JPH0371608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flame detection device for gas or oil combustion equipment.

Conventional structure and its problems Conventionally, flame detection in combustion equipment involves gas fuel passing through a gas passage and forming a flame at a flame hole.
The configuration is as shown in FIG. 1, in which a flame rod is provided in the flame to detect the ionic current.

That is, in FIG. 1, 1 is gasified fuel,
2 is a solenoid valve controlled by a signal from a control circuit 11; 3 is a fuel pipe; 4 is a nozzle; 5 is an electric insulator such as a heat-resistant porcelain material; the burner head is equipped with a flame rod 10; and 6 is a metal burner body. , 7 is a gas passage of the burner, 8 is a flame hole, 9 is a flame, 10 is a metal flame rod for detecting ion current, 11 is a solenoid valve 2 that detects the ion current of the flame.
This is a control circuit that outputs control signals to the Nozzle 4
The gas discharged from the flame rod 10 passes through the gas passage 7 and is ignited at the flame hole 8, forming a flame including the tip of the flame rod 10. Thermal ionization of gas components generates ionic current. If a positive DC voltage is applied to the flame rod 10 and a negative DC voltage to the burner body 6 in advance, a current flows from the flame rod 10 to the burner body 6. When the control circuit 11 detects the current, it detects that the gas is burning and holds the solenoid valve 2 open.

If the flame disappears due to an abnormal condition such as blowing out, the ion current disappears and the control circuit 11 detects the misfire and outputs a cutoff signal to cut off the solenoid valve 2. Close to cut off gasified fuel. However, with conventional flame rods, variations in the relative position between the flame rod and the flame hole may cause a difference in the detected ion current, or when the flame is throttled, the flame may not reach the flame rod. In addition, in general, one flame rod detects the ion current of the flame formed at one flame hole among multiple flame holes, so if one flame hole becomes clogged, the combustion equipment This will stop the safety function.

OBJECTS OF THE INVENTION The present invention solves these conventional problems, and can be expected to detect flame reliably and further improve the performance of safety functions.

Structure of the Invention The present invention includes a main burner having a plurality of flame holes, and a tip portion disposed on the upper edge surface of each flame hole so as to be in contact with the outer flame of the flame generated in each flame hole and rising upward.
It also consists of a flame rod that is electrically insulated from the main burner, and a circuit that detects the ion current flowing through the flame rod and controls combustion.
Regardless of the size of the flame, and even if any of the flame ports are blocked, the ionic current can be detected.
To provide a stable flame detection device without malfunction.

DESCRIPTION OF EMBODIMENTS The following describes embodiments of the present invention in Figures 2 to 3.
This will be explained based on the diagram.

FIG. 2 shows the system configuration according to the embodiment. 1
2 is a solenoid valve controlled by a signal from the control circuit 11, 3 is a fuel pipe, 4 is a nozzle, 5 is an electric insulator such as a heat-resistant porcelain material, and 6 is a burner head equipped with a flame rod 10. The burner body is made of metal, 7 is a gas passage of the burner, 8 is a flame hole, 9 is a flame, 10 is a metal flame rod for detecting ion current, which is arranged along the upper surface of each gas passage 7, and has a tip. 10' is located on the upper edge surface of each flame hole 8. 11 is a control circuit that detects the ionic current of any of the plurality of flames and outputs a control signal to the solenoid valve 2; 12 is a control circuit that maintains the burner head 5 and the burner body 6 in an optimal relative position and insulates the flame rod from the burner body. and a spacer made of a heat-resistant porcelain material for forming a gas passage;
3 is a fixing screw for narrowing the frame rod 10 between the burner head 5 and the spacer 12 and integrating the three.

In the above configuration, the gas discharged from the nozzle 4 passes through the spacer 12 and the gas passage 7, and then passes through the flame hole 8.
The tips 10' of the flame rods 10 are integrally arranged so as to be in contact with the upper edge surface of the flame hole 8, and the flame generated in the flame hole and rising upward thermally ionizes the gas components, producing many ions. It is configured to be in contact with the outer flame where a current is present. In advance, add the flame rod 10 and the burner body 6.
When a negative DC voltage is applied to the burner body 6, a current flows from the flame rod 10 to the burner body 6.
The control circuit 11 is connected to the tip 1 of the frame rod 10.
0' detects an ionic current, it is detected that the gas is burning, and the solenoid valve 2 is held open.

If the flame disappears due to an abnormal condition such as blowing out, the ion current disappears and the control circuit 11 detects the misfire and outputs a cutoff signal to cut off the solenoid valve 2. Close to cut off gas fuel.

The embodiment is characterized by the structure of the burner head 5 and flame rod 10 shown in FIGS. 3a and 3b. The burner head 5 is made of a heat-resistant insulator such as porcelain, and has a gas passage 7 provided with a plurality of grooves, and the same number of flame rods 10 as the grooves are provided on the upper surface of the grooves. They are gathered at the center to form one electrode.

Even when the flame is narrowed down to a small size, the tip of the flame rod 10 is located in the flame hole 8, and the flame 9 inevitably comes into contact with this, so that the ionic current can be detected without malfunction.

Furthermore, since the tip 10' of the flame rod is arranged on the upper edge surface of each flame hole 8, even if any flame hole 8 is blocked, the flame rod 10 placed in the other flame hole 8 will not be affected. Therefore, it has the likelihood of detecting ionic current.

Effects of the Invention As described above, according to the present invention, the following effects can be expected.

(1) Ion current for small flames can be reliably detected regardless of variations in the relative positions of the flame hole and flame rod.

(2) Since a flame rod is placed in each flame hole, the ionic current can be detected with high reliability in case of blockage of the flame hole.

In addition, the tip of each flame rod is placed in contact with the outer flame of the flame that is generated in the flame hole and rises upwards on the upper edge of each flame hole, so that the outer flame, which is higher in temperature than the center of the flame, is securely in contact with the flame rod. , flame current detection sensitivity can be increased.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a burner showing a conventional example, Fig. 2 is a sectional view of a burner showing an embodiment of the present invention, and Fig. 3 is a sectional view of a burner showing an embodiment of the present invention.
Figures a and b are a plan view and a side view of a burner head according to an embodiment of the invention. 2... Solenoid valve, 5... Burner head, 6... Burner body, 7... Gas passage, 8... Flame hole, 10...
...Framerod, 11...Control circuit.

Claims (1)

[Claims] 1. A main burner having a plurality of flame holes, and a flame rod provided on the upper edge surface of each flame hole so as to be in contact with the outer flame of the flame generated in each flame hole and rising upward, and electrically insulated from the main burner. A flame detection device for a combustion equipment, comprising: a circuit for detecting an ion current flowing through the flame rod and controlling combustion.