Primary flame safeguard system
US4000961A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 26, 1975 |
| Grant date | Jan 4, 1977 |
| Priority date | — |
| Expiry date | Aug 26, 1995 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N2231/12
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
Flame supervisory method and apparatus in which a cross-checking relay system is controlled jointly by time-delay factors and a two-state control signal derived from the flame and having respectively pre-flame and flame-responsive polarity characteristics produced by reflexive bias and regenerative amplification and conversion of the basic flame-detection current to a control signal determining either switch-over to full flame burner operation or lock out of the system under ignition failure conditions. The two control states of the converted flame-detection signal are of a self-locking character, the pre-flame state tending to inhibit false response of the relay system to spurious flame signals, and the converted control signal in general being highly discriminative owing to an abrupt, non-linear change in polarity differentiating it from the pre-flame state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.