JPS58178109A - Combustion method for fuel oil combined with gas - Google Patents

Abstract

PURPOSE:To perform the perfect combustion in central part, to rise the temperature at the inside of a furnace, to improve a combustion efficiency, to facilitate firing of a burner and holding of a flame, and to reduce the production of NOX, by blowing oxygen gas, combustible gas and NH3 gas into a center of the flame from the center of a nozzle. CONSTITUTION:A gas transporting pipe 32 is installed in a fuel oil pipe 18, and oxygen is fed into the gas transporting pipe 32 through an air feed pipe 31. The supplied oxygen gas passing through a center of a core communication with the gas transporting pipe is jetted into the center of a flame through a gas outlet 33. The oxygen is jetted into a flame center having a low temperature to conduct an oxygen-combustion of an unburning substance. NH3 gas is fed through the air feed pipe 31, and is jetted out through the gas outlet 33. This performs a perfect combustion, rises temperature within a furnace, improves a combustion efficiency, facilitates firing of a burner and holding of a flame, and reduces the production of NOX.

Description

[Detailed description of the invention] The present invention relates to a fuel oil spray combustion method and apparatus.

The inventors filed Japanese Patent Application No. 56-80529, ``Ultrasonic Spray Combustion Method and Apparatus Therefor,'' filed on February 22, 1980, rcOM Spray Method.

Figures 1, 2, and 3 are the rcOM spraying method of the previous application]
FIG. 2 shows the structure of the nozzle, FIG. 1 shows the structure of the core, and FIG. 3 shows a three-dimensional view of the core.

As shown in Fig. 2, there is a pneumatic feed pipe (
20) An appropriate amount of high-pressure air is passed through the air bubble regulating valve (24) through the pressure inlet, and fuel oil containing air bubbles is communicated at right angles to the through hole (10) of the core body (8) (not necessarily limited to right angles). The liquid may be discharged from a plurality of small holes (11) penetrating the outside (as long as it is in the lateral direction at an angle of 90±α).

High-pressure air is ejected from a plurality of inclined grooves (12) formed on the tapered surface (9) of the core body (8), and low-pressure air is ejected from the outer circumference of the outer cylinder (force) by a blower (15). This is a method of letting it burn.

In this method, at the outlet of the small hole (11) of the core body (8), fuel containing bubbles is ejected from inside the fuel oil pipe (
As soon as the high-pressure air bubbles in 18) jump out from the small hole (11), the pressure reaches normal pressure and expands rapidly.This sudden expansion pulverizes the accompanying oil droplets, and at the same time, high-pressure compressed air is released from the inclined groove (12). As the liquid fuel and compressed air collide, strong ultrasonic energy is generated, and this ultrasonic energy turns the squeezed liquid fuel into extremely fine mist.

According to experiments, when the pressures of liquid fuel and high-pressure air were set to four levels, the spray particles became fine particles with an average size of 30 microns.

Since the oil droplets sprayed by this nozzle are ultra-fine with an average diameter of 30 microns, it is natural that the combustion effect is improved.

In the above explanation, high-pressure air is ejected from the pneumatic feed pipe (20) through the inclined groove of the tapered surface (9) of the core body (8), but instead of high-pressure air, high-pressure steam generated in the boiler is ejected. You may. Alternatively, a mixture of high pressure air and high pressure steam may be ejected.

For the purpose of illustrating the principle, Fig. 2 shows a flow note in which a part of the high-pressure air from the pneumatic feed pipe (20) is injected into the fuel oil pipe (18) and the rest is ejected from the inclined groove (12). Since electricity costs are high, the air supply pipes are separated, and as shown in Figure 4, the supply to the fuel oil pipes is carried out by an air compressor (34).
High pressure air is passed from the pneumatic pipe (20) to the inclined groove (
12) is sent from the blower (35) to the low pressure air pipe (2).
Air may be blown through 0).

In the above method, an ultra-fine spray with an average diameter of 30 microns can be obtained and efficient combustion can be achieved, but the present invention relates to a method for further improving this combustion efficiency.

High temperature flames are sometimes required for valence melting, steel heat treatment, etc. In this case, instead of using air with an oxygen content of 21%, oxygen is mixed in the air to increase the oxygen content to 25% or 30% and burn it to increase the temperature of the flame and shorten the melting time. many.

This is effective, but to increase the oxygen content to 25%, add 5.3 volumes of expensive oxygen to 100 volumes of free air, and to increase the oxygen content to 30%, add 12.9 volumes of expensive oxygen. The disadvantage is that the operating costs are high because it has to be added.

Immediately after the flame is burned, the outer periphery of the flame has good contact with the air and is high in temperature, but the center has poor contact with the air and the temperature of the center is higher than that of the outer periphery. It is usually much lower.

