Lw720 Decanter Dewatering Centrifuge for Sludge Thickening

• After-sales Service: Video Online Support
• Warranty: 1 Year
• Type: Centrifuge
• Object: Decanter Centrifuge
• Separation Mode: Sedimentation Type
• Operating Type: Continuous Type
• Model NO.: LW/LWS series
• Installation: Horizontal
• Centrifuge Type: Horizontal Spiral Centrifuge
• Pressure: Low Pressure
• Condition: New
• Discharge Type: Self-Cleaning
• Bearing: F-a-G NSK S-K-F Bearing
• Bowl Material: Stainless Steel 304/316L/Duplex Steel
• Separation: 3phase Separation
• Feature: High Efficiency
• Key Selling Points: Famous Brand PLC
• Motor: ABB
• Transport Package: According to The Model
• Specification: According to the model
• Trademark: Shenzhou
• Origin: China

Product Description

Product Description

LW720 Decanter Dewatering Centrifuge for Sludge Thickening

Sludge dewatering Decanter Centrifuge

Sludge treatment plays an important role at wastewater treatment plants: A key component of the treatment process for drinking water and wastewater is the efficient separation and dewatering of fine-grained sludge, using mechanical means whenever possible. In particular, large wastewater treatment plants serving a population of 200,000 or more must find the most economical, optimal solution for the dewatering and thickening process. Given this imperative, reliability, high economic efficiency, and minimal maintenance are of great importance for wastewater treatment plants.

 

The centrifuge is able to process 100 - 200 m³/h (440 - 880 gpm) during thickening and 80 - 160 m³/h (352 - 704 gpm) during dewatering. The LW760 boasts features like an energy-efficient and high-performance drive,simple maintenance, and minimal personnel requirements due to a high level of automation.

 

All sewage sludge is different: "Sewage sludge is always unique - all sludge has its own characteristics, which means the overall conditions are never the same.The Shenzhou centrifuge can be customized for the quality and special characteristics of the sewage sludge treated on site.

When it comes to separating solid/liquid mixes with a high solids content, decanter centrifuges are the way to go. These solid-shell scroll centrifuges or decanters, unlike chamber filter presses, run continuously. The finely distributed solid particles are separated from the suspension by strong centrifugal forces.

Decanters are useful in a wide variety of industries throughout the world. The centrifuges are optimally adapted for the specific application. Applications range from sludge dewatering to classification or wet classification to the sorting of solids.

To obtain optimum results, solid bowl decanter centrifuges must be custom designed to suit specific separation processes.
 

What is Decanter centrifuge?

• A decanter centrifuge is a type of centrifuge that is used to separate solids from liquids in a mixture. It is a continuous process that uses centrifugal force to separate the two components. 
• The mixture is fed into the centrifuge, and the solids are separated from the liquids by the centrifugal force generated by the spinning of the centrifuge. 
• The separated solids and liquids are then discharged from the centrifuge through separate outlets.
• Decanter centrifuges are used in a wide range of industries, including chemical, pharmaceutical, food processing, and environmental engineering. 
• They are particularly useful for separating solids that are too fine or too dense to be effectively separated by other methods, such as sedimentation or filtration. 
• Decanter centrifuges are also used to dewater sludge and to separate emulsions. 
• They are known for their high efficiency, low maintenance requirements, and ability to handle large volumes of material.

Working Principle of Decanter Centrifuges

A decanter centrifuge operates on the idea of separation via buoyancy. A component with a greater density would naturally sink to the bottom of a combination, while a less dense component would float on top. Continuous spinning enhances the velocity of settling in a decanter centrifuge, creating a g-force comparable to between 1000 and 4000 G's. This drastically decreases the settling period of the components, so that mixtures that formerly required hours to settle can now be settled in a matter of seconds using a decanter centrifuge. This method of separation produces faster and more manageable outcomes.

A decanter is just a sedimentation tank wrapped around an axis. Solid particles that are heavier than liquid move to the bottom of the sedimentation tank by gravity and form a sediment (solid phase) at the bottom. A wine decanter, for example, can be thought of as a sediment vessel. The solid and liquid phases of a centrifuge are separated by centrifugal acceleration. The solid particles, which have a higher density and are hence heavier than the liquid, migrate outwards in the centrifuge's revolving bowl due to centrifugal force. The sediment forms on the inside of the centrifuge bowl's inner wall. The separation of solid particles from liquid is more faster and more efficient in a centrifuge because centrifugal forces of roughly 3000 g are applied instead of 1 g in a gravitational field.

