// FIXED FUME EXTRACTION SYSTEMS
Fixed systems, also known as vent to atmosphere systems are commonly used within manufacturing, consisting of spiral ducting, fan units and filters they are permanently installed next to the machinery they serve. In a vast majority of manufacturing cases it is a recognised and reliable way to eradicate fumes from the workplace quickly in large volumes.
It is a simple thought to vent laser fume contaminant to the atmosphere because the problem just, 'goes away' but delving deep it is a far more complex issue.
Relative to Laser Fume extraction, fixed system do suffer from some fundamental problems. Firstly any vent to air system incurs the jurisdiction of environmental regulation, regardless of the nature of the fume being vented. See here for guidelines
The regulations covering toxic fume emissions are incredibly stringent and if breached carry fiscal and operational penalties. Although filters are used within vent to air systems they are not readily replaceable when ruptured or clogged. Coupled with the fact that external venting doesn't offer variable airflow, deficiencies in the system can be quickly realised. Reduced airflow is directly related to loss of laser fume containment.
// AN EXAMPLE OF A FIXED FUME EXTRACTION SYSTEM
Apart from regulations, it costs money to either heat or cool a factory. Therefore the venting of air that has in effect been paid for, into the atmosphere is not economical.
In a modern production environment, it is necessary to have flexible production lines that can be moved as the factory grows or the production emphasis is altered. Vent to atmosphere extraction requires extensive, fixed duct-work that cannot easily be moved. If moved, this duct-work can harbour contaminants that must be cleaned up and made safe. Also, planning permission is often required to cut holes in the factory roof or walls and these holes must be sealed again if the pipe-work moves! This lengthy, expensive process interrupts valuable production time.
A re-circulating system avoids any regulations that govern external emissions. Purified air is returned to the workplace in virtually the same conditioned state/temperature, as when the air entered the machine, therefore air conditioning costs do not rise. Vacuum levels can be set and altered easily for each individual process and most systems can be easily moved, should the process move. Altogether a re-circulating system is much more cost effective, flexible and environmentally friendly than an external system.
// DisclaimerThis site aims to be impartial however it must reinforced that fixed system do have a considerable number of fundamental downfalls when used with laser fume especially.
