JP5811596B2 - Fuel spray nozzle structure - Google Patents

Description

  The present invention relates to a structure of a fuel spray nozzle in a pressure spray burner used in a liquid fuel combustion apparatus.

  The pressure spray burner used for liquid fuel combustion devices such as oil water heaters and oil heaters has a fuel pipe for fuel supplied to the burner connected between the fuel tank and the fuel spray nozzle. A fuel pump is attached to the fuel sprayer.When the fuel pump is operated, the fuel in the fuel tank is supplied to the fuel spray nozzle. The fuel pressurized by the fuel pump is atomized from the fuel spray port at the tip of the fuel spray nozzle. Thus, the gas is ejected into the burner, ignited by the discharge spark of the ignition electrode, starts combustion, and is mixed with the combustion air supplied to the burner to stably burn. When the operation of the combustor is stopped, the operation of the fuel pump is also stopped, and the discharge pressure of the fuel pump is reduced, so that the fuel supply from the fuel tank into the fuel spray nozzle is stopped and the fuel spray is stopped. Stop (see Patent Document 1).

  JP 59-27112 A

  When the operation of the combustor is stopped, the fuel supply from the fuel tank is stopped, but the fuel remains in the fuel pipe and the fuel spray nozzle, and the fuel remaining in the fuel pipe and the fuel spray nozzle Changes may cause expansion / contraction, and when the combustor is not in use, it may be pushed out of the fuel spray port or withdrawn into the fuel spray nozzle. Sometimes it remained. And since the fuel pushed out from the fuel spray nozzle directly touches the air, the oxidation easily occurs. When the oxidation proceeds while being in contact with the air for a long time, the fuel is solidified in a gel form.

Even if fuel adheres to or near the fuel spray port as described above, products that are used throughout the year, such as a water heater, operate almost every day, so that the fuel sprayed on ignition before oxidation of the adhered fuel occurs. There was no particular problem because it was blown away with the fuel to be used.
On the other hand, the heater is stored when the season is off and is not used for a long time, and there is a possibility that the fuel adhering to or near the fuel spray port may be oxidized. Normally, the fuel in the fuel tank is extracted and stored at the end of the season, but fuel remains in the fuel pipe and the fuel spray nozzle, and when this remaining fuel is pushed out of the fuel spray port during storage, the fuel spray is removed. The fuel spray gels and clogs the fuel spray nozzle when it is not used for a long period of time and may cause clogging of the fuel spray nozzle. As a result, fuel was not sprayed normally, causing many complaints such as ignition errors and poor combustion at the beginning of the season.

The present invention solves the above-described problem. A fuel pump 4 is provided in the middle of a fuel pipe 3 connecting the fuel tank 1 and the burner 2, and the liquid fuel is atomized by the discharge pressure of the fuel pump 4 to burn the burner 2. A fuel spray nozzle 5 to be supplied is provided, and the fuel spray nozzle 5 is a cylindrical nozzle body 6 and a projecting tip portion which is disposed in the nozzle body 6 and fits into an opening 6 a at the tip of the nozzle body 6. An orifice plate 7 provided with 7b, a fuel spray port 7a disposed at the protruding tip 7b of the orifice plate 7, and a nozzle cone 8 provided with a fuel supply groove 8a for guiding fuel to the fuel spray port 7a, The nozzle body 6 is composed of the orifice plate 7 and a fixing member 9 for fixing the nozzle cone 8, and is sent from the fuel pipe 3 into the nozzle body 6 by the fuel pump 4. The fuel of the pressure spray type combustor that is guided from the fuel supply groove 8a of the nozzle cone 8 to the fuel spray port 7a of the orifice plate 7 and sprays forward from the fuel spray port 7a as mist fuel. In the spray nozzle, a recess 6b is formed in the tip surface of the nozzle body 6 located below the projecting tip 7b of the orifice plate 7, and the recess 6b connects the projecting tip 7b of the orifice plate 7 to the nozzle body. than 6 distal end surface of is positioned on the front side, the forms a stepped portion 10 between the projecting tip 7b and the distal end surface of the nozzle body 6 of the orifice plate 7, when not in use in the combustor When the fuel remaining in the nozzle body 6 flows out of the fuel spray port 7a of the orifice plate 7, the fuel is discharged from the protruding tip 7b of the orifice plate 7. It induces the Kidan unit 10, characterized in that it has a fuel discharge part 11 for discharging the bottom of the outer circumferential surface of the nozzle body 6.

