Non standard equipment fixed vulcanization bed

Fluidized bed reactor refers to the suspended motion state (i.e. fluidized state) of solid particulate materials in the equipment under the action of gas flow (or liquid flow). The solid particle layer in fluidized state has the characteristics of a liquid, for example, the suspended solid particle layer can maintain a certain horizontal interface like water and has static pressure and buoyancy, and has fluidity like water. This technology is also known as gas-solid fluidization technology.
The gas flows through the bed material layer composed of solid particles. When the gas flow rate is relatively low, the solids do not move relative to each other. The gas flows through the gaps between the particles and passes through the bed layer. This is a gas-solid contact form called a fixed bed. On this basis, the gas flow rate is further increased, and the sum of the drag force of the gas on the particles (and the frictional force of the gas flowing into the surface of the particles) and buoyancy exceeds the gravity of the particles. The particles are suspended, and there is no longer any force between them. The gas-solid system has the properties of a fluid, and the solid is fluidized, at which point it is in the initial fluidized state. If the gas flow rate is further increased, the bed continues to expand. When more gas enters the system and exceeds the gas flow rate required for initial fluidization, the gas passes through the bed in the form of bubbles, which is called bubbling fluidization. As the gas velocity further increases, a large number of particles are carried away from the bed surface, and the interface on the bed surface is no longer clear, corresponding to a turbulent bed. A reactor that utilizes a bubbling or turbulent bed in gas-solid contact for gas-solid reactions is called a fluidized bed reactor.
Fluidized bed reactor, also known as fluidized bed reactor, is used in gas-solid systems. The fluidized bed phenomenon was discovered by German Fritz Winkler, and its early application in modern industry was the powder coal gasification furnace that appeared in the 1920s, which is the Winkler furnace (see coal gasification furnace); Its large-scale industrial application was petroleum catalytic cracking by Warren Lewis and others at MIT in the 1940s. At present, fluidized bed reactors have been widely used in various sectors such as chemical, petroleum, metallurgical, and nuclear industries.
Product Category
According to the application of fluidized bed reactors, they can be divided into two categories: one type mainly processes solids, such as the roasting of ores, which is called solid-phase processing; Another type of processing object is mainly fluids, such as catalytic reaction processes such as petroleum cracking and enzyme reactions, which are called fluid phase processing processes.
structural form
There are two forms of structure for fluidized bed reactors: ① There are continuous feeding and discharging devices for solid materials, which are used in solid-phase processing or fluid phase processing where catalysts are rapidly deactivated. For example, in the process of catalytic cracking, the catalyst is significantly deactivated within a few minutes and needs to be continuously separated and regenerated using the above-mentioned device. ② A continuous feeding and discharging device for solid materials, used in a reaction process where the characteristics of solid particles do not undergo significant changes for a considerable period of time (such as six months or one year).
Product advantages and disadvantages
Compared with fixed bed reactors, the advantages of fluidized bed reactors are: ① they can achieve continuous input and output of solid materials; ② The movement of fluids and particles gives the bed excellent heat transfer performance, with uniform internal temperature and easy control, making it particularly suitable for strongly exothermic reactions; ③ It is convenient for continuous regeneration and cycling of catalysts, and is suitable for processes with high catalyst deactivation rates. The rapid development of catalytic fluidized bed cracking of petroleum fractions is a typical example in this regard. However, due to the inherent characteristics of fluidization technology and the diversity of influencing factors in the fluidization process, fluidized beds have obvious limitations for reactors: ① Due to the intense circulation and agitation of solid particles and bubbles in the continuous flow process, both gas and solid phases have a relatively wide residence time distribution, resulting in inappropriate product distribution and reducing the yield of target products; ② The reactants pass through the bed in the form of bubbles, reducing the contact opportunities between gas and solid phases and lowering the conversion rate of the reaction; ③ Due to the intense impact and friction of solid catalysts during the flow process, the catalyst accelerates pulverization, coupled with the bursting and high-speed movement of bubbles at the top of the bed layer, and the removal of a large amount of fine-grained catalysts, resulting in significant catalyst loss; ④ The complex fluid dynamics and transmission phenomena within the bed make the process under unsteady conditions, making it difficult to reveal its unified laws and to operate without empirical amplification and manipulation.