JPS60232408A - Liquid fuel combustion apparatus - Google Patents

Abstract

PURPOSE:To ensure stabilized evaporating combustion in a liquid fuel combustion apparatus, by forming a recycling circuit of combustion gas between an evaporating cylinder and a flame cylinder, by throttling the outlet of a flame cylinder in a flame chamber, and by utilizing the suction effect of an injection flow by a combustion air nozzle provided in the base of a flame cylinder. CONSTITUTION:Combustion air is injected toward a suction opeining 6 provided at the outlet of narrow passage of an evaporating cylinder 5, from a combustion air injection nozzle 7 provided in the base part of a flame cylinder, via passages 8a and 8b formed inside of a flame cylinder 8. While combustion gas recycling circuit is formed by sucking combustion gas, by the negative pressure produced by fast injection flow of combustion air. An evaporating cylinder 5 is coaxially provided in the downstream side of an oil feed inlet 2. The air forcibly fed from apertures 4 being provided along the side walls of an air box 1, once turning back through the passages 8a and 8b in the flame chamber 8 reversely, exchanging heat with combustion gas on the inner walls of those passages in high temperature, being preheated in high temperature, is injected in high velocity toward the suction opening 6 of an evaporating cylinder 5 from the air injection nozzle 7. With such an arrangement, the rate of recycling gas is hardly subjected to the fluctuation of the combustion rate, and evaporating combustion can be taken place in a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION (Related Field) The present invention relates to a liquid fuel combustion device. In particular, it relates to a hydraulic spray type combustion device that burns with green flame.

(Prior art) When liquid fuel is evaporated and mixed with air as gaseous fuel and combusted, harmful substances (odors, soot, N
It has been known for a long time that it is possible to extremely reduce the amount of heat generated (e.g., 0%), and it has been put to practical use in some types of small burners in Japan.

Such a combustion device requires an evaporative mixing zone and a combustion zone. Heating oil is often used as a method for evaporation, but
There is a risk of soot generation and fire.

There are also gun-type burners, in which liquid fuel is injected into the air at high pressure from a pressure spray nozzle, atomized, and combusted without a special evaporation zone. Atomized oil particles have a significantly increased surface area, creating conditions for easy evaporation.

In evaporative combustion devices using such pressure spray nozzles, the mainstream method is to recirculate the combustion gas to recirculate the high-temperature gas and use the thermal energy to evaporate particulate liquid fuel. When making the combustion amount from one nozzle variable in a pressure spray type, if the range of variation becomes wider, the amount of recirculated gas may change.

(Objective) An object of the present invention is to provide a burner that incorporates a conventionally known recirculation system, further preheats combustion air, actively promotes evaporation of liquid fuel, and performs stable evaporative combustion over a wide range. It is something to do.

(Structure) Pressurized liquid fuel is supplied to the nozzle via the oil pipe, and is sprayed as fine oil particles from the nozzle into the evaporator cylinder, passes through the oil inlet and the inside of the combustion cylinder, and enters the evaporator cylinder from the combustion air nozzle. It is mixed with the combustion air that is blown out. At the time of initial ignition, the amount of returned oil is increased and the amount of sprayed oil is reduced to ignite. As time passes, recirculation of combustion gas occurs and the combustion tube also becomes hot, so the combustion air is preheated to a high temperature and the oil is vaporized in the evaporation tube.

The combustion chamber narrows the combustion tube outlet and forms a combustion gas recirculation circuit between the evaporator tube and the combustion tube by the suction effect of the jet of combustion air nozzle at the base of the combustion tube. Since both the air and the air are at high temperatures, the vaporization of the atomized oil particles is promoted and stable vaporization combustion takes place.

(Embodiment) Reference numeral 1 denotes a wind box, and a blower 10 is attached to the wind box. End wall 1a of wind box l
An oil feed hole 2 is provided in the center. A large number of air inlet holes 4 are provided on the outer periphery of the end wall 1a. Combustion air is supplied to the internal passage F3a of the combustion cylinder 8.

8b, the combustion air is ejected from the combustion air injection nozzle 7 at the base of the combustion cylinder toward the inlet 6 provided near the narrow diameter part of the evaporator cylinder. The combustion gas is sucked in by the negative pressure generated by the high-speed jet, forming a combustion gas recirculation circuit (arrow A in the figure).

An atomizing nozzle 3 is arranged upstream of the oil feed hole 2, and an ignition electrode 3a is provided on the outer periphery of its tip. The atomizing nozzle 3 is connected to an oil feed pipe 12 for supplying oil pressurized by a pump and a waste oil pipe (not shown) provided with a mechanism for adjusting the amount of spray.

The evaporator tube 5 is provided concentrically downstream of the oil feed hole 2, and a combustion tube 8 is further provided concentrically surrounding the evaporator tube 5. There is a partition plate 13 inside the combustion tube, and the air pushed in from the air inlet hole 4 on the outer periphery of the wind box 1 is passed through a passage 8a inside the combustion tube.

8b is once inverted, and heat is exchanged with the combustion gas on the inner high-temperature wall, and the air is preheated to a high temperature and is ejected from the air ejection nozzle 7 to the inlet 6 of the evaporator cylinder 5 at high speed.

The tip of the combustion tube 8 has a constriction structure to ensure good recirculation of combustion gas. Furthermore, a cap (not shown) made of a material having an oxidation catalytic action, such as metal or ceramic, is provided at the end of the aperture mechanism, if necessary.
It is also possible to completely eliminate unburned components.

(Effects) In the present invention, combustion air is preheated by exchanging heat with high-temperature combustion gas, and is then injected into a plurality of inlet holes drilled near the small diameter part of the evaporator tube to generate combustion gas. Since recirculation is performed, evaporative combustion can be performed over a wide range without being affected by fluctuations in the amount of recirculated gas caused by changes in the amount of combustion. In addition, evaporative combustion can be performed even with relatively heavy fuel oil. Furthermore, since the temperature inside the combustion cylinder is extremely high, the material is prone to thermal distortion.
Since the structure is relatively simple and the combustion air provides a cooling effect, such troubles can be avoided.

[Brief explanation of drawings]

The figure is a sectional view of the liquid fuel combustion device of the present invention. In the figure: A (recirculation flow) direction 1 wind box 2 oil feed hole 3 atomization nozzle 4 air inlet hole 5 evaporator tube 6 hole (for introducing recirculated combustion gas) hole 7 air jet nozzle 8 combustion tube 8a, 8b Air passage 10 Blower 11 Air control valve 12 Oil pipe 13 Partition plate and above Applicant Corona Co., Ltd. Agent Patent attorney Isamu Ohashi

Claims (1)

[Claims] [1] A liquid fuel atomizing nozzle (3) is provided upstream of the oil inlet hole (2) provided in the center of the inner end wall of the wind box (1).
An evaporator cylinder (5) having a plurality of holes (6) on the circumference near the narrow diameter part is arranged downstream of the oil inlet hole (2) for introducing combustion air and recirculated combustion gas. A combustion tube (8) having internal air passages (8a, 8b) for preheating the combustion air is provided surrounding the evaporation tube (5), and the outlet of the combustion air to the combustion tube is provided with the combustion tube (8). An air jet nozzle (7) is arranged facing the combustion air and circulating gas inlet (6) of the evaporator tube (5), and the tip of the combustion tube (8) is narrowed to a small diameter. Fuel combustion equipment. [2] The liquid fuel combustion apparatus according to claim [1], wherein an auxiliary mechanism for performing complete combustion is attached to the combustion gas outlet passage as necessary.