Flame surveying means in burner ignition

摘要

A device for liquid fuel burners includes an electrically controlled valve which allows the feeding of fuel to the burner, the valve being provided with a retaining winding for permanently allowing the flow of fuel when the burner is in operation. The device further includes a combustion chamber pre-purger and a resistor with determines the end of the pre-purging. The device also includes a flame signaller means having a photo-resistance which responds to a preset low light intensity so as to reduce the current flowing through the resistor to such an extent that its heating becomes insufficient to cause the end of the pre-purging. The photo-resistance responds to a high light intensity by activating the retaining winding of the valve and giving the signals necessary for causing the burner to enter its regular operating mode.