[Study on the electrical charging effect the water droplets in spray tower scrubber efficiency on removal feldspar particles]

One of the modern ways introduced nowadays for the increase of the collection efficiency of particulate, is the use of electric charge in wet scrubbers. These systems can be used in places in which scrubbers can be used for contaminant collection. In fact, this system only increases the collection efficiency, and it is not a new technology for contaminant collection. First, according to ACGIH recommendation for pilot study a ventilation system was designed and installed. Later, water DC was charged by using an electric exchanger. [1275 Volt, DC] and product 3x 1014 electron on system. Air velocity in duct determined by Pitottube and pressure drop and speed Equations, and calculated sampling prop diameter with isokinetic condition consideration. Samples in the two flow rates of 20.3 and 11.4 liters per minute were made and overall 72 samples were collected. Sample analysis according to weight and data analysis using SPSS software was used. 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 liters 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 liters per minute the flow charge was 91.33, 95, and 97.33 percent respectively. 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 charge, is 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

Noise induced hearing loss and its relationship with dose and exposure length

Noise Induced Hearing Loss [NIHL] is an important occupational disorder and the protection of workers against noise is essential. To evaluate the noise induced hearing loss and also presenting a statistical model based on effective variables such as the duration of employment and dose of received noise. This study was carried out on workers of a cleaners manufacturing industry. The study group composed of 209 subjects who were sleeted out of a total of 400 workers. The hearing loss was measured after rejection of age related loss. Following elimination of the effect of ear protective device, the dose of pure received noise for each subject was determined. Finding: The results indicated that the noise pressure level in different parts of the manufacturing unit was 76-107 dBA. The mean of employment duration, dose of pure received noise and total permanent hearing loss were 9.9 +/- 6.9, 135.4 +/- 11.51, and 12.52 +/- 4.1, respectively. The regression analysis of results showed that there was a direct and positive correlation between permanent hearing loss, dose of noise and the duration of employment [r=0.84, r2=0.77]. This was a significant correlation for both right [r=0.77, r2=0.6] and left ears [r=0.8, r2=0.64]. The survey of hearing loss in both ears showed that the hearing loss in left ear was greater than that in right ear. Regarding the data obtained in our study, models for calculating the either, left or Right hearing loss, were recommended by determining dose and the duration of employment in study group. Considering the NIHL, the necessity for improvement of controlling and protection measures is of prime importance