JPS6226683Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device that completely vaporizes liquid fuel and then combusts it to improve its combustion efficiency and reduce combustion noise and odor. Generally, liquid fuel has a residual portion with a high distillation temperature, and this is precipitated during the vaporization process, resulting in a decrease in vaporization ability during long-term use.
Otherwise, combustion tends to become impossible due to clogging due to residue. Therefore, the present invention relates to a liquid fuel combustion device that also solves these problems.

The conventional liquid combustion methods can be roughly divided into pot type,
There are two types: the gun type and the rotary spray type.The pot type uses combustion heat to vaporize the fuel accumulated at the bottom of the combustion cylinder and burns it sequentially. Since combustion is carried out only on the surface, the capacity cannot be increased unless the surface area of the liquid is increased, and the combustion capacity is necessarily limited. In addition, a lot of soot was generated, and the chimney structure was complicated because appropriate vertical drafts had to be provided to generate draft (drawing of the chimney). Furthermore, in fuel atomization systems, air is forced into the fuel in order to completely burn the relatively coarse particulate fuel, and pressure waves are generated from the turbulence of the combustion flame, which is a major cause of combustion noise. I was getting used to it.

In contrast, in the present invention, the fuel is vaporized before it reaches the fuel region, and then mixed with air, so the air flow inside the combustion chamber is very slow, and the pressure waves caused by the turbulence of the combustion flame are generated. Does not occur. Furthermore, by dispersing the flame into the surrounding area and subdividing the combustion flame, mixing with air is improved and energy is dispersed. These effects can greatly reduce combustion noise, and since mixing with air is done before reaching the combustion zone, complete combustion with high combustion efficiency occurs without the generation of soot. It is.

Although this is gasification combustion, solving the problems (such as residue adhesion) caused by gasification as mentioned above is a very important problem for this type of gasification combustion. It will become. The present invention is designed to solve these problems, and can be summarized as follows.

The gasification burner of this invention vaporizes in heated air at a relatively low temperature.

In order to maximize the area in contact with heated air, the oil spray particle size is minimized to the absolute minimum.

The point is that the air used for vaporization is heated with a combustion flame.

〓 The number of revolutions of the fan and the amount of oil consumed during extinguishing and ignition are varied from maximum to zero and from zero to maximum.The combination of these four points produces a very large effect. be. In other words, in order to efficiently vaporize kerosene in a short period of time, it must be heated at high temperatures, but kerosene generally contains quite a bit of tar (so-called residue) and cannot be heated to temperatures above about 300℃. This will then adhere to the hot parts. To prevent this, the vaporization section is designed to make the oil into ultra-fine particles and completely vaporize the atomized oil using heated air at a relatively low temperature of 300°C or less. For this reason, there is no adhesion of tar at all, and the mixture with air is very good, resulting in complete combustion with high combustion efficiency. Furthermore, since air serves as the vaporization means, the combustion balance changes rapidly during a transitional period, ie, when extinguishing a fire. Therefore, when extinguishing a fire, the amount of oil fed and the amount of air are changed continuously or stepwise to gradually extinguish the fire while maintaining a balance, thereby completing the combustion. Examples thereof will be described below with reference to the accompanying drawings.

In FIG. 1, 1 is a burner case, and a heater 2 is attached to the periphery of the burner case 1 in close contact with it. An outer case 3 is provided outside the burner case 1 with a suitable gap therebetween to serve as an airflow passage. Further, a large number of air ports 4 are provided on the outer periphery of the outer case 3, and a rectifying plate 5 protruding inward is attached near the air ports 4. Further, a motor 7 is provided on the bottom surface of the outer case 3 via a motor flange 6, and a shaft end of the motor 7 has a
A centrifugal fan 8 is installed inside the burner case 1, which sucks combustion air and also sprays oil. As shown in FIG. 2, in the center of the centrifugal fan 8, there is a spray cap 17 that also serves as a fan boss, and near the bottom of this spray cap 17, a plurality of spray ports 18 are provided. Oil is gushing out from this part. A mixing plate 9 is placed on the upper surface of the burner case 1, and a combustion cylinder 10 is connected to the upper surface of the mixing plate 9. A auxiliary combustion body 12 having a large number of flame ports 11 is fixed to a position close to the burner case 1 within the combustion tube 10 by a fitting 13 .

