Isolation systems prevent secondary explosions and flame propagation
Often the most devasting effects of a dust explosion are caused by flame propagation and pressure piling of flame fronts as they expand from the initial ignition location. The concept of explosion isolation is to have a device that reacts by mechanically or chemically blocking the deflagration as it expands.
Isolation systems can come in the form of passive or active solutions. Passive isolation systems tend to be triggered by the pressure flow associated with a deflagration to be activated. Active isolation systems use pressure or optical sensors to continually monitor process areas then react by activating an isolation device. Typical isolation locations include material or air pathways both upstream and downstream from process vessels like dust collectors, conveyors, dryers, and storage vessels.
Explosion Isolation Systems Activate in Milliseconds to Extinguish Flames
Whether active or passive all isolation systems are located in ductwork to stop deflagrations as they travel from vessels where an explosion initiates.
Explosion Isolation Pinch Valve
The Interceptor®-VE® is a NFPA 69 compliant isolation pinch valve. The Interceptor®-VE® valve is normally open. Upon receiving a signal from either a pressure responder or an optical sensor the Interceptor®-VE® controller is designed to immediately signal the Interceptor®-VE® valve. The Interceptor®-VE® valve will close in milliseconds to prevent the passage of hot particles, glowing embers, flame, or pressure from continuing to flow through the pipe. The medium of actuation is plant compressed air stored in a tank on the valve to ensure the fastest response possible under any plant conditions.
Explosion Isolation Slide Gate Valve
The Interceptor®-SG® explosion isolation valve is designed to prevent explosion propagation from one vessel to another through interconnected piping. The explosion isolation slide gate is a compliant solution for both NFPA 69 and FM 7-76.
The isolation valve is a normally open device, however upon receiving a signal from a pressure detector, the Interceptor®-SG® explosion isolation valve is designed to rapidly close. The medium for actuation is plant-compressed air stored in a tank on the valve to ensure the fastest response possible under any plant conditions. The valve closure principle is a slide gate that closes when a high speed solenoid valve changes state releasing the compressed air.
The Interceptor®-Ventex® is a NFPA 69 compliant passive float valve designed for explosion isolation. The valve is designed to operate by closing when the pressure wave of the explosion slams and locks the valve shut.
The valve can be configured for use as a single acting or double acting arrangement. Double acting valves are able to isolate in both directions. All Ventex® valves can be configured to isolate in the same or opposite direction of the process airflow. Vertical and horizontal valves can be built to allow for flexibility on the installation location.
The Ventex® valve is approved to isolate organic dusts, metallic dusts, hybrid mixtures, and some gases.
The Interceptor®-HRD system is an NFPA compliant High Rate Discharge chemical isolation solution. These suppression bottles contain pressurized Nitrogen and dry chemical suppressant to suppress a deflagration as it develops. A variety of sizes and nozzle designs, including USDA certified options, allow the HRD isolation bottles to be used on any application.
The HRD isolation system can be triggered by pressure detection or optical detection. Suppression bottles offer the ability to be used on ductwork in any shape or size for all applications and processes.
A micro gas generator with a 10-year service life provides a superior service life for the bottles. Additional features include a standard telescopic nozzle for sanitary, flush installs, pressure switch monitoring, OSHA lockouts, and a field-replaceable design.