The paddle dryer is a low-speed agitating dryer which is provided with a stirring slurry inside the equipment to make the wet material fully contact with the heat carrier and the hot surface under the agitation of the blade, thereby achieving the purpose of drying, and the structure is generally horizontal. Two or four axes. The paddle dryer is divided into hot air type and conductive type.
The hot air type is in contact with the dried material by a heat carrier (such as hot air) and is dried. In the conductive type, the heat carrier is not in direct contact with the material to be dried, but the hot surface and the material are in contact with each other.
A wedge-shaped hollow blade is densely arranged on the hollow shaft, and the heat medium flows through the blade through the hollow shaft. The heat transfer area in the effective volume of the unit is large, and the temperature of the heat medium is from -40 to 320 ° C, which may be water vapor or liquid type: such as hot water and heat transfer oil. Indirect transmission to heating, no air carrying heat, heat is used to heat the material, heat loss is only through the body insulation layer to the environment. The wedge-shaped blade heat transfer surface has a self-cleaning function, and the relative movement of the material particles and the wedge surface produces a scrubbing action, which can wash away the deposit on the wedge surface, and maintains a clean heat transfer surface during the test operation.
It can be seen from the structure of the device that the heat required for drying is mainly provided by the hollow blade wall surface arranged on the hollow shaft, and the heat transfer amount of the wall surface of the fire jacket only accounts for a small portion. Therefore, the heat transfer surface of the unit volume equipment is large, which can save equipment footprint and reduce capital investment.
The heat required for drying is not provided by the hot body, which reduces the heat loss carried away by the hot gas. Due to the compact structure of the device and the small number of auxiliary devices, the heat loss is also reduced. The heat utilization rate can reach 80% – 90%, using multi-effect drying, only 250kg of steam per ton of water is evaporated.
It has been mentioned that the wedge-shaped paddle drying can adjust the drying process conditions by various methods, and its operation is easier to control than the fluidized bed drying and airflow drying operations, so as to be suitable for various operations.
Since no gas is required for heating, the amount of gas used in the drying process is greatly reduced. With a hollow blade dryer, only a small amount of gas is required to carry the evaporated moisture, and the drying system does not condense dew at the dry operating temperature.
Due to the small amount of gas, the gas flow rate in the dryer is low, and the dust emitted by the body is less. The gas dust recovery of the system after drying is convenient, the size of the cyclone separator can be reduced, and the bag filter can be omitted or reduced. Gas heaters, blowers, etc. can be scaled down, saving equipment investment.
The desiccator is provided in the dryer, and the residence time of the materials in the dryer can be adjusted according to the nature of the material and the drying conditions to meet the drying requirements of the difficult-to-dry materials and the high-moisture materials. In addition, the feed rate, the shaft speed and the heat carrier temperature can be adjusted, and the material residence time can be arbitrarily selected between several minutes and several hours. Therefore, the adaptability to materials is very wide. In addition, a plurality of stirring blades are arranged in the F dryer to make the materials fully mixed in the dryer from the feeding port to the discharging port, and the product is evenly dried.
The dispersing force generated by the combined movement of the inclined surface of the rotating blade and the particle or powder layer causes the material attached to the heating ramp to be automatically removed, and the blade maintains an efficient heat transfer function. In addition, due to the reverse rotation of the two-axis blades, the material is alternately segmented (when the two-axis paddles are closest to each other) and the material on the slope of the expansion (the farthest distance between the two-axis blades) The material near the surface is stirred agly, improving the heat transfer effect. The paddle type agitator has a high heat transfer coefficient of 85-350W/(M2.K).
Transportation, convenient loading and unloading.
The evaporation of a single unit can reach 60 tons per hour.
No exhaust gas treatment device is required.
The paddle dryer consists of two to four blade shafts, a W-shaped housing with a jacket, a base and a transmission part.
The entire drying process of the material is carried out in a closed state, and the organic volatile gas and the odor gas are It is sent to the exhaust gas treatment device in a closed atmosphere to avoid environmental pollution.
Add material warehouse
Main motor
Split cylinder