JPS6016855Y2 - Safety devices for gas appliances - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device for gas appliances that prevents oxygen deficiency accidents from occurring.

Conventionally, this type of device has been equipped with an oxygen concentration cell element that has one electrode surface in front of the combustion surface of the burner in contact with the combustion flame of the burner or its combustion exhaust, and is interposed in the gas supply path by the output of the element. Types that control the opening and closing of safety valves are known, but in this case, if the gas appliance can be changed to use at least two types of gas, such as natural gas or other lift gas and city gas or other back gas, Lifting gases react sensitively to decreases in the oxygen concentration in the air, while backing gases have a delayed reaction, so even if the oxygen concentration in the air is the same, the oxygen concentration in the combustion flame or combustion exhaust will change. This causes a difference in the output of the element, which causes the inconvenience of causing variations in the closing timing of the safety valve.

The purpose of the present invention is to provide a device that eliminates such inconveniences, and is intended to provide a gas appliance that can change the use of at least two types of gas.
The electrode surface 2a of the element 2 is located in front of the element 2, with one electrode surface 2a facing each other, and the pilot burner 8 is placed facing the other electrode surface 2a of the element 2. In the device which controls the opening and closing of the electromagnetic safety means 4 interposed in the gas supply path 3 by the output of the element 2 caused by the difference in oxygen concentration between the two electrode surfaces 2a, 2a as a concentration atmosphere, a burner facing the element 2 is used. A cover 6 is provided which surrounds the combustion surface 1a of 1, the element 2, and the pilot burner 8. A shielding plate 10 is installed in an outside air introducing portion 7 formed on the lower surface of the combustion space 5 formed between the combustion surface 1a of the combustion chamber 6 and the element 2, and the opening degree thereof is adjusted according to the type of gas used.

The oxygen concentration battery element 2 has porous electrode surfaces 2 on both sides of a sintered body of zirconia or other oxygen ion conductive solid electrolyte.
a, 2a are formed and hollowed, and the electrode surface 2a facing the pilot burner 8 is placed in an atmosphere with a low oxygen concentration, so that during normal combustion of the burner 1, a relatively large amount of oxygen is generated between the electrode surfaces 2a, 2a. A concentration difference is formed and an electromotive force is generated in the element 2, and if incomplete combustion occurs during oxygen deficiency, one electrode surface 2
The oxygen concentration in the combustion flame or combustion exhaust of the burner 1 that comes into contact with the element 2 decreases, and the difference in oxygen concentration between the two electrode surfaces 2a, 2a decreases, resulting in a decrease in the electromotive force of the element 2,
When the operating value decreases to a predetermined operating value, the control circuit 9 cuts off the power to the operating solenoid 5a of the safety valve 5 and closes the safety valve 5. In this case, the type of gas used is a lift gas, e.g. The following difference occurs in the electromotive force of the element 2 depending on the case where the backing gas is used, for example, G.

That is, the lift gas 13A reacts more sensitively to a decrease in the oxygen concentration in the air than the back gas C and causes incomplete combustion at a relatively high oxygen concentration, so the electromotive force when the back gas □ is used is On the other hand, when lift gas 13A is used, the electromotive force decreases at a relatively high oxygen concentration and changes as shown by line b in Figure 4. , if the electromotive force decreases to 3QQmV, the safety valve 5
When the safety valve 5 is closed, the safety valve 5 is closed when the oxygen concentration in the air decreases to 17.5% for the back gas G, whereas the safety valve 5 is closed when the oxygen concentration in the air decreases to 19% for the lift gas 13A.
%, the safety valve 5 is closed.

Although the above is not particularly different from the conventional type described above, according to the present invention, side plate portions are provided on the front side of the combustion surface 1a, surrounding the pilot burner 8 and the oxygen concentration battery element 2 and extending toward the combustion surface 1a. 6a, 6a, a substantially U-shaped cover 6 is provided to cover the combustion space 5 between the combustion surface 1a and one electrode surface 2a facing thereto, and the cover 6 is provided with a cover 6 at the bottom of the combustion space 5. It is formed into an outside air introduction lower which is opened and closed depending on the type of gas used by a shielding plate 10.

