JPS61280306A - Liquid fuel burner - Google Patents

Abstract

PURPOSE:To obtain excellent gasified combustion by using a tapered flow arranging cylinder to convey reversely part of the combustion gas around the flow arranging cylinder. CONSTITUTION:The atomized fuel from a fuel nozzle 16 is mixed with the primary air that enters a nozzle case 14 from air introduction holes 26 and 28, and the mixture enters the combustion cylinder 9 from a primary air supply inlet 12. At this time when an ignition plug 17 is operated, combustion starts. Then the mixed gas passing through the flow arranging cylinder 13 maintains its flow speed and its dispersion is suppressed, and the mixed gas advances to the upper section of the combustion cylinder 9 which creates a recycling flow, which is aided in its heating by the air vortex at the secondary air supply opening 19 as shown by the chain lines in the figure. This recycling flow transports reversely the combustion gas and heats the mixed gas right behind the flow arranging cylinder 13, and the mixed gas burns with gasification before it reaches the upper section of the combustion cylinder 9. There the secondary air is colliding with the outer circumferential face of the flame holding cylinder 20, holding the flame in the flame holding cylinder 20.

Description

[Detailed description of the invention] (a) Industrial application field This invention is used in water heaters, hot water boilers, hot air heaters, etc. for the purpose of hot water supply and space heating, and vaporizes liquid fuel without using a heater. The present invention relates to a liquid fuel combustion device that gasifies and burns liquid fuel.

(B) Prior Art Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 59-200116, there has been a liquid fuel combustion apparatus of this type as shown in FIG. 5. This one consists of a fuel spray nozzle (2) installed at the bottom of the bottomed combustion tube (1), and a fuel spray nozzle (2) installed at the bottom of the bottomed combustion cylinder (1).
A plurality of primary air supply holes (3) that blow out primary air for combustion into the combustion tube (1) from around the nozzle (2) are installed above the nozzle (2) so as to be coaxial with the nozzle, and the combustion gas in the combustion zone is supplied to the nozzle. A rectifying cylinder (4) that is transported back to the vicinity, and a secondary combustion cylinder that is perforated in the side wall of the combustion cylinder above the rectifying cylinder (4) in a direction perpendicular to the axes of the nozzle (2) and the rectifying cylinder (4). A large number of secondary air supply holes (5) for blowing out air, and a large number of through holes (6) installed above the secondary air supply holes (5) and outside the fuel spray range of the nozzle (2). ) or an annular flame holding plate (7) having a notch.

The liquid fuel combustion device described above blows primary air with a high flow rate into the straightening tube (4) from the primary air supply hole (3), and creates a negative pressure area between the straightening tube (4) and the bottom wall of the combustion tube +1. A part of the combustion gas in the combustion zone is returned to the straightening cylinder (4) to form a recirculation flow shown by the chain arrow. It is vaporized and gasified and burned without a heater. In addition, secondary air collides perpendicularly with the mixed gas flow of vaporized fuel and primary air that has passed through the straightening tube (4), and this collision pressure promotes the mixing of vaporized fuel and air. At the same time, the combustion flame is stabilized by utilizing the vortex generated at the upper part of the flame stabilizing plate (7).

However, since the combustion gas is recirculated using the rectifying tube (4), the number of parts increases and the cost is not only high, but also the nozzle (2) and the rectifying tube (4) are connected to the combustion tube (1). ), it had to be installed while maintaining concentricity, which had the disadvantage of taking time to assemble. Also, nozzle (2)
is affected by the recirculation flow, so the heat resistance of the nozzle (2) becomes a problem, and the nozzle (2) is easily clogged due to adhesion of soot (maintenance and inspection of the nozzle (2) must be performed frequently). I had to use a flame-holding plate (
The upper part of the combustion tube (1) becomes hot and there is a risk of thermal deformation or high-temperature oxidation. I had to. In the former case, the equipment will be expensive, and in the latter case, the operating noise will be louder and
There was a problem that the C02 concentration increased and the thermal efficiency decreased.

