LW series Horizontal screw discharge sedimentation centrifuge

Product Overview

Description

LW series Horizontal screw discharge

sedimentation centrifuge

(1)  Overview of discharge sedimentation horizontal screw centrifuge

 

 

 The structure principle of discharge sedimentation horizontal screw centrifuge is that the discharge screw with eye center is set in the non hole drum. Both rotate in the same direction at high speed, but there is a certain speed difference, which is generated by the transmission system and differential. The suspension enters the inner cavity of the conveying screw through the feeding pipe. Under the action of centrifugal force, the dense solid particles settle to the inner wall of the drum to form a sediment ring layer, which is pushed to the small end of the drum by the unloading screw and discharged out of the drum. The clarified liquid is continuously discharged from the overflow port of the large end of the drum, so as to realize the solid-liquid separation of the suspension.

The performance characteristics of horizontal screw discharge centrifuge can feed, separate and discharge continuously at full speed. It has the characteristics of compact structure, easy airtight, stable operation, small noise, large processing capacity, low energy consumption, high degree of automation, low labor intensity, convenient operation and maintenance, and wide application range.

The horizontal screw discharge sedimentation centrifuge is suitable for solid-phase dehydration, liquid-phase clarification and separation, liquid-liquid-solid three-phase separation and particle classification of all kinds of suspensions with solid particle size of o005-15mm, concentration of 1-40% and temperature ≤ 100 ℃. It is especially suitable for the separation of particles with large change in concentration and suspension. Such as PVC resin, ammonium sulfite, barium carbonate, strontium sulfate, lithopone, starch, diatomite, gypsum, bauxite, soybean protein, peanut protein, juice, beverage, vegetable oil, citric acid, blood powder, titanium dioxide, kaolin Drilling mud and other processing and clean coal dehydration, fine coal dehydration, waste oil distiller's grains waste liquid, mineral classification treatment, municipal sewage treatment, power plant sludge printing and dyeing sludge, papermaking sludge and other industrial wastewater treatment fields. 

 

(2)  Model establishment method of discharge sedimentation horizontal screw centrifuge

 

Main parameters: basic code names: horizontal screw discharge sedimentation centrifuge: decanter centrifuge: three phase discharge sedimentation centrifuge: drum's nominal diameter × drum's valid active length Characteristic code of the horizontal decanter centrifuge counter flow (not marked) parallel flow three phase separate type

  

(3)  What are the main models and technical parameters of discharge sedimentation horizontal screw centrifuge

he main product models and technical parameters of discharge sedimentation horizontal screw centrifuge are: specifications processing capacity: drum's nominal diameter main motor power: power of main motor effective working length: drum's vaild active length weight: high speed: drum Speed: length  width  height

 

(4) Main technical features of discharge sedimentation horizontal screw centrifuge

 

1. The design and manufacture of discharge sedimentation decanter centrifuge are in accordance with JB /T502-2004 screw discharge sedimentation centrifuge and JB8525-1997 centrifuge safety requirements. High speed, high separation factor, large aspect ratio. When the diameter of the drum is less than 530mm, the separation speed is generally over 3000r / min, the separation factor is more than 2500, and the ratio of length to diameter can reach 5. The high speed of lw250x1000-n centrifuge is 5400r / min and the separation factor is 4000.

2. High processing capacity of single machine. The horizontal spiral discharge sedimentation series centrifuges with diameters of 250, 300, 355, 400, 450, 500, 530, 580, 650, 760, 900 (mm) are all designed according to the new fluid theory and referring to the foreign relatively new structures, with large processing capacity and good separation effect.

3. Small vibration, low noise and strong bearing capacity. The main bearings of this series of centrifuges are imported bearings with high bearing accuracy and strong bearing capacity. The parts are manufactured with high precision. The whole machine is balanced by double rotors to ensure the stability and reliability of high-speed operation. The centrifuge has low vibration and noise, and its performance is better than the requirements of national standard.

