Centrifuge Feeding Pumps for Solids Control and Waste Management

Centrifuges are greatly used in solids
control and drilling waste management systems in oil and
gas drilling industry, because it could separate out directly or together with
chemicals the fine and extra fine solid particles from the liquid at a high
rotating speed of the bowl. In a solids control system, it is always used after
the desilter and in waste management systems for drilling cuttings, it is used
after the high G dryer shaker or vertical cuttings dryer. When using together
with chemicals like dewatering, it is used after the dewatering unit.

Normally, what equipment is used to feed
the decanter
centrifuges
? Although in theory, the centrifugal pump could be used to feed
the decanter centrifuges just as the centrifugal pumps are served for the desander and desilter,
the centrifugal pump is not an ideal solution. Mostly practical options are submersible
slurry pump and screw pump.

1. submersible slurry pump: just as its
name, the submersible slurry pump has some part of the body underneath the
liquid, and it is vertically installed on the tank for feeding the decanter
centrifuge. In most cases, it is used for fixed speed decanter centrifuge. comparing
with a screw pump, it occupies less space for install and the price of
submersible slurry pump is lower than a screw pump, because the material and
producing technology is less complicated than screw pumps.

2. screw pump, also called mono pump in
practical uses, the most important parts of the screw pump are stator and
rotator, by rotating of the rotator, the transported media is conveyed evenly
and at a stable speed to the decanter centrifuge. Frankly speaking, this is
more suitable as the feeding pump of decanter centrifuges. GN always match its
decanter centrifuge with Netsch pump, which is a German brand, and the liquid
touching parts are all made of SS316L.

GN keeps research and develop the best
technology to manufacture top quality equipment ,such as Mud Gas Separator,
mud agitator, Vacuum
Degasser
and other solids control equipment for our clients,

For more information, visit GN Solids Control’s
website or call our sales.

How Solids Control Works in Dredging Project

The company who provides environmental
protection service may have the business for dredging in rivers or lakes. Many
years’ soil sedimentation down to the water bottom, leaves falling into the
water and then rot, and the trash threw into the water will make the river bed
higher and higher which leading the pollution of the water and even the cutoff
of the river flow. Therefore, we need find a solution to take out the sand,
silt and trash at the bottom of water to make the water clean.

To take the solid stuff out from the water,
we need a solid and liquid separation system to do this job. As a leading
manufacturer of solids control equipment, GN solids control luckily
jointed a project to make the lake water clean inside a residence district.
There is a dredging boat that can take the solid mixed with water from bottom
of the lake, the dirty slurry was sucked out and delivered on to the land with
smelly smell.

The slurry is fed via a steel wire box
where large size solid stuff will be blocked and collected. Then the liquid
will be pumped to GN’s solids control system. In this system, GN designed 3
stages for solids control including shale shaker,
de-sander and de-silter. Both the de-sander and
de-silter are equipped with underflow shaker that could make the discharges
from cyclone much dryer. After treated by the de-silter cyclones, the solid
stuff with size larger than 15-20 microns will be removed. And the rest solid
in the slurry is difficult to remove by using mechanical machinery.

Flocculation is a good method to gather the
ultra fine solids in the slurry. Add the flocculation agent into the slurry as
per certain ratio and then fully mix with mud agitators. The
flocculated slurry will need several times for sedimentation and then will be
pumped to belt filter press for final dewatering process. The solids will be
discharged with a thin cake shape, and the water could be discharged directly
back to later or river.  

The advantage of the filter press is to
make the solids much dryer, and disadvantage is high cost and small treating
capacity. Some other contractor will use decanter centrifuge to do the final
dewatering job on consideration of its larger treating capacity.