JPS6034910Y2 - combustion device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a combustion device in which the volume of hot air and the volume of combustion air are controlled proportionally.The configuration is simple, and by controlling the volume of hot air, combustion output The present invention provides a combustion device suitable for use in hot air heating devices, etc., which can be adjusted.

In a combustor that uses liquid fuel such as petroleum, the air used for combustion must be supplied so that the ratio with the fuel is a constant air-fuel ratio determined by a stoichiometric ratio.

However, in the past, it was extremely difficult to stably obtain a fixed supply amount due to the influence of wind and the like.

As a result, air shortage or excess air conditions occur, resulting in poor combustion conditions and reduced thermal efficiency.

Such problems due to variations in the air-fuel ratio also occur when the amount of fuel supplied is changed.

In other words, the combustion amount is adjusted by adjusting the atomization amount for the gun type, the injection amount for the pot type, and the vaporization area for the wick type, but in all cases, the amount of fuel supplied to the combustion section is adjusted. Therefore, if the air supply amount is constant, the air-fuel ratio may fluctuate and the above-mentioned problem may occur.

Therefore, the combustion amount adjustment range has to be narrow, limited by the air-fuel ratio.If you try to widen the adjustment range, the optimal air-fuel ratio must have some degree of inertia, and as a result, the combustion system becomes worse.

In addition, conventionally, the combustion amount was adjusted by directly adjusting the amount of fuel supplied, so the adjustment device had to come into contact with the fuel, which caused corrosion due to ice mixed in the fuel and deterioration of the fuel. In addition, problems such as malfunction due to adhesion of tar and the like tended to occur.

In addition, there is a fuel system that adjusts the supply amount of fuel and air in a correlated manner using mechanical damper opening/closing control means, etc. in order to maintain a constant air-fuel ratio, but this not only complicates the configuration, but also As the amount of air decreases, the allowable range of variation in the amount of fuel supplied to maintain an appropriate air-fuel ratio becomes smaller. Therefore, using mechanical opening/closing means, etc. may not be able to control the air-fuel ratio properly or may cause problems with the design of the device. There were problems such as the high degree of precision required for manufacturing.

The present invention solves the above problems, and has a structure in which combustion air is sucked into the burner by the negative pressure generated by the flow of warm air driven by a single blower, and the amount of combustion air is reduced. The present invention provides a combustion device that uses a burner having a structure in which the amount of fuel vaporized changes according to changes in the amount of fuel, and that automatically changes the amount of combustion by controlling the amount of hot air and can adjust the output.

Hereinafter, an embodiment in which the present invention is applied to a hot air heater will be described in detail with reference to the drawings.

In FIG. 1, a fuel tank 2 is provided in the lower part of the heater main body 1, a burner 3 is provided above the fuel tank 2, and a propeller-type blower 4 is provided above the burner 3, and a motor 5 that drives the blower 4 is provided above the burner 3.
I am prepared.

Between the burner 3 and the blower 4, a baffle plate 6 having a disk-like shape and a pressure control port 23 in the center is placed between the burner 3 and the blower 4 so that the pressure control port 22 faces the center of rotation of the blower 4. The pressure control ports 22 are arranged to face each other, and the size of the pressure control ports 22 is smaller than the outer diameter of the motor 5.

Moreover, the burner 3 is composed of a plurality of cylindrical members, specifically, an inner flame tube 7, an outer flame tube 8, a combustion tube 9 located on the outer periphery of these, and a lower end thereof are connected to the fuel in the fuel tank 2. The lamp wick 11 serves as a fuel evaporator and has its upper end exposed between the inner flame tube 7 and the outer flame tube 8.

Further, the inner flame tube 7 and the outer flame tube 8 each have a vaporization air port through which vaporization air constituting the primary air of the combustion air flows. a, 8a, and a premixing air lower b, 8b through which the premixing air constituting the primary air flows, and the inner flame tube 7 and the outer flame tube 8 have a primary air port arranged above the inner flame tube 7. A secondary air port 12 is provided between the closing plate 17 and the combustion tube 9 through which secondary air for combustion air flows.

Air vent for vaporization? a, 8a are located at opposite positions near the upper end of the lamp wick 11, and above them are premixing air lowers b, 8b.
is located so that the primary air and secondary air are always in the desired ratio for combustion. a, 8a premixing air port? A primary air port consisting of ports a and 8b and a secondary air port 12 are provided.

In addition, the inner air passage 13 of the inner flame tube 7 and the air passage 14 between the combustion tube 9 and the outer flame tube 8 are opened to the outside via a combustion air intake port 15 provided below the heater body 1. are doing.

On the other hand, the baffle plate 6 is larger in diameter than the combustion tube 9, has a ventilation passage 16 between them, and the space surrounded by the baffle plate 6, the combustion tube 9, and the closing plate 17 forms a combustion chamber 18. ing.

Further, the outer cylinder 19 is arranged concentrically with the combustion cylinder 9 outside the combustion cylinder 9, extends upward to the vicinity of the blower 4, and has a communication passage 23 around the outer circumference of the air baffle plate 6. 4, and the ventilation path between the combustion tube 9 and the heating cylinder 9 becomes a hot air path 20, which is opened to the outside via a hot air outlet 21 provided on the front surface of the heater main body 1.

Note that 22 indicates a hot air air supply port provided on the upper rear surface of the heater main body 1.

In addition, in the burner 3 of this configuration, combustion air (primary air and secondary air) is sucked in by the hot air flow from the blower 4, and the amount of vaporization of the fuel 10 from the lamp wick 11 is equal to the amount of vaporization air. It is configured to be approximately proportional to the flow rate of vaporizing air passing through 7a and 8a.

