7.1 纸浆清洁漂白常用流程在线视频

各位同学好
Hello, everyone

从这节课开始讲解第七章
From this class, let’s begin to introduce the Chapter VII

漂白与设备
Bleaching Machinery and Equipment

本章主要结合漂白工段
This Chapter mainly combines the production process

生产流程和工艺参数
and process parameters of the bleaching section

讲解漂白过程关键装备的
to introduce the knowledge such as

结构、材质、工作原理
structure, materials, working principles and other aspects

等方面的知识
of key equipment in the bleaching process

主要内容有以下八个方面
and the main content includes the following eight aspects

第一节主要讲解
The first section mainly explains the

纸浆清洁漂白过程的常用流程
common process of pulp cleaning and bleaching

那么后面的七节主要讲解
then the following 7 sections mainly

其中的关键装备
explain the key equipment

首先为大家介绍一下
First of all, let’s introduce the

纸浆清洁漂白常用的流程
common process of pulp cleaning and bleaching

漂白我们知道是一类通过化学反应
We are aware that bleaching is a process in which

脱除纸浆中的残余木素
the pulp is whitened by chemical reactions

或者还原纸浆中的发色基团
to remove residual lignin from the pulp

使纸浆变白的一个过程
or to reduce the chromophore in the pulp

漂白过程因为产生中段废水
Due to generating waste water in the middle section

是制浆造纸环境保护
the bleaching process is one of the most important sections

最为重视的工段
for the environmental protection of pulping and papermaking

传统漂白方法常采用低浓含氯漂白
Conventional bleaching methods often adopt low consistency chlorine bleaching

如CEH三段漂
such as CEH three-stage bleaching

（即氯化－碱处理－次氯酸盐漂白）
(i.e., chlorination-alkali treatment-hypochlorite bleaching)

那么低浓漂白废水排放量大
so the discharge of the low consistency bleaching wastewater is large

漂白废水中含有大量
The bleaching wastewater contains a lot of

有毒有害的有机卤化物（即AO X）
toxic and harmful organic halides (i.e., AOX)

废水处理难度大、成本高
the wastewater treatment is difficult and the cost is high

因此，目前已逐步被清洁漂白技术所替代
Therefore, it has been gradually replaced by clean bleaching technology

常用的漂白方法有
The commonly used bleaching methods are

氧脱木素、二氧化氯漂白
oxygen delignification, chlorine dioxide bleaching

过氧化氢漂白、臭氧脱木素等
hydrogen peroxide bleaching and ozone delignification, etc.

相比于低浓制浆
Compared with low consistency pulping

中高浓漂白过程
the pulp consistency of medium and high

纸浆浓度多在10%以上
consistency bleaching process is more than 10%

相同的反应助剂浓度
with the same consistency of reactive agent

那么产生的废水量要低得多
and the volume of generated waste water is much lower

因此，上述的清洁漂白方法
Therefore, the above-mentioned clean bleaching methods

多在中高浓度条件底下
are mostly used for conveying, mixing and bleaching

进行输送、混合和漂白的反应
under medium and high consistency conditions

那么在专业术语中
And then, in professional terms

漂白方法有专门的代号
the bleaching methods have special codes

如表所示
as shown in the table

氧脱木素工段用Oxygen的首字母O表示
The oxygen delignification section is denoted by initial O of Oxygen

二氧化氯漂白用Dioxide首字母D表示
the chlorine dioxide bleaching is denoted by the initial D of Dioxide

过氧化氢漂白用Peroxide首字母P表示
and the hydrogen peroxide bleaching is denoted by the initial P of peroxide

如果在氧脱木素当中
If hydrogen peroxide is added

加入过氧化氢进行强化
to the oxygen delignification for reinforcement

则用O和下标P表示
it is denoted by O and subscript P then

如果在过氧化氢漂白过程中加入氧气
And if oxygen is added to the hydrogen peroxide bleaching process

