JPH087232Y2 - Exhaust pipe top for outdoor open-type combustion equipment and small petroleum water heater or bath kettle equipped with the exhaust pipe top - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is directed to an exhaust pipe top that is attached to the exhaust portion of an outdoor open-type combustion device and a small petroleum water heater or an oil water heater with the exhaust pipe top. Regarding bathtub.

(Prior Art) The schematic structure of a conventional petroleum small-sized water heater is as shown in FIG. In the figure, kerosene pressurized by a pump 1 is mixed with air sprayed from a nozzle 2 and sent from a fan 4 and burned by a burner 3. The generated high-temperature combustion gas heats the water flowing from the water inlet 8 in the heat exchanger 5, and then is discharged from the exhaust pipe top 7c through the silencer 6. The water heated by the heat exchanger 5 is tapped from the tap opening 9. The noise generated by the combustion of the burner 3 is as high as about 70 to 80 dB at a distance of 1 m, and this noise is emitted to the outside from the exhaust stack top 7c along with the exhaust gas. Therefore, the noise is reduced by the silencer 6 inside the water heater. Is decreasing.

As shown in FIGS. 9 and 10, the exhaust stack top 7c has an inner cylinder 11a, which is an exhaust gas passage, on the inside of an outer cylinder 10 having an upper surface 10b, a lower surface 10a, and a plurality of exhaust ports 13 on the upper surface. It has a structure in which it stands up through 10a and a rain shield 12 is provided on the upper inside, and the exhaust gas that has entered the inner cylinder 11a is discharged to the outside from an exhaust port 13.

(Problems to be Solved by the Invention) As described above, the silencer is used in the conventional small petroleum water heater, but it is preferable that the noise level is as low as possible. For this purpose, it is necessary to further increase the size of the muffler, but with this, there is a problem that the water heater itself becomes large in size, and therefore the restrictions on the installation place become large. further,
Since the noise generated by the combustion of the burner covers the entire frequency range, there is a drawback that low-frequency noise in which sound energy is not easily attenuated cannot be sufficiently reduced by the conventional silencer.

The present invention has been made in view of the above drawbacks, and is provided with an exhaust pipe top and an exhaust pipe top of an outdoor open combustion device that can reduce noise without changing the structure and external dimensions of the conventional product body. The purpose of the present invention is to provide a small oil water heater or a bath kettle with an oil water heater.

(Means for Solving the Problems) The present invention is characterized by the following configurations in order to achieve the above-mentioned object. That is, (1) The invention according to claim 1 is an outdoor case in which an inner cylinder that is an exhaust gas passage is erected through the lower surface inside an outer cylinder having an upper surface and a lower surface and a plurality of exhaust ports provided in the upper portion. In the top of the exhaust pipe of an open combustion device for outdoor use, a partition plate connected to the inner circumference of the outer cylinder is provided on the upper outer circumference of the inner cylinder, and a cavity is formed between the partition plate and the lower surface. It is the top of the exhaust stack of an open combustion device.

(2) The invention of claim 2 is an exhaust pipe top for an outdoor open-type combustion device, which is an inner cylinder provided with a plurality of holes.

(3) The invention of claim 3 is an exhaust pipe top for an outdoor open type combustion device, characterized in that a sound absorbing material is attached to the inner circumference of the outer cylinder in the hollow portion.

(4) The invention of claim 4 or 5 is based on the above (1) and (2).
Alternatively, the petroleum small-sized water heater or the bath kettle with an oil water heater is provided with the exhaust pipe top according to (3).

(Operation) As described above, according to the first aspect of the invention, the hollow portion around the inner cylinder, which is the exhaust gas passage, is provided, and the noise is converted into the vibration of the inner cylinder to be silenced. The frequency that can be silenced is determined by the thickness of the inner cylinder and the size of the surrounding cavity,
Generally low frequencies.

According to the second aspect of the present invention, the inner cylinder is provided with a plurality of holes, and in addition to the vibration of the inner cylinder, Helmholtz resonance is generated in the holes and the cavity to muffle the sound. The frequency of the Helmholtz resonance can be arbitrarily set by changing the diameter and number of the holes, the thickness of the inner cylinder, the size of the cavity, and the like.

Further, in the invention of claim 3, since the sound absorbing material is attached to the inner circumference of the outer cylinder in the hollow portion, the frequency range in which the sound absorbing material can muffle the sound is widened.

Further, according to the invention of claim 4 or 5, since the exhaust pipe top with low exhaust gas noise is provided, a small petroleum water heater having the same size as the conventional one and low noise, or a bath with an oil water heater can be obtained.

(Example) Below, one Example of this invention is described based on drawing.

First, a schematic structure of a petroleum small-sized water heater or a bath kettle with an oil water heater provided with an exhaust pipe top according to the present invention will be described with reference to FIG. More specifically, the bath kettle with hot water supply is the hot water supply device of FIG. 1 provided with a burner for a bath and a heat exchanger (not shown).

In FIG. 1, the structure of the main body other than the exhaust stack top 7 is
Similar to FIG. 11, it is composed of a pump 1, a nozzle 2, a burner 3, a fan 4, a heat exchanger 5, a silencer 6, a water inlet 8, and a hot water outlet 9.

Next, the structure of the exhaust stack top 7, which is a feature of the present invention, will be described in detail.

