JPH025253Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to an all-primary air type burner, and more particularly to a forced primary air type burner.

(Prior art and its problems) A conventional all-primary air burner of this type has a configuration as shown in FIG. A combustion flame is formed on the surface of the ceramic plate 42, and since the surface of the ceramic plate 42 is red-hot by this combustion flame,
This conventional burner is mainly used as a radiation burner.

This radiant burner is mainly used for heating by radiant heat or for grilling appliances, but is not often used as a cooking appliance. This is because combustion exhaust gas is not effectively used and escapes, making it impossible to obtain sufficient heating efficiency.

However, because this type of burner does not require secondary air, the object to be heated is not air-cooled by secondary air as in Bunsen burners, and the combustion exhaust is also used for heating. In this case, the thermal efficiency is improved compared to a Bunsen burner.

From this point of view, we have already proposed a forced primary air type burner as one that can effectively utilize both combustion exhaust heat and radiant heat.

This has a configuration as shown in Figure 5, and uses an electric fan 2 to forcibly draw in primary air.Compared to the above-mentioned atmospheric pressure burner, the excess air ratio can be set higher, so a constant amount of gas can be maintained. The area of the combustion part for burning the amount of heat can be set small, and the radiant heat effectively reaches the heated object without loss. In other words, the degree to which a portion of the radiant heat directly escapes to the outside of the heated object is significantly reduced.

However, with this type of burner, sufficient ignition performance cannot be obtained when ignited under the same conditions as steady combustion.

This is because, as mentioned above, the excess air ratio is set high, so the jetting speed of the air-gas mixture from the flame holes (small holes 41, 41 of the ceramic plate) is lower than that of the conventional one. This is because the height is higher than that, and the ignition operation (spark generation) occurs under conditions that tend to lift.

(Technical Issues) The present invention is a forced primary air type burner with a high excess air ratio, in which the amount of air supplied by an electric fan installed at the primary air port is matched to the amount of combustion gas. The purpose is to improve the ignition performance of this combustion appliance.
The objective is to be able to set the excess air ratio under conditions that are primarily suitable for ignition during ignition.

(Means) The technical means of the present invention, which was designed to solve the above problems, includes a gas amount setting means 1 for setting the amount of gas to the burner, and an electric fan 2 that controls the amount of air supplied by the electric fan 2 for a short period of time at the initial stage of combustion. voltage setting means 3 for changing the setting applied voltage to the electric fan over time in order to adapt it over time to each time and the subsequent steady combustion; The voltage setting means 3 is provided with a delay means 6 that delays the timing of starting voltage application to the electric fan 2 by a fixed short period of time from the starting operation time, and further includes a delay means 6 for delaying the timing of starting voltage application to the electric fan 2 by a fixed short time from the time of the starting operation. Alternatively, the gas amount set by the gas amount setting means 1 up to the beginning of combustion is set to the optimum value for ignition, and the air supply amount during initial combustion is set slightly smaller than that during steady combustion.

(Operation) The above technical means of the present invention operates as follows.

The amount of gas burned in the steady combustion state of the burner and the air supply capacity of the electric fan are set to predetermined values based on the design of the burner.

When a starting operation is performed, the setting conditions are immediately set to the optimal conditions for ignition regarding the amount of gas burned, the spark generator 5 operates for a certain period of time, and the setting voltage of the voltage setting means 3 also becomes a predetermined value.

Here, since the applied voltage from the voltage setting means 3 is delayed by a certain period of time by the delay means 6 and applied to the electric fan 2, during this delay time, the primary air of the burner becomes non-forced and is the same as that of an atmospheric pressure burner. Under certain conditions, a highly concentrated mixed gas is ejected into the spark generating area. Since this mixed gas concentration has been set as a condition suitable for ignition, it is certain that ignition will occur at this point.

Then, when the delay time elapses, the voltage setting means 3
A voltage corresponding to initial combustion is applied to the electric fan 2 from then on, combustion continues for a certain short time under conditions of a lower excess air ratio than in the steady combustion state, and then shifts to the steady combustion state.

(Effects) Since the present invention has the above configuration, it has the following unique effects.

Regardless of the conditions during steady combustion, ignition is performed under optimal conditions during ignition, so ignition performance is improved.

After ignition is completed, the combustion state passes through an initial combustion state where primary air is forcibly supplied by an electric fan, and then shifts to a steady combustion state with a high excess air ratio, so the combustion state changes from ignition to the steady combustion state. The process progresses smoothly, and there are no blowouts or the like during the process.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2.

In this example, the firepower of the burner is set to "strong", "medium",
The gas circuit leading to the burner 4 has two first and second bypass circuits 71 and 72, and orifices 73 and 72 are formed in the gas circuit leading to the burner 4, respectively. 74 is inserted, and a solenoid valve is also inserted into the main gas circuit 70 and the first bypass circuit 71.

