12.2.2 长网成形装置（下）在线视频

同学们好，还记得上一个视频
Hello everyone, do you remember the question

我提出的问题吗
I raised in last video

它就是下面我们介绍一种
It is the dehydrating element table plate used

应用于高速纸机中的脱水元件：案板
in high-speed paper machinery as we introduce below

首先来介绍一下案板的类型
First, let me introduce the type of the table plate

通常可分为单件的
which is usually divided into several types of structure

双件的和组装的几种结构型式
including single-piece, double-piece and combined structure

结构如图所示
as shown in the picture

通常靠胸辊端多用单件型
Generally, a single-piece type is used at the breast roll

靠伏辊端用组合型
and a combined type is used at the couch

从图所示可知
As can be seen from the picture

单件案板的优点是使用方便灵活
the advantages of single-piece table plate are easy and flexible in use

案板之间的距离和
The distance between the table plate

案板叶片的倾角都便于调节
and the inclination angle of the blades are easy to adjust

但单件的案板造价高
But the cost of single-piece table plate is high

且由于尺寸限制
and because of the size limitation

单件案板的框架较单薄
the frame of single-piece table plate is thin

容易发生振动
and easy to vibrate

从图可知
As can be seen from the picture

多件组装案板的框架
the frame stiffness of multi-piece assembly table plate

刚度大、造价低
is large and the cost is low

但是在网案湿端使用
but the phenomenon of slurry jumping is easy to occur

较小间距的组装案板时
when a small spacing assembly table plate is used

容易发生跳浆现象
at the wet end of the fourdrinier table

所以在网案湿端常常采用
Therefore, a double-piece (or three-piece) combined table plate

叶片间隙较大的双件
with large blade clearance is often used

（或三件）组合案板（见图）
at the wet end of the fourdrinier table (see picture)

并在该案板上采用
and a blade with adjustable dip angle structure

可以调节倾角结构的叶片
is used on the plate

下面来介绍一下案板的具体结构组成
Here’s a look at the structure of the table plate

案板叶片常用的
A commonly structural pattern of the plate blade

一种结构型式如图所示
is shown in the picture

它主要是由一个锐利的前缘
It is mainly composed of a sharp leading edge

一个支承成形网的水平面
a horizontal plane supporting the forming wire

和一个倾斜的平面组成
and an inclined plane

叶片的宽度通常为
The width of the blade is usually

50～100 mm（最常用的宽度是50 mm）
50~100 mm (the most common width is 50 mm)

