JPH09210317A - Liquid fuel burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the durability of a temperature detector by providing a detector holder for holding the detector integrally with a vaporizing cylinder at the position near the bottom of the cylinder, and providing a space for suppressing thermal conduction from the cylinder to the holder between the holder and the bottom of the cylinder. SOLUTION: An air jet nozzle 24 is provided integrally with a vaporizing cylinder 11 at the part of the peripheral wall 11B of the cylinder 11, and a detector holder 27 is provided at the one side lower end portion of the extended flange 25. A space Y for suppressing the thermal conduction from the cylinder 11 to the holder 27 is formed between the one side lower end portion of the flange 25 including the holder 27 and the bottom 11A of the cylinder 11. Thus, the heat of the flame F is recovered by the cylinder 11 during burning, and the bottom 11A is raised to a high temperature, but the thermal conduction from the bottom 11A to the holder 27 is suppressed by the space Y, and the holder 27 is maintained at the lower temperature than the bottom 11A. Accordingly, even if the temperature of the bottom 11A is high, the durability of a temperature detector 30 is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a petroleum vaporization type liquid fuel combustion apparatus mainly used for petroleum fan heaters and the like.

[0002]

2. Description of the Related Art Generally, a liquid fuel combustion apparatus of this type has a bottomed cylindrical burner case in which a vaporization cylinder having an electric heater is housed. A peripheral wall portion is provided at an upper end opening of the vaporization cylinder. A burner head having a plurality of flame holes is attached to. Then, the liquid fuel and the primary air for combustion are supplied to the inside of the vaporization cylinder to vaporize the liquid fuel and mix it with the air, and the mixed gas is sent to the burner head and ejected from each flame hole in the peripheral wall portion of the burner head. The ignition rod spark is used to ignite and burn. Further, the vaporization cylinder is heated by energizing an electric heater embedded in the upper part of the peripheral wall portion of the vaporization cylinder at the start of operation, and the temperature of the bottom of the heated vaporization cylinder reaches a predetermined temperature (for example, about 240 ° C). When the temperature rises to 0, the temperature is detected by a temperature detector arranged on the peripheral wall of the vaporization cylinder, and combustion is started. After the combustion is started, the vaporization cylinder is heated by the flame formed in the flame hole of the burner head, so that the power supply to the electric heater is stopped when about 1 to 5 minutes have elapsed from the start of the combustion. in this way,
Even if the power supply to the electric heater is stopped, the vaporization cylinder is maintained at a temperature of about 240 to 260 ° C. due to the heat of the flame, the liquid fuel is continuously vaporized, and the combustion is continued.

[0003]

However, in the above-described conventional liquid fuel combustion apparatus, since the temperature of the vaporizing cylinder is maintained at a temperature of about 240 to 260 ° C., it is commercially available in Japan. When unmodified JIS No. 1 kerosene is used, there is no problem such as tar remaining in the vaporization cylinder.
If IS-1 kerosene is used, or if a liquid fuel having a higher evaporation temperature than JIS-1 kerosene is used, tar remains inside the vaporization cylinder (particularly at the inner bottom of the vaporization cylinder), and the vaporization performance is reduced. There has been a problem that the temperature is lowered and stable vaporization combustion cannot be performed. Therefore, after the start of combustion, the temperature of the bottom of the vaporizing cylinder is about 330 ° C. or higher (for example, 330 to 36
If the temperature of the bottom of the vaporization tube is maintained at a high temperature of about 330 ° C or higher during combustion, the peripheral wall of the vaporization tube can be solved. There was a concern that the temperature sensor placed in the section would be damaged in a short time.

The present invention has been made in view of the above-mentioned circumstances, and the durability of the temperature detector can be improved even when the temperature of the vaporization tube is raised to a high temperature at which tar does not remain inside the vaporization tube. The purpose is to be able to.