(c) Problems to be Solved by the Invention The problems to be solved by this invention are to ensure that gasification and combustion can be performed well without complicating the structure or having an adverse effect on the fuel injection/mist nozzle, and in addition, without using expensive heat-resistant materials. To prevent thermal deformation of a flame stabilizing member and a combustion cylinder without using or creating excess air.

B) Means for Solving the Problems In order to solve the above-mentioned problems, the liquid fuel combustion device of the present invention is provided with a primary air supply port in the center of the bottom wall of the combustion cylinder whose upper end is open. A rectifying tube that tapers toward the inside of the combustion tube is provided integrally with the bottom wall, and a large number of secondary air supply holes are provided on the upper side wall of the combustion tube. A flame stabilizing tube was provided at a position facing the primary air supply hole with a gap from the combustion tube, and a fuel spray nozzle was provided on the outside of the combustion tube near the primary air supply port.

09 Effect With this configuration, the mixed gas of fuel and primary air that has entered the rectifying cylinder through the primary air supply port is maintained at a flow velocity and advances to the upper part of the combustion cylinder while its spread is suppressed. Here, secondary air is supplied from a large number of secondary air supply holes and combustion occurs.

The area around the straightening tube becomes a negative pressure zone, so when combustion occurs, part of the combustion gas in the upper part of the combustion tube is transported back to the surroundings of the straightening tube. Therefore, the fuel that has passed through the rectifying cylinder receives combustion heat and is vaporized, resulting in gasification combustion. In this way, by providing a tapered straightening tube integral with the bottom wall of the combustion tube, a recirculation flow is formed and a portion of the combustion gas is transported back, so that the fuel spray can be sprayed at the bottom of the combustion tube. Good gasification and combustion can be achieved simply by weiring the nozzle while keeping it concentric. Moreover, since the fuel spray nozzle is not affected by the recirculation flow, there is no problem with heat resistance or soot adhesion, and less maintenance and inspection is required.

On the other hand, the secondary air discharged from the secondary air supply hole collides with the flame-holding tube at high speed, so the combustion flame at the top of the combustion tube is not regulated to the inside of the flame-holding tube, but is held in the flame-holding tube. Ru. For this reason, we use highly heat-resistant materials for flame-holding tubes and combustion tubes,
These thermal deformations and high-temperature oxidation are prevented without lowering the temperature of the combustion flame by creating excess air.

(f) Example Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 shows a liquid fuel combustion apparatus according to an embodiment of the present invention. In Fig. 1, (8) is an outer cylinder to which combustion air is supplied from a blower (not shown), and (9) is an interval at the upper part of the outer cylinder (8) that becomes a secondary air passage Ql. At the same time, the outer cylinder (8
), a circular primary air supply port provided in the center of the bottom wall (9a) of the combustion tube (9), 0
This is a straightening tube that is integrated with the bottom wall (9a) by applying a ring around the primary air supply port 0. I is a bottomed cylindrical nozzle case that is connected to the bottom wall (9a) of the combustion tube (9) and defines a nozzle chamber Q51 inside, (1e and Q7) is a nozzle chamber 0 yen. The fuel spray nozzle and spark plug installed near the primary air supply port 0, the nozzle and plug holder fixed to the bottom wall (14a) of the alpha nozzle case (141), OI is the combustion tube (9
) A large number of secondary air supply holes are drilled in multiple rows in the upper side wall of (a), near the upper end opening in the combustion tube (9),
This is a flame stabilizing tube arranged with a space between it and the combustion tube (9).

This flame stabilizing tube (A) has a large number of small holes (211) and is held at the upper end opening of the combustion tube (9) via a plurality of support pieces (2). This is a non-contact type flame detection element disposed below the case 04), and uses a phototransistor, a photodiode, etc.

