JP2596583B2 - Direct contact hot water heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a direct contact hot water heater for obtaining hot water.

2. Description of the Related Art A typical prior art direct contact hot water heater forms a heat absorbing layer above a combustion layer and sprays water from above the heat absorbing layer toward a heat absorbing material filled in the heat absorbing layer. The heat exchange is performed by directly contacting water and a combustion gas from a burner such as a gas provided in a combustion layer, and a structure is obtained in which heating is performed to obtain hot water.

Problems to be Solved by the Invention In such prior art, the high-temperature combustion gas from the burner may rise near the center and the heat absorbing material may be overheated. In such a case, the water to be heated is undesirably vaporized, and hot water cannot be obtained efficiently. There is also a problem that NOx is generated by such a relatively high temperature combustion gas.

Therefore, an object of the present invention is to provide a direct contact hot water heater capable of reducing the NOx concentration of a combustion gas, preventing heating of a heat absorbing material, and efficiently raising the temperature of hot water. .

Means for Solving the Problems The present invention forms a combustion layer provided with a burner in a cylindrical main body, forms a heat absorption layer filled with a heat absorbing material above the combustion layer, and sprays water from above the heat absorption layer. The water and the combustion gas from the combustion layer are brought into direct contact with each other, and the combustion layer is provided with a nozzle for injecting water at a position where water is directly injected into a flame formed by the burner. This is a direct contact hot water heater.

According to the present invention, since a nozzle for injecting water is provided at a position where water is directly injected into the flame formed by the burner in the combustion layer, the water ejected from the nozzle is injected into the high-temperature combustion flame. It is heated in direct contact with a mist and is thus vaporized with a high heat transfer coefficient. With the absorption of the sensible heat of the combustion flame due to the evaporation of water, the temperature of the combustion gas decreases, and it becomes possible to prevent overheating of the heat absorbing material and efficiently heat the hot water. In addition, due to the improvement of the heat transfer coefficient, the amount of the heat absorbing material can be reduced, and the size can be reduced. In addition, since the atomized water is directly injected from the nozzle into the high-temperature combustion flame, the temperature of the high-temperature combustion flame is reduced, thereby making it possible to greatly reduce NOx.

Embodiment FIG. 1 is a cross-sectional view of a direct-contact hot water heater 2 having a configuration serving as a basis of the present invention. The direct contact hot water heater 2
A storage section 5 is provided at a lower portion of the heater body 4 formed in a right cylindrical shape.
Is formed, and a combustion layer 6 is formed above the storage section 5. In the combustion layer 6, combustion is carried out by a burner 7 attached to the side of the heater body 4, and a blower 8
The fuel gas is supplied from the pipe 9 through the fuel cutoff valve 10 while the combustion air is pressure-fed. The combustion gas from the burner 7 is supplied to an exhaust pipe formed at the top of the heater body 4.
It is discharged outside from 11.

Above the combustion layer 6, a heat absorbing layer 12 is formed.
Are separated from the combustion layer 6 by a perforated plate 13 made of a heat-resistant metal material or the like. Endothermic material on perforated plate 13
14 are filled. A water spray chamber 15 is formed above the heat absorbing layer 12, in which water is sprayed toward the heat absorbing material 14 from a nozzle hole of a nozzle 17 provided at one end of a pipe 16.

The heater body 4 is provided with a nozzle 20 which is open from the combustion layer 6 side to the lower surface of the perforated plate 13. A pipe 21 is connected to the nozzle 20, and the pipe 21 is connected to the pipe 16 through a side wall of the heater body 4. Further, a pipe 22 is connected to the storage section 5 of the heater main body 4, and the hot water stored in the storage section 5 can be guided to be used for bathing and hand washing.

In the direct contact hot water heater 2 having the above-described configuration, water is sprayed from the nozzle hole of the nozzle 17 to the heat absorbing material 14 in the heater main body 4 via the pipe 16. At the same time, the fuel cutoff valve 10 is opened, fuel gas is supplied to the burner 7 from the pipe 9, and combustion air is supplied from the blower 8, so that combustion is performed in the combustion layer 6. The water thus supplied to the heat absorbing material 14 is heated by the combustion gas from the combustion layer 6, travels along the upper surface of the perforated plate 13, and is stored along the inner surface of the combustion layer 6 in the storage section 5.
Runs down inside.