则反过来用大写的P和下标O表示
then it is denoted by P and subscript O conversely

我们知道单独的一种方法很难
We are aware that it is difficult to bleach chemical pulp

使化学纸浆漂白到所需要的白度
to the required whiteness by one method alone

往往采用多种漂白方法串联
and various bleaching methods are often used in series

对纸浆连续进行漂白处理
to bleach pulp continuously

多个漂白方法的组合方式
The combination of several bleaching methods

我们称之为漂序
is called bleaching sequence

根据漂序中是否采用二氧化氯漂白
Based on whether the bleaching sequence is bleached by chlorine dioxide or not

我们将漂序分为两大类
we classified the bleaching sequence into two categories

一类称之为无元素氯漂白
one is called elemental chlorine-free bleaching

即不含元素氯漂白助剂
that is, without chlorine bleaching additives

（如氯气、次氯酸盐等）
(such as chlorine and hypochlorite, etc.)

这样一个漂白漂序
For the bleaching sequence of such a bleaching

那么我们一般用ECF表示
we generally use ECF to express it

一般情况下多特指
In general condition, it refers to

含有二氧化氯漂白的漂序
bleaching sequence containing chlorine dioxide

由于二氧化氯漂白过程
Because the disproportionation reaction

会产生岐化反应
generated during chlorine dioxide bleaching

会有少量的AOX产生
a small amount of AOX will be produced

那么另外一类是全无氯漂白
And the other one is total-chlorine-free bleaching

我们一般用TCF表示
we use TCF to express it in general

那全无氯漂白多采用
The total-chlorine-free bleaching mostly adopts

氧脱木素、臭氧脱木素、过氧化氢漂白等
oxygen delignification, ozone delignification, hydrogen peroxide bleaching

不含二氧化氯漂白的漂序
and other bleaching processes without chlorine dioxide

由于不含氯元素
Because of the absence of chlorine element

漂白过程不会产生AOX
the bleaching process will not produce AOX

目前这两类漂序在国家推行的
At present, these two types of bleach are recommended

《制浆造纸行业
as the technology to use in Evaluation Index System

清洁生产评价指标体系》
of Clean Production in Pulp and Papermaking Industry

中作为推荐采用的技术
implemented in China

那么针对不同原料
For different raw materials

或者不同的漂后浆白度要求
or different whiteness requirements of bleached pulp

采用的漂序也会有所差异
the adopted bleaching sequence will also be different

如针对硫酸盐针叶木浆
For example, for sulfate softwood pulp

那么高白度的漂白
in terms of high whiteness bleaching

我们多采用ODEDED漂序
we usually use ODEDED bleaching sequence

那么针对硫酸盐阔叶木化学浆高白度漂白
Then for sulfate broadleaf wood chemical pulp high whiteness bleaching

或者非木化学浆的漂白
or non-wood chemical pulp bleaching

那么我们一般采用ODED漂白漂序
we usually use ODED bleaching sequence

有些非木浆如蔗渣化学浆
For some non-wood pulp such as bagasse chemical pulp

当生产线所在地
when the local environmental protection requirements

环保要求很高时
of the production line are very high

我们也可以采用一些短序漂白
we can also use some short sequence bleaching

如OQP或ODP
such as OQP or ODP

下面为五个生产线漂白工艺流程的示例
The follows are five examples of bleaching processes for production lines

第一个是OD0EOD1D2
The first is OD0EOD1D2

纸浆经过单塔氧脱木素
After one tower oxygen delignification

然后进行第一段二氧化氯漂白
the pulp is subject to chlorine dioxide bleaching of the first stage

再用碱处理溶出降解的残余木素
then subject to alkali treatment to remove the degraded residual lignin

然后再用两段二氧化氯补充漂白
and then bleached with two-stage bleaching of chlorine dioxide

可以将难漂的针叶木浆
to bleach the hard-to-bleach softwood

漂到86%ISO以上的白度
pulp to a whiteness of more than 86% ISO

第二个示例是O/OD0E0D1漂白流程
The second example is the O/OD0E0D1 bleaching process

那么纸浆先进行双塔氧脱木素
The pulp is first subject to double tower oxygen delignification

再通过封闭筛选
and then goes through closed screening

筛后纸浆进行一段二氧化氯漂白
The screened pulp is subject to chlorine dioxide bleaching of the first stage