That is, in the burner 3 of this configuration, the combustion amount is approximately proportional to the combustion air flow rate.

In addition, in Figure 1, the solid line arrow indicates the flow of hot air,
Further, the dashed-dotted line arrows indicate the flow of combustion air and combustion exhaust gas.

The operation when the burner 3 having the above configuration is combusted will be explained next. The blower 4 is rotated by the drive of the motor 5, and hot air is supplied to the hot air outlet 21 via the hot air air supply port 22. 4 (solid line arrow) flows.

This hot air is transferred to the communication path 2 between the outer periphery of the baffle plate 6 and the outer cylinder 19.
4, the air inside the combustion chamber 18 is brought into a negative pressure via the ventilation path 16 due to air turbulence at the outer circumferential portion of the baffle plate 6.

Furthermore, in the case of a propeller-type blower, the vicinity of the coaxial center on the downstream side in the immediate vicinity of the blower is usually in a negative pressure region.

That is, on the downstream side near the rotation center of the blower, a flow is formed from the downstream side of the blower toward the rotation center.

On the other hand, in the case of the present invention, the control port 2 is located in the center of the air control plate 6.
2, the air in the combustion chamber 18 is sucked in the direction of the blower 4 through the pressure control port 22, and the negative pressure state in the combustion chamber 18 is further promoted.

Therefore, from the combustion air supply port 15 to the ventilation passages 13 and 1.
Combustion air is sucked into the combustion chamber 18 through 4, and since the magnitude of the negative pressure has a property that it is proportional to the hot air air flow rate, the combustion air is also proportional to the hot air air flow rate. Become.

Figure 2 is a characteristic diagram showing the pressure distribution on the downstream side of the blower 4.
The radius of the baffle plate 6 is plotted on the horizontal axis, and the radius of the baffle plate 6 is plotted on the vertical axis.
As seen here, a negative pressure region exists downstream of the blower 4.

On the other hand, the amount of vaporized fuel 10 from the lamp wick 11 is proportional to the primary air flow rate, and the vaporizing air lowers a, 8
a. Air lower for premixing b.

8b and the secondary air port 12, the amount of vaporized fuel 10 from the lamp wick 11 is approximately proportional to the hot air flow rate.

Therefore, the combustion amount of the burner 3 in the combustion chamber 18 is
It can be adjusted by adjusting the amount of air blown.

This effect is explained in Fig. 3. In Fig. 3, the horizontal axis shows the amount of warm air, and the vertical axis shows the combustion chamber pressure P, the combustion air flow rate Q1, and the combustion amount H. This shows the relationship between combustion chamber pressure P1, combustion air flow rate Q, and combustion amount H.
This shows a state that changes proportionally to the hot air air flow rate.

Furthermore, when a propeller-type blower is used as the blower 4 as in the case of this embodiment, the negative pressure region downstream of the blower usually has a pressure balance relationship with the main air flow blown by the blower 4. , resulting in a very unstable pressure state,
Not only does this significantly reduce the air blowing capacity of the blower 4, but it also becomes a cause of noise generation by the blower 4.

Therefore, as shown in the present invention, the pressure control port 23 is provided in the center of the air control plate 6, and the pressure control port 23 is provided near the rotation center of the blower 4.
By facing the pressure opening 23 from the combustion chamber 18,
Since an air flow is generated that flows to the blower 4 side through the airflow, the unstable pressure state can be eliminated, and the above-mentioned drawbacks can be significantly improved.

Further, the outer periphery of the combustion tube 9 is formed into a hot air passage 20, through which exhaust gas and air flow from a propeller fan are mixed and passed.

That is, since the high-temperature airflow is passed through, it has the effect of keeping the combustion cylinder warm.

Therefore, since there is no need to cool the flame or the like inside the combustion tube, deterioration of combustion characteristics can be prevented.

As explained above, the combustion device of the present invention has a burner whose combustion amount is approximately proportional to the amount of combustion air, and a combustion chamber in which the magnitude of the negative pressure is changed in proportion to the flow rate of hot air from the blower. A pressure control port is provided at the waist and in the center of the baffle plate, facing the center of rotation of the blower, so that when the combustion chamber becomes negative pressure, combustion air is sucked in. Since the exhaust gas from the combustion chamber is effectively discharged using negative pressure near the center, the structure is simpler than conventional combustion devices, and extremely stable combustion can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a combustion device according to an embodiment of the present invention;
FIG. 2 is a pressure distribution diagram on the downstream side of the blower, and FIG. 3 is a characteristic diagram illustrating the operation of the present invention. 3...Burner (combustion part), 4...Blower, 6...Blast plate, 9...Combustion tube, 1
5...Combustion air supply port, 16...Vent passage, 17...Closing plate, 18...Combustion chamber, 19... - Outer cylinder, 21... Warm air discharge port, 22... Air supply port for hot air.

Claims (1)

[Scope of utility model registration request] A propeller fan is disposed above the burner and facing the burner, and an outer cylinder is disposed outside the burner and the propeller fan, and between the burner and the propeller fan, a propeller fan is disposed at the center of rotation of the propeller fan. A flat baffle plate having a pressure control port is provided, a hot air path is provided between the combustion tube of the burner and the outer cylinder, a ventilation path is provided between the upper end of the combustion tube and the baffle plate, and the A combustion device in which the outer diameter of the baffle plate is larger than the outer diameter of the combustion tube.