Thickening System (THICKENING SYSTEM)
The thickening system is located after the fine screening system of the pulp line.According to different working conditions and purposes,the thickening system can be divided into washing,thickening and white water recovery of pulp. (THICKENING SYSTEM)
The design of the thickener should consider the following factors according to different applications:
- Raw materials-type,characteristics,quality.
- Output-T/D.
- Concentration——Into the pulp concentration,out of the pulp concentration.
- PH value of water-acidic or alkaline.
- Chemicals used.
- Impurities in raw materials.
- Structural material-anti-corrosion,anti-weathering,anti- acid,wear resistant.
- Size of space.
- Location,location of the paper mill.
- Power requirements.
- Finished paper/fiber separation degree,cleanliness.
Disc Filter(THICKENING SYSTEM)
Main Purpose
Disc filter is an integral part of the pulp preparation series,which is mainly used in:
a.White water generated during papermaking in the paper machine is recovered.
b.Washing and concentration of low-concentration pulp in the pulping process.
Using this machine can not only obtain good economic benefits,but also produce good social benefits.(THICKENING SYSTEM)
Working Principle
This type of equipment utilizes the gravity of the pulp water and the relative vacuum in the middle of the filter disc to produce negative pressure.The pulp is adsorbed on thefilter disc.When the filter disc rotates above the discharge tank, the spraying water of the pulp stripping is washed at a certain angle.The filter disc makes the pulp detach from the filter disc,and falls into the discharge tank,and then conveyed to the next processby the discharge screw device.
Advantages of being used as white water recovery machine:
- Stable operation,high fiber recovery,up to 90-95%.
- Stable filtration,low ppm concentration.
- High quality filtrate and ultra clean filtrate are obtained.
- The maintenance is simple,the maintenance cost is low,and the operation efficiency is high.
- Water is closed and recycled to reduce water consumption,fiber loss,white water pollution and water resources.(THICKENING SYSTEM)
Advantages as a thickener:
- The applicable range of pulp concentration is 0.5~1.5%,an
- The clear filtrate is recycled to reduce the amount of water.
- Simple fan-shaped structure,filter area and output.
- Can be adjusted.
- Efficient dehydration to obtaineficient production capacity;under the same diameter and length,the filtering (concentration)area is larger than that of vacuum pulp washer or gravity rotary screen thickener.
Compact structure,small fotprint,large processing capacity,high degree of automation,low energy consumption, strong process adaptability. (THICKENING SYSTEM)
Performance characteristics
Main Purpose
The filter plate can be stirred during operation,and the pulp concentration range of the equipment is wide,which can ensure the normal operation of the equipment for a long time.
The larger pressure difference also makes the pulp layer form faster,thicker and stronger.
The production capacity can be adjusted by increasing or decreasing the number of filter discs.
The filtrate can be used in different process systems(concentration and white water recovery) according to different zones.
Stainless steel structure makes the equipment can withstand weak acid and alkali working environment;the distribution valve uses wear-resistant materials,reliable performance and long life Sector plate structure is flexible, easy to disassemble,easy to repair and replace.
The height of the water leg cannot be less than 7 meters,which requires the height of the workshop building. (THICKENING SYSTEM)
DT multi-disc thickener/DS multi-disc filter
Performance characteristics:
The hollow main shaft is 18-sided,each group of 18 filter discs is fixed on the hollow shaft by bolts.
There are two kinds of diameter 3500mm/4500mm.
CDI4200mm multi disc filterCDI multi-disc filter is mainly used for pulp concentration in the pulping process.The adaptation range of the pulp concentration is large,and the pulp concentration can reach 8%-12%.The clear filtrate is recycled to reduce the amount of water.
CDI Multi-Disc Advantages
The rotor adopts hollow-out hexagonal structure,with 12 fan-shaped filter discs in each group;it can self-stir the pulp to prevent the fiber from settling,reduce the sensitivity of the equipment to the pulp concentration,and improve the production efficiency.
The dehydration effect is good,the pulp layer is thick,and the output is large,avoiding the accumulation of concentrated pulp,eliminating the rot pulp area,and improving the pulp concentration quality.
There is no collecting trough device between the filter discs,which shortens the filter disc spacing and saves the installation space of the equipment.