On the other hand, an opening at the tip of an oil feed pipe 14 is provided opposite the spray cap 17 provided at the center of the centrifugal fan, and the tip of the oil feed pipe 14 is connected to an oil feed pump 16 via a joint 15. It is connected. In the liquid fuel combustion apparatus having the above-described structure, first of all, electricity is turned on to the heater 2, which heats the burner case 1 and the air in the air flow path. When the burner temperature reaches a temperature sufficient to vaporize the oil, the burner temperature detector 19 detects the temperature and starts the motor 7 and oil pump 16. is equipped with a spray cap 17, so
Oil dripped from the oil pipe 14 enters the spray cap 17 and enters the spray port 1 provided around the spray cap 17.
The oil particles are blown away by centrifugal force from the fan 8 and distributed evenly to each blade of the centrifugal fan 8 located outside of the fan 8. In this part, the oil particles are finely divided, stirred, and accelerated toward the outer periphery to become ultrafine particles. It becomes scattered. Part of the oil that has become fine particles is vaporized by the air that is heated by the heater 2 and enters the vaporization chamber during the process of being sucked by the centrifugal fan 8, and the rest is vaporized by the air that enters the vaporization chamber. It is instantaneously vaporized when it hits the vaporizing cylinder.

On the other hand, the upper opening diameter of the burner case 1 is the mixing plate 9.
This part becomes a kind of mixing chamber, and the air sucked in by the centrifugal fan 8 and the oil vaporized as described above are completely mixed, resulting in a uniform mixture. I noticed that the above-mentioned combustion aid 1
The flame is ejected from the flame port 11 provided in the flame hole 2, and if ignited by an appropriate ignition source at this time, a combustion flame A is formed.

Now, when combustion starts, the combustion tube 10 is heated by the radiant heat from the combustion flame A, which further heats the combustion air flowing through the air flow passage formed by the combustion tube 10 and the outer case 3. The air sucked in by the centrifugal fan 8 reaches a temperature such that almost all of the oil droplets that have become ultrafine particles can be vaporized in this air. Once combustion starts in this manner, there is no need to energize the heater 2 at all thereafter.

Next, the combustion operation is performed as described above, but especially in the early stages of combustion, the air and burner case 1 must be heated only with the heat of the heater 2, and the heat supplied from the early stages of combustion must be heated. oil instantly
In order to achieve 100% vaporization, the capacity of the heater must be extremely large. Therefore, at the beginning of ignition, the amount of air and the amount of oil fed are made as small as possible. In other words, it should be gradually increased from zero. In this way, the burner temperature will not drop all at once, and once combustion has started, a much larger amount of heat is given to the burner case 1 and the combustion air than the amount of heat from the heater 2, so the burner temperature and the air temperature gradually rises. If the amount of combustion air and oil consumption are increased in accordance with the degree of increase, the amount of supply that matches the vaporization capacity will always be obtained, and 100% vaporization will be possible.

Furthermore, when the motor 7 and pump 16 are stopped at the same time at the end of combustion, that is, when the fire is extinguished, the vaporized oil gas remains in the burner case 1 and the temperature of the burner itself is still high. Although the combustion speed does not change, the outflow speed of oil and gas rapidly decreases, causing a loss of combustion balance and a phenomenon in which the combustion flame moves into the burner, ie, flashback occurs. Therefore, in order to solve this problem, generally called post purge,
The configuration is such that only the blower fan continues to rotate for a short period of time even after combustion has stopped. However, according to this, the fuel concentration sharply decreases for a while after combustion stops, but since the amount of combustion air is the same as during steady combustion, the amount of air becomes too large and blows out, and unburned gas blows out. . Since these unsaturated gases are composed of unsaturated carbon, they cause defects such as foul odors.