  Further, the projecting tip 7b of the orifice plate 7 is formed in a conical shape whose diameter decreases from the inner peripheral edge of the opening 6a of the nozzle body 6 toward the fuel spray port 7a, and is formed below the fuel spray port 7a. Since the fuel discharge portion 11 is formed by the tapered portion 7c, the fuel that has flowed out easily flows downward along the surface of the protruding tip portion 7b, and the fuel does not remain attached to the fuel spray port 7a or its surroundings. It was.

In the present invention, the protruding tip 7b of the orifice plate 7 exposed to the outside from the opening 6a of the tip of the fuel spray nozzle 6 is arranged to protrude forward from the tip of the nozzle body 6, and the protruding tip 7b. By forming the step portion 10 between the nozzle body 6 and the tip end surface of the nozzle body 6, the fuel discharge portion 11 is configured between the fuel spray port 7 a and the lower portion of the outer peripheral surface of the nozzle body 6.
With this configuration, the fuel flowing out from the fuel spray port 7a flows downward along the surface of the protruding tip 7b, and there is nothing that obstructs the fuel flow at the outer peripheral edge of the protruding tip 7b. Since the fuel collected at the lower end of the outer peripheral edge can flow through the step portion 10 and be discharged to the lower part of the outer peripheral surface of the nozzle body 6, even if the fuel is pushed out from the fuel spray port 7a during the season off, the fuel spray port 7a. Thus, it is possible to reduce the occurrence of complaints such as ignition errors and poor combustion due to clogging of the fuel spray ports 7a at the beginning of the season.

  Further, a recess 6b is formed on the tip surface of the nozzle body 6 located below the projecting tip 7b, and the step 10 is formed between the surface of the projecting tip 7b of the orifice plate 7 and the surface of the recess 6b. Then, since the fuel discharge part 11 can be configured without changing the positional relationship between the fuel spray port 7a and the ignition electrode, it is not necessary to adjust the mounting position and the spray angle of the fuel spray nozzle 5, and a major design change is necessary. It was easy to implement.

  Further, since the projecting tip 7b of the orifice plate 7 projecting forward from the opening 6a of the nozzle body 6 is formed in a conical shape whose diameter is reduced toward the fuel spray port 7a, the periphery of the fuel spray port 7a flows out. Since the surface to which the fuel adheres becomes smaller and the fuel comes into contact with the tapered portion 7c, it becomes easy to flow downward along the inclined surface of the taber portion 7c. It is possible to guide to the lower part of the outer peripheral surface of the fuel, and the fuel does not remain attached to the surface of the protruding tip 7b.

DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Burner 3 Fuel pipe 4 Fuel pump 5 Fuel spray nozzle 6 Nozzle main body 6a Opening part 6b Recessed part 7 Orifice plate 7a Fuel spray port 7b Protruding front end part 7c Taper part 8 Nozzle cone 8a Fuel supply groove 9 Fixing member 10 Step part 11 Fuel outlet

It is sectional drawing of the fuel spray nozzle which shows the Example of this invention. It is a front view of the fuel spray nozzle which shows the other Example of this invention. It is sectional drawing of the Example of FIG. It is sectional drawing of the fuel spray nozzle which shows the other Example of this invention. It is sectional drawing of the oil combustor which shows the Example of this invention.

