JPS5812920A - Combustion apparatus for liquid fuel - Google Patents

Abstract

PURPOSE:To properly control the rate of air for combustion in accordance with the actual spraying rate of fuel, by converting the internal pressure of a return circuit into the difference in an oil level in a fuel feeder, and by variably controlling the rate of feed air for combustion in relation to the change of difference in the oil level. CONSTITUTION:The return oil dropped down to the bottom of a return chamber 6 is returned to an oil tank or a constant oil-level regulator 15, passing through a return pipe 14, and is circulated again to a nozzle 1 by a pressure pump 16, passing through an oil feed pipe 10. An air-pressure conduit 17 is interconnected to an oil tank or a constant oil-level regulator 15 in the upper part of a return chamber 6, and the oil level in the conduit 17 is fluctuated by receiving the pressure from the return chamber 6. A part of the air-pressure conduit 17 is made up of a transparent body. Combustion can always be taken place at a constant air-fuel ratio, by automatically or manually operating a damper 19 to control the rate of air for a fan 18 for combustion, in accordance with the difference in an oil level H which is shown in the transparent part of a conduit 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device such as a gun type burner that pressurizes fuel oil and jets it out at high speed from a nozzle.
In this method, an orifice hole is provided in front of the nozzle, and the actual spray amount (the amount that passes through the orifice hole and is used for combustion) is varied by changing the relative distance between the nozzle and the orifice hole. The purpose is to properly control the amount of combustion air. Since it was difficult to vary the combustion amount of conventional orifice return type gun burners, ON-OFF control of the combustion amount was generally performed in appliances for hot water supply, space heating, and the like. For this reason, this conventional or orifice return type gun burner not only causes unpleasant temperature changes such as hot water temperature, but also has problems such as frequent ignition noise.The reason for this conventional orifice return type gun burner is detailed below. Since the actual spray amount varies, it is not possible to set the air amount according to the actual spray amount.
It has not been possible to change the amount of combustion, or in other words, the thermal power.

That is, the distance between the nozzle and the orifice (l shown in Figure 1)
The actual spray amount has a proportional relationship when looking at a single sizzle, but the proportional relationship for each nozzle is not necessarily constant. This is because even if the nozzle tare has the same specifications, the spray angle will vary by about 100 degrees due to the limit of processing accuracy. For this reason, during mass production and when nozzles are replaced during maintenance, errors in air-fuel ratio settings are likely to occur. In other words, since the interval l shown in Figure 6 shows a different range for each nozzle, if the amount of combustion air is adjusted based on this interval l, the air-fuel ratio will change for each nozzle, resulting in smoke due to insufficient air and excess air. This may cause CO1 flame lift, etc.

Therefore, it is necessary to determine the actual spray amount using an index other than the interval l, and to adjust the amount of combustion air using that index.

In FIG. 1, 1j is a nozzle, 2 is a nozzle hole bored in this nozzle, 3 is a turning part having a turning groove 4,
The space between the swirling part 3 and the spray hole 2 is a swirling chamber 5. The outer periphery of the nozzle 1 is provided with an orifice gap 7 forming a return chamber 6, and the return chamber 6 has an airtight structure communicating with the outside air only through an orifice hole 7'.

The orifice hole 7' and the nozzle hole 2 are provided on a concentric axis so that the distance l between them can be made variable, and in FIG. A piston 9 having a hole 8 is provided and
The piston 9 is inserted into a cylinder 11 having an oil feed pipe 1o at one end. Further, the spring 12 biased between the nozzle 1 and the orifice body 7 always balances the nozzle 1 and the piston 9 with the sending pressure applied to the cross section of the piston 9, and slides them into a predetermined position. The fuel oil pressurized in this way has a predetermined interval l, and
It passes through the oil feed hole 8 of the piston 9 and reaches the rotating part 3,
A plurality of swirl grooves 4 formed by the swirl portion 3 and the inner surface of the nozzle 1
to go into. The fuel oil undergoes a swirling movement in the swirling chamber 5 due to the swirling groove 4, and forms a spray having a predetermined spray angle from the spray hole 2 while gradually heading downstream.

However, even if the aforementioned nozzle 1 is at a predetermined distance from the orifice hole 7', if the spray angle from the nozzle hole is different, the actual spray amount (the amount of fuel oil passing through the orifice hole 7') will be a different value. It is natural that this will happen.

Generally, the spray angle of a nozzle varies within a width of about 100 even if it is strictly controlled, so it is necessary to determine the interval 1 for each nozzle according to the spray angle of the nozzle. This makes it virtually impossible to determine the interval l for each nozzle when mass producing the present system or when replacing the nozzle with another nozzle during maintenance.

