简介

螺旋挤压脱水机(Screw extrusion dehydrator)是一种用于凝聚、脱水的主要设备。主要由螺杆、圆筒形笼式外壳和锥体三部分组成，由挠性联轴节将螺杆轴与减速器的输出轴连接起来。
 

Brief Introduction

Screw extruder is a main equipment used for coagulation and dehydration. It is mainly composed of screw, cylindrical cage shell and cone. The screw shaft is connected with the output shaft of reducer by flexible coupling.

脱水机主要由螺杆、圆筒形笼式外壳和锥体三部分组成，由挠性联轴节将螺杆轴与减速器的输出轴连接起来。

1.螺杆

由节螺纹和轴环交替地套在螺杆轴上组成。每节螺纹和轴环分别用键固定在螺杆轴上。螺纹除第1节（进料区）为三圈等距连续螺纹外，其余各节均为单圈开放式，各节螺距均不相同，由低压侧到高压侧逐渐缩小，轮毂直径则逐渐增大以增加压力，藉以挤出橡胶中的水分。

2.圆筒形能式外壳

由固定在骨架上的笼条所组成的蓖子板构成。蓖子板分8段，每段长度不等。圆筒内径为18英寸，在垂直中心线上分成两半以螺栓紧固，以便于清洗和维修时拆卸。组成蓖子板的笼条之间被弹簧片隔开形成纵缝，以使水分流出。在圆筒内上下两侧的骨架上设有刮刀，与螺杆上的轴环位置相对应，其作用是阻止橡胶随螺杆旋转，强制橡胶改变推进方向和位置，并使之形成疏松多孔状，以利于干燥。圆筒外部设有四个供加热或冷却用的夹套，可根据工艺要求分区控制机内的温度。在丁苯橡胶生产中，只是在开车前通蒸汽预热机体时才使用。

3.锥体

这是设在出料区的锥形圆筒，可以前后移动以便与固定在螺杆轴上的环相配合。锥体前后移动是由调速电机通过四个千斤顶组成的齿轮带动的同时也设有手动调节机构。通过锥体的前后移动来增减出口锐孔的面积，以改变机内的压力，从而调节橡胶的脱水率。橡胶自锥体锐孔挤出后，被安装在螺杆轴上的刀具切成小块。由于橡胶在机内受到机被的剪力和被压缩而使温度升高，故在通过锥体锐孔时橡胶中的水分即行闪蒸，从而使橡胶呈疏松多孔状。

Main Structure and Function of Each Component
The dehydrator is mainly composed of screw, cylindrical cage shell and cone. The screw shaft is connected with the output shaft of the reducer by flexible coupling.

1. screw

The screw is composed of a screw thread and a shaft ring alternately sleeved on the screw shaft. Each thread and shaft ring are fixed on the screw shaft with keys. Except for the first section (feeding area) which is three-circle continuous threads with equal distance, the other sections are single-circle open type. The pitches of each section are different. The pitches of each section are gradually reduced from the low pressure side to the high pressure side, while the diameter of the hub is gradually increased to increase the pressure so as to extrude the moisture in rubber.

2. cylindrical energy shell

It is made of castor plates made of cage bars fixed on the skeleton. The castor plate is divided into 8 sections with different lengths. The inner diameter of the cylinder is 18 inches and is bolted in two halves along the vertical center line for easy removal during cleaning and maintenance. The cage bar consisting of castor plates is separated by springs to form longitudinal joints to cause water to flow out. A scraper is arranged on the skeleton of the upper and lower sides of the cylinder, which corresponds to the position of the axle ring on the screw. Its function is to prevent the rubber from rotating with the screw, force the rubber to change the direction and position of propulsion, and make it porous, so as to facilitate drying. There are four jackets outside the cylinder for heating or cooling, which can control the temperature in the machine according to the process requirements. In the production of styrene butadiene rubber, it is used only when steam is preheated before starting up the machine.

3. cone

This is a conical cylinder located in the discharge area, which can be moved back and forth to match the ring fixed on the screw shaft. The front and back movement of the cone is driven by the gears composed of four jacks of the speed governing motor, and at the same time there is a manual adjusting mechanism. By moving the cone back and forth, the area of the sharp hole at the outlet is increased and reduced, so as to change the pressure in the machine, thus adjusting the dehydration rate of rubber. After extrusion of the rubber cone, the cutter is cut into small pieces on the screw shaft. Because rubber is heated by shearing force and compression inside the machine, water in the rubber flash evaporated when passing through the sharp hole of the cone, which makes the rubber porous.

1、旋转过滤：污泥经絮凝剂剂絮凝后，形成一定强度的絮团，含有大量自由水的固液混合物经立式反应器溢流口进入旋转过滤机，污泥在螺旋轴轴叶片的推动下向前运动，由于重力作用进行自由脱水，滚筒与螺旋转向相反，使污泥在滚筒内不断翻滚，把絮团内部自由水不断的滤出，浓缩后的污泥经螺旋叶片推送中出料口，进入下一级脱水工序。

2、螺旋挤压：预脱水完的污泥经进料斗进入螺旋挤压机后，污泥在锥度螺旋轴和变径螺旋的作用下，使物液产生体积上压缩，从而使料液中的水分通过孔状滤筒迅速被分离出去，而固体物在不断压缩的作用下含水率逐渐下降而成为我们所需要的滤饼，最后在螺旋的输送作用下排出机外  。

Working principle

1. Rotary filtration: sludge is flocculated by flocculant to form a certain strength flocculent. Solid-liquid mixture containing a large amount of free water enters the rotary filter through the overflow port of vertical reactor. Sludge moves forward under the impetus of the helical shaft blade. Because of gravity, it is dewatered freely, and the drum turns opposite to the helix. Sludge rolls continuously in the drum, and the free water in the floc is filtered out continuously. The concentrated sludge is pushed to the outlet through the spiral blade and enters the next dewatering process.

2. Screw extrusion: After the pre-dewatered sludge enters the screw extruder through the feed hopper, the sludge is compressed in volume under the action of taper helix axis and diameter-changing helix, so that the moisture in the sludge is quickly separated through the porous filter, while the moisture content of solid gradually decreases under the action of constant compression to become the filter cake we need, and finally discharge it out under the action of screw transportation.

如酒糟、果渣、药渣、木薯渣等的脱水，大大减轻干燥机的负担，产量大幅度提高，能耗大幅度降低，是高湿物料干燥前必不可少的处理设备，经过脱水后的物料可以直接进入干燥设备。

Purpose

For example, the dehydration of distiller's grains, fruit dregs, medicine dregs and cassava dregs can greatly reduce the burden of dryer, greatly increase the output and reduce the energy consumption. It is an indispensable treatment equipment before drying of high-humidity materials. The dehydrated materials can directly enter the drying equipment.