US 12,228,455 B2
Flame monitor
Christian Deselaers, Schenefeld (DE)
Assigned to DURAG GmbH, (DE)
Filed by DURAG GmbH, Hamburg (DE)
Filed on Feb. 19, 2022, as Appl. No. 17/676,147.
Claims priority of application No. 102021106263.2 (DE), filed on Mar. 15, 2021.
Prior Publication US 2022/0291050 A1, Sep. 15, 2022
Int. Cl. G01J 5/56 (2006.01); G01J 5/00 (2022.01)
CPC G01J 5/56 (2013.01) [G01J 5/0018 (2013.01); F23N 2223/08 (2020.01)] 22 Claims
OG exemplary drawing
 
1. A flame monitor for monitoring at least one sub-region of a combustion chamber for the presence of a flame, comprising:
a flame sensor for sensing a physical variable of the flame and for generating an associated electrical sensor signal,
a dual-channel analyser circuit, connected downstream from the flame sensor, for determining whether the associated electrical sensor signal generated by the flame sensor corresponds to the flame and for outputting a safety-oriented output signal indicating the presence or absence of the flame, wherein the dual-channel analyser circuit comprises:
a first channel configured to process the associated electrical sensor signal, said first channel comprising a first analogue-digital converter in an analogue circuit, a first microcontroller belonging to a digital diagnostic comparator unit, for analysing a first signal obtained from the first analogue-digital converter, and a first relay in a relay circuit, which first relay is controlled by the first microcontroller, and
a second channel configured to process the associated electrical sensor signal, said second channel comprising a second analogue-digital converter in the analogue circuit, a second microcontroller belonging to the digital diagnostic comparator unit for analysing a second signal obtained from the second analogue-digital converter, and a second relay in the relay circuit, which second relay is controlled by the second microcontroller, wherein the digital diagnostic comparator unit is configured to compare a first result of analysis from the first microcontroller and a second result of analysis from the second microcontroller and to influence the safety-oriented output signal depending on the result of the comparison, wherein the digital diagnostic comparator unit is configured to compare a signal obtained from one of the first and second channels with an associated expected value, with the aid of both the first microcontroller and the second microcontroller.