JPH0457941B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hot air heater that blows air with low noise for heat exchange in combustion using kerosene or the like as fuel.

Prior Art A conventional technology used in an oil-burning heater will be described.

This type of hot air heater had a configuration as shown in FIGS. 4 and 5. In other words, top plate 1 and front plate 2
A combustion tube 6 is placed over the combustion section 5 installed in the ventilation duct, which consists of a bottom plate 3 and side panels 4, and a propeller blower 7 is installed on the upstream side of the combustion tube. By blowing air into the combustion chamber, warm air that has undergone heat exchange in the combustion tube is discharged from the outlet 8. Also,
A lattice-like catalyst purification filter 10 for purifying the air after combustion is disposed in a cross section in which the front of the combustion cylinder top 9 is tilted forward, and a radiation window 11 is provided so that the red-hot state of the catalyst purification filter can be seen from the outside. Radiant heat was also used for heating. 12 is a fan guard that holds a propeller blower, and 14 is an oil combustion heater.

Problems to be Solved by the Invention In this configuration, in order to extract radiant heat from the red heat of the catalyst purification filter, the front of the top of the combustion cylinder is tilted forward as shown in FIG. Therefore, the noise generated in the combustion section passes through the catalyst purification filter and is radiated toward the corner 13 surrounded by the duct top plate and the front plate. As a result, sound was likely to be muffled, and sound with a standing wave frequency matching the distance between each wall surface (top plate and bottom plate, front plate and rear plate, etc.) was likely to resonate, increasing the noise level. . When noise countermeasures were taken, problems such as a decrease in the amount of hot air blown and deterioration of combustion characteristics occurred, making it impossible to take appropriate countermeasures.

The present invention solves these conventional problems by tilting the top plate of the air duct downward toward the downstream side, and by drilling a large number of small holes in the horizontal plate behind the top of the combustion cylinder to reduce noise inside the combustion cylinder. By emitting the noise from the perforated plate and discharging the noise inside the ventilation duct to the rear of the equipment, it suppresses the muffled noise inside the ventilation duct.
In addition to reducing the noise level by preventing the occurrence of resonance phenomena such as standing waves, the system also increases the volume of warm air blown.
The purpose is to prevent deterioration of combustion characteristics.

Means for Solving the Problems In order to solve the above problems, the present invention provides a blower duct comprising a top plate, a bottom plate, side plates and a front plate, a blower on the upstream side of the blower duct, and
In addition to providing an air outlet on the lower side of the front plate on the downstream side,
A combustion tube is provided that protrudes upward from the bottom plate to approximately the center of the blower and has a combustion section in the lower part of the interior, a radiation window through which the top of the combustion tube can be seen is arranged on the front plate, and the top plate is arranged downward in the downstream direction. A catalyst purification filter is disposed on a cross section in which the front of the top of the combustion cylinder is tilted forward, and the catalyst purification filter is provided with an air passage in a direction perpendicular to the filter surface, and a horizontal plate at the rear of the top of the combustion cylinder is arranged. It was constructed from a perforated plate.

Effect The present invention has the above-described configuration, so that the acoustic impedance when looking at the top of the combustion cylinder from the combustion section is higher in the perforated plate behind the top of the combustion cylinder than in the catalyst purification filter having a passage diagonally with respect to the combustion cylinder. is small, and most of the noise generated in the combustion section is radiated from the perforated plate. The sound emitted from the perforated plate is reflected upstream by the slanted top plate above it, preventing the sound from being reflected multiple times in the ventilation duct, reducing muffled sound and standing wave resonance. Can be suppressed. As a result, a part of the frequency of the combustion sound is not amplified due to resonance, resulting in a gentle noise spectrum, which eliminates unpleasant harshness and makes it possible to provide a low-noise hot air heater. In addition, the combustion characteristics are stabilized by preventing air from entering the combustion cylinder, and a large amount of high-temperature air can be obtained, thereby improving the heating capacity.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the combustion tube 6 is placed over the combustion section 5 installed in the ventilation duct 18, which is composed of the top plate 15, the front plate 16, the bottom plate 3, and the side plates 19. A propeller blower 7 is installed on the upstream side of the cylinder. By blowing air into the air duct with this propeller blower, warm air that has undergone heat exchange in the combustion tube is discharged from the outlet 8. Further, a catalyst purification filter 10 on a lattice, which has a cross section with the front part of the combustion cylinder tilted forward, and purifies the air after combustion, is arranged so that the lattice ventilation passage is perpendicular to the filter surface, and It has a radiant window 11 configured to allow the red-hot state of the purification filter to be seen from the outside, and radiant heat can also be used for heating. Moreover, the top plate 15 of the ventilation duct is inclined downward from the upstream side in the direction of the upper side of the radiation window 11, and the rear part of the top of the combustion tube 6 is made up of a perforated plate 17.

