Hydrocyclones — desanders & desilters

What it does

Remove sand- and silt-sized drilled solids (roughly 15–74 µm) that the shaker passed, in two stages — desanders for the coarse fraction, desilters for the fine — before the centrifuge.

How it works

Feed enters the cone tangentially under pressure and is forced into a tight spiral. The centrifugal field — many times gravity near the wall — drives denser solids outward and down to the apex (underflow) while lighter fluid reverses into an inner spiral and exits the overflow at the top. Separation depends on cone geometry, feed head and flow, fluid properties, solids load and apex condition; flowing liquid alone does not confirm effective separation.

Key components

Operating parameters

Health indicators — what good looks like

• Every apex showing a fine umbrella spray with a visible air core.
• Measured feed head and flow within the specific cone OEM operating range at actual fluid density.
• Underflow solids-laden, not thin and watery.
• LGS falling across the section the cones should control.

Common problems & how to fix them

The failures this machine throws, each with a full field fix:

Field tips

• Calculate feed head whenever cones underperform: h = 19.2 × p ÷ ρ. Compare the result with the specific OEM operating range; neither low head nor the spray pattern alone identifies the cause.
• Walk the bank and read every apex: spray pattern is a diagnostic prompt, not proof of cut size; roping and absent discharge require checking head, flow, apex, wear, plugging and solids load.
• Investigate pump wear alongside feed pressure and flow, apex size, plugging and solids load; roping alone does not establish the cause.
• Run the desander before the desilter — take out the sand first so the small cones aren't flooded.