JPH0140975Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a liquid fuel combustion device that vaporizes fuel sprayed from a fuel spray nozzle by transporting combustion gas back inside a combustion tube. .

(b) Conventional technology This type of liquid fuel combustion device was developed in U.S. Pat. No. 56-13621.
As disclosed in the publication (see Figure 5),
A mixing cylinder 3 is provided in the vicinity of the bottom wall 2 inside the combustion cylinder 1, and a fuel spray nozzle 5 is made to face the opening 4 in the center of the bottom wall 2. By blowing out the atomized fuel from the opening 4 into the mixing cylinder 3, a negative pressure region is created between the mixing cylinder 3 and the bottom wall 2, and a recirculation flow shown by the arrow is formed. The combustion gas transported back from the combustion zone into the mixing cylinder 3 is used to vaporize liquid fuel such as kerosene sprayed from the fuel spray nozzle 5.

The liquid fuel combustion device described above is economical because it vaporizes without using a heater. Furthermore, since the entire flame is gasified and burns almost blue, it has the advantage of high thermal efficiency. By the way, in order to perform gasification combustion well, it is required that the combustion tube 1, the mixing tube 3, and the fuel spray nozzle 5 be concentric.
Therefore, the fuel spray nozzle 5 was attached to the bottom wall 2 of the combustion tube 1 using a nozzle holder 6. Furthermore, if such an installation is carried out, the flame inside the combustion tube 1 cannot be directly viewed from the outside of the combustion tube 1 through the opening 4, so a non-contact type flame detection element is not used. A contact type frame rod 7 was used. However, frame rod 7
is exposed to high temperature conditions due to gasification combustion,
It was easily deformed by heat, causing ground faults and making it impossible to detect flames.

(c) Problems to be solved by the invention The problem to be solved by this invention is to solve the problem in a liquid fuel combustion device that vaporizes the fuel sprayed from the fuel spray nozzle by transporting the combustion gas back inside the combustion tube.
To easily achieve concentricity between a combustion tube and a fuel spray nozzle, and to perform flame detection satisfactorily using a non-contact type flame detection element.

(d) Means for Solving the Problems In order to solve the above problems, the liquid fuel combustion device of this invention has a fuel spray nozzle mounted on a nozzle holder having a nozzle mounting hole with a series of grooves. Fix the nozzle holder to the bottom of the combustion tube,
A non-contact type flame detection element is disposed at a position where the inside of the combustion cylinder can be directly viewed through the groove of the nozzle holder.

(E) Effect When combustion occurs inside the combustion tube, a portion of the light emitted by the flame reaches the flame detection element through the groove of the nozzle holder. For this reason, the nozzle holder equipped with the fuel spray nozzle is fixed to the bottom wall of the combustion tube, so that concentricity between the combustion tube and the fuel spray nozzle can be easily obtained, and flame detection is performed using a non-contact type flame detection element. will definitely be carried out.

(f) Examples Hereinafter, examples of this invention shown in the drawings will be described.

FIG. 1 shows a liquid fuel combustion apparatus according to an embodiment of this invention. In FIG. 1, 8 is an outer cylinder to which combustion air is supplied from a blower (not shown), and 9 is arranged at the upper part of the outer cylinder 8 with a gap forming a secondary air passage 10. together with a bottomed combustion cylinder connected to the outer cylinder 8 by a closing plate 11 at the tip;
12 is a circular primary air supply port provided at the center of the bottom wall 9a of the combustion tube 9, and 13 is a circular primary air supply port provided at the center of the bottom wall 9a of the combustion tube 9;
This is a rectifier tube provided integrally with a, and is tapered upward in the combustion tube 9. 14 is the combustion tube 9
A bottomed cylindrical nozzle case connected to the bottom wall 9a and defining a nozzle chamber 15 therein; 16 and 17 are fuel spray nozzles and spark plugs disposed near the primary air supply port 12 in the nozzle chamber 15; 1
8 is a nozzle and a plug holder fixed to the bottom wall 14a of the nozzle case 14, 19 is a secondary air supply hole bored in multiple rows in the upper side wall of the combustion tube 9, and 20 is a hole in the combustion tube 9. Near the top opening,
This is a flame stabilizing tube arranged with a gap from the combustion tube 9. The flame stabilizing tube 20 has a large number of small holes 21 and is held at the upper end opening of the combustion tube 9 via a plurality of support pieces 22 . In addition, 23 is nozzle case 1
This is a non-contact type flame detection element disposed below 4, and uses a phototransistor, photodiode, etc.

As shown in FIGS. 2 and 3, the nozzle case 14 is connected to the adapter part 16 of the fuel spray nozzle 16.
The bottom wall 14a is provided with openings 24 and 25 through which the spark plugs 17a and 17a of the spark plug 17 are inserted, 11 primary air introduction holes 26, and 3 screw holes 27 for attaching the nozzle and the plug holder 18. Two primary air introduction holes 28 are provided in the side wall 14b, and two primary air introduction holes 28 are provided for attachment to the bottom wall 9a of the combustion tube 9.
The flange 14c has screw holes 29 on the periphery of the upper end opening.
It is set in.

As shown in FIG. 4, the nozzle and plug holder 18 includes a nozzle mounting hole 31 with a number of grooves 30 connected to the periphery, a plug fitting part 32, and three screw holes for mounting to the nozzle case 14. 33, and screw holes 34, 35 for inserting screws for fixing the adapter part 16a of the fuel spray nozzle 16 and the stone part 17a of the spark plug 17, respectively. The flame detection element 23 looks directly into the combustion cylinder 9 through the groove 30 of the nozzle and plug holder 18, the opening 24 of the nozzle case 14, and the primary air supply port 12.

