Vocational Schools embark on more hands-on lab time, requiring more ventilation support.
April 20, 2021
Vocational schools are refocusing on the trades and building and expanding welding schools as part of this renaissance. The hazards of breathing welding fume are documented and regulations pertaining to exposure levels are becoming more stringent. Students are not only learning how to weld but how to weld safely and protect themselves from welding fume exposure.
Clean Air Company designs, installs and services welding fume extraction systems. Telescoping fume extraction arms are common for welding schools because they are compact, fit nicely in a welding booth and can handle both overhead welding and standard table welding. The rotating hoods easily position either behind or over the weld capturing fume and particulate with an increased flow rate.
Welding fumes are transported back to a self-cleaning dust collector after passing through a spark arrestor. The spark arrestor removes sparks and slag from the air stream preventing fires and protecting filter life. The filtration of the collector uses high efficiency, fire retardant filters effective at removing up to 90% of the contaminate. The dust collector monitors the filter loading and automatically initiates a self-cleaning cycle using compressed air. The welding fume particles are pulsed off the filters where they drop down into the collection hopper for proper disposal.
Over time the filters will slowly lose the ability to be cleaned as welding particulate begins to choke the filters. The air flow will be negatively affected as the resistance within the collector increases proportionately with this accumulation of particulate. Adding a VFD drive will increase the fan speed so air flow at the welding station is not compromised as the filters. A filter alarm is also utilized to let the owner know replacement filters should be ordered.
The discharge air from the dust collector passes through a silencer to maintain low noise levels in the classroom. The silencer is designed with the fan data 8 octave bands in mind so noise reduction can be properly plotted reducing noise levels accurately.
Finally, the air passes through a secondary safety after-filter before re-entering the classroom. The safety after filter removes up to 98% of the 10% of the finer particles that passed through the primary filter resulting in the removal of 99.8% of the welding fumes. This filter is also monitored for pressure build up so that facilities staff know when to change them. The primary benefit of this filter is the ability to guarantee compliance with OSHA threshold limit values. Additional benefits include the air is evenly distributed across a large filter area to minimize the air velocity which in turn reduces the draft students feel, thus creating a more comfortable environment. The filter will also absorb noise energy, lowering the sound additionally, therefore, improving the overall classroom atmosphere. Finally, the filter provides additional protection should one of the primary filters become damaged.
Clean Air Company offers numerous solutions for handling welding fume and metal grinding dust.
• Welding Tables
• Dust Control Booths
• High Vacuum fume guns
• Ambient air cleaning
• Portable collectors
After 40 years of providing indoor air quality solutions, we are confident we can be of service to your organization. Reach out to a Clean Air specialist and begin to Breathe Clean Air.