JPH0571654U - Hot air heater - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a hot air heater that detects oxygen deficiency at a specified oxygen concentration. [Structure] A blower 5 that blows a variable amount of air, an electromagnetic pump 11 that sends a variable amount of oil, a carburetor 3 connected to the electromagnetic pump 11, a burner 2 opposite the carburetor 3, and a burner 2. The flame rod 6 that is inserted into the flame to detect the flame current, and the flame current detected by the flame rod 6 is a predetermined oxygen when the amount of air blown is periodically increased at a predetermined interval after delaying for a certain time during the slight combustion. Since the hot air heater is provided with the controller 13 that stops the combustion when it is below the depletion detection level, the combustion speed of the burner 2 becomes slower than the ejection speed, and the flame current decreases earlier, so there is no delay. Can detect oxygen deficiency.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hot air heater in which combustion is stopped when oxygen is deficient.

[0002]

[Prior Art]

 A conventional example will be described with reference to FIGS.

When a flame rod is provided in the flame of the burner and an AC voltage is applied between the flame rod and the ground electrode (flame hole), the flame current is detected by the flame rectifying action and the combustion state is detected. There is an example of a hot air heater (for example, Japanese Examined Patent Publication No. 3-37096).

[0004]

[Problems to be solved by the device]

 As shown in FIG. 2, the flame current becomes a low value as the combustion amount becomes low and the combustion amount becomes low. However, during oxygen-deficient combustion, as shown in Fig. 4, the flame current is less likely to be affected by the decrease in oxygen concentration when the combustion amount is low, and the oxygen deficiency does not appear until a dangerous state is reached. Will not be detected. In this way, since the difference between the frame current value during normal operation and the frame current value during oxygen deficiency detection is small, there are variations in the frame current value due to variations in the aircraft, or a decrease in the frame current value due to the life of the aircraft, etc. As a result, the oxygen concentration at the oxygen deficiency detection level became 16% or less, and there was a problem that the specified oxygen concentration (16% or more) could not be satisfied. In addition, when the above interval is applied from the beginning, the rotation speed switches (for example, 700 ← → 950 rpm).

[0005]

[Means for Solving the Problems]

 The present invention has been made to solve the above problems.A frame rod for detecting a frame current is inserted into the flame of a burner, and an AC voltage is applied between the frame rod and the burner. At the time of slight combustion, after delaying for a certain period of time, the air flow rate is periodically increased at a predetermined interval, and the combustion is stopped when the flame current detected through the flame rod is below a predetermined oxygen deficiency detection level.

Further, during slight combustion, the amount of air blown is periodically increased at a predetermined interval after the flame current detected by the flame rod becomes lower than the initial flame current by a predetermined value.

[0007]

[Action]

 At the time of slight combustion, after delaying for a certain period of time, the air flow rate is periodically increased at a predetermined interval, and when the flame current detected by the flame rod is below the predetermined oxygen deficiency detection level, combustion is stopped. Compared with the air flow rate, the burner combustion speed becomes slower than the jet speed, and as shown in FIG. 3, the flame current decreases earlier than the normal air flow rate, so oxygen deficiency can be detected without delay.

Further, during slight combustion, since the amount of air blown is periodically increased at a predetermined interval after the flame current detected by the flame rod becomes lower than the flame current detected by the flame rod in a normal state, the oxygen deficiency progresses. In normal conditions, the increase in air flow is not interrupted, so noise from the blower is not a concern.

[0009]

【Example】

 An embodiment of the present invention will be described with reference to FIGS.

In the figure, 1 is a main body composed of a warm air heater, 2 is a burner, and the burner 2 has a primary air hole 2a at one end and a flame hole 2b at the upper part, and a liquid fuel such as petroleum. It is installed in the main body 1 for burning. Reference numeral 3 denotes a vaporizer having a nozzle 3a, which is opposed to the burner 2. An inner duct 4 is provided behind the burner 2 to form a combustion chamber. Reference numeral 5 denotes a blower with a variable blow rate, which is installed inside the back surface of the main body 1 to blow air to the burner 2. Reference numeral 6 is a frame rod, which is provided opposite to the flame hole 2b of the burner 2 in order to detect the flame current flowing through the flame 12 of the flame hole 2b. A supporting plate 7 has a secondary air hole 7a on the front side of the main body 1, an inner filter 8 on the rear side of the main body 1, and supports the burner 2. A hot air outlet 9 is provided on the front surface of the main body 1. A blower duct 10 is attached to the main body 1 to partition the blown air from above the inner duct 4 and blower 5 to the upper part of the hot air outlet 9. Reference numeral 11 denotes an electromagnetic pump having a variable oil amount, which is connected to the carburetor 3. Reference numeral 13 is a controller for controlling the warm air heater. Since the controller 13 is composed of a microcomputer having a timer function, the flame current detected by the frame rod 6 becomes a flame current at the oxygen deficiency detection level. At this time, in order to extinguish the burner 2, the carburetor 3, the blower 5, the frame rod 6, and the electromagnetic pump 11 are connected.