脱除残余木素
to remove the residual lignin

用碱处理进行溶出
then dissolved with alkali treatment

最后进行一道补充二氧化氯漂白
and finally subject to a chlorine dioxide supplementary bleaching

这种漂序对原料的适应性很强
This bleaching sequence has strong adaptability to the raw material

目前国内大多采用这类漂序
At present, China mostly use this kind of bleaching sequence

第三个示例是OZ/QP
The third example is OZ/QP

这个示例采用的是典型的全无氯漂白
In this example, a typical total-chlorine-free bleaching is adopted

纸浆先经过
T he pulp is first subject to the

过氧化氢加强的氧脱木素
oxygen delignification enhanced by hydrogen peroxide

然后用臭氧进一步脱除残余木素
then treated by ozone to further remove the residual lignin

不洗涤直接进行螯合预处理
subject to chelating pretreatment without washing

最后进行氧加强的压力过氧化氢漂白
and finally subject to oxygen-enhanced pressure hydrogen peroxide bleaching

这一类的漂序多用于
This type of bleaching is often used for

环保要求严格
raw materials that has strict environmental protection requirements

并且易漂的原料
and is easy to bleach

如蔗渣浆的化学浆漂白
such as the bleaching of bagasse chemical pulp

第四个示例是OQP/ODP互换使用的示例
The fourth example is an example of the use of OQP/ODP interchangeably

那OQP是全无氯漂序
The OQP is a total-chlorine-free bleaching sequence

ODP是无元素氯漂序
and the ODP is element chlorine-free bleaching sequence

在这个漂序中
In this bleaching sequence

其中氧脱木素后可以采用二氧化氯漂白
chlorine dioxide bleaching can be used after oxygen delignification

也可以采用酸性螯合预处理
or acid chelating pretreatment can be used

最后用压力过氧化氢漂白
and finally pressure hydrogen peroxide bleaching can be adopted

这主要根据具体情况进行选择生产方式
which is mainly selected depending on the specific conditions

如对于蔗渣浆
For example, for bagasse pulp

设备不用任何变动
the equipment does not need any change

只需变换加入的漂白助剂
and it is only need to change the bleaching additives that need to be added

就可以用全无氯方式
The total-chlorine-free method can be adopted

生产要求比较高的食品模塑包装用浆
to produce pulp for food molding packaging with high requirements

也可以按照无元素氯方式
or the element chlorine-free method can be followed up

生产常规的漂白浆用于生活用纸的抄造
for producing the conventional bleaching pulp for household paper

最后一个示例主要针对于
The last example is mainly aimed at

化机浆或废纸浆的漂白
the bleaching of chemical pulp or waste pulp

由于漂后浆白度要求不高
Because of the low whiteness requirement of bleached pulp

只需进行一段漂白即可
only one stage of bleaching is needed

这一类的漂白多采用
This kind of bleaching is mostly done by

高浓过氧化氢漂白
high consistency hydrogen peroxide bleaching

纸浆经浓缩设备
The pulp is thickened to the consistency

浓缩到25%以上的浓度
of more than 25% by thickening equipment

再与过氧化氢等漂白助剂混合
then mixed with bleaching additives such as hydrogen peroxide

再进入高浓漂白塔中进行漂白反应
and then goes into the high consistency bleaching tower for bleaching reaction

总结一下上述典型生产流程的关键设备
Let’s summarize the key equipment of the above typical production process

每一工段的情形都差不多
The situation of each section is almost the same

先经过浓缩洗涤设备
First, the pulp is thickened to medium consistency (10%-16%)

将纸浆浓缩至中浓度（10%－16%）
or high consistency (25-40%)

或者高浓度（25－40%）
through the thickening and washing equipment

然后经过输送设备
then goes through the conveying equipment

与化学助剂的混合设备
the mixing equipment with chemical additives

最后进入漂白反应容器中进行漂白反应
and finally enters the bleaching reaction vessel for bleaching reaction

包括氧脱木素塔、过氧化氢漂白塔
including oxygen delignification tower, hydrogen peroxide bleaching tower

二氧化氯漂白塔等
and chlorine dioxide bleaching tower, etc.

根据工艺的不同
The structures and materials of the equipment will vary

这些设备的结构、材质会有所差异
depending on different process

好，这节课就讲到这里
Ok, that's all for this class

谢谢
Thank you