14.2.2 烘缸、烘毯缸和冷缸（下）在线视频

同学们好
Hello everyone

今天讲烘缸的
Today, I’m going to talk about the

冷凝水排出装置
condensate water discharge device for the dry cylinder

大多数烘缸都以蒸汽为热源
Most dry cylinder use steam as the heat source

由于蒸汽的冷凝
As the steam condenses

烘缸内就会产生冷凝水
condensate water is produced in the dry cylinder

当烘缸旋转时
When the dry cylinder rotates

冷凝水在烘缸内受到
the condensate water is subjected to

粘滞力、惯性力、离心力
viscous force, inertia force, centrifugal force

及重力的作用
and gravity in the dry cylinder

粘滞力
Viscous force

使冷凝水有跟
The condensate water has the tendency

烘缸转动的倾向
to rotate with the dry cylinder

惯性力
Inertia force

使冷凝水的运动减速
To slow down the movement of condensate water

离心力
Centrifugal force

使冷凝水与烘缸内壁紧贴
Tighten the condensate water to the inner wall of the dry cylinder

重力
Gravity

使冷凝水落到烘缸底部
cause the condensate water to fall to the bottom of the dry cylinder

冷凝水的受力情况
The stress of condensate water

与烘缸的直径
is related to the diameter of the dry cylinder

冷凝水量
the amount of condensation water

及纸机的车速有关
and the speed of the paper machinery

当烘缸直径
When the diameter of the dry cylinder

和水量一定时
and the amount of water is fixed

随着纸机车速的提高
with the increase of the speed of the paper machinery

冷凝水在烘缸内
condensate water in the dry cylinder

可以出现不同的形态
can appear different shapes

当车速在200m/min以下
When the speed is below 200 m/min

重力占优势
the gravity is dominant

这时候冷凝水
at this point, the condensate water

聚积在缸底
accumulates at the bottom of the cylinder

在烘缸内壁形成了一层
forming a very thin wetting water film

很薄的润湿水膜
on the inner wall of the dry cylinder

当车速在200到300m/min之间
When the speed is between 200 and 300 m/min

粘滞力增加
the viscous force increases

对缸底积水
There is a drag effect on the water

有拖动作用
accumulated at the bottom of the cylinder

冷凝水沿缸壁有些上升
The condensate water rises along the wall of the cylinder

然后回流到缸底
and then flows back to the bottom of the cylinder

当车速达到300m/min
When the speed reaches 300 m/min

惯性力增加
the inertia force increases

冷凝水被抛到较高的
Condensate water is thrown to a higher position

烘缸壁位置上
on the wall of the dry cylinder

但是重力仍然占优势
but gravity is still dominant

使冷凝水发生突变
causing the condensate water to mutate

从缸壁开始溃散
and break away from the wall

返回缸底
and return to the bottom of the cylinder

当车速继续增加到300m/min以上
As the speed continues to increase above 300m/min

冷凝水受到的离心力
and the centrifugal force of the

超过重力时
condensate water exceeds gravity

沿烘缸的内壁形成
a complete and uniform water ring is formed

一个完整均匀的水环
along the inner wall of the dry cylinder

冷凝水在烘缸内积存
The accumulation of condensate water

会产生很多危害
in the dry cylinder can cause a lot of damages

首先，冷凝水的导热系数
First of all, the thermal conductivity of condensate water

只有铸铁导热系数的1/88
is only 1/88 of that of cast iron

烘缸内积存冷凝水
The accumulation of condensate water in the dry cylinder

会增加烘缸的热阻
will increase the thermal resistance of the dry cylinder

降低干燥效率
reduce the drying efficiency

增加纸机功耗
and increase the power consumption of the paper machinery

其次，车速较高时
Secondly, when the speed is high

烘缸内冷凝水环的
the formation and destruction of condensate

形成和破坏（临界厚度）
water ring in the dry cylinder (critical thickness)

引起烘缸传动功率的剧烈波动
cause the sharp fluctuation of the driving power of the dry cylinder

影响纸机的正常运行
which affects the normal operation of the paper machinery

另外，冷凝水测积存
In addition, condensate water storage

还会导致烘缸部
will lead to an irregular temperature difference

出现不规则的温差
in the dry cylinder part

造成纸幅干燥不匀
resulting in unevenness and drying of the paper web

因此，必须根据不同的车速条件
Therefore, different forms of condensate water removal devices

采用不同形式的冷凝水排除装置\ N must be adopted according to different speed conditions

有效地排除烘缸内的冷凝水
to effectively eliminate condensate water in the dry cylinder

烘缸的冷凝水排出装置
There are many types of condensate water

有多种型式
discharge devices for dry cylinder

第一种是戽斗式排水装置
The first type is scoop-type drainage device.