In such a configuration, when the top of the combustion cylinder is acoustically viewed from the combustion section 5, the acoustic impedance is smaller in the rear perforated plate 17 than in the inclined passage of the catalyst purification filter 10, and the noise generated in the combustion section is smaller. is mostly emitted from the perforated plate. The sound radiated from the perforated plate is reflected to the upstream side of the ventilation duct by the inclined top plate 15 located at the top of the perforated plate, and the sound is not reflected many times in the ventilation duct, and the sound is not muffled or stagnant. Wave resonance can be suppressed. As a result, as shown in FIG. 2, some frequencies of the combustion sound are no longer amplified due to resonance, resulting in a smooth noise spectrum like the spectrum after countermeasures. Therefore, the unpleasant harshness is eliminated, and the warm air heater 20 can have low noise.

On the other hand, since there are many small holes at the rear of the top of the combustion cylinder, there is a concern that the air after combustion will leak from the small holes and reduce the effectiveness of the catalyst purification filter. Because of the air flow, it acts as an air curtain, and the air inside the combustion cylinder rarely leaks through the small holes. A catalyst purification filter is placed on the cross section of the top of the combustion tube that is tilted forward, and the horizontal plate behind the top of the combustion tube is made of a perforated plate, so the filter and perforated plate act as ventilation resistance. Since the plates are arranged horizontally to the wind flow, the air from the blower is difficult to enter into the combustion cylinder, which has the effect of providing stable combustion characteristics.

In addition, the top plate of the air duct is tilted downward to the downstream side, gradually reducing the cross-sectional area of the passage to the air outlet, and the front of the top of the combustion tube is tilted forward, so that the top plate and the combustion tube are Since the space is wide, ventilation resistance can be reduced compared to a conventional rapidly contracting passage, and the amount of air blown can also be increased. Since the catalytic purification filter is closer to the combustion part than the perforated plate, high-temperature hot air is discharged from the catalytic purification filter, and high-temperature hot air can be obtained from the outlet. Heating performance can be improved.

Effects of the Invention As described above, according to the present invention, the combustion sound is radiated from the rear of the top of the combustion cylinder, and the sound is reflected upstream by the top plate, so that muffled noise and stationary noise in the ventilation duct are avoided. It is possible to suppress the generation of wave resonance sound, reduce the unpleasant harshness, and
Noise level can be lowered. Furthermore, it has the effect of preventing air from entering the combustion cylinder and stabilizing combustion performance, and the ability to obtain high-temperature warm air from the catalytic purification filter and increase the amount of air blown, improving heating performance. can do.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a hot air heater according to an embodiment of the present invention, Fig. 2 is a plan sectional view of the same hot air heater, Fig. 3 is a noise spectrum diagram of the hot air heater, and Fig. 4 5 is a side sectional view of a conventional hot air heater, and FIG. 5 is a partially cutaway front view of the conventional hot air heater. 3...Bottom plate, 5...Combustion section, 6...Combustion tube, 7
...Blower, 8...Air outlet, 10...Catalyst purification filter, 11...Radiation window, 15...Top plate, 16...
...Front plate, 17...Perforated plate, 18...Blower duct,
19...Side plate.

Claims (1)

[Claims] 1. A blower duct consisting of a top plate, a bottom plate, side plates, and a front plate, a blower provided on the upstream side of the blower duct, an air outlet provided on the lower side of the front plate on the downstream side, and a blower duct that is connected to the blower from the bottom plate. A combustion tube is provided that projects upward to approximately the center and has a combustion section at the bottom of the interior, a radiation window is disposed on the front plate through which the top of the combustion tube can be seen, and the top plate is inclined downward in the downstream direction. A catalytic purification filter is disposed in a cross section in which the front of the top of the combustion cylinder is tilted forward, the catalytic purification filter has an air passage in a direction perpendicular to the filter surface, and the horizontal plate at the rear of the top of the combustion cylinder is composed of a perforated plate. Hot air heater.