Heat exchange of granular-fibrous materials in a fluidized bed with superimposition of hot coolant jets

Аннотация

In this article, the process of heat exchange between granular-fibrous materials in a pseudo- liquefied layer formed by the flow of liquid or gas is scientifically and technically covered. Based on the temperature difference between heat carriers (hot water, steam, gas) and materials, the efficiency of this process is ensured by the free movement of the heat carrier in the layer, the expansion of surfaces, as well as intensive convection. The focus is on parameters such as heat transfer coefficient, temperature gradient, heat capacity of the material and flow rate. The possibilities of process analysis through mathematical modeling (Fourier, Navy-Stokes equations) and experimental methods are also considered. Keywords: Heat exchange, liquefied layer, granular- fibrous materials, heat carrier, convection, heat capacity, temperature gradient, modeling, Fourier, Navy-Stokes. Introduction: Heat exchange between granular-fibrous materials in a layer diluted (falsely liquefied) with hot and coolant flows is one of the important and complex The American Journal of Engineering and Technology 151 https://www.theamericanjournals.com/index.php/tajet The American Journal of Engineering and Technology sections of the thermal technique. This process is liquefied layer is the very intensive nature of heat and widely used, especially in modern industries — mass exchange processes due to the mobility of the chemical, energy, food, pharmaceutical, building particles in the layer. It is widely used, especially in the materials production and many other industries. In chemical industry, in catalytic processes, drying, such technological processes, the process of heat roasting, granulating, washing, synthesizing or many exchange plays an important role in order to obtain a other technological processes where rapid transfer of target product, save energy or effectively use thermal heat from one substance to another is necessary. It is energy. also used effectively in the energy sector, such as activated charcoal, waste recycling, heat exchange A dilute layer is such a technological state in which a reactors. high-speed flow of liquid or gas is passed under solid particles (such as sand, granular or fibrous materials). Another important aspect in the process of heat In this case, the particles begin to move as if they had exchange in a dilute layer is the dynamics of movement lost their weight, creating an effect similar to that of of particles in the layer and the mobility of different them floating in a liquid. This layer is therefore known materials relative to each other. Especially when as the” pseudo-liquefied layer". This situation greatly granular and fibrous materials are present in the same intensifies the processes of heat and mass exchange, layer, due to their different density, shape, size, and since the surface of contact between the heat carrier thermal conductivity, the thermal distribution in the and the particles and the dynamics of movement layer may not be the same. This causes temperature increase. fluctuations in local zones within the layer. Granular-fibrous materials, on the other hand, The process is also influenced by the chemical combine two types of physical structures: the first is properties of the heat carrier, which is injected as a gas spherical or irregularly shaped granules, while the or liquid. For example, if a heat-carrying gas contains second is fibrous or filamentous. The presence of these reactive components, they can chemically react with the two different structures in one layer increases the material, causing thermal separation or absorption. In complexity of the heat transfer process. Fibers these cases, heat exchange takes place not only on a increase the surface area, but they can be slower to physical basis, but in conjunction with chemical transfer heat. Granules, on the other hand, can absorb processes, which complicates the model and or transmit heat more quickly. As a result, materials calculations. At the same time, automated monitoring with different densities, heat capacity, thermal and control systems for liquefied layers are being used conductivity and heat dissipation rates are in modern heat exchange systems. Such systems simultaneously involved in the heat exchange process. measure temperature, pressure and flow rate in real time, keeping the process in optimal condition. This The process of heat exchange is usually carried out technology is particularly important in the energy through hot or cold heat carriers — such as steam, hot facilities, Petroleum and chemical industries, providing water, cold air or other gases—. When these currents safety and efficiency. collide with particles or pass between them, heat is given or obtained due to the temperature difference. Granular-fibrous materials are special substances used In particular, convective heat exchange is at a high in these processes. They contain particles of two level because of the High freedom of movement of t