Suitability of using Silica Gel in Powder Form as an Adsorbent in the Drying Process
Abstract
Gases used in industry must meet the required parameters such as the content of gas impurities, moisture content and mechanical impurities, which have a significant impact on its subsequent use. Various industrial drying methods are used to remove moisture. Among the most used drying methods are methods based on subcooling the gas below the condensation temperature, adsorption drying methods or special methods. The article primarily deals with the drying of gases in a fluid layer of ground silica gel. It describes the issue of the suitability of silica gel as an adsorbent in any form of its structure, the advantages and disadvantages of its use.
Keywords
Download Options
Introduction
The drying process is a complicated physical process, in which the effect of heat reduces the liquid content in the substance, without changing its chemical composition.
The essence of drying is the migration of moisture in the opposite direction to the sorption process. During the general drying process, moisture moves from the porous core of the material to the surface layers and into the surrounding environment, whereupon the moisture meets the drying medium, which carries it away.
To determine the most optimal drying conditions, it is necessary to know the physical laws that affect drying in the individual phases of the entire process, the input parameters and the required performances.
Conclusion
The use of ground silica gel as an adsorbent has both advantages and disadvantages compared to classic silica gel. From an economic point of view, the drying method with the classic structure of silica gel is more advantageous, since the initial costs of changing its structure (grinding in a crushing mill) are eliminated, as well as the need to use a high-efficiency filter device. Another disadvantage of using ground silica gel is its lower weight, which makes it easier to drift. There is an increase in the height of the fluid layer, which reduces the density of the particles and the gas flows more easily around the dispersed particles. As a result of this phenomenon, their direct contact does not occur, which can be explained by the relatively high range of minimum and maximum measured humidity.
Since it was found by measurement that the removal of moisture from the gas using the method with ground silica gel and the classic structure represents a difference of only 5.2%, the drying method with classic silica gel is preferable, taking into account both economic and health aspects in the operation process. Ground silica gel carried by the air stream also has a significant impact on the life of filters, which tends to clog and reduce gas flow. Particles that are not caught by the filter can clog other parts of the device, as well as measuring instruments, which can subsequently be damaged and the given output parameters of the measured quantities can be distorted.