

Vent Collection & Destruction Systems
In recent years there has been increasing pressure to reduce emissions of Volatile Organic Compounds (VOCs) from industry. This has resulted in an increasing number of systems being installed to collect and destroy VOC emissions from process vents. These systems consist of a series of vent collection headers and a VOC destruction unit, often an incinerator, thermal oxidizer or carbon absorption bed. Experience has shown that the addition of a VCDS to an existing plant can be detrimental to the safety of the plant and hence there is a compromise between environmental improvement and safety performance.
The fire and explosion hazards associated with VCDS are often poorly understood and many incidents have been recorded. One reason for this is that these systems are often treated as simple services but are, in fact, high hazard plants in their own right.
Most problems occur as a result of disturbances in upstream equipment and consequent formation of a flammable mixture in the vent header system. These disturbances commonly occur during times of abnormal operation or as a result of maintenance operations. The effect of these upsets is a potential breach of the Basis of Safety of the plant and the ultimate consequences are often fires or explosions in the header.
High-quality design is essential for the continued safety of these systems under operation and maintenance conditions as is a tenable Basis of Safety. Haztech have an established methodology for the safe design of VCDS as well as extensive experience in the specification and design of these systems. We can assist from the conceptual design stage, development of Basis of Safety, detailed specification of equipment and design of control and safety systems right through to commissioning.