戽斗是呈蜗线性的中空铸铁管
The scoop is a linear hollow cast iron pipe

界面呈矩形
with a rectangular interface

一般采用焊接结构
It generally adopts the welding structure

固定在烘缸内传动侧端盖上
and is fixed on the drive side cover in the dry cylinder

随烘缸转动
As the dryer rotates

戽斗从烘缸下部
the scoop drains the condensate water from

把冷凝水舀出
the lower part of the dry cylinder

送到轴头内壁
to the annular gap between the inner wall of the shaft head

与烘缸供汽管之间的环隙排出
and the steam supply pipe of the dry cylinder

主要适用于300m/min以下的
It is mainly suitable for large diameter dry cylinder

低速纸机的大直径烘缸
of low speed paper machinery under 300m/min

第二种是固定虹吸管式排水装置
The second type is a fixed siphon type drainage device

用于300m/min以下低速造纸机
It is used for low speed paper machinery under 300 m/min

通常使用简单固定虹吸管
simple fixed siphon is usually used

对于550m/min以上的造纸机
For paper machinery with speed above 550m/min and

主要使用具有吸水头的虹吸管
siphon with suction head is mainly used

吸水头与烘缸内表面的
The distance between the suction head and

距离为2～3亳米
the inner surface of the dry cylinder is 2~3 mm

当车速超过200米/分时
When the speed exceeds 200m/minute

由于冷凝水有
due to the tendency of condensate water

随烘缸转动的倾向
to rotate with the dry cylinder

虹吸管应偏向烘缸转动方向
the siphon shall be mounted at a 15~20°angle

一边15～20°角安装
in the direction of rotation of the dry cylinder

虹吸管式排水装置通常采用
The siphon type drainage device usually adopts

一根带圆弧的钢管
one steel pipe with circular arc

一端与进汽头连接
wherein one end is connected with the steam intake head

另一端悬在缸体内
the other end is suspended in the cylinder body

运转时缸体与虹吸管相对运动
and the cylinder body moves relative to the siphon when running

由于悬臂固定及管子挠曲
Because the cantilever is fixed and the pipe is bent

在管头触及烘缸时
when the pipe head touches the dry cylinder

或是由于冷凝水环
or because of the hydraulic shock

形成的水力冲击
formed by the condensate water ring

容易发生损坏
it is easy to be damaged

应注意检查
the inspection shall be carried out

针对常规虹吸管易损坏
The structure of the new siphon has been improved

导致虹吸不起作用的问题
in view of the problem that the conventional siphon

新型虹吸管的结构又有改进
is easy to be damaged and the siphon does not work

比如，在虹吸管弯曲处
For example, a steel-wire hose structure

采用钢丝软管结构
is used at the bend of the siphon

靠吸管自重自然向下弯曲
which naturally bends downward by the weight of the siphon

另外，将弯管弯曲成60°角
In addition, bending the pipe to 60°angle

在水平管和弯管之间
and installing a vertical stiffener between

安装一个垂直加强筋
the horizontal pipe and the bend pipe

可使垂直虹吸管的吸水端
can make the suction end of

得到固定和稳定
the vertical siphon fixed and stable

使其挠曲和振动
so that its flexure and vibration can

减小到最低值
be reduced to the lowest value

还可以精确调节
and the gap between the suction head and

吸水头与烘缸壁的间隙
the wall of the dry cylinder can be precisely adjusted

对于300m/min以上的中高造纸机
Double-rotating siphon can be used for

可以采用双旋转虹吸管
medium-high paper machinery over 300m/min

这种结构能有效
This structure can effectively eliminate

排除成水环状的以及
condensate water which is formed into water ring

聚积在烘缸下部的冷凝水
and accumulated in the lower part of the dry cylinder

这种虹吸管固定在
The siphon is fixed on the

传动侧的烘缸盖上
dry cylinder cap on the drive side

每根管端上装有吸水头
and each pipe end is provided with a suction head

吸水头带有可调节长度的支杆
with support rod which length can be adjusted