[0005]

According to the present invention as set forth in claim 1, a liquid fuel supply means, a bottomed cylindrical vaporization cylinder for vaporizing the liquid fuel supplied by the liquid fuel supply means, and this vaporization A blower that supplies combustion air into the cylinder, a burner head that burns the mixed gas supplied from the vaporization cylinder, and a temperature detector that detects the temperature of the vaporization cylinder are provided, and in the vicinity of the bottom of the vaporization cylinder, A detector holder that holds the temperature detector is provided integrally with the vaporization tube, and heat transfer from the vaporization tube to the detector holder is suppressed between the detector holder and the bottom of the vaporization tube. This is a configuration in which a space portion for performing is provided.

According to the second aspect of the present invention, the liquid fuel supply means, the bottomed cylindrical vaporization cylinder for vaporizing the liquid fuel supplied by the liquid fuel supply means, and the combustion air in the vaporization cylinder. A blower for supply, a burner head for burning the mixed gas supplied from the vaporization cylinder, and a temperature detector for detecting the temperature of the vaporization cylinder are provided, and a temperature detector is held at a position near the bottom of the vaporization cylinder. A tubular detector holder is provided integrally with the vaporization tube, and a space between the detector holder and the bottom of the vaporization tube suppresses heat transfer from the vaporization tube to the detector holder. And a plurality of slits are provided on the peripheral wall of the detector holder.

In the liquid fuel combustion apparatus of claim 1,
During the combustion after a lapse of a predetermined time from the start of combustion, the upper part of the vaporization cylinder is heated by the combustion flame, and the temperature of the bottom part of the vaporization cylinder is a high temperature (for example, 330 to 36) that does not leave tar.
Even if the temperature rises to 0 ° C.), heat conduction from the bottom of the vaporization tube to the detector holding section is suppressed by the space, so that the detector holding section has a lower temperature (eg, 280 ° C) than the bottom of the vaporization tube.
˜310 ° C.).

[0008] In the liquid fuel combustion apparatus according to claim 2,
By making the detector holding part cylindrical, not only the holding property of the tip part of the temperature detector can be improved, but also by providing a plurality of slits on the peripheral wall of the detector holding part,
The heat dissipation of the detector holder and the tip of the temperature detector is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings of FIGS. 1 and 2
In the figure, 1 is a blower for supplying combustion air,
The blower 1 includes a motor 2 and a blower fan 3 that is a synthetic resin turbofan driven by the motor 2.
It is composed of a blower case 4 that houses the blower fan 3. Reference numeral 5 denotes a synthetic resin supporting base motor case that supports the blower 1, and an air suction port 7 to which a filter 6 is attached is integrally formed on the motor case 5.

The blower case 4 is composed of an upper case 4A and a lower case 4B combined with the upper case 4A. At the center of the upper surface of the upper case 4A, there is a heavenly standing upright member. The tubular portion 8 is integrally press-molded. The tubular portion 8 has an opening 9 formed substantially at the center of a top surface portion 8A thereof, and the vaporization burner 1 is utilized by utilizing the opening 9.
A vaporization cylinder 11 of 0 is incorporated in the tubular portion 8.

Reference numeral 12 denotes an air distribution plate which is assembled in the upper case 4A of the blower case 4 below the tubular portion 8. The air distribution plate 12 is the bottom portion 11A of the blower fan 3 and the vaporization tube 11. And the peripheral portion thereof is attached to the upper case 4A by screwing or spot welding. Further, the air distribution plate 12 has a circular recess 13 which is recessed downward toward the blower fan 3 and is integrally formed by pressing at a substantially central portion of the circular recess 13.
A plurality of vent holes 14, 14 are arranged in an annular shape outside the circular recess 13.

Reference numeral 15 denotes an air rectifying plate provided between the air distribution plate 12 and the blower fan 3.
A plurality of air guide blades 16, 16 are provided by cutting and raising on the outer peripheral portion of the. Reference numeral 17 is a rotation speed detector for detecting the rotation speed of the blower fan 3, and 18, 18 are the cylindrical portions 8
2A is a secondary air hole provided in the top surface portion 8A.