Decanter-based separation of three phases

Using a 3 phase decanter centrifuge, it is feasible to separate three stages in a single operation. For instance, oil and water, which cannot be combined due to their differing densities, are separated from a solids phase. Between the layer of oil and the layer of solids, water gathers in the middle. Thus, the two liquids can be sucked from the decanter after being separated. As in 2-phase separation, the solids are conveyed via the scroll to the discharge holes.

Typical applications of three-phase separation include the manufacture of edible oils like olive oil, the processing of oil sludge, and the creation of biodiesel, among others.

Working Principle

The separation of fluid from the sludge occurs inside the rotating decanter bowl. One can explain the internal working as follows.

• Feed Introduction: The slurry is fed into the machine through an axial feed tube, injecting it into the conveyor. The tube conveys the slurry to the center of the conveyor feed chamber.
• Acceleration / Dispersal: The injected slurry strikes against an accelerator in the conveyor feed zone. This action accelerates the flow outward through the feed ports into the bowl, forming a 'pond.'
• Separation: The solids of higher density displace the liquid and settle to the bowl's wall. The conveyor continuously scrolls the solids up the angled conical part (beach).
• Auger Rotation: The bowl-mounted gearbox causes a differential rotation between the conveyor and the bowl.
• Sludge Discharge: The flights push the separated sludge up the bowl's conical part (beach). The solids exit the bowl through 360° discharge ports at the rear end.
• Fluid Discharge: The clarified liquid rises to the pond's surface and flows over the dams in the front bowl hub. At this point, the liquid discharges from the bowl.

Factors Affecting Performance

Certain decanter features have a direct impact on the performance of the decanter. These factors are adjustable for optimization.

• Decanter Bowl Speed: The bowl speed or RPM signifies the effective centrifugal force generated by the decanter. Depending on the fluid and type/density of solids, the centrifugal force is the key factor affecting performance.
• Auger or Conveyor Speed: The relative rotation of the auger versus the bowl relates to the speed at which the separated sludge is conveyed out of the bowl. High sludge content applications require a fast conveyor speed to maximize efficiency.
• Pond Depth: The thickness of the fluid layer formed around the bowl's inner wall is the pond depth. Deeper ponds lead to clearer centrate and wetter solids. Shallower ponds lead to dryer solids and murkier centrate.
  Weir plate adjustments allow pond depth changes. Example weir plates are shown below.
• Beach Angle: The angle of the conical part of the bowl is known as the beach angle. Varying the beach angle has a direct impact on the separated sludge dryness.
• Conveyor Pitch: The distance between the conveyor flights is the conveyor pitch. A shorter pitch enhances the decanter's solids' separation capacity and increases the torque on the gearbox.

 

Types of Decanters

Decanter centrifuges are available in 2 configurations, namely 2-phase and 3-phase. In other words, solid-liquid and solid, liquid, liquid separation.

2 Phase

The two phase-type is a solid-liquid separator. In other words, it separates the fed slurry into a solid phase and one liquid phase.

Most de-sludging duties use a two-phase design. These include industrial sludge thickening, municipal wastewater, hemp biomass separation, etc.

Tricanter is also known as Three-Phase Decanter.

A 3-phase type separates solids from 2 immiscible fluids. In other words, a 3-phase decanter centrifuge produces a solid phase and two separate liquid phases.

For example, a 3-phase configuration separates crude oil from tank bottom sludge and water. Olive oil separation from water and biomass is another example.

Explosion Proof

A decanter centrifuge with applications in hazardous or explosive environments needs special design considerations. The special-purpose centrifuges are referred to as Explosion Proof Decanters.

The NEC classification for these areas in the domestic market comes under the Class 1 Division 1 zones. Therefore, it is common to refer to these decanters as Class 1 Div 1 rated machines.

Environments where flammable gases, fluids, or dust are present require using explosion-proof decanters. Refiners, Offshore Oil Platforms, Mines, Chemical Plants Effluent, and similar locations mandate these classifications.

Our article about Explosion Proof Centrifuges provides detailed information about these centrifuge classifications for explosion-proof or hazardous areas.

Advantages

Decanters compete with other separation technologies such as filter presses, screw presses, etc.

Though all these different equipment has advantages, decanters have some specific benefits. These benefits are due to the decanter centrifuge being a mechanical separator.

