Complaint
Tower refers to equipment used for physical processes such as separation or absorption, and for changing the composition of complex gas or liquid mixtures. Also known as "tower equipment". The ratio of height to diameter is large, and there are certain accessories installed inside and outside the tower. The internal components are used to make the gas in the material in close contact with liquid, gas with solid, liquid with liquid or liquid with solid, and the surface is constantly updated to complete the process of mass transfer (usually accompanied by heat transfer).Tower is a process equipment with a cylindrical welded structure, consisting of a cylinder, a head (or cover), and a support. It is a non-standard equipment designed and manufactured specifically for a certain production process requirement. Tower is a vertical equipment used for chemical unit operations such as distillation, purification, absorption, and distillation, widely used for mass and heat transfer between gas-liquid and liquid-liquid phases. According to the structural classification of tower components, towers can be divided into plate towers and packed towers. If the container only contains materials without conducting chemical reactions or other physical and chemical processes, without facilities or simple auxiliary structures, it is also known as a tank. Containers are divided into two types by type: vertical (with a vertical axis) and horizontal (with a horizontal axis). Most towers belong to pressure vessels.
Equipment for transferring substances between gas and liquid phases or between liquid and liquid phases. According to structure, there are two main categories: plate tower and packed tower. A certain number of trays are installed inside the tray tower, and gas is transmitted through bubbling or jetting in contact with the liquid layer on the tray. The packing tower is equipped with a certain height of packing, and the liquid flows from top to bottom along the packing, while the gas contacts the liquid film countercurrent from bottom to top for material transfer. Commonly used in distillation, water absorption, extraction, and other operations.
A packed tower is a mass transfer equipment that uses the packing inside the tower as a contact component between the gas and liquid phases. The body of the packed tower is a vertical cylinder, with a packing support plate installed at the bottom. The packing is placed on the support plate in a disorderly or integral manner. Install a packing press plate above the packing to prevent it from being blown by the upward airflow. The liquid is sprayed onto the packing from the top of the tower through a liquid distributor and flows down the surface of the packing. Gas is sent from the bottom of the tower and distributed through a gas distribution device (small diameter towers generally do not have a gas distribution device). It flows continuously through the gaps in the packing layer in a countercurrent manner with the liquid, and on the surface of the packing, the gas-liquid two phases are in close contact for mass transfer. The packed tower belongs to a continuous contact gas-liquid mass transfer equipment, and the two-phase composition changes continuously along the tower height. Under normal operating conditions, the gas phase is a continuous phase, while the liquid phase is a dispersed phase.
When the liquid flows downwards along the packing layer, there is a tendency to gradually concentrate towards the tower wall, causing the liquid flow rate near the tower wall to gradually increase. This phenomenon is called wall flow. The wall flow effect causes uneven distribution of gas-liquid two-phase flow in the packing layer, resulting in a decrease in mass transfer efficiency. Therefore, when the filling layer is high, it is necessary to segment and set up a redistribution device in the middle. The liquid redistribution device includes two parts: a liquid collector and a liquid redistribution device. The liquid flowing from the upper packing is collected by the liquid collector and sent to the liquid redistribution device. After redistribution, it is sprayed onto the lower packing. The packed tower has the advantages of large production capacity, high separation efficiency, small pressure drop, small liquid holding capacity, and large operating flexibility.