The vaporizing burner 10 is a liquid fuel (kerosene).
Has a bottomed cylindrical vaporization cylinder 11 for vaporizing, and the top end opening of the vaporization cylinder 11 is equipped with a burner head 20 having a cylindrical shape having a plurality of flame holes 19, 19 on its peripheral wall. A diaphragm plate 21 is fitted and mounted inside the vaporization cylinder 11 below the burner head 20. Reference numeral 22 denotes a burner ring made of a heat-resistant metal, which is arranged on the outer peripheral portion of the burner head 20. The burner ring 22 is screwed to the upper end surface of the vaporization cylinder 11, and the burner ring 22 and the peripheral wall portion of the vaporization cylinder 11 are connected. A small gap 23 for supplying secondary air is formed between the upper end surface of 11B.

The vaporizing cylinder 11 is made of an Al-Mn-based heat-resistant aluminum alloy, and an air jet nozzle portion 24 is provided in a part of the peripheral wall portion 11B of the vaporizing cylinder 11.
1, the outlet 24A of the air ejection nozzle portion 24 is opened toward the tangential direction of the peripheral wall portion 11B, and the inlet 24B having a larger diameter than the outlet 24A is stored in the tubular portion 8. It is opened to the air chamber X. A part of the air ejection nozzle portion 24 on the inlet 24B side is the vaporization cylinder 11
Is provided so as to project laterally, and a flange 25 is formed integrally with the air ejection nozzle portion 24 at the tip of the protruding air ejection nozzle portion 24 on the inlet 24B side.

The heat-resistant Al alloy used as the material of the vaporization cylinder 11 contains Al as a main component and contains Si, Fe, N in addition to Mn.
i, Ti, Cu, Mg, etc. are contained, and Mn is 2.5 to
The content is 6.0% by weight, which is the highest except for Al.

The lower end portion of the flange 25 on one side is extended to a position near the bottom portion 11A of the vaporization cylinder 11, and is also extended to a position near the bottom portion 11A of the vaporization cylinder 11. At the lower end portion of one side of the flange 25, a cylindrical detector holding portion 27 having a horizontal insertion groove 26 in the center is provided so as to project laterally integrally with the flange 25. The detector holding portion 27 from the vaporization cylinder 11 is provided between the lower end portion on one side of the flange 25 including the portion 27 and the bottom portion 11A of the vaporization cylinder 11.
A space portion Y that suppresses heat conduction to is formed.

Reference numeral 28 denotes an electric heater such as a sheathed heater embedded in the upper portion of the peripheral wall portion 11B of the vaporization cylinder 11, and the peripheral wall portion 11B of the vaporization cylinder 11 in which the electric heater 28 is embedded.
The upper part of is placed and fixed on the top surface portion 8A of the cylindrical portion 8. Reference numerals 29 and 29 denote six heat recovery protrusions integrally formed on the upper end of the peripheral wall portion 11B of the vaporization cylinder 11 so as to face the peripheral wall of the burner head 20, and these six heat recovery protrusions are provided. As shown in FIG. 3, the parts 29, 29 are each formed in a columnar shape, and the diameter thereof is set to about 6 to 8 mm and the height is set to about 6 to 10 mm.
Are provided at substantially equal intervals in the circumferential direction at the upper end of the peripheral wall portion 11B of the peripheral wall portion 11B so that the vaporization cylinder 11 can efficiently recover heat.
Is integrally formed on the upper end of the peripheral wall portion 11B of the vaporization cylinder 11, so that the bottom portion 11A of the vaporization cylinder 11 during combustion is about 330-
It is heated to a high temperature of 360 ° C.

