All Zero-Smog® fume extraction systems consist of three basic parts: a collection point where fumes are captured, an airflow source to pull fumes through the system, and a filter system to remove the pollutants before the cleaned air is returned to the workplace atmosphere. Recirculation of clean conditioned air saves energy, lowers costs, and may help with environmental regulations compliance.
THE COLLECTION POINT
The most efficient fume extraction systems remove the fumes as close as possible to their source. The best way to accomplish this is always dictated by the type of work being done:
For tasks involving a small work area, such as hand soldering, the collection point can be situated extremely close to the source of the fumes, right at the tip of the soldering iron. This is called Tip Extraction.
For tasks that involve a larger working area, such as the application of adhesives, a higher volume fume extraction method must be used, consisting of a cone-shaped nozzle situated over the source of the fumes. This is called Volume Extraction.
Tip Extraction utilizes a small diameter fume extraction tube mounted directly on the soldering iron. Weller FE Series soldering irons have a built-in fume extraction tube, and there are Zero-Smog fume extraction tube kits that can be retro-fitted to most non-fume extraction Weller soldering irons.
For tip extraction, optimal airflow through the tube should be approximately 20 l/min. (4.5 gallons/min.). The open end of the tube should be positioned no further than 15 mm away from the point of the soldering tip. To guarantee optimal performance, the fume extraction tube and hoses should be checked daily and cleaned if necessary.
Volume Extraction uses a large-diameter angled or cone-shaped nozzle positioned over the source of the fumes with a flexible extraction arm, an adjustable articulated arm, or a combination of the two. The nozzle should be angled toward the workbench and as close to the source of the fumes as possible. Optimal airflow through the nozzle should be a minimum of 40 m3/h.
THE AIRFLOW SOURCE
The airflow source for all Zero-Smog systems is a vacuum pump that provides airflow (vacuum) to pull the dangerous fumes through the system. The kind of pump used depends on the type of fume extraction system:
• Tip extraction systems typically require lower airflow, but higher vacuum (up to 12,000 Pa for efficient fume extraction).
• Volume extraction systems need a much lower vacuum (generally 2,800 Pa maximum) but require a high airflow rate for efficient fume extraction.
THE FILTER SYSTEM
The Zero-Smog filter system utilizes three types of filters:
- a dust filter to remove larger particles
- a micro filter to remove almost all smaller particles and increase the lifetime of the gas filter. The separation degree of this filter is 99.97 % DOP.
- a gas filter where the airflow is cleaned. The gas filter is made of activated carbon with a chemisorbant substance.
The chemisorbant increases the lifetime of the filter and adds the benefit of filtering a wider spectrum of gases. The filter is dimensioned for optimal contact time between gas filter media and the gases in the airflow.
Most Zero-Smog filter systems can be upgraded with a HEPA micro filter as the last stage for clean room applications. This guarantees that there are no particles left in the air after filtration.
The lifetime of the filter varies from 3 to 12 months, depending on working hours, quantity of particles, and type of pollution. Most Zero-Smog filter systems are equipped with a filter guard indicating when the filter should be replaced.
