1. Types of tower internals: mainly including liquid distributor, packing fastening device (packing tower), packing support device (packing tower), liquid collecting box (plate tower), tray support device (plate tower), liquid redistributor inlet outlet device, gas feed distribution device, demister, etc. 2. Gas liquid distributor, collector: 1) trough type liquid distributor: it is a kind of liquid distributor with excellent comprehensive performance. The trough type liquid distributor has the advantages of simple installation, uniform liquid distribution, high spray point density low pressure drop, which is widely used at present. 2) Tray type gas-liquid distributor: the tray type gas-liquid distributor has the functions of liquid collector, liquid distributor, gas distributor, etc. it has the advantages of low occupied space, strong anti blocking ability, no entrainment of liquid foam, large operating flexibility low pressure. 3) Baffle type liquid collector: the baffle type liquid collector is a device which is placed under the packing layer to collect the liquid in the tower whose distribution uniformity has reached the requirements for redistribution side line extraction. It does affect the uniformity of gas distribution, the pressure drop is small, which can be ignored. 3. Demister: the demister is installed in front of the gas outlet on the top of the tower to separate the liquid drops entrained in the tower gas, which only reduces the material loss reduces the harmful components entrained in the vent gas, so as to avoid environmental pollution. 1) Structure composition: it is mainly composed of screen block supporting device of fixed screen block composed of screen screen grid. The screen is a gas-liquid filter screen of various materials, the gas-liquid filter screen is composed of metal wire non-metal wire. The wire mesh demister can only filter the larger liquid foam suspended in the air flow, but also filter the smaller small liquid foam, which is widely used in the gas-liquid separation devices in chemical industry, petroleum, tower manufacturing, pressure vessel other industries. 2) Main principle: the gas is filtered through the wire mesh woven in the demister to remove the entrained mist. 3) Main type: drawer type demister adopts Hg t21586-98 standards, which is composed of several mesh demister elements is inserted into the tower through guide rail. The demister is characterized by operation maintenance. The demister can be replaced outside the tower. It is suitable for absorption tower drying tower of sulfuric acid plant. 4) Material: the wire mesh demister can be made of domestic imported high-quality materials. 4 tower packing: packing is the mass transfer element installed in the packing tower, which is mainly used to expand the contact area between liquid phase gas phase improve the separation efficiency of the tower. There are two kinds of commonly used packing: random packing regular packing. 1) The basic idea of design structure type specification: promote the continuous improvement of separation efficiency, improve the contact uniform distribution of fluid (liquid phase gas phase) in the tower; gradually expand its throughput to improve its production capacity to meet the needs of industrial production. Correct selection of packing is of great significance to improve the operation efficiency economic effect of the tower. 2) The basic requirements for packing: high mass transfer efficiency, large gas-liquid contact surface. That is to say, it is required to have a large specific surface area, the filler surface is easy to be wetted by liquid. Only wetted surfaces are gas liquid contact surfaces. Large production capacity small gas pressure drop. Therefore, it is required that the void ratio of the packing layer is large. It is easy to cause bias current furrow flow. Durable with good corrosion resistance, high mechanical strength necessary heat resistance. It's easy to get materials cheap. Regular packing is a kind of packing arranged in accordance with uniform geometry stacked neatly in the tower. Features: it can achieve the minimum pressure drop of each theoretical stage, so it can reduce the material temperature at the bottom of the tower save energy. It is especially suitable for the separation of multi-stage separation thermosensitive system. The separation efficiency is high, the resistance is small, the flux is large, the operation flexibility is large, the amplification effect is obvious. At the same time, it can overcome the random flow of liquid in bulk packing make the liquid tend to be evenly distributed. It has been proved that the regular packing has been successfully used in large tower. Type: regular packing includes metal hole plate, metal thorn hole plate, metal plate mesh (mesh), metal mesh, plastic hole plate, grid (glitch), etc.