Reference numeral 30 denotes a temperature detector in which a detection element (not shown) such as a thermistor for detecting the temperature of the vaporization cylinder 11 is built in the tip portion thereof, and the tip portion of the temperature detector 30 is the detector holding portion. It is inserted into the insertion groove 26 of 27 and held by the detector holding portion 27, and the other end thereof penetrates the tubular portion 8 and is exposed to the outside.

Reference numeral 31 is a burner stand assembled on the top surface 8A of the cylindrical portion 8, 32 is a frame rod for detecting the flame F, 33 is an ignition plug, and 34 is the vaporizing cylinder 11
It is a fuel nozzle for supplying liquid fuel (kerosene) therein, and this fuel nozzle 34 communicates with a fuel tank (not shown) via an oil feed pipe 35 and a fuel pump (not shown).

The bottom 11A and the peripheral wall 11B of the vaporization cylinder 11 have a film thickness of about 20 to 40 .mu.m on substantially the entire inner surface.
A heat resistant coating film (not shown) is formed. This coating film is obtained by applying an organic resin heat-resistant paint or an inorganic resin heat-resistant paint on the inner surface of the vaporization cylinder 11 and then baking it.

In the above structure, when the temperature of the detector holder 27 reaches about 220 ° C. by energizing the electric heater 28, the temperature detector 30 detects it and the blower 1 operates, and Pre-purge for about 5 seconds. By the operation of the blower 1, the room air passes through the filter 6 and enters the motor case 5 through the air suction port 7 and is sucked into the blower case 4. The air sucked into the blower case 4 is sent to the air storage chamber X in the tubular portion 8 through the ventilation holes 14 of the air distribution plate 12, and the air sent to the air storage chamber X is It is supplied to the inside of the vaporization cylinder 11 as primary air through the air ejection nozzle portion 24.

Here, a fuel pump (not shown) starts its operation about 5 seconds after the start of operation of the blower 1, and liquid fuel is ejected from the fuel nozzle 34 and supplied into the vaporization cylinder 11. The liquid fuel supplied into the vaporization cylinder 11 is instantaneously vaporized in the vaporization cylinder 11 and mixed with primary air, and this mixed gas is sent into the burner head 20 through the passage of the diaphragm plate 21. It is ejected from the flame holes 19 and is ignited by the spark of the ignition plug 33, and a blue flame F is formed on a side portion of the flame hole 19 to start combustion.

On the other hand, the rest of the air sent into the air storage chamber X in the tubular portion 8 is ejected as secondary air into the burner stand 31 from the secondary air holes 18, 18, and a part of it is burner ring 22. Is supplied to the root portion of the flame F through a gap 23 between the upper end surface of the vaporizing cylinder 11 and the rest of the burner ring 22.
Rises along the outer surface and is supplied to the flame F to promote secondary combustion. Then, by controlling the rotation speed of the motor 2 and the oscillation speed of the fuel pump (not shown), the combustion amount is switched from strong to weak in multiple stages or proportionally.

When the combustion is started in this way, the heat of the flame F is conducted from the heat recovery projections 29, 29 and the burner ring 22 to the vaporization cylinder 11 to recover the heat, and about 2 from the start of the combustion.
After 5 minutes have passed, even if the power supply to the electric heater 28 is stopped, the vaporization cylinder 11 is maintained at a high temperature, the liquid fuel supplied into the vaporization cylinder 11 continues to be vaporized, and the combustion state continues. Then, after about 30 to 40 minutes have passed from the start of combustion,
The temperature in the vicinity of the bottom 11A of the vaporization cylinder 11 having the slowest temperature rise also becomes a high temperature state of about 330 to 360 ° C.