  The present invention will be described with reference to the embodiments shown in the drawings. Reference numeral 2 denotes a bottomed cylindrical burner for burning petroleum-based fuel, 12 a wind tunnel disposed so as to cover the entire circumference of the burner 2, and 13 to the burner 2. A combustion blower for sending combustion air. When the combustion blower 13 is driven, combustion air is sent into the wind tunnel 12 and air is supplied into the burner 2 through an air hole provided in the side wall of the burner 2. .

  1 is a fuel tank for storing fuel to be supplied into the burner 2, 5 is a fuel spray nozzle installed on the side wall of the burner 2, 4 is a fuel pump for sending fuel from the fuel tank 1 to the fuel spray nozzle 5, and 3 is a fuel spray nozzle 5 and the fuel pump 4 are connected to each other. When the fuel pump 4 is operated, the fuel in the fuel tank 1 is pumped up and pressurized by the fuel pump 4, and is mist from the tip of the fuel spray nozzle 5 connected by the fuel pipe 3. It can be sprayed into the burner 2 as a fuel.

  14 is an ignition electrode installed on the side surface of the burner 2 so that the tip is located in front of the fuel spray nozzle 5, 15 is an ignition transformer for applying a high voltage to the ignition electrode 14, and the ignition operation of the heater is performed. When this is done, the combustion blower 13 and the ignition transformer 15 are energized, and the combustion blower 13 starts operation and the generated wind is sent to the burner 2 as combustion air, and the ignition transformer 15 is ignited. A high voltage is supplied to the electrode 14 to generate a discharge spark at the tip of the ignition electrode 14. When the fuel pump 4 is energized and fuel is sprayed from the fuel spray nozzle 5, the mist fuel is ignited and combustion is started.

  In FIG. 1 for explaining the fuel spray nozzle 5, 6 is a cylindrical nozzle body, 6 a is an opening formed in the front end surface of the nozzle body 6, and 7 is a substantially disk-shaped metal plate, with fuel spray in the center. An orifice plate provided with a port 7a, 7b is a projecting tip portion in which the central portion of the orifice plate 7 where the fuel spray port 7a is formed projects one step from the periphery, and the orifice plate 7 is a nozzle from the rear side of the nozzle body 6. Mounted in the main body 6, the protruding tip 7 b fits into the opening 6 a of the nozzle body 6, and the protruding tip 7 b of the orifice plate 7 is exposed to the outside from the opening 6 a. Further, a conical recess centered on the fuel spray port 7a is formed on the rear surface of the orifice plate 7 on the opposite side to the protruding tip portion 7b.

  Reference numeral 8 denotes a nozzle cone disposed on the upstream side of the orifice plate 7 in the nozzle body 6. The outer diameter of the nozzle cone 8 is set smaller than the inner diameter of the nozzle body 6, and the tip of the nozzle cone 8 is formed in a conical shape. It is made to correspond to the shape of the rear surface of the orifice plate 7. Reference numeral 8 a denotes a fuel supply groove formed radially from the top of the conical tip of the nozzle cone 8. When the nozzle cone 8 is mounted in the nozzle body 6, the tip of the nozzle cone 8 is in contact with the concave portion of the orifice plate 7. A gap 16a through which fuel passes is formed between the outer peripheral surface of the nozzle cone 8 and the inner peripheral wall of the nozzle body 6, and the fuel supply groove 8a of the nozzle cone 8 serves as the gap 16a and the fuel spray port 7a of the orifice plate 7. And is continuous.

  9 is a cylindrical fixing member for fixing the nozzle plate 8 and the orifice plate 7 mounted in the nozzle body 6, and 17 is a screw formed between the inner peripheral surface of the nozzle main body 6 and the outer peripheral surface of the fixing member 9. The fixing member 9 is mounted from the rear part of the nozzle body 6 and is attached by screwing of the screw part 17, and the fixing member 9 presses the nozzle cone 8 toward the tip side of the nozzle body 6 so that the nozzle cone 8 is an orifice. It is fixed in close contact with the plate 7.