The pulp stripping device is designed at the positiondirectly above the filter disc,and the pulp concentration and stripping effect are improved by delaying the pulp stripping time. (THICKENING SYSTEM)
Difference from the old
Compared with traditional multi disk,CDI multi disk has the following advantages:
The rotor is used instead of the central shaft.When the rotor is running in the tank,it acts like an agitator. In this way,the pulp with relatively high degree of freedom can be handled,and the pulp will not be blocked in the tank.
Open design rotor pulp processing capacity is high, minimum space requirements,low maintenance cost and reliable operation.
There is a discharge tank between the filter plates,and the pulp cake falls directly into the discharge tank,so the pulp will not be blocked in the tank.What’s more, without pulp blocking in the discharge chute,the fan will not be damaged,and other parts will not be damaged.
VDF5200 multi disc filter
VDF multi-disc filters are mostly used for white water recovery.Normally,the concentration of white water is low,and it is not easy to form a good fiber filter layer on the fan blade.It is necessary to add long fiber pulp and white water to the white water to improve the pulp entering the multi-disc Material concentration in order to form a good filter layer on the net and help filter white water.
Difference from the old
Compared with traditional multi disk,VDF multi disk has the following advantages:
The rotor is used instead of the central shaft.When the rotor is running in the tank,it acts like an agitator.In this way,the pulp with relatively high degree of freedom can be handled,and the pulp will not be blocked in the tank.
Each filter disc is composed of 20 leaves,which are covered with a filter screen.The filter screen is made of polyester.It has the advantages of good heat shrinkage and long service life.
The fan piece is installed on the fan piece bracket and connected with the central axis,instead of the fan piece directly connected with the central axis.This unique design,when the fan screen is worn,damaged or blocked, and the fan must be replaced,the operator can easily remove the fan for replacement,so as to facilitate the maintenance and repair of the fan.
Disc Thickener(THICKENING SYSTEM)
It is used for washing and concentration of low consistency pulp in pulp and paper industry;the feed concentration is 0.5-1.5%;the output concentration is 3-4%. (THICKENING SYSTEM)
Working Principle
The pulp with a concentration of 0.5-1.5%enters the thickener from the feed pipe and uses the pulp outside the filter disc Perform gravity dehydration with the difference of white water level in the filter plate.With the rotation of the filter disc,a part of the concentrated pulp flows to the pulp discharge position,enters the pulp discharge tank after overflow,and the other part of the pulp follows the filter disc during the water filtration process.When the filter disc turns out of the liquid surface,The pulp on the mesh surface loses its adhesion,peels off from the filter plate under the pressure of water,and then enters the pulp trough after overflowing.The pulp concentration is about 3-4%.The pulp concentration and production capacity can beadjusted by the spindle speed.
Performance Characteristics
Disc design.
The transmission is variable speed.
Omnidirectional swing sprinkler.
Low power requirements.
No need for vacuum water legs,low installation height.
The filter surface is composed of several groups of filter discs,with large effective area,which can filter a large amount of white water during operation.Under the same
The combined disc filter drum greatly increases the filtering area,has high production efficiency,low energy consumption per unit output and small floor area.
It adopts stainless steel mesh filter disc,which has firm and durable structure,convenient installation and disassembly,and good corrosion resistance.
Reasonable cleaning and peeling structure, the filter screen is not easy to block,and has strong dehydration capacity.
The concentration of the filtered white water is lower than that of the rotary screen thickener.
Single screw Press
Main Purpose
Used for dewatering and concentration of various pulps.Using the effect of mechanical pressure,under high concentration and high pressure,the pulp is compressed and dehydrated to achieve the function of extracting black liquor or concentrating the pulp.The pulp concentration is 9-12%,and the pulp concentration is 28-32%.It can be used in series with oblique spiral concentrator or multi-disc filter to achieve the required concentration of heat dispersion,and is the key equipment of heat dispersion system.(THICKENING SYSTEM)
Working Principle
The screw extruder is essentially a conveying screw that rotates in the screen cylinder.As the volume between the spiral piece and the screen cylinder gradually decreases,the pulp is forced to discharge water (liquid)through the screen plate due to the gradual increase in pressure,leaving the fibers behind.
The friction between the pulp and the screen cylinder is greater than the friction between the pulp and the spiral. In this way,the pulp can be prevented from rotating together with the screw,so that the screw can force the pulp to the outlet.