其中水平支承平面的宽度是12mm
wherein the width of the horizontal support plane is 12 mm

叶片的前角通常是30～45°
The front angle of the blade is usually 30~45°

倾斜面的倾角为1～5°
and the inclination angle of the inclined plane is 1~5°

网速快时
When the wire speed is fast

要求前缘平面及斜面较短
the leading edge plane and inclined plane are required to be shorter

前缘角（β）较小
and the leading edge angle (β) is smaller

通常靠近胸辊端的
Usually the inclined angle (α) of the table plate

案板斜面角（α）小些
near the breast roll is smaller

靠近伏辊端的
and the inclined angle of the plate

案板斜面角大些
near the end of the couch is larger

案板排列的间距
The spacing of the table plate

靠胸辊端较大
near to breast roll is larger

为130～350mm
which is 130~350mm

靠伏辊端较小
and smaller close to the couch

为90～180mm
which is 90~180mm

图是常用于
Four types of table plates which is commonly used

车速在 500m／min以上
in the paper machinery with the speed of

的造纸机的四种案板
more than 500 m/min are shown in the picture

a、案板表面镀碳化钨
a. The surface of the table plate is coated with tungsten carbide

在前缘平面上
The front surface was sprayed with

用碳化钨喷镀0.05～0.25mm厚
tungsten carbide of 0.05~0.25mm thick

b、案板整体用陶瓷等
b. the whole table plate is made of

耐磨材料制成
ceramic and other wear-resistant materials

斜面作成弧形
the inclined plane is made into an arc

c、镶嵌式案板
c. Mosaic table plate

在前缘面的后部
A trapezoidal strip of ceramic

即磨损最严重处
or silicon carbide or alumina

镶嵌一条陶瓷或碳化硅
is inserted at the rear of the leading edge

或氧化铝材质的梯形条
where the wear is most severe

或整个前缘面镶嵌一条梯形条
or a trapezoidal strip is inserted at the whole front edge face

d、可调式的案板
d. Adjustable table plate

在不耐磨的底块上
A wear-resistant plastic cover

罩上一个耐磨的塑料套
is placed on a non-abrasive bottom block

底块上的小孔使
The holes in the bottom block

空腔与气源连通
connect the cavity to the air source

可通入压缩空气
The amount of the dehydrating can be adjusted

或抽真空以调节脱水量的大小
by replenishing compressed air or vacuum-pumping

一般车速较低的造纸机
high-density polyethylene

可使用高密度聚乙烯
or polytetrafluoroethylene, polyphenol oxygen

或聚四氟乙烯、聚酚氧
chlorinated polyether and other plastic products

氯化聚醚等塑料制品
can be used in paper machinery with low speed

目前案板在最大磨损点
At present, ceramic inserts are commonly used

普遍使用陶瓷镶嵌件
at the maximum wear point of the table plate

案板组件一般
and 3~6 pieces of table plates

含有3～6块案板
are contained in the table plate assembly

为什么案板可以用于高速纸机中呢
Why can the table plate be used in high-speed paper machinery

下面来学习一下案板的脱水原理
Let’s take a look at the dehydration principle of the table plate

案板的脱水原理
The dehydrating principle of the table plate

和案辊有相似之处
is similar to that of the table roll

即两者都是在
that is, both are dehydrated

真空抽吸作用下进行脱水
under the action of vacuum suction

如图所示
As shown in the picture

当成形网运行到
when the forming wire is in contact

与案板锐利的前缘接触时
with the sharp leading edge of the table plate

首先是将悬附在网下的水层刮去
the water layer suspended under the wire is first scraped away

接着，成形网和网上的浆料
Next, the forming wire and the pulp on the wire

进入水平的支承平面
enter the horizontal support plane

在这个区间会有一部分水层
In this section, a part of the water layer

随成形网进入到
will enter the area between the forming wire

成形网和叶片之间
and the blade with the forming wire

造成在案板上发生的正压脉冲
resulting in a positive pressure pulse on the table plate

当成形网移动至倾斜平面上时
When the forming wire moves to the inclined plane

在初始的阶段
at the initial stage

成形网会下垂而沿斜面运动
the forming wire will sag and move along the inclined plane

但成形网的张力会很快使
but the tension of the forming wire will quickly

成形网与倾斜面脱离
separate the forming wire from the inclined plane

并与倾斜面组成一个楔形空间
and form a wedge-shape space with the inclined plane

案板的脱水作用
The dehydrating effect of the table plate

就主要是发生在这一区间内
mainly occurs in this section

从图可以看出
It can be seen from the picture that

相比于案辊
the pressure-vacuum pulse on the table plate

案板上的压力—真空脉冲比较缓和
is more mild than that on the table roll

其脱水过程的压力波动
and the pressure fluctuation and the maximum pressure

和最高压力都比案辊脱水时小
in the process of dehydration are smaller than that of the table roll

因而对网上纸浆的扰乱较小
therefore the disturbance to the pulp on the wire is smaller

和有利于提高保留率
and it is beneficial to improve the retention rate

因而可以用于高速纸机中
hence it can be used in high-speed paper machinery

以下是案板和案辊
The following is the comparison of the performance

两者的性能比较
of the table plate and the table roll

1、真空区长
1. Vacuum zone is long

没有压力最高点
no pressure peak

脱水量大、缓和
large and mild dehydrating quantity

2、抽吸力小而均匀
2. The suction force is small and uniform

可使纸浆获得微湍动
which can make the pulp get micro-turbulence

改善纸页的组织
improve the structure of the paper sheet

提高成纸质量
and improve the quality of the paper

3、可以改变斜面的长度
3 the dehydrating quantity and the pulsation intensity

和后角的大小
can be controlled by changing

控制脱水量和脉动强度
the length of the inclined plane and the size of the rear angle

4、案板能延长网的寿命
4. Table plate can prolong the life of the wire

尤其对聚酯网更为适宜
especially for the polyester wire

5、案板没有转动部分
5. There is no need to consider the dynamic balance

不需考虑动平衡
because the table plate without rotating part

下面我们来了解一下
Now let’s take a look at the

案板的设计和选用
design and selection of the table plate

该问题主要围绕着
The problem is mainly related to the

宽度、倾角、叶片距离
width, inclination angle, blade distance

前角及几何形状几个参数
front angle and geometric shape

1、案板宽度的选用
1. Selection of width of table plate

一般选择倾斜平面的宽度
The plate with a width of about 50mm

约50mm的案板
on the inclined plane can not only meet

则既可以满足结构上必要刚度的要求
the requirements of the necessary stiffness of the structure

又能有足够的脱水量
but also can have enough dehydrating quantity

和纸浆扰动性能
and pulp disturbance performance

动力消耗也较低
and the power consumption is low

2、案板倾角的选用
2. Selection of the inclination angle of the table plate

一般说来
Generally speaking

纸浆的浓度越高
the higher the pulp concentration

也就是越向网案的干端
that is, the closer to the dry end of the wire

案板的倾角应增大
the angle of the table plate should be increased

相反，在网案的湿端
In contrast, a smaller angle of inclination

应使用较小倾角的案板
should be used at the wet end of the fourdrinier table.

