Decanting centrifuge operation and smooth operation suggestion

XI'AN, China - Oct. 20, 2016 - PRLog -- Decanting centrifuge use

A decanting centrifuge is a tool used in viscosity control and it is also solids-removal equipment. It is a machine with an internal cylinder, or bowl, that rotates at high speeds (1800~3200 rpm). As drilling fluid is pumped into and conveyed through the rotating bowl, it is subjected to a large centrifugal force that increases the separation or settling rate of the suspended solids. The higher-mass particles separate fastest along the wall of the rotating bowl.

An important distinction is that while screens and hydrocyclones are used to separate and discard larger drilled-solids particles, centrifuges are used to separate and discard smaller, ultra-fine particles, both drilled solids and barite.

Why use a centrifuge?

Short answer: To remove drilled solids.
During drilling operations, drilled solids accumulate and degrade in size, which causes viscosities and gel strengths to increase, especially in weighted drilling fluids. These fluids necessarily contain concentrations of weight material solids. A centrifuge will separate ultra-fine (less than 2 microns barite and 3 microns drilled solids) from larger, desirable-size barite particles and drilled solids, which, while undesirable, are not as harmful to fluid flow and wall building properties. http://www.aipusolidcontrol.com/html/products/centrifuge....

Expensive treatment additives are also discarded with the ultra-fines stream. However, most chemical treatment expense is directed to combat actions of ultra-fine drilled solids. While some additions will be necessary, the ultimate result is lessened additive and barite usage, and the removal of drilled solids will be beneficial.

Reduced viscosity of the fluid within the bowl with dilution enhances separation. Dilution fluid should be added sufficient to maintain an effluent with a funnel viscosity between 35 and 37 seconds.

While centrifuging a water-based system, beneficial bentonite will be discarded along with drilled solids and must be replaced. Usually one or two sacks of bentonite per hour of centrifuge operation over and above normal treatment levels will benefit especially filtration and wall building characteristics. Centrifuge adjustments, other than varying dilution fluid rate, are seldom needed and should be left to a centrifuge mechanic. http://www.aipusolidcontrol.com/html/2016/solids-control-...

Decanting cenrifuge smooth operation reminders

1. Before startup, rotate bowl or cylinder by hand to make sure it rotates freely.

2. Start centrifuge first, before starting the drilling-fluid feed pump or dilution water.

3. Set drilling-fluid mud and dilution rates according to manufacturer's recommendations, which usually vary according to mud weight.

4. Shutdown:
. Turn off drilling fluid feed .

. Turn off dilution water

. Turn off machine