Source Capture: Efficient and Cost-Effective
Source ventilation, or source capture, has many advantages that help ensure the safety of workers and promote energy saving.
Source capture involves controlling pollutants directly at their point of emission, regardless of the type of pollutant: dust, vapour, gas, smoke, etc.
This type of ventilation offers several advantages.
First, the pollutant does not have time to disperse in the ambient air. This ensures excellent protection for the machine operator. Furthermore, since the ambient air remains clean, all the other workers also benefit. This is a very important advantage, in addition to lower operational costs compared to general ventilation. While the latter provides similar results in terms of worker exposure, it fails to protect those working at the emission source.
Another advantage of source capture is that the airflow required for proper pollutant control is very low compared to general ventilation. Consequently, the number of air changes per hour can be reduced and the result will remain the same. With source capture, we are no longer talking about thousands of cubic feet per minute per workstation. In fact, if we compare the airflow rates required, the difference is striking. Source capture requires 90%-95% less airflow than conventional general ventilation for similar protection.
Lower airflow also means installing and operating smaller dust extraction devices and a smaller duct network. The factory’s negative pressure is significantly reduced, which also lowers energy costs. Lastly, because workers’ exposure to the pollutant is controlled directly at the source, as prescribed by the law, some personal protective equipment can become practically unnecessary, depending on the conditions.
Various basic elements must be considered to obtain a sufficient emission capture and ensure the respiratory protection of workers. These include :
- The energy produced by the procedure
- The temperature of the emissions
- The velocity of the pollutant emission
- The direction of the emission
- The flow velocity of ambient air
- The speed of capture
Remember, the distance between the emission and the vacuum should never be neglected and should always be as short as possible.
High Speed, Low Volume
By using a high-speed, low-volume capture method, we obtain the following additional advantages:
Very small sensors, often called microsensors, help capture emissions at the source without harming the machine operator or the operation.
The high-speed, low-volume procedure creates a vacuum power source, which helps generate the capture speed required for microsensors to function properly and effectively contain the emission.
In addition to meeting the requirements for elimination at the source, a source capture system also provides excellent protection for workers while promoting excellent energy control. However, the design must be rigorous and meet specific criteria.