JPH094821A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE: To permit the prevention of remaining of tar in an evaporating tube, maintaining of stabilized evaporating performance for a long period of time and improvement of durability of a temperature detector, detecting the temperature of the evaporating tube, even when modified kerosene or liquid fuel having a high evaporating temperature is employed. CONSTITUTION: This liquid fuel combustion device is provided with a burner case 9, an evaporating tube 1, evaporating liquid fuel supplied by a liquid fuel supplying means 12, a temperature detector 30, detecting the temperature of the evaporating tube 1, a burner head 20, having a plurality of flame ports 21 on the peripheral wall 20A thereof and mounted on the upper end opening of the evaporating tube 1, and a fan, supplying combustion air into the evaporating tube 1. The upper end unit of the evaporating tube 1 is provided with a plurality of heat recovering projections 29, 29, opposed to the peripheral wall unit 20A of the burner head 20 and increasing the temperature of lower part of the evaporating tube 1 to a vale not less than about 330 deg.C during combustion, integrally while the temperature detector 30 is installed at the lower part of the evaporating tube 1.

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 oil 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 the electric heater embedded in the peripheral wall of the vaporization cylinder at the start of operation, and is heated by the flame formed in the flame hole of the burner head after the combustion is started. When 1 to 5 minutes have passed, the power supply to the electric heater is stopped. 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. by 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.
When IS1 kerosene is used, or when liquid fuel having a higher evaporation temperature than JIS1 kerosene is used, tar remains inside the vaporization cylinder, vaporization performance deteriorates, and stable vaporization combustion occurs. There was a problem that I could not do it.

The present invention has been made in view of the above situation, and prevents tar from remaining inside the vaporization cylinder even when using altered kerosene or liquid fuel having a high evaporation temperature,
It is intended to maintain stable vaporization performance for a long period of time and to enhance the durability of a temperature detector that detects the temperature of the vaporization cylinder.

[0005]

According to the present invention, a burner case, a vaporization cylinder which is housed in the burner case and which vaporizes the liquid fuel supplied by the liquid fuel supply means, and the temperature of the vaporization cylinder are detected. The vaporization cylinder includes a temperature detector, a burner head having a plurality of flame holes in a peripheral wall portion, which is attached to an upper end opening of the vaporization cylinder, and a blower for supplying combustion air into the vaporization cylinder. A plurality of heat recovery projections that are opposed to the peripheral wall of the burner head and that raise the temperature of the lower portion of the vaporization cylinder to about 330 ° C. or higher during combustion are integrally provided at the upper end of the This is a configuration in which the temperature detector is installed in the lower part of the vaporization cylinder.

In the liquid fuel combustion apparatus according to the second aspect of the present invention, the vaporization cylinder is made of a heat-resistant aluminum alloy capable of being heated to about 450 ° C. or higher.

[0007]

As described above, at the upper end of the vaporization cylinder, a plurality of heat recovery projections that face the peripheral wall of the burner head and that raise the temperature of the lower portion of the vaporization cylinder to about 330 ° C. or more during combustion. Since the part is integrally provided, during the combustion after a predetermined time has elapsed from the start of combustion, the heat of the heat recovery protrusion that is roasted and heated in the high temperature part of the flame reaches the lower end of the vaporization tube. The temperature of the lower part of the vaporization cylinder reaches a high temperature of about 330 ° C or higher, and even when deteriorated defective kerosene or liquid fuel with a high evaporation temperature is used, tar can be suppressed from remaining inside the vaporization cylinder, and it can be prevented for a long time. A good vaporization state is maintained. Also, since the temperature detector that detects the temperature of the vaporization cylinder is installed at the bottom of the vaporization cylinder, the temperature detector is located at the lowest temperature part of the peripheral wall of the vaporization cylinder, improving durability. To be done.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings of FIGS. In the figure, 1 is a bottomed cylindrical vaporization cylinder made of die-cast with an open top, and this vaporization cylinder 1 is made of an Al—Mn-based heat-resistant aluminum alloy. An air introduction port 2 that is opened in the tangential direction of the peripheral wall portion is provided in part. The heat-resistant Al alloy used as the material of the vaporization cylinder 1 is A
l as a main component, in addition to Mn, Si, Fe, Ni, Ti,
Cu, Mg, etc. are contained, and Mn is 2.5 to 6.0% by weight.
And other than Al have the highest content.

