JPH072745U - Burner ignition detection device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a burner ignition detection device capable of stable flame detection by eliminating false signals to the flame rod during ignition by electric spark. [Structure] An electric spark is generated by applying an AC voltage of 100 V or 200 V to the primary side by a high voltage generating transformer for ignition and generating a high voltage on the secondary side to generate a spark between spark rods. However, when the applied voltage on the primary side reaches the rated voltage, a rectifier is inserted between the cables that electrically connect the frame rod and the detection circuit, and the applied voltage on the primary side is rated. Short-circuit the rectifier when the voltage is lower than the voltage. However, the rectifier rectifies the current only in the direction from the flame plate to the frame rod.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a flame detection device using a frame rod used in a gas burner or the like.

[0002]

[Prior art]

 As a flame detector that is often used in gas burners, frame rods are often used because they are structurally simple to manufacture and have excellent functionality. As the flame detection principle of the flame rod, conductivity due to ionization of the flame is used. In the detection by conductivity, since an erroneous detection is caused by the contact between the flame lot and the conductive material such as the flame plate, an AC voltage is applied between the frame rod and the flame plate, and the direct current flowing by the rectification by the ionized flame The current is detected and the flame is detected. The rectifying action is that when an AC voltage is applied to the flame rod and flame board, a current flows from the flame rod to the flame board. The problem in this case is that the current flowing through the flame rod and flame board at the time of flame detection is about 5 to 15 μA, which is a low current, so current is applied to the flame rod due to the electromagnetic field generated during ignition by electric spark. In many cases, there is a false detection that a flame is present.

[0003]

[Problems to be solved by the device]

 The problem to be solved by the present invention is to provide a burner ignition detection device capable of stable flame detection by eliminating false signals to the flame rod during ignition by an electric spark.

[0004]

[Means for Solving the Problems]

 In the electric spark, a transformer for generating a high voltage for ignition applies an AC voltage of 100V or 200V to the primary side to generate a high voltage on the secondary side to generate a spark between the spark rods. When the applied voltage on the primary side reaches the rated voltage, insert a rectifier between the cables that electrically connect the frame rod and the detection circuit, and check that the applied voltage on the primary side is the rated voltage or less. Short pass the rectifier if. However, the rectifier shall conduct current only in the direction from the flame plate to the frame rod.

[0005]

[Action]

 When a low voltage AC voltage is applied to the flame disc and flame rod during combustion, a current usually flows from the frame rod in the direction of the flame disc. For this reason, during spark ignition by applying voltage to the ignition transformer, by inserting a rectifier that allows current to flow only in the direction from the frame rod to the detection circuit, in the middle of the cable to the flame rod and the detection circuit, The electrical noise generated in the frame rod causes a current to flow only from the frame rod in the direction of the detection circuit, which prevents erroneous detection with a flame.

[0006]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an embodiment of the present invention and shows an outline of a flame detection circuit. An AC voltage is applied between the frame rod and flame board, and a rectifier is installed in the cable between the frame rod and the detection circuit so that current flows from the frame rod toward the detection circuit, and a contact is provided in parallel with the rectifier. The contact point is set to open when the rated voltage is applied to the primary side of the ignition transformer. Further, it may be arranged in series with the rectifier, and the other contacts may be closed when the rated voltage is applied to the primary side of the ignition transformer and opened when not applied. The direction of current flow from the flame rod to the detection circuit when the rated voltage is applied to the primary side of the ignition transformer is as shown in FIG. The direction of current flow when the rated voltage is not applied to the primary side of the ignition transformer is as shown in FIG.

[0007]

[Effect of device]

 By implementing the present invention, it is possible to detect a flame with a simple current detection circuit and an electric circuit. Due to the electrical noise of the spark rod during ignition, electrical noise flowing from the flame rod to the detection circuit causes a flame. False detection of presence can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view of the rectifying action of the flame rod and the flame board by the flame.

[Explanation of symbols]

 1 Rectifier 2 Relay 3 contact

Claims (1)

[Scope of utility model registration request] 1. An ignition detection device for a burner, comprising an ignition device including a spark rod and an ignition transformer, and having a flame rod and a flame detection circuit, wherein a current is supplied only to the detection device from the flame rod to a cable between the flame rod and the detection device. If a rectifier is installed and a contact is provided in parallel with the rectifier and the voltage to the primary side of the ignition transformer is detected,
An ignition detection device for a burner, which opens its contacts and allows only current to flow from the flame rod to the detection circuit during spark ignition.