Effect of mist nozzle supply pressure on the ammonia absorption process

Abstract

The article shows the effect of the supply pressure of fog nozzles on the process of ammonia sorption. In the tests, the nozzles flow characteristics Q=f(p) and the dependence of NH3 concentration as a function of the water stream feeding in time at different supply pressures were determined. For the TF 6 NN, TF 6 V, NF 15, CW 50 nozzles, measurements were carried out at the following supply pressures: 0.1 MPa; 0.2MPa; 0.3MPa; 0.4MPa; 0.5MPa. It was observed that the greatest effect of nozzle feed pressure on ammonia sorption efficiency may be expected at lower pressure values. At higher values, the sorption rate becomes stabilized and even starts to decrease. The decreases in the sorption rate constant observed for higher pressures may be due to a reduction contact time of the droplet and the achievement of the critical mixing rate of ammonia vapors in the air intensively saturated with water streams. This is due to diffusion rate limitations. The measurements show that the use of supply pressures for fog nozzles above 0.4 MPa is not justified. It should be noted that varying the feed pressure of nozzles of various designs can affect their ammonia sorption efficiency differently. The type of nozzle and supply pressure affects the distribution of droplets in space. The angle of dispersion and the shape of the generated jet have a critical influence on the efficiency of the sorption process. Complete filling of the space and a large spray angle assure relatively high sorption efficiency.

Keywords

• process safety
• nh3 removal
• sorption curve
• k-factor
• water spraying
• mist nozzles