Reference numeral 3 denotes an electric heater such as a sheathed heater embedded in the upper part of the peripheral wall of the vaporization cylinder 1, and 4 denotes a primary air cylinder whose one end is connected to an air inlet 2 of the vaporization cylinder 1. The primary air cylinder 4 Is connected at its other end to the casing 8 of the blower 7 containing the air supply fan 6 driven by the motor 5, and the primary air for combustion from the blower 7 is introduced into the vaporization cylinder 1 through the air introduction port 2. It is something to send. 9 is a vaporization cylinder 1
A bottomed cylindrical burner case 10 is provided on the outer periphery of the secondary air pipe 10 for feeding secondary air for combustion into the space X between the burner case 9 and the vaporization cylinder 1. 10A of the tip end of the secondary air pipe 10 penetrates the peripheral wall portion 9A of the burner case 9 to face the inside of the burner case 9 and is opened near the peripheral wall portion 9A. Similarly to the primary air cylinder 4, it is connected to the casing 8 of the blower 7.

Reference numeral 11 denotes a tip outlet portion 1 of the secondary air pipe 10.
It is a blower guide made of a metal plate attached to the inner surface of the peripheral wall portion 9A of the burner case 9 so as to cover 0A.
1 is about 5 to 1 with the tip outlet portion 10A of the secondary air pipe 10.
Burner case 9 so that they face each other with a space of 0 mm.
The secondary air, which is mounted on the inner surface of the peripheral wall 9A, prevents secondary air flowing out from the tip outlet 10A of the secondary air pipe 10 from directly contacting the peripheral wall of the vaporization cylinder 1.

Reference numeral 12 denotes a fuel nozzle arranged concentrically with one end of the air inlet 2 and the primary air cylinder 4, and the fuel nozzle 12 has its tip end facing the inside of the vaporization cylinder 1. Liquid fuel such as kerosene is ejected into the vaporization cylinder 1, and the other end thereof communicates with the inside of the fuel tank 15 via the fuel supply pipe 13 and the fuel pump 14 such as an electromagnetic pump. Reference numeral 16 denotes a detachable cartridge tank for supplying liquid fuel to the fuel tank 15.

Reference numeral 17 is a die-cast diaphragm plate fitted and mounted in the upper opening of the vaporizing cylinder 1. The diaphragm plate 17 is an Al--Mn heat-resistant Al which has the same excellent heat resistance as the vaporizing cylinder 1.
It is made of an alloy, and a cylindrical portion 17A that forms the throttle passage 18 is integrally formed in the center of the diaphragm plate 17 so as to be integrally formed. Reference numeral 19 is a baffle plate disposed immediately below the cylindrical portion 17A of the diaphragm plate 17, and is spaced from the cylindrical portion 17A.

Reference numeral 20 denotes a ceiling-shaped cylindrical burner head mounted on the upper part of the vaporization cylinder 1, and a plurality of flames for ejecting a mixed gas are ejected on a peripheral wall portion 20A of the burner head 20 as shown in FIG. The holes 21, 21 are provided by being divided into upper and lower three stages, and the inner and outer surfaces of the peripheral wall portion 20A of the burner head 20 are in close contact with the peripheral wall portion 20A, and the flame hole wire net 22,
22 is provided. Reference numeral 23 denotes the throttle passage 1 of the diaphragm plate 17.
8 is a mixed rectifying cylinder arranged inside the burner head 20 so as to cover the upper part 8. The mixed rectifying cylinder 23 is formed by drawing a heat-resistant stainless steel plate into a substantially convex shape when viewed from the side, and its center is formed. In the top surface of the heavenly cylindrical portion 23A provided on the bottom portion and on the annular flat surface portion 23B provided on the lower outer periphery, a large number of small holes 24, 2 each having a diameter of about 2 mm are set.
4, 25, 25 are provided, and the peripheral wall portion of the heavenly cylindrical portion 23A is a non-perforated wall. The diaphragm plate 17, the burner head 20, and the mixing rectifying cylinder 23 are provided with a plurality of mounting screws 26.
It is fixed to the vaporization cylinder 1 at.