When water is sprayed from the nozzle hole of the nozzle 20 toward the perforated plate 13, the water absorbs the sensible heat of the combustion gas and is heated to be vaporized. As a result, the temperature of the combustion gas decreases, causing so-called channeling in which the combustion gas mainly flows through the central portion of the combustion layer 6, and the central portion of the perforated plate 13 is easily overheated. Channeling can be prevented, the perforated plate 13 and the heat absorbing material 14 can be prevented from overheating, heat resistance can be improved, and NOx can be reduced. Further, the water injected from the nozzle hole of the nozzle 17 comes into contact with the heat absorbing material 14 and evaporates, and the latent heat of the water vapor efficiently heats the water from the nozzle hole of the nozzle 17. Accordingly, the amount of the heat absorbing material 14 can be reduced, and the size of the hot water heater 2 can be reduced. In this way, the high-temperature hot water whose temperature has been raised is stored in the storage unit 5. The hot water in the storage unit 5 is used for bathing and hand washing through the pipe 22.

FIG. 2 is a direct contact hot water heater according to one embodiment of the present invention.
It is sectional drawing of 2a. In this embodiment, the nozzle 20a is provided on the side wall of the heater body 4, and a part of the atomized water sprayed from the nozzle 20a directly collides with the flame formed by the burner 7. As a result, the temperature of the combustion flame is reduced, and the concentration of NOx generated in the combustion flame is further reduced.

In the above-described configuration examples and embodiments, the pipes are connected to the nozzles 20 and 20a.
Although the pipes 21 and 21a branched from 16 are connected to supply water to the nozzles 20 and 20a, water is guided from the other water source separately provided by directly connecting the pipes to the nozzles 20 and 20a. In such a case, the nozzle 17 and the nozzles 20, 2
It is possible to make the amounts of water injected from 0a and 0a different.

Effect of the Invention According to the present invention, since atomized water is directly injected into a combustion flame by a nozzle provided in a combustion layer, the temperature of the combustion flame is reduced by latent heat due to water vaporization. This makes it possible to obtain high-efficiency and high-temperature hot water, reduce the amount of heat-absorbing material, and reduce the size. In addition, the lowering of the temperature of the combustion flame can greatly reduce the NOx concentration of the combustion gas, and also lowers the temperature of the combustion gas, preventing overheating of the heat absorbing material, improving the durability of the heat absorbing material, and improving the long-term performance. It can be used.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a configuration which is the basis of the present invention, and FIG.
FIG. 1 is a sectional view of one embodiment of the present invention. 2,2a: Direct contact hot water heater, 4: Heater body, 5
...... Reservoir, 6 ... Combustion layer, 7 ... Burner, 11 ... Exhaust pipe, 12 ... Heat absorbing layer, 14 ... Heat absorbing material, 15 ... Sprinkling chamber, 17,2
0,20a …… Nozzle

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshimichi Ohara 5-1-1 Hirano-cho, Higashi-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Kunihiro Kobayashi 8-6-31, Miwa, Nagano City, Nagano Prefecture ( 72) Inventor Kazuo Kobayashi 832-4 Shimoyo Plane, Inari-cho, Nagano City, Nagano Prefecture (56) References Japanese Utility Model Sho-62-198446 (JP, U) Japanese Utility Model Sho-58-167835 (JP, U) Japanese Utility Model Sho-56-118329 (JP, U)

Claims (1)

(57) [Claims] 1. A combustion layer having a burner is formed in a cylindrical main body, a heat absorption layer filled with a heat absorbing material is formed above the combustion layer, water is sprinkled from above the heat absorption layer, and the water is burned. Direct contact with the combustion gas from the bed, wherein the combustion bed is provided with a nozzle for injecting water at a position where water is directly injected into a flame formed by the burner. Contact hot water heater.