3、案板叶片之间距离的选用
3. Selection of distance between blades of table plate

对于不同的车速
For different speed

不同的叶片倾角和纸浆浓度
different blade inclination angle and pulp concentration

避免跳浆现象的
the minimum spacing value

最小间距值是不同的
to avoid pulp jumping is different

在纸浆浓度为
In the wet end of the fourdrinier table

0.5～1.2％的网案湿端
with pulp concentration of 0.5~1.2%

需要增大案板间的距离
it is necessary to increase the distance between table plates

则浆液跳动的倾向减弱
and the tendency of pulp jumping is weakened

在纸浆浓度为
When the pulp concentration is 1.7~2.5%

1.7～2.5％的网案干端
a suitable blade spacing is also needed

同样需要一个适宜的叶片间距
in the dry end of the fourdrinier table

以防止脱下的网下水层
to prevent the water layer from

重新被吸回纸幅中
being sucked back into the paper web

影响案板的脱水效果
which affects the dehydrating effect of the table plate

4、案板前角的选用
4. Selection of the front angle of the table plate

案板的前角为30°左右时
When the front angle of the table plate is about 30°

具有良好的刮水性能
it has good performance of water scrapping

前角过小时
The front angle is too small

不易保持叶片前缘锐直
to keep the blade leading edge sharp

容易发生缺陷并造成积浆
and is prone to defects and pulp accumulation

叶片前角增大至45°左右时
When the front angle of the blade increases to about 45°

大约有85％的网下水层
about 85% of the water layer under the wire

被叶片的前缘刮除
is scraped off by the leading edge of the blade

余下的水分经过网孔
and the remaining water is re-entered

重新进入到浆液中
into the pulp through the mesh

会造成一些有利于
which will cause the disturbance

防止纤维絮聚的扰动
to prevent the flocculation of the fiber

有益于纸幅的成形
and benefit the forming of the paper web

叶片前角的选用
The selection of blade front angle

与造纸机车速有关
is related to the speed of paper machinery

低速纸机上可以使用较大的前角
Large front angle can be used on low-speed paper machinery

车速高于400m/min的时
When the speed is higher than 400 m/min

一般是选用30°左右的前角
it is generally to choose a front angle of about 30°

5、案板的几何形状精度要高
5. The geometric accuracy of the table plate should be high

案板叶片的几何形状
The geometry of the table plate

精度要求较高
requires high precision

例如，在叶片倾斜平面的
For example, when the height difference of

一端高度相差1mm米时
one end of the blade inclined plane is 1 mm

大约会造成1／4°的倾角误差
the dip error is about 1/4°

它可以引起 8％的脱水量的变化
which can cause 8% change ofdehydrating quantity

案板叶片脱水量变化
The most sensitive angle section of change of

最敏感的倾角区间是在1.5～2.5°
dehydrating quantity of table plate blade is 1.5~2.5°

是在常用的倾角范围内
which is in the commonly used angle range

这就要求案板的维修和安装
which requires the high accuracy of

都应有较高的准确度
maintenance and installation of table plate

下面来学习真空脱水装置
Let’s learn about a vacuum dehydrating device

真空脱水箱
a vacuum dehydrating box

真空吸水箱是
Vacuum suction box

传统的真空脱水元件
is a traditional vacuum dehydrating element

纸浆到达真空吸水箱时
When the pulp reaches the vacuum suction box

浓度已达到2％～3％
the pulp concentration has reached 2%~3%

一般地，在低速造纸机上
Generally, on the low-speed paper machinery

纸浆通过真空吸水箱后
the pulp concentration can reach about 11%

浓度可达到11％左右
after passing through the vacuum suction box

在高速造纸机上
on the high-speed paper machinery

真空吸水箱后纸浆浓度
the pulp concentration can reach 15% above

可高达15％以上
after going through the vacuum suction box

在不同造纸机上
On different paper machinery

真空吸水箱的装配数量
the assembly quantity of

为2～10个不等
vacuum suction box is 2~10

其真空范围为10～33kPa
and the vacuum range is 10~33 kPa

真空吸水箱总管上的
The vacuum degree on the main pipe of

真空度一般小于 40kPa
vacuum suction box is less than 40 kPa

在高速造纸机上亦有高达80kPa的
and it is up to 80 kPa on the high-speed paper machinery

真空脱水箱的结构如图所示
The structure of the vacuum dehydrating box is shown in the picture

真空吸水箱由箱体
The vacuum suction box is composed of

和面板两部分组成
the box body and the plate

真空吸水箱箱体一般用
The box body of vacuum suction is made of

木材、铸铁、钢板或铸铝制成