Next, the operation of this embodiment will be described.

When the hot air heater is turned on, the carburetor 3 is energized, and when the carburetor 3 reaches the vaporization temperature, the electromagnetic pump 11 is energized and the oil supplied from the electromagnetic pump 11 is carburetor. The gas is vaporized at 3, and the vaporized gas is ejected from the nozzle 3a to the burner 2. At this time, the primary air and the vaporized gas flowing in from the primary air holes 2 are premixed and ejected from the flame holes 2b of the burner 2 to form the flame 12 there. A frame rod 6 is provided in the flame 12. When an AC voltage is applied between the flame rod 6 and the ground electrode (flame hole 2b), the flame rod 6 detects the flame current by the rectifying action of the flame and detects the combustion state.

The controller 13 of the present invention delays the combustion for a certain period of time in the slight combustion and then switches the rotation speed of the blower 5 (for example, 700 ← → 950 rpm) to temporarily increase the blown air amount. As shown in, the normal air-fuel ratio and flame current are set to λA = 0.8 and IA, respectively, and the air-fuel ratio and flame current when the air flow rate is temporarily increased are set to λB = 1 and IB, respectively. When the increased air flow rate is set to, the combustion speed increases, the flame shortens, and the flame current increases, so that IA <IB. However, if the air flow rate is temporarily increased during oxygen deficiency, the air-fuel ratio will further increase, for example, the air-fuel ratio and flame current will be λC = 1.2, IC, and the combustion speed will decrease compared to the normal air flow rate. However, the flame becomes longer and the flame current decreases, so that IA> IC, and if the air flow rate is temporarily increased during oxygen deficiency, the flame current decreases rapidly, so there is no delay and the oxygen deficiency detection level becomes low. The specified oxygen concentration (16% or more) can be satisfied.

Further, the interval of increase in air flow is increased by multiplying by the frame current which is several μA lower than the frame current in normal time, so that the interval of increase in air flow is increased in normal time when oxygen deficiency does not progress. Since it does not hang, the noise of the blower 5 is not a concern. Also, since the interval for increasing the air flow is taken at the time when the oxygen deficiency in the room progresses, it becomes a notice of oxygen deficiency and the safety can be further enhanced.

[0015]

[Effect of the device]

 According to the present invention as described above, the combustion is stopped when the flame current detected by the flame rod is below the predetermined oxygen deficiency detection level by delaying for a certain period of time during the slight combustion and periodically increasing the air flow rate at a predetermined interval. Therefore, the oxygen deficiency detection level can satisfy the specified oxygen concentration (16% or more) without being delayed.

In addition, since the air flow rate was periodically increased at a predetermined interval after the flame current became a predetermined value lower than that during normal combustion during slight combustion, the air flow rate was normally increased when oxygen deficiency did not progress. Since the interval of increase of is not taken, the noise of the blower does not matter. Also, since the interval for increasing the air flow is taken at the time when the oxygen deficiency in the room has advanced, it is a notice of oxygen deficiency.

Therefore, there is an effect that a safe and convenient hot air heater can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a warm air heater showing an embodiment of the present invention.

FIG. 2 is a detection characteristic diagram of an air-fuel ratio and a flame current of a warm air heater according to an embodiment of the present invention.

FIG. 3 is an oxygen deficiency detection characteristic diagram of a warm air heater according to an embodiment of the present invention.

FIG. 4 is an oxygen deficiency detection characteristic diagram of a warm air heater showing a conventional example.

[Explanation of symbols]

 2 Burner 3 Vaporizer 5 Blower 6 Frame rod 11 Electromagnetic pump 13 Controller

Claims (2)

[Scope of utility model registration request] 1. A blower (5) for blowing a variable amount of air,
An electromagnetic pump (11) for variable oil supply, a carburetor (3) connected to the electromagnetic pump (11), a burner (2) opposite to the carburetor (3), and the burner (2) ), Which is inserted in the flame of (1) and detects the flame current, and this flame rod (6) and burner (2).
In addition to applying an AC voltage between and, the flame current detected by the flame rod (6) is detected as a predetermined oxygen deficiency when the amount of air blown is periodically increased at a predetermined interval after being delayed for a certain time during slight combustion. A warm air heater comprising: a controller (13) for stopping combustion when the level is below a level. 2. The controller (13) periodically increases the amount of air blown at a predetermined interval after the flame current detected by the flame rod is lower than the normal flame current detected by the flame rod by a predetermined value during slight combustion. The warm air heater according to claim 1, wherein