把虹吸管支持在
to support the siphon in a

对烘缸内表面的固定位置上
fixed position on the inner surface of the dry cylinder

吸水头与烘缸之间的
the height of the water diversion joint between the

引水缝高度为1.25～2毫米
suction head and the dry cylinder is 1.25~2 mm

其排水原理是
The drainage principle is as follows

当冷凝水形成水环时
when condensate water forms a water ring

利用虹吸或喷射原理排水
it is drained by siphon or injection principle

当冷凝水聚集在下部时
when condensate water accumulates in the lower part

排水与戽斗相同
the drainage is the same as that of the scoop

双旋转虹吸管可以保持
The double rotating siphon can keep the

冷凝水层的厚度<0.8毫米
thickness of condensate water layer less than 0.8 mm

传热效率得到显著提高
and the heat transfer efficiency is improved remarkably

旋转虹吸管排水时
When the rotary siphon drains

除了克服提升凝结水重力
in addition to overcome the resistance

产生的阻力外
caused by lifting the gravity of condensate water

还要克服离心力上升的助力
but also to overcome the assistance of centrifugal force

特别是高速造纸机
especially in high-speed paper machinery

冷凝水受到的离心力成倍增加
the centrifugal force of condensate water is multiplied

烘缸和排水管之间的
The pressure difference between the dry cylinder

压差要非常大
and the drainage pipe shall be very large

这是烘缸内壁
This is the inner wall of the dry cylinder

即使只有很薄的滞留层水环
even if only a very thin retention layer of water ring

仍会产生很大热阻
will still produce a large thermal resistance

影响传热效率
affecting the heat transfer efficiency

和纸机运行性能
and paper machinery performance of operation

为解决冷凝水滞留问题
In order to solve the problem of condensate water retention

可以对旋转虹吸式
some improvements can be made

排水装置做一些改进
to the rotary siphon drainage device

比如在烘缸内设置扰流棒
For example, a turbulence bar is arranged in the dry cylinder

使冷凝水环产生振荡
to cause the condensate water ring to oscillate

然后，冷凝水被扰流棒
then, the condensate water is directed

导向成为轴向流动
by the turbulence bar into an axial flow

进入端部环形槽内
into the annular slot at the end

被固定虹吸管排出
and is discharged by a fixed siphon

这种扰流棒一般高60mm
The turbulence bar is 60 mm high

宽50mm左右
and 50 mm wide

可以采用磁力固定
It can be fixed by magnetic

或是弹性加紧环固定
or elastic tightening ring

为进一步提高
In order to further improve the

烘缸的传热效率
heat transfer efficiency of the dry cylinder

烘缸的结构也
the structure of the dry cylinder

进行优化改进
is also optimized and improved

发展出多开口烘缸
and the multi-opening dry cylinder

及夹层烘缸
and the interlayer dry cylinder are developed

多开口烘缸
Multi-opening dry cylinder

蒸汽通过在烘缸
The condensate water is discharged out

内表面上纵向开的
of the dry cylinder by the flow of steam

小沟槽内的流动
through the small grooves lengthwise

将凝结水排出缸外
open on the inner surface of the dry cylinder

而使凝结水形成的
to minimize the heat insulation water ring

隔热水环降到最小值
formed by the condensate water

夹层烘缸
Interlayer dry cylinder

蒸汽直接通入到
steam goes directly into the ring wall

接近烘缸圆周的环壁中去
near the circumference of the dry cylinder

可以降低烘缸的重量
which can reduce the weight of the dry cylinder

并减少大型烘缸中蒸汽引进
and reduce the problem of steam inlet and

和凝结水排出难的问题
condensate water discharge in the large-scale dry cylinder

而且传热性能等非常好
and heat transfer performance is very good

但制造成本比较高
but the manufacturing cost is relatively high

今天的课就讲到这里
So much for this lesson

谢谢大家
thank you all