The spray pattern varies in response to the feed head (inlet pressure), feed rate and cyclone apex opening. To maximize overall desander efficiency, the spray pattern of each cone must be balanced for optimal performance. This is done by observing the lower discharge pattern and then adjusting the apex opening to achieve the correct discharge angle for the prevailing feed rate and inlet pressure. The spray patterns of cyclone underflow are adjusted through changing orifice nuts with different diameters.


 
Ideally, the spray angle of underflow is between 20° and 30°. When the spray angle is greater than 30°, a hollow center is formed. In normal operation, this pattern is undesirable. This spray pattern indicates that the exit diameter of the apex is too large, and an excessive amount of liquid discharges along with the solids flowing from the bottom of the cone. Correct this condition by using an orifice nut with a smaller diameter.


 
When the spray angle is less than 20°, a hollow center is formed. In normal operation, this pattern is undesirable. This spray pattern indicates exit diameter of the apex is too small, the solids discharge is too dry, and excessive solids are being discharged with the liquid from the upper discharge. Correct this condition by using an orifice nut with a bigger diameter.