KST – KROMSCHRÖDER SYSTEM TECHNOLOGY
Flame control (SIL 3, PL e)
The flame supervision device is a component of the automatic burner control unit which complies with EN 298.
Each burner is fitted with its own automatic burner control unit.
Non-combusted gas in the combustion chamber → explosion
Determining the required SIL pursuant to IEC 62061
Frequency & exposure duration Fr: < 1 per h to ≥ 1 per day; > 10 min → 5 points
Probability Pr: without flame control, this event is likely to occur. → 4 points
Avoidance Av: avoiding the hazard is impossible. → 5 points
Effects: death, loss of an eye or arm
Determining the required PL pursuant to ISO 13849-1
Severity of injury S: severe (usually irreversible injury including death) → S2
Frequency and/or duration of hazard exposure F: frequent to continuous and/or long exposure to hazard → F2
Possibility of avoiding hazard or limiting harm P: hardly possible → P2
Enter the calculated values in the adjacent “app” to determine the required safety level.
The required SIL and PL can be achieved with these products. The calculation (see below) provides verification of this.
Sensor and logic: automatic burner control unit PFU (the ionization electronic is a sensor combined with the logic system.)
Actuator: solenoid valves for gas VAS
The flowchart shows how the products are integrated into the application to achieve the required safely level.
Calculating the SIL, PL
Select products in the adjacent “app”. Depending on the product click on whether the function should have one or two channels and enter the demand rate per hour or per year.
Select or enter the following values
“Sensor and logic combined + actuator”
Logic: burner control unit PFU
Actuator: solenoid valve for gas VAS 1
Demand rate: 1 per hour