1.    Introduction to Airflow Dryer

The wet material is quantitatively, evenly and continuously added to the lower part of the dehydrating tube by a speed-adjustable screw feeder, and is dispersed by the high-speed hot air flow. In the process of gas-solid co-current flow, heat and mass transfer are carried out to dry the material. Entering the cyclone separator with the airflow, the dried solid material is collected after separation and the exhaust gas is discharged through the fan. Due to the high-speed flow of gas relative to the material particles and the large contact area between the gas and solid phases, the volume heat transfer coefficient is quite large. Airflow drying is suitable for processing materials with small particle size and the drying process is mainly surface gasification.

2. Equipment characteristics

(1) High drying intensity: Due to the high airflow speed, the particles are well dispersed in the gas phase, and the particles can fully contact the airflow, which greatly increases the effective drying area. At the same time, due to the dispersion and stirring effect during drying, the gasification surface is constantly renewed, so the heat transfer and mass transfer process of drying is relatively strong.

(2) Short drying time: The contact time between gas and solid phases is very short, generally 0.5-2s, and up to 5s. Therefore, heat-sensitive or low-melting-point materials will not be overheated or decomposed to ensure their dehydrating quality.

(3) High thermal efficiency: Airflow drying adopts gas-solid co-current operation. In the surface gasification stage, the material temperature is always consistent with the wet-bulb temperature of the gas it contacts, generally not exceeding 60-65 degrees Celsius. At the end of drying, the material is in the temperature-rising stage, the gas temperature has been greatly reduced, and the product temperature will not exceed 70-90 degrees Celsius, so high-temperature gas can be reused.

(4) Large processing capacity and simple equipment: The air flow dryer is simple in equipment, occupies a small area, and requires little initial investment. At the same time, it can combine drying, crushing, sieving, conveying and other unit processes, which not only simplifies the process, but also makes the operation easy to control automatically.

(5) Wide range of applications: Airflow drying can be applied to various powdery and granular materials. When feeding directly into the airflow drying tube, the particle size can reach 10mm, and the moisture content can be between 10%-40%.

(6) Optional heat sources: steam heat exchange, electric heating, gas and oil, coal-fired indirect hot air furnace, coal-fired flue gas or mixed heat sources.

(7) The particles are worn and crushed to a certain extent for the high airflow speed. It is not suitable for granular products that strictly require a certain crystal form. It is also not suitable for materials that are easy to stick to the wall, very viscous, and materials that need to be dried to below the critical moisture content, nor for materials that will produce toxic gases during drying.

3. Applicable materials

(1) Chemical industry: calcium hydrogen phosphate, plastic resin, copper sulfate, ferrous sulfate, zinc sulfate, sodium fluorosilicate, p-aminophenol, sodium sulfate, various inorganic and organic salts;

(2) Food: potato starch, corn starch, sweet potato starch, cassava starch, glutinous rice flour, konjac flour, modified starch;

(3) Feed: rice bran, liquor grains, brewer's grains, rapeseed meal, active yeast, alcohol grains, feed trace elements (sulfates);

(4) Other categories: oral glucose, enzymes, coal dust, sawdust, wood chips, currants, puffed grain hulls.

4. Specification

5. Sketch Map