Reference numeral 27 is a combustion ring arranged on the outer periphery of the burner head 20. The combustion ring 27 is made of a heat-resistant stainless steel plate and is mounted on the upper end of the vaporization cylinder 1 with a screw (not shown). It's stopped. Further, the annular wall 27A of the combustion ring 27 facing the peripheral wall portion 20A of the burner head 20 is provided with a plurality of vertical slits 28, 28 at predetermined intervals in the circumferential direction.

Reference numerals 29 and 29 designate six heat recovery projections integrally formed on the upper end of the peripheral wall of the vaporization cylinder 1 so as to face the peripheral wall 20A of the burner head 20.
As shown in FIG. 5, each of the individual heat recovery protrusions 29, 29 is formed in a columnar shape, and has a diameter T of about 7 mm and a height H of about 8 to 10 mm, and has an annular shape. About 25 to 35, which are substantially equal to each other in the circumferential direction of the upper end of the vaporizing cylinder 1
It is provided with a space S of mm so that heat can be efficiently recovered in the vaporization cylinder 1, and the plurality of heat recovery projections 29, 29 are integrally formed on the upper end of the vaporization cylinder 1 to achieve combustion. The bottom wall of the vaporization tube 1 is heated to a high temperature of about 330 to 360 ° C.

Reference numeral 30 denotes a temperature detector such as a burner thermistor for detecting the temperature of the vaporization cylinder 1, and the temperature detector 30 detects the temperature near the bottom wall of the vaporization cylinder 1 so that the lower end of the vaporization cylinder 1 can be detected. Is installed in a horizontal groove provided at the lower end of the peripheral wall of the vaporization cylinder 1, and a proper position in the middle thereof is a fixture 31 as shown in FIG.
Is fixed to the peripheral wall portion 9A of the burner case 9.

A heat-resistant coating film 32 having a film thickness of about 20 to 40 μm is formed on substantially the entire inner surfaces of the peripheral wall portion and the bottom wall portion of the vaporization cylinder 1. The coating film 32 is obtained by applying a heat-resistant organic coating on the inner surface of the vaporizing cylinder 1 and then baking it.

Reference numeral 33 is a frame rod for detecting the presence or absence of the flame F formed in the flame hole 21 of the burner head 20 and 34 for detecting the oxygen concentration, 34 is an ignition rod for igniting the mixed gas ejected from the flame hole 21, and 35 is an ignition rod. A hot air blower duct that guides air blown from a warm air blower (not shown) to a warm air blowout port (not shown), and 36 is a bottom wall portion 3 of the warm air blower duct 35.
5A is a combustion cylinder provided upright, the burner head 20 is exposed to the lower part of the combustion cylinder 36, 37 is a filter provided at the combustion air inlet 38, and 39 is the rotation of the air supply fan 6. It is a rotation detector that detects a number.

In the above structure, when the temperature of the lower part of the vaporization cylinder 1 reaches about 250 ° C. by energizing the electric heater 3, the temperature detector 30 detects the temperature rise and the blower 7
Is operated, and a pre-purge for about 5 seconds is performed, and after this pre-purge, the fuel pump 14 is operated. By the operation of the fuel pump 14 and the blower 7, liquid fuel is supplied from the fuel nozzle 12 via the fuel supply pipe 13, and primary air for combustion is supplied from the air inlet 2 via the primary air cylinder 4, respectively. It is supplied to the inside of the vaporization cylinder 1.

