JPS5956009A - Combustion cylinder - Google Patents

Abstract

PURPOSE:To widen the area of irradiation and improve the efficiency of irradiation as well as to widen the range of adjustment of volume of combustion by a method wherein an air hole projected upwardly is arranged in a combustion chamber. CONSTITUTION:In a combustion chamber A, a local eddy current is produced under an action of fed air flow near an air feeding part and at a part near the wall surfaces of an inner flame cylinder 2, outer flame cylinder 3 and a lower red heating cylinder 4, where the gasified gas and air are mixed, the central part makes a nearly layered flow and a high concentration of gasified gas is generated. Therefore, when the gas ascends up to the secondary combustion part, it may produce a dispersed combustion and a yellow flame. However, the gas flow ascending in a substantial laminated flow through the air port 7 promotes a mixing action with air and the gasified gas under a low eddy current produced by the projected part and at the same time air is supplied to the central part of the combustion chamber A having a high concentration of gasified gas. Thereby, a premixing rate of gasified gas and air is improved and a production of blue flame at the secondary combustion part is promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dual-tube type combustion tube having an inner flame tube and an outer flame tube having a large number of small holes.

Conventional structure and its problems A combustor is a combustor in which the combustion chamber is formed by an inner flame tube and an outer flame tube with many small holes, and the high-temperature gas flow heats red-hot bodies such as wire mesh, punched metal, lath, etc. As home heaters such as portable kerosene stoves, they have many advantages, such as not requiring a power source, being small and lightweight, making them easy to move, less likely to break down, and being comfortable with radiant heating, making them the mainstream of home heaters.

Conventionally, this combustion tube (8) has the configuration shown in Figure 1. In other words, 1 is a lamp wick whose lower end is not shown in the figure, but it is immersed in the fuel in the fuel tank provided at the bottom. The upper end is exposed in the combustion chamber. 2 is an inner flame tube with many small holes, 3 is an outer flame tube with many small holes,
A combustion chamber is formed in the gap with the inner flame cylinder 2. 4 is a red-hot tube connected to the outer flame tube 3, made of lath, punched metal wire mesh, etc., and has a larger aperture ratio than that of the outer flame tube 3;
6 is an outer cylinder made of a heat-resistant light-transmitting material such as glass, and 6 is an outer cylinder 6.
There is a metal outer cylinder that holds the flame cylinder 2, an upper lid that is connected to the inner flame cylinder 2 and has air holes, and a flame regulating plate 8 that is fixed to the upper lid 7.

In the above configuration, in a steady combustion state, the fuel gas vaporized from the tip of the lamp wick 1 mixes with air supplied by natural draft from the small holes and openings of the inner flame tube 2, outer flame tube 3, and incandescent tube 4. While partially burning, air (secondary air) supplied from the air hole of the final upper lid 7 causes complete combustion. In any type of combustion method, air supply (primary air) up to the secondary combustion position (secondary air is supplied)
Since the gas is supplied in an extremely dispersed state (because it is supplied from the small holes in the inner and outer flame tubes 2 and 3), the lower part of the combustion chamber contains more unburned gas components, and the higher the part, the more unburned gas The ingredients become diluted, making complete combustion difficult. Therefore, a method has been used in which air is supplied intensively to achieve complete combustion while leaving a suitable amount of unburned gas components. However, in this method, the combustion heat obtained by secondary combustion does not contribute to the red heat of the red-hot cylinder 4, so the ratio of radiant energy to the amount of fuel consumed is low, and the radiation assistance is poor. If there is even a slight increase in wind, there will be insufficient mixing with air, and a yellow spot will appear at the tip of the secondary combustion flame due to diffuse combustion, causing visual discomfort and causing soot and odor. Therefore, in actual use, the exposure height of the lamp wick 1 is lowered and the combustion amount is adjusted to a value that does not cause macular spots, so the optimal combustion amount adjustment range is extremely narrow in a combustor rated at 2100 kcall, A. JP range V was 200 to 3ookcal/h.Objective of the invention The present invention solves these drawbacks by increasing the radiation efficiency by widening the radiation area and reducing the occurrence of macular spots at high combustion rates. The purpose of this is to provide a combustion tube with a wide range of combustion amount adjustment.

Structure of the Invention To achieve this object, the present invention provides an air hole projecting upward into the combustion chamber on the outside of the inner flame tube.

