In the detection of flammable gases and toxic gases in […]
In the detection of flammable gases and toxic gases in petrochemical enterprises, in addition to the special requirements of very few objects, a large number of alarm systems should be used. The flammable gas alarm and indicator alarm can be a unit meter or a dedicated data acquisition system mounted on the instrument panel. The flammable gas alarm should include two basic units: a signal setter and a flash alarm.
Indicates that the alarm should have at least three basic functions: signal settings, signal indication, and flash alarms. It can also be composed of two parts: an indicator and an alarm.
In order to ensure the reliability of the detection alarm system, the alarm controller or signal setter should be set independently of the combustible gas alarm one-to-one. The flash alarm can be shared with other instrument systems, but alarms for important alarms and automatic protection should be set independently. The signal from the recording device (or DCS) and the interlock system should be output from the alarm controller or signal setter. When the detector or indicator alarm sends both the analog signal and the alarm contact signal, it is best to connect the alarm contact signal to the alarm and interlock system. The analog signal is connected to the DCS indicator record. The alarm and interlock system signals cannot be used. Take it out of the DCS.
The data acquisition system can also be a relatively independent unit in the DCS, mainly used for combustible gas alarms; the unit should include data acquisition components and operational display devices.