Here, the fuel supplied to the inside of the vaporization cylinder 1 is contacted with the inner wall surface of the vaporization cylinder 1 and is vaporized, and this vaporized gas is mixed with primary air to form a mixed gas, which is a throttle plate. It flows into the mixing straightening cylinder 23 through the throttle passage 17 of 17. A part of the mixed gas that has flowed into the mixing rectifying cylinder 23 is a large number of small holes 25,
5 toward the lower stage flame hole 21 and the middle stage flame hole 21 and jets from each of these flame holes 21, 21 and the rest rises in the heavenly cylindrical portion 23A, and the heavenly cylindrical portion In 23A, the mixture is promoted toward the top surface portion and passes through a large number of small holes 24, 24 in the top surface portion. The mixed gas that has passed through the small holes 24, 24 heads to the upper flame holes 21 and the middle flame holes 21 and is ejected from the flame holes 21. In this way, the mixed gas ejected from each flame hole 21 is ignited by the spark of the ignition rod 34, forms a flame F, and starts combustion.

On the other hand, the secondary air for combustion sent into the burner case 9 through the secondary air tube 10 is the secondary air tube 1
0 blown out from the tip outlet section 10A, and this blower guide 11
Flow into the space X between the vaporization cylinder 1 and the burner case 9 and rise in the space X through the gap between the upper part of the vaporization cylinder 1 and the upper part of the burner case 9,
The secondary combustion of the flame F is promoted by being supplied to the outer periphery of the flame F.

When the combustion is started in this way, the heat of the flame F is conducted from the heat recovery projection 29 and the combustion ring 27 to the vaporization cylinder 1 to recover the heat, and about 2 to 5 minutes have passed since the start of the combustion. At this point, even if the power supply to the electric heater 3 is stopped, the vaporization cylinder 1 is maintained at a high temperature, the liquid fuel supplied into the vaporization cylinder 1 continues to vaporize, and the combustion state continues. Then, after about 30 to 40 minutes have elapsed from the start of combustion, the temperature near the bottom wall of the vaporization cylinder 1 having the slowest temperature rise also reaches a high temperature state of about 330 to 360 ° C.

According to this embodiment, the six heat recovery projections 2 are provided so as to face the peripheral wall portion 20B of the burner head 20.
9, 29 are integrally provided on the upper end of the peripheral wall of the vaporization cylinder 1, and the diameter T of these six heat recovery projections 29, 29 is about 7 mm.
In addition, the height H is set to about 8 to 10 mm, and after about 30 to 40 minutes from the start of combustion, the temperature in the vicinity of the bottom wall of the vaporization cylinder 1 that is less likely to rise than the upper portion is set to about 330 ° C or more. The temperature is raised and maintained at a high temperature (about 330 to 360 ° C.). Therefore, even when the deteriorated defective kerosene or the liquid fuel having a high evaporation temperature is used, various components in the fuel are instantaneously evaporated without remaining, and the tar is prevented from remaining on the wall inside the vaporization cylinder 1, and the vaporization cylinder is prevented. In No. 1, a good vaporized state is maintained for a long period of time, and stable vaporized combustion can be continued. Moreover, since it is possible to prevent tar from remaining inside the vaporization cylinder 1, it is possible to improve the situation in which the liquid fuel that has penetrated into the tar continues to evaporate after the fire is extinguished, and a strong odor is generated during the extinction.

Further, since the temperature detector 30 such as a burner thermistor for detecting the temperature of the vaporization cylinder 1 is installed at the lower end portion of the vaporization cylinder 1, the temperature detector 30 is the most peripheral wall portion of the vaporization cylinder 1. Since it will be placed in a place with low temperature, durability will be improved. That is, when the temperature in the vicinity of the bottom wall of the vaporization cylinder 1 is raised to a high temperature of about 330 ° C. or higher (about 330 to 360 ° C.), about 400 ° C. in the middle part of the peripheral wall of the vaporization cylinder 1.
The temperature rises up to about 450 ° C. at the front and rear and at the upper end portion of the peripheral wall of the vaporization cylinder 1, which causes a problem in durability of the temperature detector 30. As described above, if the temperature detector 30 is installed at the lower end portion of the vaporization cylinder 1, the temperature detector 30 does not have a risk of failure such as disconnection.

