Explosion Proof Devices
Explosion Venting Device
The calculation of the explosion venting area of the dust removal system, as well as the design, selection and installation of the explosion venting device shall meet the requirements of GB/T 15605.
Inerting Device
The selection of inerting device should meet the following requirements:
Determine the type of inert gas or powder medium charged into the dust collector according to the dust explosion characteristics.
When inert gas is used as the charging medium, a continuous monitoring device for oxygen content in the dust collector box is set to alarm. When the oxygen concentration is higher than the set value, an audible and visual alarm signal is issued, which is interlocked with the control device of the dust removal system for protection.
When the inert powder is used as the charging medium, the flow rate and injection pressure of the charging powder shall be calculated according to the dust concentration in the dust collector box not greater than 50% of the lower explosion limit. If there is a dust collector connected with aluminum powder, magnesium powder, coal powder, etc., or powder production and processing systems with the same explosion characteristics, which may cause explosion hazards when mixed with oxygen, powder should not be used as an explosion-suppressing medium to be charged into the dust collector.
The explosion-proof device that fills the dust collector with inert gas or powder medium has the monitoring function of abnormal operation and failure shutdown. When abnormal operation and failure shutdown occurs, an audible and visual alarm signal is issued, and it is interlocked with the control device of the dust removal system for protection.
Triggered Barriers
The selection of explosion-proof devices meets the following requirements:
The explosion-proof device should be installed outside the factory building.
According to the characteristics of dust explosion, the anti-explosion strength of the dust collector and the air duct, the explosion-proof device is selected, and the installation position of the explosion-proof device on the main air duct is determined.
The starting of the explosion-proof device shall be interlocked with the protection of the control device of the dust removal system.
Explosion Suppression Device
The selection of explosion suppression device meets the following requirements:
According to the characteristics of dust explosion, the anti-explosion strength of the dust collector and the air duct, the explosion suppression device is selected, and the installation position of the explosion suppression device in the air duct and (or) the dust collector is determined.
The activation of the explosion suppression device shall be interlocked with the protection of the control device of the dust removal system.
Explosion-Proof Measures
1. The selection and installation of electrical equipment, monitoring device, alarm and control device installed in the dust environment explosion hazardous area shall meet the requirements of GB12476.1 and GB 12476.2.
2. The electrical connections of electrical circuits, electrical equipment, monitoring devices, alarms and control devices set in the dust explosion hazardous area shall meet the requirements of GB 50058.
3 The anti-static measures of the dust removal system should meet the requirements of GB 12158, the protective grounding of electrical equipment, monitoring device alarm and control devices should meet the requirements of GB 50058, and the air duct of the dust removal system should not be used as the grounding conductor of electrical equipment.
4. The electrical circuit, electrical equipment, monitoring device, alarm and control device should be free from dust accumulation.