In the present invention, based on the discovery that the internal pressure of the return chamber 6 has a proportional relationship with the actual spray amount, a detection means that can easily detect the actual spray amount is used. This provides a liquid fuel combustion device that can vary the amount of combustion and optimize the air-fuel ratio.

A specific example thereof will be described in detail below along with 'Feature 1□11.

FIG. 2 shows the distance l, the actual spray rate (the amount of spray that passes through the orifice hole 7' relative to the amount of spray from the nozzle 1), the internal pressure (negative pressure) of the litter chamber 6, and the orifice hole 7 in the configuration shown in FIG. ' shows the correlation with the spray angle. Interval e is 0 to 1
．． In the range of 3111111, almost all of the spray passes through the orifice hole 7'. The actual spray rate during this period was approximately 100.
%. Further, the negative pressure in the return chamber 6 is gradually increasing. This negative pressure is caused by the air in the return chamber 6 being attracted in the direction of movement of the spray.

When the interval l is in the range of 0 to 1.311 m, a donut-shaped air flow path 13 is formed between the spray and the orifice hole 7', and outside air is introduced through the air flow path 13 to relieve negative pressure. There is. Therefore, the range in which the air flow path 13 decreases as the distance l increases (1-0 to 1.3 mm)
f represents the tendency of the negative pressure in the return chamber 6 to increase.

When the distance 1 is approximately 1.3 mm, the spray angle rapidly decreases and increases to a value that is smaller than the original spray angle of the nozzle 1.

This is because the negative pressure in the return chambers increases considerably just before the interval 1 reaches 1.3 mm, so the negative pressure in the return chamber 6 expands the spray angle of the nozzle 1 itself, which in turn spreads to the air flow path 13.
is narrowed to increase the negative pressure in the return chamber 6, thereby increasing the spray angle and the negative pressure in the return chamber e in a self-exciting manner. Stabilize. At this time as well, the actual spray rate is approximately 100%.

Further, when the distance l is between 1.3 and 2.1-, as the spray □ mist cut off by the orifice hole D increases, the momentum with which the spray attracts the air in the return chamber e also decreases, and the return chamber 6 The negative pressure decreases in conjunction with the amount of unsprayed water.

Further, when the interval l is 2 InIn or more, the internal pressure of the return chamber 6 becomes positive pressure. This is because the pressurizing force of the fuel oil is applied to the return chamber 6, and the increase in the return fuel oil increases, causing the pressure in the return chamber 6 to rise.

As is clear from the above explanation, at intervals of 1.3 to 2.
It can be seen that between 1M, there is a constant relationship between the decrease in the actual spray rate and the decrease in the negative pressure, and the actual spray angle also decreases. Therefore, if the air-fuel ratio is properly controlled in the range where the actual spray rate and the negative pressure are in a proportional relationship at this interval e = 1.3 rrm or more, the combustion Proportional control of quantity becomes possible.

An embodiment that enables the above proportional control will be specifically described below.

In FIG. 1, the return oil dropped below the return chamber 6 passes through the return pipe 14 and returns to the oil tank or constant oil level device 16, and is again transferred to the nozzle 1 by the oil feed pipe 10 and the pressure pump 16. It is something that circulates. Further, above the return chamber 6, a pneumatic conduit 17 communicates with the oil tank or oil level device 16. The return pipe 14 and the pneumatic conduit 17 are necessarily inserted under the oil level of the oil tank or the constant oil level device 16, and the return chamber 6
It must not impede the airtightness of the With this configuration, when the interval l is within the range of 1.3 to 2.0111111, the pneumatic conduit 17 receives the pressure of the return chamber 6 to raise and lower the liquid level within the pipe.

This liquid level height difference H in the pneumatic conduit 17 is used as an index indicating the actual spray amount. As described above, although the interval 1 can be easily confirmed from the outside, it does not accurately indicate the actual spray amount due to variations in the nozzles 1. On the other hand, the liquid level height difference H in the pneumatic tube is caused by the kinetic energy of the actual spray passing through the orifice hole 7', so it almost indicates the actual spray amount even if there are variations in the nozzle. .

By appropriately increasing or decreasing the pressure of the pressure pump 16, the nozzle 1
moves on the axis, and at this time, the actual spray rate is at its maximum at the highest point where the liquid level is high, and even if the pressure of the pointed pump 16 is increased, the actual spray rate is hardly affected and can be decreased. If so, the actual spray rate will decrease as the liquid level decreases. A portion of the pneumatic tube 17 is made of a transparent material so that this situation can be checked from the outside. In addition, if the air volume adjustment damper 19 of the combustion blower 18 is operated automatically (photo sensor, etc.) or manually in conjunction with the liquid level described above, combustion can be performed at a constant air-fuel ratio at all times. It is something. Further, an air swirling vane 20 is provided in front of the orifice body 7 to promote mixing and diffusion of combustion air and spray to form a good turbulent diffusion flame.

