Oil Sludge Centrifuge
I. Oily sludge treatment
Production of oily sludge
Sludge treatment is a complete set of
production process, using the principle of oxidative
demulsification and centrifugal separation. Its main equipment is
composed of dosing system, feeding system, separation system,
conveying system, and control system.
After the oily sludge is collected and
heated by steam, a suitable number of additives like demulsifier
and active agent are added in it, so that the oily water in the
emulsified state is broken. After demulsification, a
high-efficiency LWS series three-phase centrifuge is adopted to
realize the continuous separation of oil, water, and slag in the
oily sludge, and the water separated and the oil-water mixture not
demulsified are directly sent to the sewage treatment system for
treatment. Then, a LW series two-phase centrifuge with high
efficiency is used for dehydration. The crude oil residue in the
dehydrated slag phase can be recovered by the combustion or thermal
desorption process. The separated crude oil is collected and then
purified by a three-phase flottweg separator. The purified oil can
be reused.
Separation performance:
1, About 80~90% oil can be recovered (relating to oil density,
demulsification effect, temperature, etc.), and the recovered oil
can be used for refining purpose after further purified by the
flottweg separator;
2, The water content of the oil phase after separation can reach ≤3
~ 5%;
3, The dryness of the slag phase after centrifugation can reach 40
~ 60%, and its total volume is reduced by over 80% compared to that
before separation;
★ Three-phase centrifuge model and technical parameters
Item | Unit | LWS250×1025B(X) | LWS350×1435B(X) | LWS450×1845B(X) | LWS520×2150B(X) | LWS580×2400B(X) | LWS650×2600B(X) |
Throughput | m3/h | ≥1 | ≥3~5 | ≥5-10 | ≥10-15 | ≥15-20 | ≥20-30 |
Roller diameter | mm | 250 | 350 | 450 | 520 | 580 | 650 |
Length-to-diameter ratio | | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4 |
Speed | rpm | 5000 | 4000 | 3500 | 3200 | 3000 | 2800 |
Separation factor | | 3500 | 3136 | 3087 | 2982 | 2948 | 2854 |
Differential speed | rpm | 1~50 | 1~35 | 1~34 | 1~34 | 1~30 | 1~27 |
Main motor power | kW | 11 | 22 | 30 | 45 | 55/75 | 75/90 |
Ancillary motor power (kW) | kW | 4 | 5.5 | 7.5 | 15 | 18.5 | 22 |
Weight | kg | 1250 | 2500 | 4000 | 5200 | 6500 | 8000 |
Boundary dimension (L×W×H) | mm | 2500×800×1150 | 3700×1050×1400 | 3800×1150×1600 | 4800×1250×1800 | 5300×1750×1382 | 5600×1850×1500 |
Note: The throughput is related to material characteristics.
X" indicates that the heavy phase liquid is discharged by the
centripetal pump with back pressure;
The overall dimensions will vary depending on the way the
centrifuge is drained.
★ Two-phase centrifuge model and technical parameters
Item | Unit | LW250×1025B | LW350×1435B | LW450×1845B | LW520×2150B | LW580×2400B |
Throughput | m3/h | 0.5-3 | 3~10 | 8~15 | 15-20 | 20-30 |
Roller diameter | mm | 250 | 350 | 450 | 520 | 580 |
Length-to-diameter ratio | | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 |
Speed | rpm | 5000 | 4000 | 3200 | 3000 | 2800 |
Separation factor | | 3500 | 3136 | 2580 | 2620 | 2546 |
Differential speed | rpm | 1~50 | 1~35 | 1~34 | 1~34 | 1~36 |
Main motor power | kW | 11 | 22 | 30-37 | 45-55 | 75-90 |
Ancillary motor power (kW) | kW | 4 | 5.5 | 7.5 | 15 | 18.5 |
Weight | kg | 1250 | 2500 | 4200 | 5200 | 6500 |
Boundary dimension (L*W*H) | mm | 2500×800×1150 | 3700×1050×1200 | 4300×1150×1450 | 5100×1250×1600 | 5520×1450×1700 |
Note: The throughput is related to material characteristics. |
Oily sludge treatment system diagram
Separation performance:
1. About 80~95% oil can be recovered (relating to oil
density, demulsification effect, temperature, etc.), and the
recovered oil can be used for refining purpose after further
purified by the flottweg separator;
2, The water content of the oil phase after separation can reach ≤3
~ 5%;
3, The dryness of the slag phase after centrifugation can reach 40
~ 60%, and its total volume is reduced by over 80% compared to that
before separation;
Oily wastewater treatment flow chart
III. Drilling oil-based mud solid-waste treatment
Oilfield drilling requires drilling
oil-based mud according to the drilling depth and geological
conditions. The mud's basic composition is oil, water, organic
clay, and oil-soluble chemical treatment agent. OBM resists high
temperature and calcium salt erosion, which is beneficial to the
stability and lubrication of the well wall. The mud features good
performance and small damage to oil and gas layers, and wide
application in various types of drilling platforms. However, the
slag generated in the equipment of drilling solid control system
(vibrating screen, centrifuge, and dryer) has seriously affected
the environmental safety and must be treated in a harmless manner.
