Causes and Solutions of Sand Fill in Hydrocyclones

Hydrocyclones are major components in drilling mud desander, drilling mud desilter and mud cleaner and assist most of their works. A hydrocyclone has a upper casing, a lower casing, a underflow mouth as well as auxiliary parts. The upper casing is an inlet chamber in cylindric with an inlet pipe on one side and a vortex tube in top middle as the overflow. The lower casing is a cone whose angle ranges from 15°~20° at the tip. The underflow mouth is located at the bottom as the discharge port for solids.

Hydrocyclones


Hydrocyclones in drilling mud desilter


Hydrocyclones in mud cleaner

The work principle of hydrocyclones is to separate two or several components with different densities with the aid of centrifugal force. After the mixture is sent into hydrocyclones by certain pressure, it gradually flow into a high-speed rotation where the heavy phase form an outer swirl by moving downwards along the axis, outwards along radial direction, downwards again along the cone till they flow out of underflow; while the light phase form upward inner swirl by moving towards axis and upwards till they go out from overflow outlet. Thus, the separation is done.

work principle of hydrocyclones
 

Sand fill is the commonest anormaly to hydrocyclone and is categorized as:

Sand fill at the underflow: it happens as a consequence of improper adjustment that results in dry bottom or of excessive silt content which brings about overloaded hydrocyclone. It should be removed immediately as it affects the purification ability and accelerates abrasion of lining and vortex tube. Usually the best ways are to enlarge underflow outlet or to have more solids taken away by preceding equipment.

Sand fill at the inlet: it can be partial or overall. Partial sand fill decelerates fluid flow inside inlet, leaks enormous drilling fluids from underflow and sometimes clean mud which may flow backwards from the overflow as, at that time, hydrocyclone is not more functional than a hopper. Overall sand fill is prone to back flow drilling mud from the overflow. Inlet sand fill generally stems from poor drilling fluids management, and most likely from going round the shale shaker or abrading shaker screens.

About KOSUN

Founded in 1992, Xi’an KOSUN Machinery Co., Ltd. (KOSUN) specializes in drilling, sales, services and manufacturing of solids control, drilling waste management and all other related equipment. With 20 years of experience, we are totally committed to customer satisfaction.KOSUN’s main solids control equipment include shale shaker, decanter centrifuge, mud cleaner, desander, desilter, centrifugal pumps, vacuum degassers, mud tanks, shaker screens and the complete set of various solids control systems.

Over 20 years of development, KOSUN has formed a strategic layout integrating three centers and two industries. The Production, R&D and Domestic Sales Center is located in Xi'an China, the Overseas Project Management Center and International Trade Center in Beijing China and the Oilfield Services and Oilfield Engineering Center in Aktobe Kazakhstan in Central Asia. The two industries are traditional equipment manufacturing industry and drilling waste management service industry respectively.