When the dewatered pulp enters the discharge bin from the screening section,its pressure control,concentration and flow stability are very important.To achieve this,the back pressure system restricts the pulp to form a “paste plug”at the end of the spiral.(THICKENING SYSTEM)
In addition,the screw shaft is equipped with a sieve plate in this area to dehydrate inward.A high-density material plug is formed at the front of the spiral blade,and is pressed in the direction of the screen cylinder in the screen cylinder.The screen hole is tapered and the pulp side is slightly smaller,which can avoid fiber accumulation and blockage of the screen hole.
Performance Characteristics
Concentration through shaft and screen cylinder Pneumatic reverse pressure guarantees the consistency of the pulp consistency.
The large compression ratio effectively guarantees the pulp concentration.
There is an internal dewatering device with holes on the discharge side to effectively ensure the consistency of dewatering inside and outside the pulp layer.f necessary,the intermal dewatering device can be cleaned with a recoil device to ensure the smoothness of the internal dewatering channels.
The equipment is reliable and wear-resistant.
The pulp concentration is high, suitable for the working concentration requirements of the heat dispersion system.
Simple operation and low energy consumption.
Twin Wire Press
Main Purpose
Widely used in pulp washing,dehydration,concentration and wet pulp board making,especially widely in heat dispersion system of waste paper pulp,high-concentration bleaching of mechanical pulp,regrinding of coarse residue,etc.;molding section of commercial pulp board machine;wood Concentrate of pulp with better flitration performance such as pulp;washing and concentration of low-freedom mechanical pulp and grass pulp;incoming pulp concentration 3.5-4.5%,out-pulp concentration 25-35%.
Working Principle
The low-concentration pulp is sprayed from the feed box to the net,and is first dewatered by gravity and low pressure difference in the wedge-shaped area of the upper and lower screens,and then enters the first pair of press rolls.It is further concentrated and enters the second pair of high-pressure rollers for high-strength squeezing.
The pulp is concentrated to a high concentration of 25%-32%through the comprehensive dewatering of the filter screen,screen and press rollers,and then from the second pair of transmission rollers The white water in the pulp is discharged from the white water tank at the bottom of the rack after passing through the net case.
The double-network double-pressure squeezing machine adopts a frequency conversion motor to adjust the speed of the network to adapt to changes in process conditions such as throughput,feed concentration,and type of pulp to ensure stable operation of the equipment.(THICKENING SYSTEM)
Performance Characteristics
The double-net wedge-shaped dehydration principle is applied,and the dehydration filter plate and dual-pressure roller device are combined for dehydration.
Automatically adjust the network speed to adjust the dewatering amount and the pulp concentration to ensure the stable requirements of the process on the pulp concentration;adapt to various pulp types such as waste paper pulp, free pulp,chemical pulp and mechanical pulp.
The combination of two dehydration zones with a mesh-wedge-shaped dehydration filter plate and a double-pressure roller device has a novel structure,less fiber loss,and low concentration energy consumption.
The concentration is stable and the operation is stable.
High Speed Washer(THICKENING SYSTEM)
Main Purpose
ZNG high-speed washer has a very high removal rate of ink particles,fillers and other small impurities in waste paper pulping.
It is mainly used for pulp washing and concentration in the waste paper treatment system with ONP or mow as raw materials.
The feed concentration is 0.8-1.2%,and the output concentration is 10-15%.It has outstanding advantages in deinking washing and concentration.
Working Principle
The pulp is dewatered under the combined action of the squeezing
between the mesh belt and the main and driven rollers and the centrifugal force generated by the high-speed rotation.
Performance Characteristics
Quickly remove the moisture of the pulp,with high pulp concentration.
Effective removal of ink particles,high ash removal rate(more than 90%),significantly improved whiteness.
High speed operation,thin pulp layer,good washing effect,adjustable mesh tension.
Motor frequency conversion and speed regulation,automatic deviation correction of network,stable operation.
Improved design,high efficient washing of thick pulp layer,less fiber loss.
Totally enclosed structure,clean environment,low noise.
The whole machine adopts the cantilever structure,which can use the endless net.It is easy to change the net and does not need the support.
Simple guide wire and tension control.
No need for vacuum water,reduce installation cost.
High concentration efficiency,excellent washing effect and low washing energy consumption.
Compact structure,flexible installation,small size and large capacity.
Low fiber loss and low operating cost.
After washing,the pulp can directly enter the screw extruder without intermediate concentration.
White Water Screen(THICKENING SYSTEM)
Main Purpose
Mainly used for solid-liquid separation,white water fiber recovery and clean filtration.