All the other technologies use media separation, which has inherent drawbacks.

The following is a list of advantages of decanter centrifuges over filtration methods.

1. Process Adaptability:

Decanter centrifuges can easily handle product variations. They can produce consistent separation results even with varying flow rates. These centrifuges can handle process fluid mix variations without final product degradation.

2. Compact Dimensions:

Decanter centrifuges have a smaller footprint than belt and filter presses of similar capacity. This small size allows for the installation of decanters in small, confined spaces.

3. Vapor Tight Design:

The basic design of decanters includes a rotating bowl in an enclosed chamber. This design prevents odors, undesirable fumes, and gases from contaminating the operating space.

4. Low Labor Costs:

Fluid separation through a decanter is practically an automatic process. This process requires minimal manual attendance service, thereby reducing associated labor costs.

5. Reduced Operating Cost:

Since only worn parts are replaceable in decanter centrifuges, it minimizes long-term operating costs. Filter media need constant replacement in other separation methods.

6. Long Service Life:

Robust design and construction are primary features of decanter centrifuges. Besides, high-quality construction material helps decanters perform with reliability for extended periods. Replaceable wear parts such as sludge discharge ports enable long service life.

7. Easy and Quick Installation:

Decanter centrifuge systems are self-contained and are thus easy to install. The speed and ease of commissioning allow them to be productive quickly.

8. Wide Range of Particle Separation:

The decanter separates particle size range from 1 Micron to 15 mm or larger. This ability gives decanters a significant advantage over media filters with fixed apertures.

9. Three-Phase Separation:

Besides separating solids from liquids, three-phase decanters (tricanters) also separate immiscible liquids. This separation co-occurs with solids separation.

10. Easy Adjustments for Desired Separation Phase:

The decanter centrifuge user can adjust sludge dryness or centrate clarity quickly and easily. This ease of phase quality adjustment is an added benefit lacking in filtration equipment.
The installed weir plate controls the separated phase dryness by changing the pond depth.

Disadvantages

A decanter centrifuge has certain disadvantages when compared to other solid-liquid separation equipment. The following is a list of the main limitations.

1. Capital Expense:

Decanter centrifuges have a higher cost than filters and similar separation devices. Performance improvement and wear preventive options can further add to this cost.

2. Light Particle Separation

Centrifuges leverage the difference in specific gravities between solids and liquids to separate. When the solids (such as biological cells) have a specific gravity close to the liquid's, the decanter cannot separate them.

3. Power Requirement:

Large horsepower motors power decanter centrifuges. Compared to filtration machines, these drive motors need a higher operating current.

4. Noise and Vibration:

Decanter centrifuges have heavy rotating bowls, and other rotation of heavy masses causes vibrations that lead to noise. These decanters create noise levels in the 70-80 dB(A) range.

Details

Reference standard                                                                                                                                                          

Technical parameter

Name	Unit	Parameter
Model	LWM760	LWM760*3040-N
Capacity	M3/h	10-160M3/H
Solid content	%	0.5~20
Design Rotation speed	r/min	2260Variable frequency speed regulation
Working rotation speed	r/min	2000Variable frequency speed regulation
Max Separation factor	G	2060/Variable frequency speed regulation
Drum diameter	Mm	760
Drum length	mm	3040
Slag outlet		Wear-resistant ceramic or hard alloy
Mud scraping position of spiral blade		Surface spray welding tungsten carbide protective coating
Drum		AISI304/316 stainless steel/2205/2507Duplex steel
Screw		AISI304/316 stainless steel/2205/2507Duplex steel
Hood		AISI304stainless steel
Feed pipe, Drainage and slag discharge pipe		AISI304stainless steel
Machine base		High Quality Carbon Steel
Screw Torque	Nm	25000
Differential speed	Rpm	45-80/Stepless adjustable
Differential adjustment accuracy value	Rpm	≤1
Noise	dB(A)	90
vibration	mm/S	7.1
Motor power	KW	185(380/3/50HZ)
explosion protection level		EEx e II T3
Rated voltage	V	600
Protection class	IP	56
Insulation class		F
Frequency conversion electric control cabinet	760	ZK1

