The hot air of the airflow dryer enters the dryer and quickly impacts the material and mixes with the material in an instant to maximize the contact area between the fluidization and the air to rapidly evaporate the water. The gas-solid two phases are separated by dust separation to obtain the product. Pulsed airflow drying is based on the addition of a thicker buffer tube to the straight tube airflow dryer to increase the relative motion of the gas-solid two phases and thereby increase the drying rate. It is suitable for the drying of filter cake materials with little or no viscosity. Generally, it needs mechanical dehydration before drying. The drying time of the airflow dryer is generally 1-4 seconds, and the product has left the dryer before the temperature has risen, so it is suitable for drying the heat sensitive material.
The dry form of water is mainly surface water, and it is difficult to meet the process requirements for materials containing more internal water. The machine can be designed into a blast system, an air intake system, a drum air intake system according to the process requirements, and the air blower can double as a diffuser. In the drum fan system, the fan can be steplessly changed by the frequency converter, so that the system “0 pressure†can be accurately controlled at the feeding place or the cyclone of the cyclone. For the common welding pipelines of flammable and explosive materials, the temperature is too high due to the accumulation of materials. The factory has a unique processing technology to make the materials such as the inner wall of the drying pipe and the flange joints absolutely smooth to ensure that the materials do not stay in the device.
The drying strength is large, and the equipment investment is saved: the processing capacity of the airflow drying equipment is the largest, and the evaporation water capacity is from 50kg/h to 1500kg/h, while the equipment volume is small and the investment is saved, which is not comparable to other drying equipment.
High degree of automation, good product quality: airflow drying materials are all carried out in the pipeline, the drying time is very short (only O.5-2 seconds), so automation can be achieved, the product is not in contact with the outside world, the pollution is small, and the quality is good.
Airflow dryer Drying intensity Large airflow drying Because the airflow velocity is high, the particles are well dispersed in the gas phase, and the entire surface area of ​​the particles can be used as the effective effective area for drying. Therefore, the drying effective area is greatly increased. At the same time, the gasification surface is continuously renewed due to the dispersion and agitation during drying, and therefore, the heat transfer and mass transfer processes of the drying process are strong. The drying time is short and the contact time of the gas-solid two phases is extremely short. The drying time is generally 0.5 to 2 seconds and the longest is 5 seconds. The thermal denaturation of materials is generally a function of temperature and time, and therefore, heat sensitive or low melting materials do not cause overheating or decomposition and affect their quality.
The airflow dryer has high thermal efficiency and airflow drying adopts gas-solid phase cocurrent operation. Moreover, in the surface gasification stage, the material is always at the wet bulb temperature of the gas it is connected to, generally not exceeding 60~65 °C, and the temperature of the material rises at the end of dryness. At the stage, the gas temperature has been greatly reduced and the product temperature does not exceed 70 to 90 °C. Therefore, a high temperature gas can be used. A gas drying tube with a diameter of 0.7m and a length of 10~15m can process 25 tons of coal or 15 tons of ammonium sulfate per hour. The airflow dryer has simple equipment, small footprint and low investment. Compared with the rotary dryer, the floor space is reduced by 60% and the investment is about 80%. At the same time, unit processes such as drying, pulverizing, sieving, and conveying can be combined, which not only simplifies the process, but also facilitates automatic control. Wide range of applications Airflow drying can be used for a variety of powdered materials.
In the choice of heating mode, the airflow drying equipment has greater adaptability. The user can select steam, electricity and hot blast stove according to the conditions of the local area, and at the same time, according to the heat resistance temperature (or hot air temperature) of the material: ≤150°C When steaming is optional, ≤200°C, electric heating (or steam heating, electric compensation or heat transfer oil heating); ≤300°C, coal-fired hot blast stove; ≤600°C, fuel hot blast stove.