Next, the operation of the above-described embodiment device will be explained.

First, when liquid fuel such as kerosene (particle size: 70 μm) is sprayed from the fuel nozzle 16, the fuel is mixed with the primary air supplied into the nozzle case 14 from the primary air introduction holes 26 and 28, and 12 into the combustion cylinder 9. At this time, when the spark plug 17 is activated, combustion starts. Since the amount of air in the nozzle chamber 15 and the lower part of the combustion cylinder 9 is small, combustion takes place in the upper part of the combustion cylinder 9 where secondary air is supplied from a large number of secondary air supply holes 19.

In this way, once combustion starts, the combustion quickly shifts to gasification combustion. In other words, since the tapered straightening tube 13 is provided around the primary air supply port 12, the flow rate of the mixed gas of fuel and primary air passing through the straightening tube 13 is maintained, the spread is suppressed, and combustion is achieved. Proceed upward into the tube 9. Therefore, the area around the straightening tube 13 becomes a negative pressure zone, and a recirculation flow shown by the chain arrow is formed. In addition, a small vortex 36 (Karman vortex) is formed by the secondary air discharged from the secondary air supply hole 19,
These vortices 39 encourage recirculation flow. This recirculation flow introduces a portion of the combustion gas and transports it back, so that the fuel that has passed through the inside of the straightening tube 13 receives combustion heat and is vaporized. Then, the particles become fine particles of several micrometers by the time they reach the upper part of the combustion tube 9, where they undergo gasification and combustion.

In the upper part of the combustion tube 9, there are many secondary air supply holes 1.
Since the secondary air discharged from the flame stabilizing tube 9 collides with the outer circumferential surface of the flame stabilizing tube 20 at high speed, the flame dispersed around the periphery of the combustion tube 9 is regulated to the inside of the flame stabilizing tube 20, and the flame stabilizing tube 20 It is held at 20. In addition, flame-holding cylinder 2
A part of the fresh air that collided with the flame-stabilizing tube 20 is supplied to the inside of the flame-stabilizing tube 20 through the small hole 21, and the rest is supplied to the combustion tube 9.
are supplied to the upper end openings of the air and used as secondary air, respectively.

During combustion, the flame detection element 23 connects to the nozzle and the groove 3 connected to the nozzle mounting hole 31 of the plug holder 18.
0, sensing the light emitted by the combustion flame through the opening 24 of the nozzle case 14 and the primary air supply port 12;
Perform flame detection. Furthermore, even if there are variations in the combustion flame, the reflected light is supplied to the flame detection element 23 from the primary air introduction hole 26 of the bottom wall 14a of the nozzle case 14, so the flame detection element 23 can stably detect the flame. be. Furthermore, the flame detection element 23 monitors the combustion flame in the center of the combustion tube 9 through the groove 30, and the flame stabilization tube 20 is removed from the field of view, so that the flame stabilization tube 20, which becomes red hot immediately after the end of combustion, is detected. It can be made so that it does not detect the emitted infrared rays, so there is no need to worry about malfunctions.

According to this embodiment, a nozzle and plug holder 18 having a nozzle mounting hole 31 with a continuous groove 30 is provided.
Since the fuel spray nozzle 16 is attached to the fuel spray nozzle 16 and the nozzle and the plug holder 18 are fixed to the nozzle case 14 connected to the bottom wall 9a of the combustion tube 9, a jig is used to connect the fuel spray nozzle 16 and the combustion The cylinder 9 can be easily aligned concentrically, and good gasification and combustion can be achieved. Moreover, since the flame detection element 23 is arranged at a position where the inside of the combustion tube 9 can be directly viewed through the nozzle and the groove 30 of the plug holder 18, flame detection can be performed reliably using a non-contact type. . In addition, the flame detection element 2
3 monitors the flame through the groove 30, so that the infrared rays emitted by the red-hot body such as the flame-holding tube 20 after combustion is not detected, and erroneous flame detection can be avoided. Furthermore, the groove 30 can also be used as an inlet for primary air.

(g) Effects of the invention This invention is structured as described above, so
Not only can concentricity between the combustion tube and the fuel spray nozzle be easily obtained and stable gasification combustion can be performed, but flame detection can be ensured using a non-contact flame detection element outside the combustion tube. can be done. Furthermore, since flame detection is performed through the groove, the flame detection element can be prevented from falsely detecting a flame due to infrared rays emitted by the incandescent body, and the groove can also be used as a combustion air supply port.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the device of this invention, Fig. 2 is a plan view of the nozzle case used in Fig. 1,
FIG. 3 is a sectional view, FIG. 4 is a plan view of the nozzle and plug holder used in FIG. 1, and FIG. 5 is a sectional view showing an example of a conventional device. 9... Combustion cylinder, 9a... Bottom wall, 16... Fuel spray nozzle, 18... Nozzle and plug holder (nozzle holder), 23... Flame detection element, 30...
Groove, 31... Nozzle mounting hole.

Claims (1)

[Scope of utility model registration request] In a liquid fuel combustion device that vaporizes fuel sprayed from a fuel spray nozzle by transporting combustion gas back inside a combustion cylinder, a fuel spray nozzle is attached to a nozzle holder having a nozzle mounting hole with a series of grooves. Also, a liquid fuel combustion device characterized in that the nozzle holder is fixed to the bottom of the combustion cylinder, and a non-contact flame detection element is disposed at a position where the inside of the combustion cylinder can be directly viewed through the groove of the nozzle holder. .