Further, since the die-cast vaporization cylinder 1 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% by weight is A
The temperature of the upper end of the vaporizing cylinder, which is most likely to rise in temperature, is about 4 because it functions to enhance mechanical properties such as heat resistance and strength.
Even if the temperature rises to 50 ° C. or higher, thermal deformation such as swelling or melting can be prevented.

Further, in the above-described embodiment, the heat-resistant coating film 32 having a film thickness of about 20 to 40 μm is formed on substantially the entire inner surfaces of the peripheral wall and the bottom wall of the vaporization cylinder 1. When the film thickness of the coating film 32 is set to about 20 to 40 μm, the thermal insulation effect of the coating film 32 is suppressed while maintaining the permeability of the liquid fuel in the coating film 32, and the temperature of the surface of the coating film 32 is controlled by the vaporization cylinder 1. The temperature can be substantially equal to the temperature, and the effect of suppressing the residual tar is enhanced.
That is, when the film thickness of the coating film 32 is 50 μm or more, the coating film 3
2 itself serves as a heat insulating material, and the surface temperature of the coating film 32 becomes lower than the temperature of the vaporization cylinder 1, and vaporization of the liquid fuel is suppressed accordingly. When the film thickness of the coating film 32 is 15 μm or less,
The permeability of the liquid fuel is deteriorated, and the granular fuel on the vaporization surface jumps up, delaying vaporization.

[0027]

As described above, according to the liquid fuel combustion apparatus of the present invention, the temperature of the lower portion of the vaporization cylinder is set to about 330 by the plurality of heat recovery projections provided integrally on the upper end portion of the vaporization cylinder.
Since it is configured to raise the temperature above ℃, it prevents tar from remaining inside the vaporization cylinder and maintains a good vaporization state for a long period of time even when deteriorated defective kerosene or liquid fuel with a high evaporation temperature is used. In addition to being able to suppress the generation of odors during fire extinguishing, it not only enhances the reliability of using deteriorated defective kerosene or liquid fuel with a high evaporation temperature, but also uses a temperature detector that detects the temperature of the vaporization cylinder. Since it is installed in the lower part of the vaporization tube, the temperature detector is protected against the high temperature of the vaporization tube, and the durability of the temperature detector can be improved.

In the liquid fuel combustion apparatus according to the second aspect, since the vaporizing cylinder for vaporizing the liquid fuel is made of a heat-resistant aluminum alloy which can be heated to about 450 ° C. or higher,
The temperature at the upper end of the vaporizing cylinder where the temperature rises most is about 450
It is possible to prevent thermal deformation such as swelling and melting even when the temperature rises to above ° C.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the overall configuration of a liquid fuel combustion device showing an embodiment of the present invention.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is an enlarged cross-sectional view of a main part with a cross-section different from FIG.

FIG. 4 is an enlarged plan sectional view of the same main portion.

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

FIG. 6 is a view showing the relationship between the flame holes of the burner head and the heat recovery projections of the vaporization cylinder.

[Explanation of symbols]

 1 Vaporizing Tube 7 Blower 9 Burner Case 12 Fuel Nozzle (Fuel Supply Means) 20 Burner Head 20A Peripheral Wall of Burner Head 21 Flame Hole 29 Heat Recovery Projection 30 Temperature Detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuyoshi Saito 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A burner case, a vaporization cylinder which is housed in the burner case and which vaporizes the liquid fuel supplied by the liquid fuel supply means, a temperature detector which detects the temperature of the vaporization cylinder, and a peripheral wall portion. The burner head has a plurality of flame holes and is attached to the upper end opening of the vaporization cylinder, and a blower for supplying combustion air into the vaporization cylinder. The burner head is provided at the upper end of the vaporization cylinder. Facing the peripheral wall of the
In addition to integrally providing a plurality of heat recovery projections for raising the temperature of the lower portion of the vaporization cylinder to about 330 ° C. or higher during combustion,
A liquid fuel combustion apparatus, wherein the temperature detector is installed in a lower portion of a vaporization cylinder. 2. The liquid fuel combustion apparatus according to claim 1, wherein the vaporization cylinder is made of a heat-resistant aluminum alloy capable of being heated to about 450 ° C. or higher.