In order to uniform distribution of liquid in the large horizontal-tube low temperature multi-effect distillation (MED) desalination, the spray characteristics of a hollow nozzle were studied experimentally. A centrifugal nozzle spray characteristic test-bed and a radial spray density measurement device were designed and built independently. The spray cone angles of the nozzles were obtained by marking the spray edge with the spray photographs taken by the high-speed camera. The variations of flow rate, spray cone angle and radial spray density versus spray pressure, as well as the radial spray density versus spray height were the main focus of the present work. The experimental results showed the export flow rate with the increase of inlet pressure, and the growth rate of flow rate tended to be slower. In normal experiment conditions, the spray cone angle was determined by the angle of the divergent section at the nozzle outlet, while it shrank the inner edge of the circular liquid film due to the loss of power under gravity, and the spray of the hollow nozzle exhibited a regular annular shape. As the inlet pressure increased, the effective spray area extended to the center as a whole, and the peak value of spray density also increased obviously, the symmetry of which was improved and the spray density was basically symmetrical when the pressure was 349 kPa. While increasing spray height had an opposite effect. With the increasing of spray height, the two peaks gradually moved away from the center and the radial droplet distribution was more uniform. The peak value of spray density decreased but always dominated, and the effective spray area expanded outwards. When designing the horizontal-tube evaporation distributor, the operating pressure should be controlled reasonably depending on the uniformity of nozzle spray density. The ineffective spray area can be eliminated effectively according to the principle of peak-valley superposition.
Liang ZHAO Juanjuan JIAO Peng WANG Xiaojing ZHU Qinggang QIU Shengqiang SHEN
. Experimental investigation on spray characteristics of hollow nozzle for liquid distribution[J]. The Chinese Journal of Process Engineering, 2019
, 19(6)
: 1085
-1092
.
DOI: 10.12034/j.issn.1009-606X.218321
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