According to the present embodiment, the air jet nozzle portion 24 is provided at a part of the peripheral wall portion 11B of the vaporization cylinder 11.
Is provided integrally with the inlet 2 of the air jet nozzle 24.
A lower end portion of one side of the flange 25 formed at the tip portion on the 4B side is extended to a position near the bottom portion 11A of the vaporization cylinder 11, and a temperature detector is attached to the lower end portion of the extended side of the flange 25. A detector holding portion 27 for holding the tip portion of 30 is provided, and one lower end portion of the flange 25 including the detector holding portion 27 and the bottom portion 11 of the vaporization cylinder 11 are provided.
A space Y that suppresses heat conduction from the vaporization cylinder 11 to the detector holding portion 27 is formed between A and A, so that the combustion is performed about 30 to 40 minutes after the start of combustion. Is a plurality of heat recovery projections 29, 29 and the burner ring 2.
The heat of the flame F is recovered by the vaporization cylinder 11 by 2 and the like, whereby the bottom 11A of the vaporization cylinder 11 rises to a high temperature of about 330 to 360 ° C., but the detector holding portion 27 from the bottom 11A of the vaporization cylinder 11 The heat conduction to the is suppressed by the space Y,
The detector holding portion 27 does not have the same temperature as the bottom portion 11A of the vaporization cylinder 11, and is 280 to 280 lower than the bottom portion 11A of the vaporization cylinder 11.
A temperature of 310 ° C. is maintained. Therefore, the temperature of the bottom portion 11A of the vaporization cylinder 11 is about 330 to 36 at which tar does not remain.
Even at a high temperature of 0 ° C., the durability of the temperature detector 30 whose tip is held by the detector holder 27 can be improved.

Further, since the detector holder 27 has a cylindrical shape, the flange 25 does not have to be so thick,
The depth of the insertion groove 26 can be increased, and the tip of the temperature detector 30 can be reliably held.

In the embodiment described above, six heat recovery projections 29, 29 are integrally provided on the upper end of the peripheral wall portion 11B of the vaporization cylinder 11 so as to face the peripheral wall portion of the burner head 20. , The diameter of these six heat recovery projections 29, 29 is set to about 6 mm to 8 mm, and the height is set to about 6 to 10 mm,
After a lapse of about 30 to 40 minutes from the start of combustion, the temperature near the bottom portion 11A of the vaporization cylinder 11 where the temperature is less likely to rise than the upper portion is maintained at a high temperature of about 330 ° C or higher (about 330 to 360 ° C). As a result, even when deteriorated defective kerosene or liquid fuel having a high evaporation temperature is used, various components in the fuel can be instantaneously evaporated without remaining, and tar can be prevented from remaining on the inner surface of the vaporization cylinder 11. The vaporization cylinder 11 can maintain a good vaporization state for a long period of time and can continue stable vaporization combustion.

Further, since the die cast vaporization cylinder 11 for vaporizing the liquid fuel is made of an Al-Mn heat-resistant Al alloy, Mn contained in an amount of 2.5 to 6.0 wt% is
Since Al has a function of enhancing mechanical properties such as heat resistance and strength, even if the temperature of the upper end of the vaporization cylinder 11 where temperature rises most easily rises to about 450 ° C. or higher, thermal deformation such as swelling or melting Can be prevented.

Further, a heat-resistant coating obtained by applying an organic resin heat-resistant paint or an inorganic resin heat-resistant paint having a film thickness of about 20 to 40 μm and baking it on substantially the entire inner surface of the bottom portion 11A and the peripheral wall portion 11B of the vaporization cylinder 11. Forming a film. When the film thickness of this coating film is set to about 20 to 40 μm, the thermal insulation effect of the coating film is suppressed while maintaining the wettability of the liquid fuel in the coating film, and the temperature of the coating film surface is set to the temperature of the vaporizing cylinder 11. The temperatures can be substantially the same, and the effect of suppressing tar residue is enhanced.
That is, when the film thickness of the coating film is 50 μm or more, the coating film itself serves as a heat insulating material, and the surface temperature of the coating film becomes lower than the temperature of the vaporizing cylinder 11, and the vaporization of the liquid fuel is suppressed accordingly. It
Further, when the film thickness of the coating film is 15 μm or less, the wettability of the liquid fuel deteriorates, the granular fuel on the vaporization surface jumps, and vaporization is delayed.