FIG. 2 is a side view showing an embodiment of an exhaust stack top according to the present invention, and FIG. 3 is a sectional view taken along the line AA of FIG. The exhaust pipe top 7 has an outer cylinder 10 having an upper surface 10b and a lower surface 10a and a large number of exhaust ports 13 provided in the upper portion, and an outer cylinder 10 penetrating the lower surface 10a.
Inner cylinder 11 provided with a partition plate 10c that is erected inside and is connected to the inner circumference of the outer cylinder 10 on the outer circumference of the upper part, a cavity portion 14 formed between the partition plate 10c and the lower surface 10a, inside the upper surface 10b Composed of 12 mounted rain shelters. The inner cylinder 11 has a plate thickness of 0.4 mm, and the cavity 14 has a size of about 0.00335 m ³ .

FIG. 4 is a side view showing another embodiment of the exhaust stack top according to the present invention, and FIG. 5 is a sectional view taken along line BB in FIG. The basic structure of the exhaust stack top 7a is the same as that of the embodiment shown in FIGS. 2 and 3, except that the inner cylinder 11 is provided with about 25 holes 15 having a diameter of 2φ. Further, FIG. 6 is a side view showing another embodiment of the exhaust stack top according to the present invention, FIG.
The drawing is a sectional view taken along the line CC of FIG.

The basic structure of the exhaust stack top 7b is the same as that of the embodiment shown in FIGS. 4 and 5, except that the sound absorbing material 16 is attached to the inner periphery of the outer cylinder 10 in the cavity 14.

Comparing the noise reduction effects when the above three types of exhaust pipe tops are used for, for example, a petroleum small-sized water heater based on the drawing numbers, FIG. 6, FIG. 7> FIG. 4, FIG. 5> FIG. The order is shown in Fig. 3.

Next, FIG. 8 shows a result of comparing noises when the exhaust pipe top 7a shown in FIGS. 4 and 5 of the present invention and the conventional exhaust pipe top 7c are attached to the small petroleum water heater having the same structure. In the figure, (a) is the case where the exhaust stack top 7a and (b) is the exhaust stack 7c. 125Hz, 250Hz, 500H showing the highest noise by frequency.
It is clear that the noise level of the exhaust stack top 7a according to the present invention is reduced by about 2 to 3 dB in the frequency range of z.

(Effect of the device) When the exhaust pipe top according to the present invention is applied to the production of small petroleum water heaters, noise can be reduced without changing the specifications such as the external dimensions of the water heater main body, and the user and surrounding The environment is not disturbed by human discomfort. Also,
Since the size of the exhaust stack top itself is almost the same as that of the conventional one, it is extremely convenient without being restricted by the installation location of a water heater or the like.

[Brief description of drawings]

FIG. 1 is an explanatory view of a schematic structure of a petroleum small-sized water heater or a bath kettle with an oil water heater having an exhaust pipe top according to the present invention, and FIG. 2 is a side view showing an embodiment of the exhaust pipe top according to the present invention, 3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 is a side view showing another embodiment of the exhaust stack top according to the present invention, and FIG. 5 is a sectional view taken along the line BB in FIG. FIG. 7 is a side view showing another embodiment of the exhaust stack top according to the present invention, FIG. 7 is a sectional view taken along the line CC of FIG. 6, and FIG. 8 is a small petroleum hot water supply using the conventional exhaust stack top and the present invention. Fig. 9 is a side view of a conventional exhaust stack top, and Fig. 10 is D- in Fig. 9 showing the noise of the machine.
Sectional view D and FIG. 11 are explanatory views of a schematic structure of a conventional petroleum small-sized water heater or a bath kettle with an oil water heater provided with an exhaust stack top. Explanation of symbols 1 ... Pump, 2 ... Nozzle, 3 ... Burner, 4 ... Fan, 5 ... Heat exchanger, 6 ... Silencer, 7, 7a, 7b, 7c
…… Exhaust stack top, 8 …… Inlet, 9 …… Outlet, 10…
… Outer cylinder, 10a …… Lower surface, 10b …… Upper surface, 10c …… Partition plate, 1
1, 11a …… Inner cylinder, 12 …… Rain shield, 13 …… Exhaust port, 14 ……
Cavity, 15 ... hole, 16 ... sound absorbing material.

Claims (5)

[Scope of utility model registration request] 1. An exhaust system for an outdoor open-type combustion device in which an inner cylinder, which is an exhaust gas passage, is erected through the lower surface inside an outer cylinder having an upper surface and a lower surface and a plurality of exhaust ports provided in the upper portion. In the cylinder top, a partition plate that is connected to the inner circumference of the outer cylinder is provided on the outer circumference of the upper part of the inner cylinder, and a cavity is formed between the partition plate and the lower surface. Top. 2. The exhaust pipe top for an outdoor open-type combustion device according to claim 1, wherein the inner cylinder is provided in a plurality of holes. 3. An exhaust pipe top for outdoor open-type combustion equipment according to claim 1, wherein a sound absorbing material is attached to the inner circumference of the outer cylinder in the hollow portion. 4. A petroleum small-sized water heater comprising the exhaust stack top according to claim 1, 2 or 3. 5. A bath kettle with an oil water heater, comprising the exhaust pipe top according to claim 1, 2, or 3.