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US 7,088,253 B2Granted
Flame detector, method and fuel valve control
AssigneeProtection Controls Inc.
InventorFred Grow
Life of this patent
Estimating the term…
Abstract
A flame detector and burner fuel valve control has an ultraviolet sensitive, cold cathode, gas discharge tube in a DC quench circuit. In the presence of a flame, the circuit generates a pulse signal at a frequency related to the intensity of radiation from the flame. The pulse signal from a contaminated tube is at a higher frequency. A frequency discriminator circuit distinguishes between a flame responsive signal and a contaminated tube signal and controls the burner fuel valve.
Claims33
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a non-pulsed DC supply;
- a cathode/anode circuit, including a quench circuit, series connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- and
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between a desired flame responsive pulse signal and an undesired pulse signal to generate an output signal.
2 more elements
A flame detector circuit, comprising:
- a UV flame sensor tube having a cathode and an anode;
- a non-pulsed DC supply;
- and
- a cathode/anode circuit including a parallel resistor-capacitor quench circuit series connecting the UV tube with the DC supply.
1 more element
In a flame detector circuit having a UV flame sensor tube with a cathode and an anode, a DC supply, a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if the UV tube is contaminated or in the absence of a burner flame, the method of calibrating said detector circuit, comprising:
- exposing said UV tube to a flame to generate a pulse signal at a frequency greater than a selected frequency;
- and
- attenuating the flame to which the tube is exposed to generate a desired pulse signal at said selected frequency.
A flame detector comprising:
- a UV gas discharge tube having anode and cathode electrodes;
- a non-pulsed DC power supply;
- a quench circuit series connected with the UV tube anode and cathode electrodes and said power supply.
A flame detector circuit comprising:
- a UV flame sensor tube having two identical electrodes;
- a DC power supply;
- a switching circuit connecting the UV electrodes and the quench circuit with the power supply, each UV tube electrode alternately having positive and negative charges and alternately serving as anode and cathode, a desired pulse signal being generated by action of the quench circuit in the presence of a burner flame, and undesired pulse signals being generated by action of the quench circuit if the UV tube is contaminated or in the absence of a burner flame, and
- a discriminator circuit responsive to the pulse signal to distinguish between desired and undesired pulse signals.
1 more element
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal at a selected frequency being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals at other frequencies being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- and
- a frequency dependent charge pump discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal.
2 more elements
A flame detector circuit in a burner fuel valve control comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal;
- and
- an output circuit comprising a combustion safeguard and a flame simulator responsive to the desired flame responsive pulse signal to generate a flame rod current, said combustion safeguard being responsive to the flame rod current to operate said fuel valve.
3 more elements
In a burner fuel valve control having
- a UV flame sensor tube with a cathode and anode,
- a non-pulsed DC supply,
- a cathode/anode circuit, including an RC quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in the cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame,
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between a desired flame-responsive pulse signal and an undesired pulse signal, to generate an output signal, and
- an output circuit responsive to said output signal to open said fuel valve in response to the output signal with said desired pulse signal and to close the fuel valve in response to the output signal with an undesired pulse signal, the improvement comprising:
- a lockout circuit responsive to an abnormal condition of the flame detector circuit to close said fuel valve.
3 more elements
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal;
- and
- a circuit responsive to the desired pulse signal for periodically increasing the DC voltage applied to the UV sensor tube, increasing susceptibility of the UV sensor tube for contamination.
3 more elements
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal;
- and
- a high voltage DC power supply for the UV tube anode/cathode circuit and a low voltage DC supply for the discriminator circuit, said high voltage DC supply having a minimum operating voltage, and a circuit for disabling the low voltage DC supply if the high voltage DC supply is less than said minimum.
3 more elements
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal;
- and
- a buffer circuit between said UV tube cathode/anode circuit and said discriminator.
3 more elements
A burner fuel valve control comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal;
- an output circuit which controls a fuel valve in accordance with the output signal of the discriminator circuit;
- and
- an optocoupler between said discriminator circuit and said output circuit.
4 more elements
A flame detector circuit comprising:
- a UV flame sensor tube having a cathode and an anode;
- a DC supply;
- a cathode/anode circuit, including a quench circuit, connecting the cathode and anode of the UV tube with said DC supply, a desired pulse signal being generated in said cathode/anode circuit by action of the quench circuit in the presence of a burner flame and undesired pulse signals being generated in said cathode/anode circuit by action of the quench circuit if said UV tube is contaminated or in the absence of a burner flame;
- a discriminator circuit responsive to the pulse signal in said cathode/anode circuit for distinguishing between the desired flame responsive pulse signal and an undesired pulse signal to generate an output signal the discriminator circuit including an optocoupler which is subject to electrical noise;
- and
- an electrical noise detector which disables the discriminator circuit on the occurrence of electrical noise.
3 more elements
Dependencies are inferred from the claim text.