  In addition, the outer diameter dimension of the distal end side of the screw portion 17 of the fixing member 9 is set smaller than the inner diameter dimension of the nozzle body 6, and a gap 16 b is formed between the outer peripheral surface of the fixing member 9 and the inner peripheral wall of the nozzle body 6. doing. 9a is a fuel flow hole formed in the side surface of the fixed member 9 that connects the internal space of the fixed member 9 and the gap 16b, 16 is a fuel flow gap in which the gaps 16a and 16b are continuously formed, and 18 is a nozzle body. 6 is a filter member disposed at the rear end of the nozzle 6, and the filter member 18 is screwed onto a screw portion in the nozzle body 6.

  Reference numeral 19 denotes a connecting portion that connects the nozzle body 6 and the fuel pipe 3, and the connecting portion 19 of the embodiment is formed of a cap nut, and a screw portion formed on the outer peripheral surface of the rear end portion of the nozzle body 6; The nozzle body 6 and the fuel pipe 3 are connected by screwing.

  When the fuel sent from the fuel pipe 3 by the fuel pump 4 passes through the filter member 18, fine dust and dust are removed and sent into the nozzle body 6, and the fuel flows from the internal space of the fixed member 9. Since it flows into the fuel circulation gap 16 through the hole 9a and is pumped as it goes to the fuel spray port 7a through the fuel supply groove 8a of the nozzle cone 8, it sprays as mist-like fuel from the fuel spray port 7a. be able to.

  Further, when the fire extinguishing operation of the heater is performed, the energization of the combustion blower 13 and the fuel pump 4 is stopped, and the discharge pressure of the fuel pump 4 is lowered, so that the spraying of fuel from the fuel spray port 7a is stopped. extinguish a fire.

  By the way, when the heating season is over, the fuel in the fuel tank 1 is used up, or the fuel in the fuel tank 1 is taken out and stored in a warehouse or the like. However, the fuel in the fuel pipe 3 and the nozzle body 6 is not extracted, and the fuel pipe 3 and the nozzle body 6 are stored in a state where the fuel remains. Fuel such as kerosene used in the heater will oxidize if left in contact with air, but fuel in the fuel pipe 3 and nozzle body 6 will not touch the air directly, so there is no concern about oxidation. It can be stored until the next season.

However, the fuel in the fuel pipe 3 and the nozzle body 6 expands and contracts due to changes in temperature, and the fuel expanded in summer when the temperature rises may be pushed out from the fuel spray port 7a. Although it flows downward along the surface of the protruding tip 7b, if the protruding tip 7b and the tip of the nozzle body 6 are on the same surface as in the prior art, the tip of the nozzle body 6 surrounding the protruding tip 7b The fuel flow may stop and may remain attached to the fuel spray port 7a and its surroundings.
Since the fuel adhering to the fuel spray port 7a is in direct contact with air for a long time until the start of the winter heating season, the fuel undergoes an oxidation reaction, and the liquid fuel gradually becomes a gel-like lump. If this state is repeated, the fuel mass in the form of gel may cause clogging of the fuel spray port 7a.

  Thus, when the fuel spray port 7a is clogged during the off season, fuel is not normally sprayed from the fuel spray port 7a when attempting to start the operation of the heater at the beginning of the heating season. It has been found that many complaints have been made that repeated ignition mistakes or that even if ignited, a normal flame is not formed but a combustion failure occurs and stops.

  The present invention is a proposal for preventing the occurrence of clogging of the fuel spray nozzle 5 which causes the above-mentioned claims such as ignition mistakes and poor combustion. In the embodiment of the present invention, the opening of the nozzle body 6 is provided. The protruding tip 7b of the orifice plate 7 fitted to 6a is configured to protrude forward from the tip of the nozzle body 6. Reference numeral 10 denotes a step formed between the protruding tip 7b of the orifice plate 7 and the tip surface of the nozzle body 6. Reference numeral 11 denotes a fuel discharge portion constituted by the protruding tip 7b of the orifice plate 7 and the step 10. is there.

