Coal Cement Industry: pulverised Fuel, MBM, PSP, Powder Explosion Suppression Venting Explosion vent doors Isolation Silos Filters Elevators Mills Ducts PipelinesCement and Steel Coal and Sustainable Energy: Venting DoorsThe cement and steel industries have a long association with coal as a source of heat in their kiln plant but now they experience the changing times of more sustainable fuels sources from tyres to sludge pellets.

The Re-closing Door MethodSince most of the plant is located outside venting is not a major problem but they need to vent a lot of kinetic energy from the mills to filter to silos and prevent the reintroduction of flesh air after the explosion event to minimise subsequent fires or secondary explosions. The most popular choice for endurance and efficiency is the Thorwesten reclosing vent doors and flame diverters. Vent 1 vents the primary explosion force reducing the velocity to the filter. Vent 2 deflects the resultant flame from the Filter. The Filter and silo are then vented as individual components without the concern of flame jet ignition. Many of these systems are further protected by inerting using Nitrogen or CO2. Important in these industries are the durability of the explosion door and its reclosing feature to prevent the ingress of air after the explosion, minimising the potential fire damage.EXPLOSION DOORS: Self reclosing, resettable & re-useable venting doors, plant & buildings cementThe TV Explosion Door from ATEX is a high performance explosion venting solution for aggressive environments. It provides economical explosion relief and prevents secondary fire damage from oxygen intake by rapidly re-closing after the explosion is vented. We also offer a light weight door forbuilding protection. Features Fast response time High efficiency vent area Designed for aggressive environments Long service life (low maintenance) Low cost of operation Spring-assisted automatic re-close prevents oxygeningress and the 'chimney' effect. Air-cushion design causes smooth deceleration, avoiding damage to the supporting structure. Optional vacuum breakers protect against implosion caused by rapid air cooling inside the vessel.Available Options Construction: hot-dip-galvanised steel or stainless steel. Vacuum breakers Heating system (prevents obstruction by freezing weather) Proximity switch (can be used to actuate secondary protection devices)Concept and OperationSelf-re-closing Explosion Doors open against one or more baffle plates to absorb its kinetic energy. This dramatically reduces damage to the supporting structure. After venting the door re-closes and the unique door catches reseal the vent opening, minimizing the damage from fire. In contrast, standard Explosion Vent Panels allow air supply into the protected vessel after the initial explosion, increasing the potential damage from fire, especially in dust collectors and silos.

The explosion doors can be round or rectangular, to facilitate most industrial applications. The round explosion doors are ideal for silos and other vessels requiring top-mounting. The rectangular explosion doors are available for heavy and light industrial environments. The units can be mounted in a horizontal or vertical position. The heavy industrial explosion doors are used on vessels such as dust collectors. The light industrial units can be used on weak structures such as buildings. After explosions in virtually closed vessels, rapid cooling can cause destructive vacuums. An integrated vacuum breakeris available to prevent implosion.EXPLOSION RELIEF PANELS: Cost effictive, round & square, vacuum resistant bursting discATEX explosion vent panels are designed to provide cost-effective pressure relief, preventing overpressure damage to the vessel wall. Features Extra low cost. Low maintenance. Wide range of relief pressures. Optional pressure fatigue resistance.Available Options Range of sizes, both round and square. Triple-section and domed designs ensure long service life. Optional hygienic design (to pharmaceutical standards) Optional flanges, seal gaskets and tools to suit various applications for high temperature, vacuum and pressure resistance (especially pressure pulsing).. Available with break-wire monitoring (can be used to actuate secondary protection devices).Concept and OperationNon-re-closing and non-reusable weak panels which form part of the protected vessel wall, are designed to burst at a predetermined pressure early in the development of an explosion. This results in the main force of an explosion being dissipated into a designated safe venting area, preventing deformation or rupture of the protected plant.

Q-Pipe (Q-Rohr) Q-Box Flameless Explosion Venting System Inside BuildingsThe Q-Pipe & Q-Box Flameless Explosion Vent from Atex is a safe indoor venting solution for explosion protection of indoor processes in personnel areas. It uses a stainless steel mesh filter to quench vented explosions and arrest flames. Features Ideal for small volume venting inside buildings. Low cost installation and reconditioning after actuation. Stand-alone, passive protection system. Single integrated unit reduces the need for costly suppression systems. Full compliance with NFPA and European requirements.

Available Options Wide range of sizes. Integrated break-wire monitoring as standard (can be used to actuate secondary protection devices).

Concept and OperationThe Q-Pipe (now also available as a Q-Box) Flameless Vent System was developed in response to a specific need, i.e. explosion venting inside buildings. Traditional explosion venting technologies require a safe venting area (usually outdoors), where there is no risk of secondary explosions or harm to personnel. Explosion vented plant has to be ducted out to a designated (external) safe area (usually within 3 to 6 metres). The only alternative was to strengthen vessels to withstand greater explosion pressures and/or to install relatively expensive explosion suppression systems.

The Q-Pipe design allows venting of explosions without the attendant risks of an external fireball and without the use of vent ducts. It is essentially a flame-arrester comprising a porous, heat-absorbing surface in the form of a pipe. The vented explosion enters the pipe, the gases are cooled as they pass through the porous surface, dust is filtered out and the flame is quenched. The internal surface-area of the Q-Pipe is designed so that the effective vent area is almost the same as if the vent itself was free.Explosion Diverter: Mechanical explosion isolation device, vented flame pressure, safe area, passive self closing rupture disc.The TV Explosion Diverter from ATEX is a mechanical explosion isolation device which protects ductwork and attached vessels by diverting vented flame and pressure to a safe area. Features Self-closing explosion door. Passive system requires no electrical controls. Sentinel switches to electrically signal other devices e.g. extinguishing barriers, emergency plant shutdown etc. Requires little or no reconditioning after an explosion.Available Options Rupture disc or self-re closing mechanism. Ranges from 100 to 1100 mm diameter.Concept and OperationOperates by altering the direction of the natural flow to vent pressure and flame through an integrated explosion door. When an explosion occurs it accelerates down the pipeline into the U-bend of the diverter. Rather than change direction, the explosion hits the door and vents out to a safe area. When the energy has dissipated, the door will reclose preventing oxygen from entering the pipeline. It prevents flame jet ignition and pressure-piling from travelling down pipelines but cannot totally guarantee stopping explosions.