Model	Diameter(mm)	Lenght(mm)	Max speed	L/D ratio	G-force	Capacity(m3/h)	Main motor power(Kw)	Weight(kg)	Dimension(mm)
LW250*1000	250	1000	5000	4	2722	0.5-5	7.5	950	2120*1250*680
LW300*900	300	900	4200	3	2964	1-6	11	1160	2150*1300*900
LW300*1200	300	1200	4000	4	2784	2-6	11	1350	2450*1300*900
LW355*1160	355	1160	3600	3.3	2576	2-8	15	1400	2470*1350*830
LW355*1460	355	1460	3600	4	2576	2-10	15	1800	2750*1350*830
LW400*1200	400	1200	3200	3	2294	3-12	18.5	1800	2730*1600*1080
LW400*1600	400	1600	3000	4	2016	3-15	22	2000	3130*1600*1080
LW450*1800	450	1800	2800	4	1976	4-25	37	2500	3320*1700*1130
LW500*2000	500	2000	2800	4	1750	5-35	45	4000	3520*1800*1170
LW530*1855	530	1855	2600	3.5	2006	5-38	55	4680	3885*1350*1600
LW530*2120	530	2120	2400	4	1709	5-40	55	4800	4150*1350*1600
LW550*2000	550	2200	2800	4	2414	6-40	55	5700	4570*1380*1600
LW650*1950	650	1950	2200	3	1761	6-45	75	5000	4840*1510*1720
LW650*2600	650	2600	2000	4	1456	6-65	90	6000	5490-1510*1720
LW720*2160	720	2160	2000	3	1612	7-80	120	6000	5200*1600*1800
LW720*2880	720	2880	2000	4	1306	7-90	120	8000	3100*1600*1800
LW800*2400	800	2400	1800	3	1451	20-100	150	12000	5820*2000*1300
LW800*3200	800	3200	1800	4	1451	20-120	150	13000	7100*2000*1300

 If you want to know more please contact me:Cathy 

 

Application
1. Industrial and municipal wastewater treatment
2. Oil&gas drilling mud/fluid control
3. Washing, separation and dewater of starch
4. Mycelium and zymtotic fluid separation for antibiotic
5. Dewatering of soybean and wheat protein
6. Dewatering of fish power and fish meat
7. Dewatering of vinasse
8. Clarification and extraction of fruit juice
9. Separation and purification for animal and vegetable oil
10. Production and purification of olive oil, palm oil, avcado oil
11. Separation and purification for coal tar
12. Grading of kaolin and grapgite
13. Grading and dewatering of dyestuff and pigment
14. Froth flotation for cleaned coal and dewatering of coal mud
15. Grading and dewatering of minerals working principle

Sizing

A decanter centrifuge comes in different designs and sizes. For optimum process efficiency, sizing is a critical parameter in selection.

A machine rated 100 gallons/minute of wastewater will likely process 20 gallons/minute of thick waste oil. Therefore, the user should carefully consider the process-fluid properties and decanter design features to size a proper decanter for each process.

Other design features such as auger pitch, beach cone angle, gearbox ratio, bowl speed, and auger speed significantly affect decanter sizing. Consulting an experienced centrifuge company with extensive application history is highly desirable and recommended.

Equipment Cost

Decanter centrifuges are capital equipment based on their expected operating life and durability. Their price depends on the manufacturer and size/capacity.

A new machine (from a quality, established manufacturer) starts from around $50K for a small capacity unit to over $1M  for a large capacity machine. Accessories such as explosion-proof upgrades, control systems, pumps, etc., are optional and add to the cost.

Remanufactured models range from 40% to 60% compared to new models of similar capacity.

Operating Costs

Decanter centrifuge operating costs can be categorized as follows.

Power Consumption

The only power-consuming component of these centrifuges is the motors. Consider the following example:

Your cost per kWh: 25 ¢
Capacity:  5 GPM
Volume processed per hour: 300 Gallons
Cost per gallon processed: 25 ¢ / 300 = 0.08 ¢

Spare Parts

The availability of spare parts is an important consideration for the longer-term operating costs.

For 'no-name' decanters, the buyer wholly depends overseas on a single source manufacturer. Stock, availability & part cost are essential considerations for critical equipment.

On the other hand, generic spare parts are readily available for established, brand-name manufacturers. The manufacturers themselves have parts stock worldwide for quick delivery.

Labor

Decanter centrifuges are continuous processing, self-contained machines, which means there are no operating labor costs involved. Only service and maintenance require labor.

Chemical Use

Specific processes need chemicals to aid separation, an extra cost the buyer should consider.

Maintenance & Service

Decanters from high-quality manufacturers are generally very reliable. As long as the user maintains them per the manufacturer's recommendation, they provide reliable service.