Next, the internal pressure of the return chamber 6 is controlled so that the interval l is within a predetermined range (
In the example, a correlation with the actual spray amount is shown between N=1.3 and 2.1 mm. This range is pneumatic conduit 1
This is the direction in which the distance between the nozzle 1 and the orifice hole 7' is made wider than the maximum value of the liquid level in No. 7. A regulating device provided so that the nozzle is movable only within this proportional range will be described below.

As shown in FIG. 1, a regulating screw 21 is attached to a part of the return chamber 6.
When the liquid level in the pneumatic conduit 17 is at its highest, the regulating screws 2111 and -2 are engaged with a part of the nozzle 1 so that the interval l is /=1.3 to 2.
．． 1 mm, that is, the nozzle 1 is configured to move only within a range where there is a correlation between the actual spray amount and the negative pressure in the return chamber. By providing this regulating device, the negative pressure in the return chamber uniquely indicates the actual spray amount, and therefore it is easier to spray from the outside than when there are two ranges that indicate the actual spray rate with the same negative pressure. rate is detectable. That is, if this regulating device was not provided, it would be necessary to vary the interval 4 over the entire range and check the change in the liquid level height difference H in the pneumatic conduit 17 to confirm that it was within the proportional range. By adding a regulating device, once the regulating device is set when installing the nozzle, there is no need to check whether it is within the proportional range, and the 17Ω liquid level height difference H in the pneumatic conduit can be understood as the immediate actual spray rate. It is something. In addition, the liquid level height difference H can be detected with an extremely simple configuration.Furthermore, the mechanism for hydraulically driving the nozzle 1 described above can also be performed using other methods or means for arbitrarily changing the interval l. Of course it's a good thing. Furthermore, the above-mentioned regulating device can also be achieved by using electrical means, such as electrically regulating the upper limit of the pressurizing pump oil pressure, in addition to mechanical means such as screws, to achieve the same effect.

As described above, according to the present invention, since the actual amount of the injection rod can be accurately determined by visual inspection, it is possible to provide appropriate combustion air and achieve complete combustion. This can prevent deterioration in efficiency. Furthermore, it is highly convenient to use because the current amount of combustion can always be displayed to the user as an indicator of the amount of combustion. Furthermore, by detecting the liquid level height difference H by electrical means and linking it with combustion air, automatic air-fuel ratio control is possible without using a complicated sensor mechanism, and this type of combustion device The purpose is to further expand the use of this technology in general equipment.

ζ 4. Brief explanation of the drawings
FIG. 1 is a side sectional view of an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the correlation between the burst spray rate 1 amount interval 1, the IJ turn chamber pressure, and the spray angle.

1... Nozzle, 6... Return chamber (return circuit), -r/... Orifice hole, 1
4...Return pipe (return circuit), 15
...Oil tank or constant oil level device, 16...
・Pressure pump, 17...Pneumatic conduit, 18...
...Blower for combustion, 19... Air conditioning tamper 1L... Distance between nozzle and orifice hole,
H...Liquid level height difference.

Claims (1)

[Scope of Claims] (1) A sliding nozzle that ejects fuel, a fuel supply device that supplies the fuel to the nozzle, and a passage amount of the fuel that is downstream of the nozzle and is ejected from the nozzle. a return circuit that communicates with the outside air through the orifice hole and recovers a surplus of the ejected fuel to a fuel supply device; and a combustion air supply device, the nozzle and the orifice hole In a liquid fuel combustion device that varies the amount of fuel passing through the orifice hole by changing the relative distance from the orifice, the internal pressure of the return circuit is converted to a liquid level height difference H of the fuel stored in the fuel supply device, A liquid fuel combustion device characterized in that the amount of combustion air supplied is varied in relation to changes in the liquid level difference H. @) The return circuit and the oil tank are connected through a pneumatic conduit, and all or part of the pneumatic conduit is formed into a transparent body, so that the liquid level difference H can be visually observed through the pneumatic conduit. A liquid fuel combustion device according to claim 1. (3) A device that converts the oil level height difference H into an electrical signal and drives a combustion air conditioning device using the electrical signal. (4) A liquid fuel combustion device in which the distance l between the nozzle and the orifice hole is a constant distance.