The principle of the present invention is explained in Fig. 4.Fuel oil pipe (18)
A gas transport pipe (32) is installed in the middle of the gas transport pipe (32).
) from the air supply pipe (31), and the oxygen gas sent passes through the center of the core connected to the gas transport pipe and is injected into the center of the flame through the gas outlet (33). This oxygen is injected into the center of the flame, where the temperature is low, and unburnt materials are combusted with oxygen.

According to the experimental results, when burning with the nozzle shown in Figure 2, the flame is reddish, but with the nozzle shown in Figure 4, the amount of air sent by the pneumatic pipe (20) and the blower (15) is 1.
% of oxygen was blown into the furnace, the color of the flame instantly became whitish and the temperature inside the furnace rose by more than 50°C.

In addition, when oxygen injection was stopped, the whitish flame instantly returned to its original red color and the temperature dropped by more than 50°C. This is because the conventional oxyfuel combustion method increases the oxygen content of the air being blown into it. Oxygen consumption increases, but the present invention does not introduce a large amount of oxygen into the secondary air for combustion, but merely blows a small amount of oxygen into the center of the combustion flame, so oxygen consumption is drastically reduced. ``In the above test, 100% oxygen was blown in, but even if 50% oxygen or 30% oxygen air was blown in, there was a slight effect, although it was inferior to 100% oxygen. The effect can be improved by increasing the dose.

In the case of propane gas and city gas, which have self-combustible properties when burning fuel, the gas ignites immediately after being ejected and does not go out, but in the case of fuel oil, the sprayed oil first evaporates and becomes gas. Since the principle is that the oil is ignited at the 50X', 100X', etc. end of the nozzle, the lower the quality of the oil, the slower the gasification, the longer the distance, and the weaker the flame holding power. There is a risk of extinguishing the fire during combustion.

In the method of the present invention, if a quickly combustible gas such as propane gas or city gas is sent from the air pipe (31) and a small amount is spouted from the gas outlet (33), ignition is easy, and the flame is extinguished due to side heat from the flame. There's nothing to do.

Recently, NOx in combustion exhaust gas has become a problem, and when alkaline gas such as NH3 gas is introduced into combustion gas,
It is known that OX decreases by more than 50%. In the present invention, NH3 gas is sent from the air pipe (31) to the gas outlet (33).
) The amount of NOx can be reduced by emitting it properly.

In the above, oxygen gas is ejected from the gas outlet (33) to the center of the flame to increase the temperature of the flame and promote combustion, flammable gas is ejected to ignite and stabilize the flame, and N1-13 gas is ejected to reduce NOx. However, by ejecting not a single gas but a mixture of the above two or three types of gas from the gas outlet (33), a combination of the above two types of results or an integrated result of the three types can be achieved. is obtained.

As mentioned above, in addition to the previous invention of ultrasonic fine powder mist, the present invention also provides a method of directing a single gas or a mixture of two or three gases such as oxygen gas, combustible gas, and NH3 gas to the center of the combustion flame from the center of the nozzle. It has excellent features such as complete combustion in the center, temperature increase in the furnace, improvement in combustion efficiency, ease of ignition and flame holding, and reduction in NOx, which can be either single or combined.

This method can be applied not only to fuel oil alone, but also to COM mixed with emulsified oil emulsified with water and pulverized coal.

The structure of a conventional fuel oil sprayer is that fuel oil is usually sprayed at a high velocity of 5 Q nr /see, 1 QQ m /see, etc. from a small diameter nozzle, and a gas transport pipe is installed in the center of this nozzle. It is extremely difficult to establish a

In the present invention, the structure of which is shown in FIG. 2 and the principle diagram shown in FIG. (18
) can have a large diameter freely, and instead of injecting fuel oil and gas from the same pipe as in the past, fuel oil is injected into the core body (
The structure is such that gas is injected from the center of the core body (18) through small holes on the sides of the core body (18), so this structure is optimal for carrying out the method of the present invention.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are explanatory views of the present invention, and FIG. 4 is a diagram showing the principle. (8) --- Core body (12) --- Inclined groove (1
1)...Small hole (18)...Fuel oil pipe (20
)...Pneumatic feed pipe (33)...Gas outlet (20
')...Low pressure air pipe (34),...Air compressor (31)...Air pipe (35),...Blower (32)...Gas transport pipe Applicant: Director of Miura Engineering International Co., Ltd. President Mitsugu Miura

Claims (2)

[Claims] (1) As detailed in the main text, fuel oil or fuel oil containing high-pressure gas or water vapor is discharged from a fuel oil pipe, the discharged oil is atomized with air, and secondary air is sent to the center of the combustion flame. A method for burning fuel oil in combination with gas, characterized by injecting oxygen gas, fuel gas, and ammonia gas alone or in a mixture of two or three types of gas. (2) As detailed in the main text, a fuel oil discharge pipe is installed laterally from the fuel oil pipe for fuel transportation, an air jet groove is provided at the fuel oil discharge port, and a gas supply pipe is connected to the fuel oil pipe. A fuel oil sprayer characterized by having a gas ejection pipe that opens at the tip of the core body.