This invention prevents the combustion balance from collapsing due to sudden changes in the amount of oil and air when extinguishing a fire, and gradually extinguishes the fire while maintaining the balance. The amount of oil fed and the amount of air are decreased continuously or stepwise by phase angle control or voltage control. Therefore, complete combustion is maintained until just before the fire is extinguished, and the above-mentioned defect of generating a bad odor does not occur.

As explained above, this invention uses complete gasification combustion, and of course there is no generation of tar noise, etc.
By controlling the phase angle or voltage of the motor and pump so that the fan rotation speed and oil consumption change continuously or stepwise from zero to the maximum value and from the maximum value to zero when igniting and extinguishing the fire.
It can always achieve complete combustion both when ignited and when extinguished, and has extremely high industrial value.

Here, we will discuss the control of the motor and pump mentioned above. In other words, at the early stage of combustion in the liquid fuel combustion device of the present invention, the air and burner case must be heated only by the heat of the heater, and it is possible to instantaneously vaporize 100% of the oil supplied from the early stage of combustion. Then, the capacity of the heater must be made very large. Therefore, in the present invention, at the beginning of ignition, the amount of air and the amount of oil fed are made as small as possible, that is, they are made to gradually increase from zero using the phase angle control or voltage control. In this way, the burner temperature will not drop all at once, and once combustion has started, a much larger amount of heat will be given to the burner case and combustion air than the amount of heat from the heater, so the burner temperature and air The temperature gradually rises.

If the amount of combustion air and oil consumption are increased as described above in accordance with the degree of increase, a supply amount that matches the vaporization capacity will always be obtained, and 100% vaporization will be possible.

Furthermore, if the motor and pump are stopped at the same time at the end of combustion, i.e., when the fire is extinguished, there will be some vaporized oil and gas remaining in the burner case, and the temperature of the burner itself will still be high, so the combustion rate will decrease. Even though it does not change, the outflow velocity of oil and gas rapidly decreases, causing a loss of combustion balance and a phenomenon in which the combustion flame moves into the burner, that is, flashback occurs. Therefore, in order to solve this problem, conventionally, a configuration called post-purge has been adopted in which only the blower fan continues to rotate for a short period of time even after combustion has stopped. However, according to this, although the fuel concentration rapidly decreases for a while after combustion stops, the amount of combustion air is the same as during steady combustion, so the amount of air becomes too large and blows out, causing gas to blow out. Since these unsaturated gases are composed of unsaturated carbon, they cause defects such as foul odors.

Therefore, the present invention uses phase angle control or voltage control to prevent the combustion balance from collapsing due to sudden changes in the amount of oil and air when extinguishing a fire, and to gradually extinguish the fire while maintaining the balance. The amount of oil fed and the amount of air are then reduced continuously or in stages.

Therefore, complete combustion is maintained until just before the fire is extinguished, and the above-mentioned defect of generating a bad odor does not occur.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a liquid fuel combustion device showing an embodiment of the present invention, and FIG. 2 is a sectional view of a fuel atomization section. 1... Burner case, 2... Heater, 7... Motor, 8... Fan, 11... Burner port, 12... Combustion aid, 16... Pump.

Claims (1)

[Scope of utility model registration request] a burner case that communicates with the air flow passage and is equipped with a heater; a combustion aid that is close to the air flow passage and forms a flame port; a centrifugal fan installed in the burner case; The liquid fuel combustion device consists of a refueling mechanism with an oil outlet opening in the center of the burner, and a control mechanism that detects the temperature of the burner case and energizes the heater only when the burner case temperature is low. hand,
The motor and pump are controlled in phase angle or voltage so that the fan rotation speed and oil consumption change continuously or stepwise from zero to the maximum value and from the maximum value to zero when igniting and extinguishing the fire. A liquid fuel combustion device characterized by: