BLEACHING DEINKING SYSTEM ( BLEACHING DEINKING SYSTEM )
With the improvement of environmental awareness, the technology of using secondary fibers to produce high-grade white paper has been continuously improved and developed,which requires bleaching and deinking treatment of waste paper pulp;the main purpose of the bleaching and deinking system is to remove the hydrophobicity of waste paper Impurities,such as ink particles,fllers,etc., increas the whiteness of the paste,improve its visual cleanliness, and try to keep the minimum loss of fibers.(Horizontal flotation deinking cell） (BLEACHING DEINKING SYSTEM)
In a deinking pulp line,there are many equipments responsible for removing ink particles and improving the whiteness of the pulp.Among them,the main bleaching and deinking devices are flotation deinking tanks and various bleaching towers.
(BLEACHING DEINKING SYSTEM)
In a deinking pulp line,there are many equipments responsible for removing ink particles and improving the whiteness of the pulp.Among them,the main bleaching and deinking devices are flotation deinking tanks and various bleaching towers.
The flotation deinking cell s used for flotation deinking of various waste paper pulps.It can remove ink particles from th pulp of mortar (non-deinking pulp),and can also remove some light impurities such as fillers and stickies.At present,the commonly used deinking cells include horizontal flotation deinking tanks and vertical flotation deinking cells.
Horizontal flotation deinking cell(BLEACHING DEINKING SYSTEM)
Horizontal flotation deinking cell-the best scheme of Deinking Line whitening technology
Working principle of horizontal flotation deinking cell
When the horizontal flotation deinking cell is working, the pulp is first pumped into the pulp inlet of the first flotation unit,and then enters the tank through the jet under the pulp inlet.
The jet adopts the Venturi pinciple, where the pulp flows through It will automatically draw in air to form a mixture of pulp and fine air bubbles.
The pulp-gas mixture is ejected from the opening below the jet and is evenly distributed to the bottom of the tank.(Horizontal flotation deinking cell(BLEACHING DEINKING SYSTEM)
The air bubbles in it adhere to the ink particles and rise from the bottom of the tank to the liquid surface with the ink particles, and then overflow the weir plate enters the foam collection tank, and the good pulp is pumped from the pulp outlet pipe at the bottom of the tank to the pulp inlet main pipe and bubble generator of the second flotation unit, and then the next air float deinking process is performed, and the rest is deduced by analogy.
（Horizontal flotation deinking cell）
When the horizontal flotation deinking cell is working,the pulp is first pumped into the pulp inlet of the first flotation unit,and then enters the tank through the jet under the pulp inlet.
The jet adopts the Venturi Inlet principle,where the pulp flows through It will automatically draw in air to form a mixture of pulp and fine air bubbles.The pulp-gas mixture is ejected from the opening below the jet and is evenly distributed to the bottom of the tank.
The air bubbles in it adhere to the ink particles and rise from the bottom of the tank to the liquid surface with the ink particles,and then overflow. The weir plate enters the foam collection tank, and the good pulp is pumped from the pulp outlet pipe at the bottom of the tank to the pulp inlet main pipe and bubble generator of the second flotation unit,and then the next air float deinking process is performed,and the rest is deduced by analogy.
Working principle of fluidizer
Internal structure of horizontal flotation deinking cell
Advantage
A deinking cell integrates one stage 4-6 stage and two stage 1-2 stage flotation unit,and adopts streamlined tank body.The equipment arrangement is simple and the function is more complete.Therefore,it can effectively improve the flotation efficiency and reduce Energy loss.
The deinking cell adopts an optimized design of advanced step diffusion bubble generator(multi-stage ejector structure),which can effectively generate turbulence of different degrees,form tiny bubbles of different sizes, efficiently remove 5-500 micron ink particles,and have good deinking effect,Whiteness of good pulp is high.
The deinking cell is equipped with a special ink channel.9Horizontal flotation deinking cell(BLEACHING DEINKING SYSTEM)）
After the ink is discharged,it will no longer contact the pulp,and the ink removal effect is good.
The volume of the tank is large,the residence time of the pulp in the cell is long,the ink absorption effect is good,and the ink removal effect is good.
The deinking cell is provided with a two-stage flotation unit,and the ink residue discharged from the first stage flotation through the weir overflow is sent to the second stage for flotation treatment,which can increase the final discharge concentration of the ink residue and effectively reduce fiber loss.
The deinking cell adopts a step-diffusion bubble generator with low pressure difference,and the minimum pulp feeding pressure is only 0.09MPa,so it can greatly reduce the pulp pump head and low power consumption.
It is reliable to use,easy to operate,and stable in quality.
The closed structure will not cause leakage or overflow,and the environment is clean.
The upper and lower double-layer piggyback structure saves space.
Vertical flotation deinking cell(BLEACHING DEINKING SYSTEM)
The BN-ZFM type closed flotation deinking cell belongs to the vertical flotation deinking tank structure.It adopts multi-stage flotation. The dispersion of air and the mixing with the pulp are completed by a specially designed non-blocking jet system.Has the following characteristics:
Working principle of vertical flotation deinking cell
The pulp enters into the first stage of the fluidizer through the pump at a certain feeding pressure(about 0.155mpa).The air brought into the fluidizer disperses into the flotation bubble with the best diameter to fully mix with the pulp,and enters into the feeding chamber of the first stage of the flotation cell along the tangent line.
At the bottom of the feeder house there are partitions with small gaps,which allow air to rise from one section to another and finally to the top of the flotation cell.
The pulp passes through the isolation plate to the pulp chamber,and the bubble generated by the nozzle floats to the upper part of the flotation cell The foam is collected into the cone and then flows through the foam tube(or pulp pipe)from the center to the bottom of the flotation cell.
At the same time,the pulp from the good pulp pipe enters the next pulp pipe.The pulp pipe is located at the bottom of the pulp tank in the center of the flotation cell. The good pulp is pumped into the next section. Each section of the flotation cell repeats this cycle, and the good pulp of the last section flows into the liquid level regulating tank at the upper part of the flotation cell, and then is distributed to the next process.
Working principle of fluidizer
Advantage
- The equipment is equipped with a 4~5 level separation structure,which forms a multi-level flotation with clear layers,which prevents the mixing of pulp between different flotation stages.
- The unique device structure allows the pulp to circulate internally, and the air is repeatedly used in the pulp,which greatly improves the utilization rate of the air and the ink removal rate in the pulp.
- Theunique design of the ejector ensures that high-quality air is mixed with the pulp to effectively remove ink particles.
- The deinking cell uses a non-clogging jet,the pulp feed pressure is about 0.155MPa,and the number of pulp pumps required is small.
- The ink concentration after flotation is high,and the fiber loss is low.
- During normal operation,there is no need to clean,no water spray pipe,no need to consume clean water,the flotation cell is always
- The closed structure will not cause leakage or overflow,and the environment is clean.(BLEACHING DEINKING SYSTEM)
- With vertical design,a single set of floor space is small.
The bleaching system includes high-concentration oxidative bleaching and medium-concentration reductive bleaching.High-concentration oxidative bleaching is a H202 bleaching system,which uses high concentration,descending bleaching,mainly to increase the whiteness of the pulp;medium-concentration reducing bleaching is a FAS bleaching system,which uses Thee concentration and rising bleaching are mainly to prevent the paper from turning yellow and consolidate the whiteness of the pulp.
Other bleaching and deinking equipment(BLEACHING DEINKING SYSTEM)
HIGH CONCENTRATION BLEACHING TOWER
The high-concentration bleaching tower is a bleaching reaction device for high-concentration pulp.It is mainly used for high-concentration hydrogen peroxide bleaching,with a bleaching concentration of 28-32%.
The high-concentration bleaching tower is mainly composed of tower body parts,bulk materials,screw propellers,and pumps. （ BLEACHING DEINKING SYSTEM ）
The pulp enters the bleaching tower from the top of the tower through a screw conveyor,and stays in the tower for a certain period of time.After bleaching,the pulp is pumped out by the pulp pump at the bottom of the tower.(BLEACHING DEINKING SYSTEM)
Structural characteristics of high concentration bleaching tower:
The tower body adopts a tapered structure,which reduces the possibility of pulp bridge.
The dilution function in the middle and bottom realizes the functions of high-concentration bleaching and low-concentration conveying.
MEDIUM CONCENTRATION BLEACHING TOWER
The medium-concentration bleaching tower is a medium-concentration pulp bleaching reaction device,which is mainly used for medium-concentration FAS reduction bleaching,with a bleaching concentration of 8-10%.
MEDIUM THICK MIXER
The medium-concentration mixer is used in the medium-concentration bleaching section of the pulp and paper industry to fully and evenly mix chemicals or steam with the pulp.
The medium-concentration mixer is composed of a mixing chamber,stirring teeth,a spindle drive,a base,and a motor.
Structural characteristics of medium-thick mixer:
- A three-blade rotor is used.The rotor rotating at high speed fluidizesthe pulp,which destroys the fiber network structure and facilitates the full mixing of the pulp.
- The internal reception is provided with spiral ribs to avoid pulp retention in the shell and reduce pressure loss.
- The rotation direction of the rotor isperpendicular to the flow direction of the pulp,which avoids the separation and overflow of the bleaching agent and saves chemicals.
- After being directly connected to the medium-concentration pump, the energy saving is remarkable.