As shown in FIGS. 2 and 3, the nozzle case I has an opening (24) into which the adapter part (16a) of the fuel spray nozzle ae and the stone part (17a') of the spark plug (171) are inserted, respectively. 11 primary air intake holes (26
) and three screw big ends for attaching the nozzle and plug holder 0119 are provided on the bottom wall (14a), two primary air introduction holes (to) are provided on the side wall (14b), and the combustion tube (9) Two screw holes for mounting on the bottom wall (9a) (
C) is provided on the flange (14c) around the upper opening.

As shown in Figure 4, the nozzle and plug holder are
An additional nozzle hole 00 with a large number of grooves (7) connected to the periphery;
Plug fitting part C33, three screw holes C33i for attaching to nozzle case 04), and fuel spray nozzle (I6
) has screw holes G for inserting screws for fixing the adapter part (i6a) and the stone part (17a) of the spark plug aη, respectively. Then, the flame detection element (2-block↓ nozzle and the groove (7) of the plug holder 08),
Opening 04 of nozzle case 0) and primary air supply port O
The inside of the combustion tube (9) is directly viewed through z.

Next, the operation of the apparatus of the above-mentioned embodiments 1 to 1 will be explained.

First, when liquid fuel such as kerosene (particle size 70μnL) is sprayed from the fuel nozzle Oe, the fuel is sprayed through the primary air introduction hole (2f
9 (a) While being mixed with the primary air supplied into the nozzle case (14), the primary air advances from the primary air supply port (+21) into the combustion tube (9).At this time, when the spark plug (171 is activated, the combustion starts.Combustion starts in the nozzle chamber Q5)
Since there are few air lines in the lower part of the combustion tube (9), secondary air is supplied from a large number of secondary air supply holes (one special) in the upper part of the combustion tube (9).

In this way, once combustion starts, the combustion quickly shifts to gasification combustion. In other words, since the tapered straightening tube OS is provided around the primary air supply port a, the mixed gas of fuel and primary air passing through the straightening tube 0 maintains its flow velocity and is suppressed from spreading. , combustion tube (9
) move upwards. For this reason, the area around the straightening tube becomes a negative pressure zone, and a recirculation flow shown by the chain arrow is formed. Furthermore, small interpolation (Karman vortices) are formed by the secondary air discharged from the secondary air supply hole OI, and these vortices 6→ assist the recirculation flow. This recirculation flow entrains a part of the combustion gas and transports it back, so the fuel passes through the inside of the rectifying tube (9) and is vaporized by receiving combustion heat. By the time it reaches the upper part of the particle, it becomes fine particles of several micrometers, and gasification and combustion occur here.

At the upper part of the combustion tube (9), the secondary air discharged from the many secondary air supply holes OI collides with the outer peripheral surface of the flame stabilizing tube (A) at high speed, so that the periphery of the combustion tube (9) The flame dispersed in the flame stabilizing tube is held at the end of the flame stabilizing tube while being restricted to the inside of the flame stabilizing tube. In addition, part of the fresh air that collided with the flame stabilizing tube (2Q) is supplied to the inside of the flame stabilizing tube (2Q) through the small hole 0υ, and the rest is supplied to the upper opening of the combustion tube (9). Secondary air blower is used.

During combustion, the flame detection element t2S connects the nozzle and the groove (7) connected to the nozzle insertion hole C(1) of the plug holder 08, and the opening c of the nozzle case 0X! 41 and the primary air supply port 0, the light emitted by the combustion flame is sensed to perform flame detection.

In addition, even if there are variations in the combustion flame, the reflected light is supplied from the primary air introduction hole 2 of the bottom wall (14a) of the nozzle case α to the flame detection element e column, so the flame detection element (c) is stable. flame detection is possible. Furthermore, the flame detection element (c) monitors the combustion flame in the center of the combustion tube (9) through the grooves, and since the flame stabilization tube (a) is removed from the field of view, red-hot heat immediately after combustion Flame-holding tube (can be made so that it does not detect infrared rays emitted by the shaft, so there is no need to worry about malfunction.