Ongoing maintenance involves periodic gearbox oil changes and bearing lubrication. The primary service involving bearing replacement is every few years, depending on the severity of use.

Processes involving abrasive solids, such as drilling mud, will need scroll or screw rebuild based on wear rate.

Company Profile

Liaoyang Shenzhou Machinery Equipment Co., Ltd. belongs to SHENZHOU Group. We are the professional manufacturer of Centrifuge & Separator, Liquid Filling Machine and packing machine. With many years producing experience, our factory have become leading manufacturer with professional technical team and Independent after-sale department.

Our international trade department can supply the whole project service. With many years development, we have known which factories have strong product with competitive price and we have built long-term and stable cooperation relationship with them. Our main area are the food and pharmacy project. Our successful project are coconut oil production line, liquid filling production line, packing production line and the tablet press production line, soft gelatin production line and so on. Our aim is providing you efficiently solution and superior after-service. We sincerely hope YOU are our next customers! Exported country: At present, our products have been exported to South Korea, India, Denmark, Russia, Georgia, Jordan, Bangladeshi, Tailand, Ethiopia, Finland, the United States, Canada, Australia, Spain, Japan, Colombia, Romania and so on more than 30 countries

Packing & Delivery

1.Parking:standard wooden box
2.Spare parts :we supply some parts and accessories for free.
3.Electronic module:it is made up of electronic control cabinet.
4.Special tools:we supply a set special tools for free.
 

FAQ

What are the uses of a decanter centrifuge?

Decanter centrifuges include thickening of wastewater sludge, separation of solids from crude oil, sewage treatment, chemical precipitate concentration, fish meal separation, separation of carbon black, grease trap waste de-sludging, etc.

What are the phases separated by a decanter centrifuge?

A decanter centrifuge separates the solids or sludge from liquids. The separated sludge is also known as the cake. The clarified liquid phase discharged from the decanter is known as the centrate.

What is the difference between a wine decanter and centrifugal decanter?

A wine decanter is used to separate or settle out the sediment from wine using gravity. A centrifugal decanter uses rotation to magnify the force of gravity thousands of times to separate sediment from liquids for industrial uses.

What is the typical centrifugal force generated by a decanter centrifuge?

A decanter centrifuge generates over 3,000 times the force of gravity. Smaller decanters rotate at a higher RPM than larger diameter decanters, but the effective centrifugal force is similar.

Are decanter centrifuges nosiy?

Decanter centrifuges are rotating devices and therefore generate noise during operation. The typical noise level of an operational decanter is in the 70 to 80 dB(A) sound level.

Can the sludge dryness of a decanter centrifuge be adjusted?

The dryness of the sludge separated by a decanter centrifuge is adjustable by changing some of the settings of the decanter. For example, by reducing the liquid pond depth, a user may get dryer separated sludge.

What are the main parts of a decanter that are subject to excessive wear?

The sludge conveyor and sludge discharge ports are the main parts of a decanter that are subject to wear in a decanter centrifuge. The wear is due to the constant movement of abrasive particles across the surface of these parts.

New versus Remanufactured

New machines from branded manufacturers like SHENZHOU is the first choice. However, given the cost of new models, buyers often seek remanufactured decanters from trusted and established companies.

Important considerations before buying a remanufactured decanter centrifuge

• Manufacturer of the original centrifuge.
• Credentials & experience of the re-manufacturer.
• Previous use.
• Wear status of the bowl and conveyor.
• Parts used in the rebuild - especially bearings.
• Balancing of major rotating components.
• Vibration check and complete testing of the centrifuge assembly per OEM specifications.

We have condensed 35 years of our centrifuge specialty into a 9 Step Guide to Selecting Your Perfect Industrial Centrifuge.

Decanter centrifuges are perfect for separating liquids from high amounts of solids. Realistically, they can continuously separate over 50% (v/v) solids from liquids. Decanter centrifuges can produce up to 4000 g's of centrifugal force, sufficient to separate particles down to 50µ.

The following are some of the industries using our remanufactured decanters.

• Crude Oil Tank Bottoms
• Oilfield Drilling Mud
• Waste Oil De-Sludging
• Hemp Biomass Solvent Extraction
• Industrial Wastewater
• Municipal Sludge Dewatering
• Fish Meal Stick-water
• WVO De-Sludging
• Paint Industry Wastewater
• Rendering Plants Sludge Thickening
• Food Industry Waste Streams