Iran Occupational Health

  Background and aims: One of the modern ways introduced nowadays for increasing the collection efficiency of particulate, is the use of electric charge in wet scrubbers. These systems can be used in places in which scrubbers are suitable for contaminant collection. In fact, this system only increases the collection efficiency, and it is not a new technology for contaminant collection. 

  Methods: First, according to ACGIH recommendation for pilot study a ventilation system was designed and installed. Later, water was charged by using an DC electric exchanger (1275 Volt, DC)& product 3×1014 electron on system. Air velocity in the duct was determined by Pitot tube, pressure drop and speed equations, and sampling prop diameter was calculated considering isokenetic conditions. Sampling was performed at two flow rates of 20.3 and 11.4 liter per minute and in overall 72 samples were collected.

 Sample analysis was performed using gravimetric method and data analysis was performed using SPSS software.

      Results: The collection efficiency of inhalable particles in the flow rate of 20.3 liter per minute in a non-electric intervention, and electric intervention with positive and negative charge was 66, 77.67 and 73 percent and in the flow rate of 11.4 liters per minute 60, 69.43 and 68.32 percent respectively. For non-inhalable particles the efficiency in the flow rate 20.3 liter per minute in a non-electric intervention and electric intervention with positive and negative charge was 94.67, 98.33 and 97.67 percent, and in the flow charge of 11/4 liter per minute the flow charge was 91.33, 95, and 97.33 percent respectively.

  Conclusion: The results obtained from the experiments, showed that in a certain flow rate, electric intervention increases the efficiency of inhalable particle collection. By the way, this electric intervention has no significant effect on non-inhalable particle collection. Also, the effect of electric intervention with positive chargeis higher than electric intervention with negative charge, and with the increase of water flow rate there is an increase in the collection efficiency of the inhalable and non-inhalable feldspar particles.