The diameter of the orifice is set in advance according to the set firepower, and the diameter of the orifice is set in advance according to the set firepower, and the diameter of the orifice is
1 is open, "strong" fire power, first solenoid valve 81
When only the second solenoid valve 82 and the first solenoid valve 81 of the first bypass circuit 71 are closed, the fire power is "medium", and when the second solenoid valve 82 and the first solenoid valve 81 of the first bypass circuit 71 are closed, the fire power is "weak". (See Fig. 1) The first and second solenoid valves 81 and 82 are inserted into an electric circuit as shown in Fig. 2, and are set to "strong", "medium", and "weak".
1st, 2nd, and 3rd operation buttons 91, 92, 9 for
The first operation in step 3 sets each corresponding gas circuit configuration, and the second operation completely closes the gas circuit. For this reason, the output of each operation button is input to the solenoid valve circuit for gas amount setting via a flip-flop circuit (FF circuit 10, the same applies hereinafter), and the FF when the first operation button 91 is pressed for the first time is
Output from the circuit 10 (hereinafter referred to as "strong" output),
Due to the first press operation of the second operation button 92
The OR circuit output of the output from the FF circuit 10 (hereinafter referred to as "medium" output) and the output from the FF circuit 10 (hereinafter referred to as "weak" output) by the first press operation of the third operation button 93 is connected to the bypass circuit. The signal is input to the first switch 11 that drives the main valve 80 inserted on the upstream side of the engine, and is also input to the first timer 12 for setting the initial combustion time.

In addition, first and second solenoid valves 8 for gas flow rate setting are provided.
1 and 82, the first solenoid valve 81 is a series circuit of the second switch 13 which is turned ON by the output from the first timer 12 and the second switch 14 which is turned ON by the output of the OR circuit, or "strength"
It is operated by the fourth switch 15 which is turned ON by the output, and the other second solenoid valve 82 is operated by the fifth switch 15 which is turned ON by the "medium" output.
It is designed to be operated by a switch 16.

The first, second, and third operation buttons 91 described above,
92, 93 and an OR circuit of "strong" output, "medium" output, and "weak" output, the second and third switches 13, 14 and "strong" which are turned ON by the output of this OR circuit
The combination of the fourth switch 15, which is turned ON by the output, and the fifth switch 16, which is turned ON by the "medium" output, and the first and second solenoid valves 81 and 82 is the gas amount setting described above. This is method 1.

Next, the voltage setting means 3 outputs an AND output between the "strong" output and the output of the first timer 12, an AND output between the "medium" output and the first timer 12, and further outputs a "weak" output.
By the AND output of the output and the first timer 12,
Voltage setting circuits 31 and 3 each set separately
2, 33 and the output of the first timer 12,
The first timer 12 includes an initial voltage setting circuit 34 for preferentially setting the voltage applied to the electric fan 2 to that for initial combustion during this output time.
A second timer 61 and a sixth switch 6 are connected to the output circuit of
A delay means 6 consisting of a combination with 2 is incorporated. The initial combustion is set to 30 seconds by the first timer 12, and the delay time is set to 1 to 2 seconds by the second timer 61.

Next, the spark generator 5 is set to "strong", "medium",
It is operated by the OR output of the "weak" output, so the OR output is the 7th switch 5.
1 is applied. Further, the operation of this spark generator 5 is stopped by the output of the flame detection device 52, and the operation of the eighth switch 53 is stopped by the output when flame is detected.
is turned ON, the circuit to the spark generator 5 is opened, and the operation is stopped.

Incidentally, the negative output of this flame detection device 52 and the output of the third timer 54 whose set time is about 10 seconds are
The above-mentioned FF circuits 10 and 1 are connected via the AND circuit 55.
It is input to the reset switches 0 and 10. First, second, third operation buttons 91, 92, 9
In the same way as in the case of the second push operation (in the case of a stop operation), the third timer 54
If there is no flame detection output from the flame detection device 52 after the set time elapses, the operation of each part is stopped.

In the case of the above embodiment, when any one of the first, second, and third operation buttons 91, 92, and 93 is pressed, the gas amount and electric fan capacity corresponding to the respective heating power are set, but at the same time, the ignition operation is At the time of ignition, the electric fan 2 is first stopped by the second timer 61 while the gas amount is preferentially set at the time of ignition (heating power with only the first solenoid valve 81 closed). If the ignition is completed, the first timer 1
During the initial combustion time set by 2, the electric fan 2 operates at the applied voltage set by the initial voltage setting circuit 34. Thereafter, when the first timer 12 times up, the combustion mode shifts to steady combustion with the amount of gas and the capacity of the electric fan 2 preset by the first, second, and third operation buttons 91, 92, and 93.

In this case, the amount of gas during initial combustion, including the time of ignition, is set to a value corresponding to "high" thermal power, and the capacity of electric fan 2 is slightly lower than that during steady combustion at high thermal power80. It is set to have a capacity of about %.

A time chart regarding the electromagnetic valve, the motor capacity of the electric fan, etc. in each of the above embodiments is as shown in FIG.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the gas circuit according to the embodiment of the present invention, Fig. 2 is an explanatory diagram of the electric circuit, Fig. 3 is a time chart of each part, and Figs. 4 and 5 are explanatory diagrams of the conventional example. In the diagram 1...Gas amount setting means, 2...Electric fan, 3
...Voltage setting means, 6...Delay means, 5...Spark generator.

Claims (1)

[Scope of utility model registration request] Setting the amount of gas to the burner in a forced primary air type burner with a high excess air ratio, in which the amount of air supplied by an electric fan installed at the primary air port is matched to the amount of combustion gas. A set applied voltage of the electric fan is set over time in order to adapt the air supply amount by the electric fan 2 to a short period of time at the initial stage of combustion and during steady combustion thereafter. The voltage setting means 3 includes a voltage setting means 3 that changes the voltage, and an ignition spark generator 5 that is put into operation for a certain period of time by a starting operation. A delay means 6 is provided to delay the time by a certain short time from the time, and further sets the gas amount set by the gas amount setting means 1 to an optimal value for ignition during the delay time or until the initial combustion stage, and also sets the gas amount set by the gas amount setting means 1 to an optimal value for ignition, A forced all-primary air burner whose feed rate is set slightly lower than that during steady combustion.