4. It has multiple protection devices and reliable operation. This series of centrifuges are generally equipped with differential overload protection or moment limiting coupling and other protection devices. According to the needs, it can also be equipped with safety protection devices such as vibration protection, temperature monitoring and protection, feed regulation, etc., to protect the whole machine through automatic alarm and forced shutdown.

 

5. The differential system is reliable. The differential of this series centrifuge generally adopts planetary gear or cycloidal pin wheel differential. According to the need, it can also be equipped with full hydraulic differential system. Mechanical differential generally adopts domestic famous brands, and hydraulic differential system adopts imported brands. The differential has high manufacturing precision, good performance and reliable operation.

 

6. Anti corrosion and wear resistance of key parts. In general, the key parts such as the screw pushing surface, the feeding distribution part of the spiral body and the slag outlet of the drum are generally spray welded or overlaid with cemented carbide wear-resistant layer. For special purpose centrifuges, the inlaid cemented carbide wear-resistant block or the wear-resistant sleeve or the wear-resistant ceramic plate are used, which has the advantages of corrosion resistance, wear resistance and long service life.

 

7. It has a variety of driving and speed regulating modes. According to different requirements, the corresponding driving, differential and speed regulating modes can be selected to adjust the rotating speed and differential speed of the drum, so as to achieve better separation effect and adapt to various separation occasions.

 

8. Good sealing and explosion-proof performance. For inflammable, explosive and other special separation occasions, there are special design and manufacture of sealing and flame-proof models for selection, and the sealing and explosion-proof performance is good, safe and reliable. The service life of mechanical seal is 8000 hours, and that of air seal is over 15000 hours.

 

9. The electrical control system is advanced and reliable. Electrical control system has common type, explosion-proof type, microcomputer automatic control and other forms. The CDs central control system can also be used for remote monitoring and automatic operation according to the needs. The electrical control system adopts domestic famous brands or imported components with reliable performance.

 

10. Excellent material selection. The parts in contact with materials of this series of centrifuges are generally made of high-quality high-strength austenitic stainless steel or duplex stainless steel, with sufficient strength and superior corrosion resistance. 

 

(5)  Typical structure of discharge sedimentation horizontal screw centrifuge

 

After the countercurrent mixture enters the drum, the clarifier and sediment move in reverse direction and flow to their respective outlets respectively. The counter current type is a standard model, suitable for most separation occasions. After the mixed liquid enters into the drum, the clarifier and the sediment move in the same direction during separation. After separation, the clarified liquid flows back through the skimming pipe to avoid the sediment scouring by the feed liquid. The parallel flow structure is more suitable for separation of low concentration and difficult separation materials.

Three phase separation two kinds of liquid phase and one kind of solid phase with density difference enter into the drum, under the action of centrifugal force, the solid phase will settle and two kinds of liquid phase will appear stratification, so as to realize liquid-liquid-solid three-phase separation, which is suitable for liquid-liquid-solid three-phase separation with density difference.

  

 (6)  The driving and speed regulating methods of the decanter centrifuge are as follows

 

The input shaft of the differential driven by single speed motor is fixed. By changing the pulley, the speed of the drum and the differential speed are adjusted respectively. This speed regulation mode is suitable for material separation with stable process. Two frequency converters are used to control the driving of main and auxiliary motors respectively. The double frequency converter is used to control the driving of main and auxiliary motors, and the speed and differential speed of the drum are adjusted respectively. The main motor drives the drum and the hydraulic motor is used to adjust the differential speed. The speed of drum driven by main motor is adjusted by frequency converter, and differential speed is changed by hydraulic motor. The relationship between various rotational speeds of discharge sedimentation horizontal screw centrifuge and the difference speed between the rotating drum speed and the discharge screw speed: nrotation = N1 x I1 n rotating drum speed r / min N1 - main motor speed (the main motor speed is read by the main motor name plate or adjusted by frequency conversion speed regulation) R / min I1 the transmission ratio between the main motor and the drum pulley drive, and the differential speed between the drum and the discharge screw: n = (N1) X i1-n2 x I2) / I difference  n - differential speed between drum and discharge screw R / min I difference - fixed transmission ratio of differential mechanism N2 - speed of auxiliary motor (the speed of auxiliary motor is read from the name plate of auxiliary motor or adjusted by frequency conversion speed regulation) R / min I2 the transmission ratio between auxiliary motor and differential belt pulley When hydraulic motor or full hydraulic differential device is used, the speed of unloading screw is directly regulated by hydraulic motor or hydraulic differential device, and the differential speed between drum and discharge screw is the output speed of hydraulic motor.

