The relationship between energy consumption and hot air temperature of sand dryer

Sand dryer is an industrial equipment mainly used to reduce the moisture content of sand and improve its use value. The equipment uses hot air to contact with sand, evaporates moisture quickly and achieves drying. It has the characteristics of energy saving, easy operation and environmental protection, and is widely used in construction, glass manufacturing and other industries. The design of sand dryer usually includes components such as heat source equipment, feeder, drum dryer, dust collector, etc., which can adjust the drying parameters according to the humidity and particle size of sand to ensure the quality and safety of sand after drying.

The increase in hot air temperature will accelerate the evaporation rate of moisture from the surface of sand to the air, thereby improving drying efficiency and shortening drying time. This is because high temperature can provide more heat energy, accelerate the migration of moisture inside the material and the vaporization of surface moisture. The higher the hot air temperature, the better. Excessive hot air temperature may lead to energy waste, and may cause local overheating of sand, over-drying or gelatinization, damage the physical properties of sand, such as darkening of color, decreased activity, etc., and may increase the thermal stress of equipment and affect the service life of sand dryer.

Excessively high hot air temperature may also increase the heat carried away by the flue gas, reduce thermal efficiency, and increase energy consumption. In actual operation, it is necessary to select an appropriate hot air temperature according to the initial moisture content of the sand, the particle size distribution, and the specific conditions of the drying equipment, so as to minimize energy consumption while ensuring the drying quality and efficiency.

For sand with uneven particle size distribution, small particles have a relatively large specific surface area, and the water is easier to evaporate, and the drying speed is fast; while the water diffusion inside large particles is slow, and the drying time is longer. If the sand contains a large amount of fine powder, this part of the material is easy to adhere to the surface of the particles during the drying process to form a coating layer, which hinders the evaporation of water and thus reduces the drying efficiency.

Reasonable particle size distribution can optimize the drying effect of the sand dryer. Generally, sand with smaller particle size is more suitable for low temperature and long time drying, while sand with larger particle size can improve the drying efficiency by appropriately increasing the hot air temperature. For sand with larger particle size, its particle size distribution can be adjusted through pre-treatment steps such as pre-crushing and screening, so that it is more conducive to the rapid removal of water and improves the overall drying efficiency.