After treatment, the oil content of the slag is less than 1% and
the oil is further purified and reused.
The collected drilling OBM solid wastewater is
subjected to high-speed stirring in proportion, and a suitable
amount of demulsifier, active agent, and other additives are added,
so that the oily water in the emulsified state is broken. The
vibrating screen is used before separation to remove large
particles of soil, sand, glass bottles, mineral water bottles,
convenient bags, gauze, and other solid wastes, and then the
high-efficiency LW series two-phase centrifuge is adopted to
separate continuously the (oil + water) + slag. After heated by
steam, the separated liquid phase enters the sedimentation tank, in
which the supernatant is removed, and the liquid phase settled at
the bottom of the tank is mixed with the slag phase separated by
the centrifuge. The residual oil is recovered by the thermal
desorption process.
Separation performance:
1,It can recover about 90% of oil (relating to demulsification
effect, temperature, etc.);
2,The solid content of the liquid phase after separation can reach
≤5~8%;
3,The dryness of the slag phase after separation can reach 40 ~
60%;
Drilling oil-based mud solid waste treatment process
IV. Technical descriptions of the centrifuge
★ Extremely low infrastructure investment and good on-site operating
environment
Compared with the conventional filter-type equipment
(plate-and-frame filter, belt machine, etc.), the high-performance
centrifuge is compact and efficient, covering only about a third of
land, needless of auxiliary gas source, high-pressure water, and
with simpler pipe structures at the inlet and outlet. Moreover, the
operation environment is more humanized, and the skid-mounted
integrated device has the characteristics of compact structure,
convenient installation, low requirements for infrastructure, and
convenient movement. The centrifuge is widely used in the harmless
treatment of oily sludge in oilfield drilling.
★ Stable operation, low failure rate, and low maintenance cost
Compared with the filter type
equipment, the centrifuge does not require any filter cloth or
filter screen, so as to avoid the trouble of clogging and of
replacing the filter cloth. The operation and maintenance costs of
the equipment are low.
★ Modular design, easy to operate
Our design philosophy: To lower the
requirements on the skills, educational level, and labor intensity
of operators, and realize one-button start and stop of the control
system, fault self-diagnosis, and safety self-protection.
★ Operator configuration and labor intensity
The high-performance centrifuge is an automatic
and continuous working mode for feeding-separating-slag (liquid)
discharging. The whole process requires no human intervention.
Multiple sets of equipment require only one inspector (in
conjunction with other positions). Unlike frame and plate-and-frame
filter, the slag discharging process does not require manual
cutting, greatly reducing the labor intensity of the operator.
★ Ingenious, unique, and diversified heavy liquid-phase discharging
structure
The heavy liquid phase separated by the
three-phase centrifuge can adopt two different liquid discharging
modes, namely gravity discharging and discharging through the
built-in centripetal pump with pressure, wherein the latter
includes liquid layer fixed mode and the online adjustable mode of
heavy phase liquid layer, which is selected according to the
process conditions.
★ High performance wear-and corrosion-resistant cemented carbide
As the oily sludge contains a lot of
hard particles and impurities such as sand, glass, and metal, if
the centrifuge does not adopt reliable wear-resistant
configuration, its service life and running stability will be
seriously affected. The wear-resistant solution is completely
targeted. According to the material characteristics (pH value,
corrosive substance, solid particle size hardness, etc.), cemented
carbide or ceramic can be selected, and the cemented carbide can be
either YG6, YG8, or various modified tungsten-cobalt alloys with
the hardness of 89~93 (HRA), which can fully meet the application
fields of the centrifuge.
Double-motor double-frequency conversion common DC bus constant
torque control technology
★ CIP washing system
The fully automatic control system is equipped with a CIP washing
system, which can effectively solve the problem that it is not
completely cleaned during the shutdown process and effectively
avoid the equipment troubles caused by artificial factors.
★ Humanized centrifugal configuration
Spiral bearing (in the drum, concealed) lubrication technology: the
lubricant is filled from the outside of the hood. (Unique
technology in domestic centrifuges) The hood adopts a hinged
opening structure and is equipped with a high-pressure gas strut to
assist the opening.
Vibration and temperature sensor (optional) at the position of the
main bearing housing.
★ Light phase liquid layer adjustment technology
From the current three-phase centrifuge structure for liquid
transportation of centripetal pumps adopted at home and abroad, the
adjustment of the light phase liquid layer requires disassembling
the centrifuge, and replacement takes more than 8 hours. The
centrifuge, with the patented technology of our company, just
requires opening the hood to adjust the light phase liquid layer.
★ Variable pitch technology
Variable pitch technology is a relatively advanced technology in
the world. It can effectively reduce the screw pushing torque,
improve the processing capacity, and further reduce the sediment
water content.
★ Constant torque control technology
The constant torque control of the centrifuge is the most advanced
control mode in the world. The real-time monitoring of the actual
output torque of the constant torque variable frequency motor
through the high-performance auxiliary inverter is compared with
the set torque value, and PID is used to adjust the material
pushing speed of the screw conveyor in real time. The centrifuge
can achieve continuous, stable, and economic operation.