JPH0212444Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a forced draft combustion device used in gas water heaters and the like.

(Prior Art) In the conventional forced draft combustion apparatus shown in FIG. The discharge port 7 of the centrifugal fan 6 is connected to the bottom opening 10 of the burner case 2, and the lower end of the partition body 3 is made to face the discharge port 7, so that the air blown from the centrifugal fan 6 is transferred to the partition body 3. The air is divided into primary air and secondary air. Note that reference numerals 8 and 9 are porous rectifier plates provided in the secondary air chamber 5 below the burner 1.

(Problem that the invention aims to solve) However, in the conventional method, when changing the combustion amount of burner 1, it is necessary to change the air blowing capacity by controlling the rotation speed or damper according to the combustion amount. 6, the air blowing pressure distribution at the discharge port 7 is different between the large capacity side and the small capacity side. In this case, the ratio of the amount of secondary air compared to the amount of primary air decreases rapidly, and combustibility deteriorates significantly on the small capacity side.

In order to solve this problem, as shown in Japanese Utility Model Application Publication No. 181943/1983 to which the present applicant applied, a gap should be provided in the dividing plate that divides the primary air passage and the secondary air passage. Conceivable. However, in the above-mentioned publication, while the primary air amount and the secondary air amount are balanced, for example, the air distribution in the secondary air passage is biased in the longitudinal direction around the fan's discharge port due to the structure of the combustion device. Moreover, the excess air flowing through the gap will aggravate the non-uniformity of the air distribution, thereby deteriorating the combustibility of the gas burner.

(Means for solving the problems) This invention aims to solve the above problems.
The burner case, in which a large number of burners are arranged side by side, is divided into a primary air chamber and a secondary air chamber, and ventilation passages are provided on both sides of the bottom opening of a partition to communicate the two chambers.

(Function) When the pressure on the primary air chamber 4 side at the discharge port 7 increases on the small capacity side, a part of the primary air supplied from the discharge port 7 to the primary air chamber 4 side is divided into the primary air chamber and the secondary air. Due to the pressure difference created between the chambers, the air flows from the primary air chamber to the secondary air chamber through the ventilation passage, so that the significant pressure difference between the two chambers is reduced and the primary air volume and secondary air volume are balanced, Moreover, the primary air flows into both sides of the bottom opening in order to correct the non-uniformity of the air blow distribution in the secondary air chamber, thereby improving the combustibility of the burner at low capacity.

(Embodiment) FIG. 1 is a sectional view of a main part of an embodiment of the present invention, in which a large number of small holes 11 are formed on both sides of the partition 3 shown in FIG. room 4
A ventilation path is formed to allow communication between the secondary air chamber 5 and the secondary air chamber 5. FIG. 3 shows other embodiments of the above-mentioned ventilation passage, and FIG. 3A shows one in which a slit hole 11a is provided, and FIG. A gap 11b is provided between the bottom surfaces, and FIG. 3C shows a structure in which an opening is provided in the partition plate 3 and a cylindrical body 11c with both ends open is attached to the opening.

In the above configuration, when the centrifugal fan 6 is driven, the air discharged from the discharge port 7 is divided by the partition 3 into the primary air chamber 4 and the secondary air chamber 5, and is supplied to the primary air chamber 4. The air is supplied as combustion primary air into the burner 1 together with the gas discharged from the nozzle, while the secondary air in the secondary air chamber 5 is rectified by the rectifier plates 8 and 9 and then supplied as the combustion secondary air of the burner 1. Supplied.

By the way, on the small capacity side, from the discharge port 7 to the secondary air chamber 5
Even if the amount of secondary air sent into the primary air chamber 4 is significantly reduced compared to the amount of primary air sent into the primary air chamber 4, the pressure difference generated between the two air chambers 4 and 5 causes the primary air chamber 4 to
The primary air sent into the chamber is transferred from the ventilation path to the secondary air chamber 5.
Since the air flows out into the chamber as secondary air, the amount of air in both chambers 4 and 5 is balanced, and the combustibility of the burner 1 is maintained in a good state. In addition, since the ventilation passages are provided on both sides of the discharge port 7, the secondary air that is directly supplied from the discharge port 7 to the secondary air chamber 5 is difficult to be supplied to both sides of the secondary air chamber 5, and is placed in the center. The above-mentioned problem that air is concentrated in the longitudinal direction and the air distribution in the secondary air chamber 5 is uneven can be solved by blowing air from the primary air chamber 4 to the secondary air chamber 5 from both sides of the burner case 1. It is possible to eliminate uneven distribution and further improve combustibility.

(Effects of the invention) As explained above, the present invention has a partition that divides the air blown from the centrifugal fan into primary air and secondary air, and divides the inside of the burner case into the primary air chamber and the secondary air chamber. A ventilation passage is provided on both sides of the bottom opening to connect the two chambers.
When a blowing pressure difference occurs between the two chambers, the blowing air flows out from the above-mentioned ventilation path to the low-pressure side air chamber, and the primary air volume and secondary air volume are balanced regardless of the blowing capacity of the centrifugal fan. It is provided by
Moreover, in this case, the non-uniformity of the air blow distribution in each air chamber is corrected, and it is possible to improve the combustibility of this type of forced draft combustion apparatus.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of the present invention;
FIG. 2 is a cross-sectional view of the same example, FIG. 3 is a cross-sectional view of a main part showing another embodiment of the present invention, and FIG. 4 is a vertical cross-sectional view of a conventional example. 1... Burner, 2... Burner case, 3... Partition body, 4... Primary air chamber, 5... Secondary air chamber, 6
...Centrifugal fan, 7...Discharge port, 10...Opening,
11...Small hole (ventilation path).

Claims (1)

[Scope of utility model registration request] A discharge port of a centrifugal fan is connected to the bottom opening of a burner case in which a large number of burners are arranged side by side, and a partition body with a lower end facing the bottom opening is disposed inside the burner case, so that primary air flows inside the burner case. A forced ventilation type, characterized in that the partition is divided into a chamber and a secondary air chamber, and a ventilation path is provided on both sides of the partition body sandwiching the bottom opening to connect the primary air chamber and the secondary air chamber. Combustion device.