  If it is this structure, the fuel which flowed out from the fuel spray port 7a will flow along the surface of the protrusion front-end | tip part 7b, and will adhere along the step part 10 from the lower end of the protrusion front-end | tip part 7b. When the fuel adhering to the stepped portion 10 comes into contact with the tip end surface of the nozzle body 6, a pulling force is applied, flows from the stepped portion 10 to the tip end surface of the nozzle body 6, and guides the fuel below the outer peripheral portion of the nozzle body 6. Is something that can be done.

  The particle size of the fuel that is gradually pushed out from the fuel spray port 7a while the heater is stopped is substantially the same as the inner diameter of the fuel spray port 7a, flows downward along the surface of the protruding tip 7b, and protrudes to the protruding tip. The particle size of the fuel collected at the lower end of 7b is larger than the inner diameter of the fuel spray port 7a. For this reason, if the height of the step portion 10 is set to be equal to or less than the inner diameter of the fuel spray port 7a, it becomes easier to contact the tip surface of the nozzle body 6 when the fuel adheres to the step portion 10. The fuel is smoothly guided from the portion 10 to the tip surface of the nozzle body 6.

  With this configuration, the fuel flow is not blocked at the lower end of the protruding tip 7b, and the fuel does not remain on the surface of the fuel spray port 7a and the protruding tip 7b in the vicinity so as to form a film. Therefore, even if fuel is pushed out from the fuel spray port 7a during the heating season off as in the past, there is no need to worry about the fuel spray port 7a becoming clogged. It no longer causes complaints such as defects.

  In the other embodiment shown in FIG. 2, 6 b is a recess formed by cutting out a part of the tip surface of the nozzle body 6, and the recess 6 b is arranged in a fan shape below the projecting tip 7 b of the orifice plate 7. Since the front end surface of the nozzle body 6 is located behind the front end surface of the protruding front end portion 7b, the step portion 10 can be formed between the front end surface and the protruding front end portion 7b. Further, the recess 6b is set so that the width of the inner edge side of the opening 6a is smaller than the diameter of the projecting tip 7b and larger than the diameter of the fuel spray port 7a, and the center line extending in the vertical direction of the recess 6b is the fuel spray. It coincides with the center of the port 7a, so that the fuel flowing from the fuel spray port 7a along the surface of the protruding tip 7b can be reliably guided to the recess 6b. Since the recess 6b has a shape that spreads downward, the fuel guided to the recess 6b can flow smoothly to the lower part of the outer peripheral surface of the nozzle body 6. Even with this configuration, the fuel that has flowed out of the fuel spray port 7a is fuel. No longer remain on the surface of the spray port 7a and the projecting tip 7b in the vicinity thereof, and the fuel spray port 7a is not clogged.

  If it is this structure, it can implement | achieve by the simple method of processing a part of front end surface of the nozzle main body 6, and forming the recessed part 6b. Further, there is no need to change the mounting position of the fuel spray nozzle 5, and various tests and large-scale design changes for verifying the optimum positions of the fuel spray port 7a and the ignition electrode 14 are performed when adopting the present invention. It is not necessary and can be realized easily.

  In another embodiment of the present invention shown in FIG. 4, the projecting tip 7b of the orifice plate 7 is formed in a conical shape whose diameter is reduced toward the fuel spray port 7a, and the projecting tip 7b is formed in a plane. Compared to the above, the surface to which the fuel adheres is smaller around the fuel spray port 7a. Reference numeral 7c denotes a tapered portion formed on the surface of the conical protruding tip portion 7b. When the fuel flows out and flows downward, the tapered portion 7c is located immediately below the fuel spray port 7a. Therefore, the fuel is easy to flow along the tapered portion 7c without adhering to the surface around the fuel spray port 7a. For this reason, even when the amount of fuel flowing out from the fuel spray port is very small, it can be reliably guided to the lower end of the protruding tip 7b.

