inside the room and the other end connected to the suction part of the fan 10. An open hollow section 13 is formed. A water supply pipe 14 is connected to the heat exchanger 6 by loosely fitting the hollow portion 13 of the shaft 12 therein. In the above configuration, when the fan motor 8 is now driven, indoor air is sucked into the fan 10 through the hollow portion 13 of the shaft 12 along with the exhaust gas.

The amount of air flowing through the hollow portion 13 is small and does not affect the exhaust temperature, but it is cooled by the water flowing through the water supply pipe 14 and has a sufficient function of cooling the inside of the motor 8. Therefore, the motor 8 does not overheat.
This can prevent mechanical and electrical failures caused by heat. Although air is used as the cooling medium in the above embodiment, it is also possible to use the hollow portion 13 itself as a part of the water supply pipe.

Further, when applied to a hot air heater, a part of the air reaching the heat exchanger may be bypassed to flow into the hollow portion 13.

As explained above, in the present invention, the fluid before reaching the heat exchanger is made to flow into the hollow part of the motor shaft to cool the motor from the inside, so there is no overheating of the motor due to exhaust heat, and thermal failure is avoided. It is possible to reliably prevent this, and it also has excellent practical effects such as no dew condensation due to a drop in exhaust gas temperature as in the conventional case.

[Brief explanation of drawings]

The figure is a partially cutaway sectional view of a forced air supply and exhaust gas instantaneous water heater showing an embodiment of the present invention. 4...Burner, 6...Heat exchanger, 8.
...Fan motor, 12...Motor shaft,
14...Fluid passage (water supply pipe).

Claims (1)

[Claims] 1 A fan motor is installed on the exhaust side of the combustion section consisting of a burner and a heat exchanger, and the motor shaft of this fan motor is
A forced air supply/exhaust type combustion device, which has a hollow shape with both end faces open, and has a fluid passage provided in the hollow portion through which part or all of the fluid flows before reaching the heat exchanger.