In this configuration, the fuel gas vaporized from the lamp wick mixes with the air supplied from the small holes in the inner and outer flame tubes, partially burns, and rises up the combustion chamber from the outside. The medium heat section of the combustion chamber, which is farthest from the hole, is affected by the supplied airflow and rises in a laminar flow, resulting in poor mixing with the air and a lack of air. However, the protruding air creates eddy currents to promote mixing and makes it easier for air to be supplied to the inside of the combustion chamber, making it difficult for diffuse combustion to occur and macular spots to occur. Furthermore, since the upper incandescent cylinder is heated by the high-temperature exhaust gas after secondary combustion, the amount of heat in the high-temperature exhaust gas, which conventionally becomes convection heat, is converted to radiant heat, making it possible to create a combustion cylinder with a high radiation effect.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

In Figure 2, 1 (not shown) is a cylindrical lamp wick whose lower end is immersed in a fuel tank provided at the bottom and the upper part is exposed during combustion, and 2 is a cylindrical lamp with many small holes. 3 is a cylindrical outer flame cylinder having many small holes; 4 is a cylindrical outer flame cylinder;
6 is a cylindrical lower glowing tube made of lath, punched metal, wire mesh, etc. and connected to the outer flame tube 3; 6 is a cylindrical outer tube made of a heat-resistant, light-transmitting material such as glass; 6 is an outer tube; The inner flame tube 3, the outer flame tube 3, and the metal outer tube 6 are held substantially concentrically by cross pins or the like. Al is a protruding air port that protrudes upward toward the combustion chamber in the upper part of the inner flame tube 2, 8 is a separator plate connected to the inner flame tube 2, and 9 is made of lath, punched metal, wire mesh, etc. An upper glowing cylinder 1o provided on the upper part of the separator 8 is an upper lid that holds the upper glowing cylinder 8, and has an air port 11. 12 is an air port (secondary air port) provided between the inner flame tube 2 and the upper red portion 8. Further, the gaps between the inner flame tube 2, the outer flame tube 3, and the lower glowing tube 4 form a combustion chamber.

When the tip of the lamp wick 1 is ignited in the above configuration, the combustion heat and the airflow supplied by natural draft from the small holes at the bottom of the inner flame tube 2 and outer flame tube 3 vaporize the fuel 1'=1, causing the inner flame to ignite. It mixes with air supplied from the cylinder 2, the small holes of the outer flame cylinder 3, and the opening of the lower glowing cylinder 4, and rises in the combustion chamber A while being partially combusted. At about i/7a, the inner flame cylinder 2 and the outer flame fi! near the air supply part in the combustion chamber A! 3,
In the part near the wall of the lower glowing cylinder 4, the supplied airflow creates a polar [vortex flow, and the vaporized gas and air are mixed, but the central part is almost laminar and has a high concentration of vaporized gas. state. Therefore, when it rises to the secondary combustion part, the secondary air causes diffuse combustion and causes macular spots. However, due to the air lower, which is the main part of this embodiment, the gas flow that has risen in a nearly laminar flow is promoted to mix air and vaporized gas by the small vortex generated by the protrusion, and the combustion with a high concentration of vaporized gas is Since air is supplied to the center of the room, the premixing ratio of vaporized gas and air is improved, and blue flame formation in the secondary combustion section is promoted.

The high-temperature waste gas stream burned in the secondary combustion section flows through the upper red-hot cylinder 9.
In this method, the incandescent cylinder 9 is heated by the high-temperature waste gas flow after the secondary combustion, which rises while heating the incandescent cylinder 9 along the When the secondary combustion is a diffusion flame, the secondary combustion flame becomes longer and the macula is cooled by the red-hot tube 9, which interrupts the burning and tends to generate soot. becomes more likely to occur. However, in the case of a blue flame caused by premix combustion as in this embodiment, the secondary combustion flame is short and the red-hot tube 9 is heated mostly by the exhaust gas that has finished combustion, so there is no soot adhesion resistance, etc. iJ in case of method
: Turning the secondary flame into blue flame is an essential requirement.

Furthermore, according to this embodiment, even if the amount of vaporization increases to some extent, premixing within the combustion chamber A is promoted, so that diffusive combustion is less likely to occur in the secondary combustion section and macular spots are less likely to occur. Therefore, compared to the conventional example, the combustion amount can be adjusted within a wider range.
According to experiments, the critical combustion amount for macular development is approximately 300 kca.
It was over 1/h.

Effects of the Invention The combustion tube according to the present invention has the following advantages: The blue flame of the secondary combustion flame is promoted, and there is a wide range of combustion amount that is visually comfortable (no macular spots occur).

■ The upper incandescent tube can be heated by the high-temperature waste gas flow, expanding the radiant area and increasing radiant efficiency.

The following effects can be obtained.

FIG. 3 is a sectional view of a main part showing one embodiment of the present invention. ,i,I),Fig.

2...Inner flame 0η1.3...Outer flame tube, 4...
...lower glowing tube, 6...outer cylinder, 6...
...Metal outer cylinder, 7...Air port, 9...
Upper glowing tube, 12...Secondary air port.

Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] An inner flame cylinder having a large number of small holes, an outer flame f: 1] and a metal outer cylinder are positioned concentrically, an outer cylinder made of light transmitting material such as glass is placed on the upper part of the metal outer cylinder, and an outer flame cylinder is placed on the upper part of the outer flame cylinder. A lower glowing cylinder made of wire mesh punching metal, lath, etc., an upper glowing cylinder provided at the upper part of the inner flame cylinder through a secondary air port, and an air hole projecting upward toward the combustion chamber in the upper part of the inner flame cylinder. A combustion tube with a