 

(7)  Decomposition of key parts in discharge settling horizontal screw centrifuge

The discharge screw with eye center is set in the non hole drum. While the two rotate in the same direction at high speed, there is a certain speed difference, which is generated by the transmission system and differential. The suspension enters the inner cavity of the conveying screw through the feeding pipe. Under the action of centrifugal force, the dense solid particles settle to the inner wall of the drum to form a sediment ring layer, which is pushed to the small end of the drum by the unloading screw and discharged out of the drum. The clarified liquid is continuously discharged from the overflow port of the large end of the drum, so as to realize the solid-liquid separation of the suspension.

     

        drum

        Discharge screw

        Hydraulic pump station

   

        Gear differential

        

        Spray welding hard alloy wear resistant layer

    

        End cap

 

(8)    Application conditions and adaptability adjustment of discharge sedimentation horizontal screw centrifuge

 

The basic conditions of the centrifuge are as follows

The separated material is a mixture of solid and liquid, such as suspension, which is not emulsion. There must be a density difference of more than 0.06g/cm3 between the phases of suspension or mixture

The results show that the concentration of the suspension is 1-40%; the solid particles are 0.005-15 mm; the operating temperature of the separation process is less than or equal to 100 ℃; the proper viscosity; separation purposes: solid-phase dehydration, liquid-phase clarification and separation; liquid-liquid-solid three-phase separation; particle size classification. Different separation materials have different separation characteristics. Even for the same separation material, different process methods and working conditions also have different separation characteristics. The quality of separation material directly affects the separation effect and processing capacity of centrifuge. Settlement velocity is a very important index to measure the separation characteristics, which plays a decisive role in settlement separation. The settling velocity mainly depends on the particle size, particle shape, density difference between solid and liquid and their viscosity. Then, the settling speed can be adjusted and improved by the following measures: adjusting the working temperature to improve the viscosity and increase the density difference between liquid and solid; adding flocculant to coagulate particles, increase the size of solid particles and change the shape of solid particles. In view of some difficult separation materials, in addition to the corresponding adjustment measures for the separated materials, the corresponding adjustment and improvement can be made to the centrifuge: increase the length diameter ratio, adjust the rotating speed of the drum, and adjust the differential speed between the drum and the discharge screw

Adjusting overflow radius of liquid phase outlet by changing half cone angle of drum

Change the screw head number and helix angle of discharge screw

To adjust the technical parameters of horizontal screw centrifuge by adding BD plate structure and improve the relevant parts, except that the separation speed, differential speed and overflow radius of liquid phase outlet can be adjusted in a small range at the separation site, the rest must be determined before the production of centrifuge products. In addition, according to the different corrosivity of the separated substance, the materials with different anti-corrosion ability are matched with it. Therefore, when the customer inquires, please give the characteristic parameters, working conditions and separation requirements of separation materials in detail. Note: separation factor is a characteristic parameter of centrifuge, which refers to the ratio of centrifugal force and gravity of separated materials in centrifugal force field. Generally, the greater the separation factor, the better the separation effect. The formula for calculating the separation factor FR is: FR = M.R. ω 2 / g = R. ω 2 / g ≈ 1.12r.n2.10-3 where n is the rotating speed of the drum and R is the turning radius of the drum, the unit is m