Next, to explain its operation, when using a backing gas, the outside air opening 7 is fully opened to perform the combustion operation of the burner 1, and when doing so, the electromotive force of the oxygen concentration cell element 2 increases as shown in Fig. 4 above. If the safety valve 4 is closed when the voltage changes as shown in line a and decreases to a predetermined operating value, for example 300 mV, the voltage will decrease to the operating value when the oxygen concentration in the air decreases to 17.5%. The safety valve 4 is then closed.

Furthermore, when using lift gas, the burner 1 is operated with the outside air introduction lower half open or fully opened, but when doing so, the introduction of outside air into the combustion space 5 is regulated and the inside of the space 5 is becomes an atmosphere with a relatively low oxygen concentration, and the oxygen concentration battery element 2
The difference in oxygen concentration between the two electrode surfaces 2a, 2a of the element 2 is reduced, and the electromotive force generated by the element 2 is reduced, and the oxygen concentration in the combustion space 5 is regulated to be low during incomplete combustion due to lack of oxygen. Therefore, the oxygen concentration does not decrease suddenly, and the electromotive force gradually decreases, and its change characteristics become like that of green stone C in Figure 4. At an oxygen concentration of 17.5%, the electromotive force decreases to 300 mV and the safety valve 5 is closed.

In addition, in the one shown in the second figure, the outside air introduction lower is opened and closed by sliding the shielding plate 10 back and forth, but for example, as shown in the third figure, the outside air introduction lower is opened and closed by sliding it up and down. Alternatively, the shielding plate 10 may be detachably attached to open and close the outside air introduction lower.

In this way, according to the present invention, the combustion surface 1a of the burner 1 facing the oxygen concentration battery element 2 and the cover 6 that surrounds the element 2 and the pilot burner 8 are opened at the top and bottom to allow outside air to be introduced from the bottom. Therefore, the cover 6 can prevent the flame from fluctuating due to cross winds, etc., stabilize the output of the element 2, and especially reduce the combustion space 5 formed between the combustion surface 1a of the cover 6 and the element 2. Since the outside air introduction lower formed on the lower surface is provided with a shielding plate 10 whose opening degree is adjusted according to the type of gas used, a limited amount of outside air is introduced into the combustion space 5 by the shielding plate 10. Moreover, since the amount can be adjusted using the shield plate 10, the safety valve can be activated by changing the output when the oxygen concentration in the air decreases to the same desired oxygen concentration regardless of the type of gas used. In addition, since the outside air is supplied to the pilot burner side without being controlled, the pilot burner, whose combustion is unstable, will misfire first compared to burner 1, which means that the oxygen concentration in the air will not reach the desired oxygen concentration. This has the advantage that there is no inconvenience caused by closing the safety valve and extinguishing the burner 1 due to a misfire before it occurs.

[Brief explanation of drawings]

Fig. 1 is a cutaway plan view of one example of the device of the present invention, and Fig. 2 is a cutaway plan view of an example of the device of the present invention.
FIG. 3 is a cross-sectional side view showing another opening/closing mechanism for the outside air inlet, and FIG. 4 is a line diagram illustrating its operation. 1... Burner, 1a... Combustion surface, 2.
... Oxygen concentration battery element, 2a ... Electrode surface, 3 ... Gas supply path, 4 ... Safety valve,
5... Combustion space, 6... Cover, 7...
...Outside air intake.

Claims (1)

[Scope of utility model registration request] A gas appliance that can use at least two different types of gases is provided with an oxygen concentration battery element 2 in front of the combustion surface 1a of a burner 1 provided therein, with one electrode surface 2a facing the element 2. The pilot burner 8 is placed facing the other electrode surface 2a, and the other electrode surface 2a is set in an atmosphere with a low oxygen concentration, and gas is generated by the output of the element caused by the difference in oxygen concentration between the two electrode surfaces 2a, 2a. For controlling the opening and closing of the electromagnetic safety valve 4 interposed in the supply path 3, a cover 6 is provided which encloses the combustion surface 1a of the burner 1 facing the element 2, the element 2, and the pilot burner 8. The top and bottom are open so that outside air can be introduced into the cover 6 from the lower part, and outside air is formed on the lower surface of the combustion space 5 formed between the combustion surface 1a of the cover 6 and the element 2. This is a safety device for gas appliances in which a shielding plate 10 is provided on the inlet portion 7 to adjust the opening degree according to the type of gas used.