According to this embodiment, a recirculation flow is formed in the straightening tube (II) that is integrated with the bottom wall (9a) of the combustion tube (9), and a part of the combustion gas is transported back around the straightening tube. The nozzle case Q4) and the nozzle and plug holder (IgI
The bottom wall (9) of the combustion tube (9) is connected to the fuel spray nozzle H through the
Good gasification and combustion can be achieved simply by attaching it concentrically to a). In addition, the fuel spray nozzle (IF5) is shut off by the recirculation flow and the rectifier tube, and is cooled by the missing airflow, so there is no problem with soot adhesion or heat resistance, and maintenance is possible. Inspection is almost unnecessary.Furthermore, secondary air is made to collide with the flame stabilizing tube (A) from the numerous secondary air supply holes O1 provided in the upper side wall of the combustion tube (9), and the combustion flame is kept in the flame stabilizing tube. (Since the flame is held within the flame holding tube (9A), the flame holding tube (9), and the combustion tube (9) are efficiently cooled by secondary air while regulating the flame inside the flame holding tube (9A). At the same time, it can be prevented from being overheated by the combustion flame, and 5U can be added to these.
It is possible to prevent thermal deformation and high-temperature oxidation while using inexpensive materials such as S305. Moreover, since there is no need to use excess air, operational noise can be reduced, CO□ concentration can be suppressed, and thermal efficiency can be improved. Furthermore, since a large number of small holes 00 were provided in the flame-holding tube (2
Inside K of the flame-holding cylinder (A), which is part of the secondary air that collided with 1,
The remainder can be guided to the upper end opening of the combustion tube (9) to perform stable gasification and combustion.

(G) Effects of the Invention Since the present invention is constructed as described above, the straightening tube is integrated with the bottom wall of the combustion tube, thereby reducing the number of parts, and the combustion tube, the straightening tube, and the fuel spray nozzle are concentric. can be easily obtained, the structure can be simplified, assembly can be facilitated, and good gasification and combustion can be performed.

Moreover, the problem of heat resistance of the fuel spray nozzle and the problem of clogging due to adhesion of soot are solved, and maintenance and inspection of the fuel spray nozzle can be reduced. In addition, the flame-holding tube and combustion tube are efficiently cooled by secondary air, and the combustion flame is regulated inside the flame-holding tube, so it is possible to use inexpensive materials for these to reduce the cost of the device. I can do it. Furthermore, since these thermal deformations and high-temperature oxidation can be prevented without using excess air, operational noise can be reduced and thermal efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the device of the present invention, Fig. 2 is a plan view of the nozzle case used in Fig. 1, Fig. 3 is a sectional view of the nozzle case used in Fig. 1, and Fig. 4 is a FIG. 5 is a cross-sectional view showing an example of a conventional device. (9)...Combustion tube, (9a)...Bottom wall, 0-ring...- Missing air supply port, a3... rectifier tube, 0e・
...Fuel injection nozzle, OI...Secondary air supply hole, (
4)... Flame-holding tube, Cυ... Small hole. Applicant Sanyo Electric Co., Ltd. and one other agent Patent attorney Mamoru Sano Figure 1

Claims (2)

[Claims] (1) A primary air supply port is provided in the center of the bottom wall of the combustion cylinder whose top end is open, and a rectifying pipe that tapers inward toward the combustion cylinder is provided around the primary air supply port integrally with the bottom wall; A large number of secondary air supply holes are provided in the upper side wall of the combustion tube, and a flame stabilizing tube is provided near the upper end opening in the combustion tube and at a position opposite to the secondary air supply holes with a space between the combustion tube and the combustion tube. A liquid fuel combustion device characterized in that a fuel spray nozzle is provided on the outside of the combustion cylinder near the primary air supply port. (2) The liquid fuel combustion device according to claim 1, wherein the flame stabilizing tube has a large number of small holes.