Solutions for Four Common Underflow Problems of Cyclone

Apr 16, 2014

When cyclone works, high-speed swirling movement generates the air column and low-pressure area, creating suction towards underflow outlet. Inject some water into cyclone by certain pressure and adjust the outlet till it allows no fluid flow, meaning it reaches the balance point. This cyclone is called balanced cyclone, often found in mud cleaners where solid-content fluids enters and solids leave through underflow outlet.

However, some problems may arise adjusting the underflow outlet:

1. “Dry Underflow”: Relatively smaller outlet can pile a layer of dry silt between it and the balanced point. When ultra-fine solids enter, its water goes through the layer and dewatered solids block the outlet, causing dry plug. And this is called “dry underflow” adjustment.

2. “Wet Underflow”: Relatively larger underflow outlet can discharge conical rotating liquid. And this is called “wet underflow”.

3. “Radial” Discharge: Commonly, two flows move mutually reversely at the apex, one is the air inhaled and another the solid-content slurry discharging radially, forming an annular curtain there. Inhaled air keeps the outlet open and the cyclone efficient.

4. “Rope-like Discharge”: When the solid content excessively exceeds the designed capacity, the cyclone is over-loaded and solids flow out outlet in a rope-like shape, making no air or annular curtain but a nozzle possible. Then, some solid phase within limits will turn around and out from vortex finder.