A large amount of white water will be generated in the papermaking process.At present,there are several ways for paper mills to process white water:
Reuse thick white water to adjust pulp;
The thick and dilute white water is partially reused in the pulp workshop;
The remaining white water is processed by a multi-disc filter machine,partly drained,and part of the super clear filtrate is reused.
Because the ultra-clear filtrate of the multi-disk filter produced by most manufacturers does not reach the 50ppm clarity,if it i directly used for the washing of nets and felts,it is easy to block the nets and felts,so many paper mill still need to to after filtering the super clear filtrate of the disc filter or directly using clean water to rinse the net and the felt,this causes a high consumption of clean water,which is a great waste in terms of environmental protection and cost.
Now the white water screen developed by our company has successfully solved the problem of white water reuse:
The maximum clarity of the white water treated by the white water sieve is less than 30ppm;it can be used for spray water in the net and wool cloth,vacuum pump seal and white water recovery machine(usually referred to as multi-disc white water recovery machine)spray water and general washing water;Reduced consumption of clean water.
If the white water under the net is used directly,the temperature of the rinse water can be increased by 10oC,which can enhance the cleaning effect,reduce heat loss,increase the operating temperature of the paper machine,improve the water filtration and drying effect,and increase the speed and output of the paper machine;
Recycle the fiber in white water to reduce fiber loss.
The white water treated by the white water sieve will not block the nozzle when used as flushing water.(paper making machinery)
Performance Characteristics
It can be treated in single stage or multiple stages,and the treated white water can meet the spray water standard;
Closed circulation system to achieve the effect of energy saving,fiber recovery,and reduction of sewage discharge.
The increase of paper machine operating temperature can increase vehicle speed and output;
Small running power and large processing capacity;
Not affected by fluctuations in normal treatment water volume;
No clogging design;
High solid removal rate;
Low maintenance cost.(paper making machinery)
Bow Screen(THICKENING SYSTEM)
Bow screen——effective separation of solids and filtrate In the paper industry,it can be used in the following applications:
Fiber Recycling
Fiber recovery form white water
Recycling fibers during process changes (variety changes or process spillage,etc.)
Concentrate
Tail pulp of pressure screen /slag remover.
Good pulp of pressure screen/slag remover.
Damaged paper.
Remove Solids
sewage disposal
Spray water purification
Classification
Long fiber separation
Separation of non-wood fibers
Fiber/Filler Separation
Deinking and washing
Coated paper washing
Selection of Bow screen
There are three types of arc screens available:single,double and triple bodies,all of which are constructed of stainless steel.Each set of curved screens has one to three screen plates.The supply of all Micra screens is assembled and easy to install.Pulp weir plate flushing and optional automatic back pressure flushing can be controlled independently or by the DCS system.(paper making machinery)
Working Principle
The pulp concentration from the pump to the arc sieve is 0-2%.The pulp enters the sieve plate tangentially at a high flow rate.
After the pulp is injected into the arc sieve plate,it is separated into filtrate and solids.The fine suspended solids pass through the sieve together with the filtrate Plate,and the fibrous material is left on the sieve plate in the direction of pulp flow injection to achieve the purpose of filtration.At the same time,the solids collected on the net roll down with the help of the liquid flow,and the liquid continuously scours the screen grid to make it self- cleaning,thereby completing the entire process of continuous self-purification of the screen and continuous collection of solids.
Performance Characteristics
The selection of sieve plates and the wide range of production capacity make the arc sieve obtain excellent and outstanding results in various applications.
Stainless steel grid-shaped curved screen plate with a slit width of 50-250 microns.
Adjustable pulp feed weir can quickly respond to changes in the process;the adjustment can be performed while the equipment is running,
Automatic pulp feed weir plate flushing and sieve plate swing spraying achieve trouble-free operation,and the advanced design ensures that no clogging will occur even under harsh conditions.
Pressure feeding and wide curved wedge-shaped mesh screen provide effective operation and high production capacity.The slope of the wedge-shaped screen improves the ability of the screen to separate filtrate.
No rotating and vibrating parts,reliable operation.
Fully enclosed structure,no leakage,clean working environment.
The overall stainless steel structure has strong environmental applicability.
No power transmission required,compact structure,easy installation,operation and maintenance.
The rugged structure and simple design make the repair rate extremely low,and no special tools are needed for repair and maintenance.
