JPH02103306A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To achieve a reduction in noise and a maximum of combustion in amount is available and to stabilize the combustion irrespective of combustion using a premix or diffused combustion by providing in the center inside a cylindrical combustion chamber with a tubular tapering reducing in size a nozzle-flame hole device in combination for fuel and an axial-flow blower approximately concentrically and with the nozzle-flame hole device in a position facing the tubular tapering reducing in size. CONSTITUTION:A spiral flow of air for combustion, which flows downstream toward a tubular tapering part 2 reducing in size while it encircles a nozzle-flame hole device 4, forms a negative-pressure region at the periphery of the nozzle-flame hole device 4. On the other hand, pressurized fuel, fed through a proportional valve 5 and a fuel pipe 6, is ejected from the nozzle-flame hole device 4 toward a tubular tapering part 2 reducing in size downstream. The spiral flow of air and the fuel, as a result of their collision, form a flame-staying region downstream from the nozzle-flame hole device 4. Thus part of the fuel and part of the air are supplied to the flame-staying region and, for the rest, diffusion and mixing at high speeds are promoted with the fuel drawn into the spiral flow of air as they flow downstream. After ignition by means of an igniting device which operates after the start of a blower 3, a flame is sustained at the flame-staying region downstream from the nozzle-flame hole device 4 so that a stabilized long spiral flame can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to heat source devices such as domestic water heaters, space heaters, and cooking devices.

2. Description of the Related Art As shown in FIG. 3, a conventional combustion device of this type is provided with a swirl vane 19 in a combustion air passage 10 in a cylindrical combustion chamber 1. The air is swirled to form a swirling flame near the fuel nozzle 4 at the center of the combustion chamber 1. (For example, Jikko 63-65
Publication No. 78) Problems to be Solved by the Invention However, the above configuration has the following problems due to the method of supplying combustion air. In other words, premix combustion results in noisy combustion, while diffusion combustion increases the fuel flow rate due to the increase in combustion amount and increases the flow rate of ambient air flow, which reduces the blow-off limit and tends to cause unstable combustion in the flame holding area. There were issues such as:

The present invention solves such conventional problems, and
The primary objective is to obtain as large a combustion amount as possible with low noise, and to obtain stable combustion regardless of whether the combustion is diffusion or diffusion combustion.

The second purpose is to obtain a stable combustion variable over a wide range.

Means for Solving the Problems In order to achieve the above-mentioned first object, the present invention provides a fuel nozzle/flame hole and an axial blower in the center of a cylindrical combustion chamber with a reduced taper tube shape, and a substantially concentric air blower. The nozzle/flame hole is provided in the tapered tube.

Furthermore, in order to achieve the second object, the present invention includes a detection section that detects the rotation speed of the axial flow blower, and a control section that controls the rotation speed of the axial flow blower according to the amount of combustion by the fuel proportional valve. It was established.

Operation The combustion apparatus of the present invention has the above-described configuration, so that the pressurized fuel is injected from the nozzle/flame hole into the cylindrical combustion chamber having the shape of a reduced taper tube via the proportional valve. At this time, the air flow supplied into the combustion chamber is formed by an axial blower to form a swirling flow between the combustion chamber wall and the nozzle/flame hole, and is narrowed down by the reduced taper pipe section and flows out downstream of the combustion chamber. Therefore, a stagnation region 2 is formed in the collision area of fuel and air directly above this nozzle/flame hole. The spouting fuel is then covered by swirling air, promoting diffusion and mixing, and ignited by an ignition source, forming a long swirling flame downstream while maintaining a strong and stable flame in the stagnation region.

In addition, by configuring the proportional valve for fuel and the rotation speed control section of the blower to be controlled in conjunction with each other, the appropriate air hole can always be obtained, and a wide range of variable combustion amount can be stably obtained. It is something.

Example Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical combustion chamber having a reduced taper tube 2, and an axial blower 3 is provided coaxially upstream of the center of this combustion chamber 1. 3
A fuel nozzle/flame hole 4 connected to a fuel pipe 6 via a fuel proportional valve 5 is provided on the downstream side of the reduced taper pipe 2 on a substantially solid shaft.

In the above configuration, a swirling flow of combustion air is formed in the combustion chamber at the same time as the motor of the axial blower 3 rotates, and the downstream reduced tapered pipe 2 surrounds the nozzle/flame hole 4.
flows to. At this time, an eclipse region is formed around the nozzle/flame hole 4. On the other hand, the pressurized fuel passes through the proportional valve 5 and the fuel pipe 6 and is downstream from the nozzle/flame hole 4 into the reduced taper pipe 2.
It is ejected towards. A stagnation region is formed in the wake of the nozzle/flame hole 4 due to the collision of the contracted flow of the swirling air flow and the fuel. As a result, some of the fuel and air are supplied to the stagnation region, and the rest flows downstream while being drawn in by the swirling flow of air, promoting diffusion and mixing at high speed. Then, the flame is ignited by an ignition source (not shown) activated after the blower 3 rotates, and the flame is maintained in a stagnation region downstream of the nozzle/flame hole 3 to stably form a long swirling flame.

Next, other embodiments will be described. The difference from the above embodiment is that, as shown in FIGS. 3a and 3b, a rotation speed control section 8 is provided which detects and controls the rotation speed of the axial flow blower 3 according to the amount of combustion from the proportional valve 5. That's true. By controlling the rotational speed of the blower 3 according to the combustion amount, an appropriate air ratio can always be obtained, and the combustion amount can be stably varied over a wide range.

Effects of the Invention As described above, the present invention includes a fuel nozzle/flame hole and an axial blower in the center of a cylindrical combustion chamber with a reduced taper tube shape.
Since this is a combustion device in which the nozzle/flame hole is provided in a substantially concentric shape and is provided in the tapered tube, it is possible to maintain stable flame stability and achieve a large combustion amount with low noise.

In addition, by installing a detection unit and a control unit that detect and control the rotation speed of the blower, and by interlocking control according to the combustion amount from the proportional valve, an appropriate air ratio can always be obtained according to the combustion amount, so it can be used over a wide range of applications. This makes it possible to obtain a combustion amount variable range more stably.

[Brief explanation of drawings]

FIG. 1 shows a combustion device according to an embodiment of the present invention.
...Combustion chamber, 2...Reduction taper tube, 3...
...Axial flow blower, 4...Nozzle and flame hole, 5
...Fuel proportional valve, 7...Rotation speed detection section, and...Rotation speed control section. Name of agent Patent attorney Shigetaka Awano Figure (ζshi) (b)

Claims (2)

[Claims] (1) A fuel nozzle/flame hole and an axial flow blower are provided approximately concentrically in the center of the combustion chamber having a reduced taper pipe portion,
and a combustion device in which the nozzle/flame hole is provided adjacently to the reduced taper pipe section. (2) A control means for detecting and controlling the rotation speed of the axial flow blower is provided, and the rotation speed of the axial flow blower is controlled according to the amount of combustion from the nozzle/flame hole by the proportional valve. combustion equipment.