FIG. 7 shows another embodiment of the present invention. The same structural parts as those of the above-described one embodiment are denoted by the same reference numerals and the description thereof will be omitted. The different structure will be described. In this other embodiment, as shown in FIG. 7, a plurality of slits 36, 36 are provided along the axial direction of the peripheral wall of the detector holding portion 27 formed in a tubular shape.
Is provided.

In the above-described structure, the detector holder 27 itself and the tip of the temperature detector 30 held by the detector holder 27 by the plurality of slits 36, 36 are disposed from the blower 1 to the air storage chamber. The contact area with the air sent to X is increased, the heat dissipation is improved, and the temperature rise at the tip of the detector holder 27 and the temperature detector 30 can be further suppressed.

[0032]

As described above, according to the liquid fuel combustion apparatus of the present invention, even when the temperature of the bottom portion of the vaporizing cylinder is raised to a high temperature which does not leave tar during combustion, the detector holding portion Since the heat conduction from the bottom of the vaporization tube to the bottom of the vaporization tube is suppressed by the space, the detector holder can be maintained at a lower temperature than the bottom of the vaporization tube, and the durability of the temperature detector held by the detector holder is improved. be able to.

In the liquid fuel combustion apparatus of claim 2,
By making the detector holding part cylindrical, not only the holding property of the tip part of the temperature detector can be improved, but also by providing a plurality of slits on the peripheral wall of the detector holding part,
The heat releasing property of the detector holding portion and the tip of the temperature detector is improved, and the durability of the temperature detector is further improved.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a liquid fuel combustion apparatus showing an embodiment of the present invention.

FIG. 2 is a sectional view of the same liquid fuel combustion device.

FIG. 3 is a perspective view of the vaporization cylinder in a state where the tip of the temperature detector is also held.

FIG. 4 is a bottom view of a vaporization cylinder alone, which is also partially cut away.

FIG. 5 is a front view of the vaporizer tube alone.

FIG. 6 is a sectional view taken along line AA of FIG.

FIG. 7 is a perspective view of a vaporization cylinder showing another embodiment example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blower 11 Vaporization cylinder 11A Bottom of vaporization cylinder 20 Burner head 27 Detector holding part 30 Temperature detector 34 Liquid fuel supply means 36 Slit Y Space part

Front page continuation (72) Inventor Mitsuyoshi Saito 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A liquid fuel supply means, a bottomed cylindrical vaporization cylinder for vaporizing the liquid fuel supplied by the liquid fuel supply means, a blower for supplying combustion air into the vaporization cylinder, and a vaporization cylinder. A burner head for burning the supplied mixed gas, and a temperature detector for detecting the temperature of the vaporization cylinder are provided, and in the vicinity of the bottom of the vaporization cylinder, a detector holding portion for holding a temperature detector is a vaporization cylinder. A liquid which is integrally provided and has a space between the detector holding portion and the bottom of the vaporization tube which suppresses heat conduction from the vaporization tube to the detector holding portion. Fuel combustion device. 2. A liquid fuel supply means, a bottomed cylindrical vaporization cylinder for vaporizing the liquid fuel supplied by the liquid fuel supply means, a blower for supplying combustion air into the vaporization cylinder, and a vaporization cylinder. A burner head for burning the supplied mixed gas and a temperature detector for detecting the temperature of the vaporization cylinder are provided, and a cylindrical detector holding portion for holding the temperature detector is provided at a position near the bottom of the vaporization cylinder. A space that is provided integrally with the vaporization cylinder and that suppresses heat transfer from the vaporization cylinder to the detector holding portion is provided between the detector holding portion and the bottom of the vaporization cylinder. A liquid fuel combustion apparatus, wherein a plurality of slits are provided on a peripheral wall of the container holding portion.