wood, cast iron, steel plate or cast aluminum

小型造纸机上的
The vacuum suction box on

真空吸水箱是木质的
a small paper machinery is made of wood

较大型的造纸机上采用
The structure of steel welding or cast iron

型钢焊接或铸铁的结构
is adopted on the larger paper machinery

现代化造纸机上多使用
The modern paper machinery mainly uses

硅铝合金或不锈钢焊接的箱体
silicon aluminum alloy or stainless steel welded box body

一般铸造的结构箱体的
The vacuum suction box of the structure box body

真空吸水箱如图所示
of the general cast is shown in the picture

真空吸水箱面板的材质
The material of the vacuum suction box plate

与成形板相同is the same as that of the forming plate

低速纸机For low-speed paper machinery

覆盖真空箱面的材质the material covering vacuum box surface

一般为高密度聚乙烯is generally the high density polyethylene

高速纸机使用诸如
hard materials such as silicon carbide or

碳化硅或氧化铝等硬质材料
aluminum oxide are used at high-speed paper machinery

开孔形状有圆孔、长孔
There are 3 kinds of openings including

和条缝等三种
round hole, long hole and slot

下面来介绍
The following is a description of

真空脱水箱的脱水过程
the dehydration process of the vacuum dehydrating box

对于在低车速低真空度的真空吸水箱
For a low-speed, low-vacuum vacuum suction box

湿纸幅在一个真空吸水箱上的
the dehydration process of wet paper web on a

脱水过程大致可分为三个阶段
vacuum suction box can be divided into three stages

最初，湿纸幅的含水量很高
At first, the moisture content of the wet paper web is very high

水分是在真空造成的
and the moisture is filtered out

压差作用下过滤而排出的
under the pressure difference caused by vacuum

常称为自由脱水阶段
often called the free dehydration stage

继之，湿纸福在压差作用下被压缩
Next, wet paper web is compressed under the action of pressure difference

发生压缩脱水
and compression dehydration occurs

最后，空气开始穿透纸幅
Finally, the air begins to penetrate the wet paper web

将纤维间的一部分水分
bringing a part of the moisture between the fibers

随气流带入吸水箱内
with the airflow into the suction box

形成所谓空气动力脱水
forming a so-called aerodynamic dehydration.

也就是说真空脱水经过
In other words, vacuum dehydration

自由脱水、压缩脱水
has three stages: free dehydration

空气动力脱水三个阶段
compression dehydration and aerodynamic dehydration

在空气动力脱水过程中
In the process of aerodynamic dehydration

空气穿透浆层的这一点
the air penetrates this point of the pulp layer

即是“干线”
that is, the “dry line”

也称为“水线”的位置
also known as the “water line” position

从图中可以看出
As can be seen from the picture

水线即是镜面消失之处
the water line is the optical effect produced in the place

所产生的光学效应
where the mirror disappears

其纸浆浓度约7%
and its pulp concentration is about 7%

接下来是网部最后的
And then there’s the last dehydrating device

脱水装置：伏辊
in the wire section: couch

湿纸幅经过真空吸水箱后
After passing through the vacuum suction box

在伏辊上进一步脱水the wet paper web is further dehydrated on the couch

达到一定干度
to reach a certain degree of dryness

具有足够的湿强度
and has enough wet strength

从而顺利地从成形网表面
so that it can be successfullypeeled from the surface of forming wire

剥离传递到压榨部\ Nand then transferred to the press part

纸幅到达伏辊的
The degree of dryness of the paper web

干度一般为12％～18％
to the couch is generally 12%~18%

伏辊可将其干度
and the degree of dryness of the couch

提高到18％～25 ％
can be increased to 18%~25%

伏辊是长网部的一个主要驱动点
The couch is a main driving point of the fourdrinier section

在结构上主要分为
which is mainly divided into two types

普通伏辊和真空伏辊两大类
ordinary couch and vacuum couch

真空伏辊的结构如图所示
The structure of the vacuum couch is shown in the picture

由真空室和辊壳两大部件组成
which consists of two parts: the vacuum chamber and the roller shell

辊壳一般用锡青铜离心浇铸制成
Roller shell is generally made of tin bronze centrifugal casting

主要是靠真空抽吸力来脱水的
which is mainly dehydrated by vacuum suction

其优点是操作方便
It has the advantages of being convenient in operation

脱水率高high in dehydrating rate

网的磨损小、引纸方便等small in wear of the wire and easy in threading of paper, etc.

本节内容就讲到这里So much for this section

谢谢同学们thank you all