LW screw discharge decanter centrifuge

Overview

LW Screw discharge decanter centrifuge is a series of internationally advanced centrifuge products independently developed by our factory on the basis of introducing and digesting foreign advanced technology. The method is mainly apply to that field of 'solid-liquid' two-phase and 'solid-liquid-liquid' three-phase separation in similar production processes such as urban domestic wastewater, tap wat, industrial wastewater, chemical industry, food, pharmacy, fly ash slurry, tobacco leaf reprocessing, metal and nonmetal ore dressing and the like.

Structure

LW spiral discharge sedimentation centrifuge is mainly composed of main motor, auxiliary motor, differential, spiral body, drum, main bearing, base, cover and transmission device.

Working Principle

The suspension enters the rotary drum from the discharge port of the spiral body through the feed pipe, solid phase particles with larger specific gravity are deposited on the inner wall of the rotary drum under the action of centrifugal force generated by high-speed rotation, and the spiral blades moving relative to the rotary drum continuously scrape off the solid phase particles deposited on the inner wall of the rotary drum and push the particles out of the slag discharge port. The separated clear liquid overflows out of the rotary drum through the opening of the liquid layer adjusting plate. The relative motion between the spiral body and the rotary drum (namely the differential speed) is realized by the differential gear, and the size of the differential gear is controlled by the auxiliary motor, so that the continuous separation process of materials by the centrifuge is realized.

1. Differential; 2. Supernatant Inlet and Outlet; 3. Supernatant; 4. Screw Rotor; 5. Solids Settling on the Inner Wall of the Bowl; 6. Solid Dewatering Zone; 7. Solids Discharge Outlet; 8. Hollow Main Shaft with Built‑in Feed Pipe

Product Characteristics

1. Strong adaptability:

• various special requirements of materials and processes for centrifuges are fully considered in the design, and the main functional components are optimized in terms of specificity and adjustability. As long as the user explains the place of installation and use, the physical and chemical characteristics of the materials handled, and the process requirements before purchasing the machine, we will provide the user with the most suitable model.

2. Long service life

The centrifuge drum, spiral body, hood and other parts in contact with materials are made of high-quality stainless steel, with sufficient acid and alkali resistance, to ensure the service life of the machine.

3. Beautiful appearance

The base of this machine adopts steel plate welding structure, and the surface is treated by special process, which is smooth, light, generous and beautiful, giving people a sense of overall beauty.

4. Operation safety: 

The operating parts shall be protected by safety covers. Torque protection, power control, vibration and temperature protection can be selected as required, which can effectively eliminate or reduce the damage caused by sudden failure to the machine.

5. Good operating environment: 

The centrifuge separates the materials in a completely closed condition to ensure that the operation site is clean and pollution-free, and to keep the production environment clean and sanitary.

6. Energy and power saving, strong manufacturability

The centrifuge adopts double motor and double frequency conversion energy feedback differential speed system, which can carry out flexible stepless adjustment and online intelligent control of differential speed, and can adjust the differential speed at any time according to the change of materials.

7. Easy operation and high degree of automation

The feeding, separation, unloading and other processes of the centrifuge are continuously and automatically carried out under high-speed operation. The automatic control of centrifugal separation and centrifugal washing process can be realized by using programmable controller.

8. Special inclined plate spiral design

It can effectively double the settlement area and accelerate the settlement speed.

• Greatly improve the clarity of the clear liquid and effectively reduce the solid content of the clear liquid.
• The length-diameter ratio of the centrifuge is relatively increased to improve the processing capacity.
• Under the same treatment effect, it can reduce the length-diameter ratio, greatly improve the rigidity of the centrifuge, reduce the volume of the machine, and make the centrifuge run more reliably and smoothly.

9. Unique vortex feed inlet design

The vortex structure is adopted to accelerate the material to enter the rotary drum, shorten the contact distance between the material and the liquid pool, reduce the disturbance of the separated solid phase caused by the feed, improve the processing capacity, and avoid the blockage in the spiral body and the locking of the feed pipe. The tungsten carbide hard alloy is overlaid at the material outlet, thereby prolonging the service life of the spiral body.
 

1. Buffer Plate; 2.Material; 3. Solid Phase; 4. Large Cone Angle; 5. Liquid Phase 

10. Reasonable length-diameter ratio

Large length-diameter ratio can increase the settling area of the material, extend the residence time of the material in the drum, and improve the solid removal rate, which is the goal of the centrifuge.

11. Large Cone Angle

The advantages of the large cone angle drum structure are as follows: the extrusion force of the spiral body on the filter cake is enhanced, the solid content of the filter cake is improved, and the filter cake is drier, the liquid is clearer and the operation is more economical under the same separation factor.

12. Buffer plate structure

The buffer plate structure spiral body is an internationally advanced technology for municipal sludge dewatering, organically combines the centrifugal technology and the extrusion technology, and has the following characteristics:

• The depth of the liquid pool is deep, and the clarification section of the rotary drum is longer.
• The liquid is clearer.
• The organic sludge can be further compressed to make the mud cake drier.
• The dosage of flocculant is reduced.

13. The key parts are designed with hard alloy and drum anti-wear technology.

Have a variety of anti-wear technology, such as tungsten carbide coating, tungsten carbide surfacing, hard

The wear-resistant technology of our factory has reached the international advanced level and is in the leading position in China, which greatly improves the stability and reliability of the machine. The thrust face adopts carbide insert technology, which can increase the service life by more than five times.

The inner wall of the drum body adopts an anti-wear strip structure, which effectively prevents the inner wall of the drum from being worn and is beneficial to better pushing out the slag.

14. Replaceable 360 ° opening

Slag discharge port of semicircular wear-resistant tungsten carbide hard alloy til.

15. Double-motor double-frequency conversion common DC bus control model

• The main and auxiliary motors of the centrifuge are driven by a frequency converter respectively, and the auxiliary motor is always in the generator state under the action of the drum differential. Due to the use of the dual-motor dual-frequency common DC bus drive mode, the electric energy generated by the auxiliary motor can be reasonably utilized, and the energy recovery problem can be better solved.
• Dual-motor dual-frequency common DC bus drive mode has wider adjustment range, realizes stepless adjustment of speed and differential, adapts to the occasion where process parameters often change, and has incomparable advantages over other control modes.

Control schematic diagram of dual-moto

Three-phase Power Supply; 2. Main Frequency Converter; 3. DC Bus; 4. Auxiliary VFD; 5. Energy Feedback; 6. Generator Mode

16. Automatic control system with PLC and touch screen

This control system adopts programmable logic controller (PLC) as the core, color LCD touch screen as the human-machine interface, centrifuge adopts double motor and double frequency conversion control, and high-performance vector frequency converter forms energy feedback drive. The operation and setting of all the equipment of the dehydration unit are completed on the touch screen. At the same time, the fault can be eliminated on the spot according to the information displayed on the touch screen, and it can be connected with DSC through the field bus.
The system adapts to the change of material concentration and flow through two control modes of constant torque and constant differential speed, improves the adaptability of the centrifuge to the production process, ensures good separation effect and stable operation state, and is a control system with simple operation and complete functions.

Technical Parameters