JPH0264306A - Combustion device - Google Patents

Abstract

PURPOSE:To enable a small-sized device to be attained and improve an effect of sound muffling action by a method wherein the second number of acoustic natural vibration determined by a volume of a mixture chamber of a burner, a sectional area of a flame port and a length of flowing direction of mixture gas over the flame port is set to be equal to the first number of acoustic natural vibration determined by a volume of a combustion space, a sectional area of a discharging cylinder and its length. CONSTITUTION:The number of acoustic natural vibration determined by a volume of a combustion space A comprised of an air chamber 1, a combustion chamber 2, a heat exchanger 3 and a discharging chamber 4 and the like, a sectional area of a discharging cylinder 5 and a length of the discharging cylinder is set to equal to the number of acoustic natural vibration determined by a volume of a mixture gas chamber 6 at a burner B for igniting air with fuel, a sectional area of a flame port 7 and a length of flowing direction of the mixture gas within a flame port 7. As a result, the burner itself may act as a resonance type sound muffling unit so as to realize a remarkable sound muffling effect. In case that the number of acoustic natural vibration is difficult to set due to combustion, a burner partition 11 having some small holes 12 is arranged within the mixture gas chamber 6 and then an easy setting of the number of vibration can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion device that heats water or air by burning fuel, and relates to reducing the noise of the device.

Conventional technology Figure 3 shows a conventional low-noise combustion device, where 1 is an air chamber;
2 is a combustion chamber, 3 is a heat exchanger, 4 is an exhaust chamber, 5 is an exhaust stack,
6 is a mixture chamber, 7 is a flame port, 8 is a combustion fan, 9 is a nozzle, and 10 is a muffler. Air supplied to the air chamber 2 from the combustion fan 8 and fuel supplied from the nozzle 9 are combusted in the combustion chamber 2 by a burner consisting of a mixture chamber 6 that mixes some air and fuel and a flame lower. do. After the combustion gas exchanges heat with water or air in the heat exchanger 3, it is transferred to the exhaust chamber 4.
After the noise is muffled by a muffler 10 installed in the exhaust pipe 5, the air is exhausted from the exhaust pipe 5.

Problems to be Solved by the Invention In such a conventional device, since the muffler 10 is located in the exhaust chamber 4, the device becomes large, and since the muffler 10 is not located in the combustion chamber 2, where the pressure fluctuation is the largest, the silencing effect is small. There were other issues.

Means for Solving the Problems In order to solve the above problems, the present invention provides a volumetric combustion space consisting of an air chamber supplied with air from a combustion fan, an exhaust stack, a combustion chamber, a heat exchanger, and an exhaust chamber. A mixture of a burner that mixes and burns air supplied from a combustion fan and fuel supplied from a nozzle at a first acoustic natural frequency determined by the length of The second acoustic natural frequency determined by the volume of the chamber, the cross-sectional area of the flame port, and the length in the direction in which the mixed gas flows through the flame port are set to be equivalent.

The air supplied to the air chamber by the combustion fan and the supplied fuel are combusted in the combustion chamber by a burner consisting of an air-fuel mixture chamber that mixes some of the air and fuel, and a flame port. The combustion gas exchanges heat with water or air in a heat exchanger, is collected in an exhaust chamber, and then exhausted from an exhaust stack. At this time, the vibration is caused by the flame formed at the flame port, and is determined by the volume of the combustion space consisting of the air chamber, combustion chamber, heat exchanger, and exhaust chamber, the cross-sectional area of the exhaust stack, and the length of the exhaust stack. Noise is generated with a peak at the acoustic natural frequency. Therefore, for this acoustic natural frequency, in a burner that burns air supplied from a combustion fan and fuel supplied, the volume of the mixture chamber, the cross-sectional area of the flame nozzle, and the direction in which the mixed gas flows through the flame nozzle are determined. The acoustic natural frequencies determined by the lengths are set to be the same.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, the same members as in FIG. 3 are designated by the same reference numerals. In addition, 11 is a burner partition, 12
is a small hole, A is a combustion space, and B is a burner exit. In FIG. 1, air supplied from a combustion fan 8 to an air chamber 1 and fuel supplied from a nozzle 9 are fed into a burner B consisting of a mixture chamber 6 and a flame lower, which mixes some of the air and fuel. ,
It burns in the combustion chamber 2. The combustion gas is passed through the heat exchanger 3.
After exchanging heat with water or air, it is collected in the exhaust chamber 4 and exhausted from the exhaust pipe 5. At this time, the flame formed in the lower flame causes vibrations, and the volume of the combustion space A, which consists of the air chamber 1, the combustion chamber 2, the heat exchanger 3, the exhaust chamber 4, etc., the cross-sectional area of the exhaust stack 5, and the exhaust stack. Acoustic natural frequency f determined by the length of
Noise with a peak of 1 is generated.

here, Acoustic natural frequency f=c/2J S VTYC: Speed of sound S: Cross-sectional area of exhaust stack ! : Length of exhaust stack ■: Volume of combustion space It is expressed as

Generally, in a combustion device, f 1 =100 to 30
0Hz, and for this acoustic natural frequency, the volume of the mixture chamber 6, the cross-sectional area of the flame lower, and the flame lower in a burner that burns the air supplied from the combustion fan 8 and the fuel supplied from the nozzle 9. The acoustic natural frequencies r2 determined by the lengths in the direction in which the mixed gas flows are set to be the same. As a result, the burner itself acts as a resonant muffler and exhibits a remarkable muffling effect. In addition, if it is difficult to set the acoustic natural frequency f2 due to combustion,
Burner partition 1 with small holes 12 bored inside the mixture chamber 6
It is also possible to easily set it by providing 1.

Effect of the invention As described above, the present invention has the following effects.

(υ Since the burner itself also serves as a resonance muffler, there is no need for additional space for a muffler, allowing the device to be made smaller.

(2) Since the burner itself, which is located in the combustion chamber where the pressure fluctuation is the largest, also functions as a muffler, the sound muffling effect is significant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a combustion device in an embodiment of the present invention;
FIG. 2 is a sectional view of the burner of the device, and FIG. 3 is a front view of the conventional combustion device. 1... Air chamber, 2... Combustion chamber, 3...
... Heat exchanger, 4 ... Exhaust chamber, 5 ...
...Exhaust pipe, 6...Mixture chamber, 7...
Burner port, 8... Combustion fan, 9... Nozzle, 11... Burner partition, A... Combustion space, B... Burna.

Claims (2)

[Claims] (1) A burner consisting of an air chamber to which air is supplied from a combustion fan, a mixture chamber that mixes the air and fuel to create a mixed gas, and a flame port from which the mixed gas is ejected, and the air chamber; It comprises a combustion space section consisting of a combustion chamber, a heat exchanger, and an exhaust chamber, and an exhaust stack communicating with the exhaust chamber, and depending on the volume of the combustion space section, the cross-sectional area of the exhaust stack, and the length of the exhaust stack. a first acoustic natural frequency determined, a second acoustic natural frequency determined by the volume of the mixture chamber, the cross-sectional area of the flame port, and the length of the flame port in the direction in which the mixed gas flows; A combustion device that equalizes . (2) The combustion device according to claim (1), wherein the inside of the mixture chamber of the burner is divided into a plurality of parts by a burner partition having small holes.