If the taper portion 7c is formed from the tip surface of the nozzle body 6, the tip surface of the nozzle body 6 may be positioned forward from the corner portion of the outer peripheral edge of the taper portion 7c due to a dimensional error during manufacture. Since the fuel flowing along 7c may be stopped at the inner edge of the opening 6a of the nozzle body 6 and may not flow smoothly, the dimensional accuracy of the parts is required and the cost is increased. For this reason, in the embodiment, the taper portion 7c of the projecting tip portion 7b is formed from the front position with respect to the tip surface of the nozzle body 6, and the step portion 10 is provided between the taper portion 7c and the tip surface of the nozzle body 6. The fuel that flows downward along the tapered portion 7 c is directed to the tip surface of the nozzle body 6 through the step portion 10.
With this configuration, even if a slight dimensional error occurs, the outer peripheral corner portion of the taper portion 7 c is located in front of the nozzle body 6, so that the fuel is generated at the fitting portion between the protruding tip portion 7 b and the inner peripheral edge of the nozzle body 6. Thus, it is possible to reliably and smoothly guide to the lower part of the outer peripheral surface of the nozzle body 6. In addition, the dimensional management of parts and the accuracy management of assembly dimensions are facilitated, and an increase in manufacturing cost can be suppressed.

Claims (2)

A fuel pump (4) is provided in the middle of the fuel pipe (3) connecting the fuel tank (1) and the burner (2), and the liquid fuel is atomized by the discharge pressure of the fuel pump (4) to burn the burner (2). Provided with a fuel spray nozzle (5) to be supplied inside,
The fuel spray nozzle (5) has a cylindrical nozzle body (6) and a projecting tip portion (6a) which is disposed in the nozzle body (6) and fits into an opening (6a) at the tip of the nozzle body (6). 7b), an orifice plate (7), a fuel spray port (7a) disposed at a protruding tip (7b) of the orifice plate (7), and a fuel for inducing fuel to the fuel spray port (7a) A nozzle cone (8) having a supply groove (8a), and a fixing member (9) for fixing the orifice plate (7) and the nozzle cone (8) in the nozzle body (6). And
The fuel sent from the fuel pipe (3) into the nozzle body (6) by the fuel pump (4) is sent from the fuel supply groove (8a) of the nozzle cone (8) to the fuel of the orifice plate (7). In a fuel spray nozzle of a pressure spray type combustor that is guided to the spray port (7a) and sprays forward from the fuel spray port (7a) as a mist fuel,
Forming a recess (6b) in the tip surface of the nozzle body (6) located below the protruding tip (7b) of the orifice plate (7);
Said recess (6b) is is positioned in front than the tip surface of the nozzle body the protruding tip portion (7b) of said orifice plate (7) (6), wherein the projecting tip of the orifice plate (7) A step (10) is formed between (7b) and the tip surface of the nozzle body (6);
When fuel remaining in the nozzle body (6) when the combustor is not used flows out from the fuel spray port (7a) of the orifice plate (7), the fuel is supplied to the protruding tip (7b) of the orifice plate (7). ) To the stepped portion (10), and a fuel discharge portion (11) for discharging to the lower portion of the outer peripheral surface of the nozzle body (6) is configured. The projecting tip (7b) of the orifice plate (7) is formed in a conical shape whose diameter decreases from the inner peripheral edge of the opening (6a) of the nozzle body (6) toward the fuel spray port (7a). The structure of the fuel spray nozzle according to claim 1, wherein the fuel discharge portion (11) is constituted by a tapered portion (7c) formed below the spray port 7a.

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