Hollow blade dryer

Abstr: 1. Structure principle: hollow blade dryer is mainly composed of W-shaped shell with jacket, two hollow blade shafts and transmission device. The shaft end is equipped with a rotary joint for hot medium introduction. The heating medium is steam, hot water or heat transfer oil. The heating medium is passed into the shell jacket and two hollow impeller shafts, and the materials are heated and dried by conduction heating. The structure of hollow propeller blade shaft is different for different materials

1、 Structure principle:

Hollow blade dryer is mainly composed of W-shaped shell with jacket, two hollow blade shafts and transmission device. The shaft end is equipped with a rotary joint for hot medium introduction.

The heating medium is steam, hot water or heat transfer oil. The heating medium is passed into the shell jacket and two hollow blade shafts, and the materials are heated and dried by conduction heating. The structure of hollow propeller shaft is different for different materials.

The material is added from the feeding port. Under the stirring action of the two hollow impeller blades, the interface is updated. At the same time, the material is pushed to the discharge port, and the dried material is discharged from the outlet.



2、 Equipment features:

1. The equipment is compact in structure and occupies a small area. According to the structure of the equipment, the heat needed for drying is mainly provided by the walls of many hollow blades densely arranged on the hollow shaft, while the heat transfer from the jacket wall only accounts for a small part. Therefore, the heat transfer surface of the unit volume equipment is large, which can save the equipment area and reduce the infrastructure investment.



2. The heat utilization rate is high. The heat needed for drying is not provided by hot gas, which reduces the heat loss taken away by hot gas. Due to the compact structure of the equipment and less auxiliary devices, the heat loss is also reduced. The utilization rate of heat can reach 80% - 90%.



3. The wedge-shaped blade has the self-cleaning ability, which can improve the heat transfer effect of the blade. The dispersive force produced by the joint movement of the inclined plane of the rotating blade and the particles or powder layer makes the materials attached to the heating inclined surface easy to be removed automatically, and the blade maintains the high-efficiency heat transfer function. In addition, due to the reverse rotation of the two axis blades, the materials on the inclined plane are alternately compressed (when the distance between the inclined planes of the two axis blades is ^ close) and the materials on the inclined plane are expanded (when the two axis blades are far away from each other), so that the materials near the heat transfer surface are stirred violently and the heat transfer effect is improved. The heat transfer coefficient of wedge paddle agitated dryer is 85-350 w / (M 2 · K)



4. With less gas consumption, some auxiliary equipment can be reduced or omitted accordingly. Since no gas is needed for heating, the amount of gas used in the drying process is greatly reduced. Only a small amount of gas is needed to carry the moisture content of evaporation by using wedge-shaped paddle dryer. The amount of gas used is very small, so the drying system can not condense dew under the condition of drying operating temperature.



Due to the small amount of gas, low gas flow rate in the dryer, less dust carried by the gas, the gas dust recovery of the system after drying is convenient, the size of cyclone separator can be reduced, and the bag filter can be omitted or reduced. The scale of gas heater and blower can be reduced to save equipment investment.

5. Wide adaptability of materials and even drying of products. Overflow weir is set in the dryer to adjust the material retention in the dryer according to the material properties and drying conditions. The retention of materials in the dryer can reach 70% - 80% of the volume of the cylinder, and the residence time of the materials can be increased to meet the drying requirements of the hard to dry materials and high moisture materials. In addition, the feeding speed, shaft speed and temperature of heat carrier can be adjusted, and the residence time of materials can be arbitrarily selected between a few minutes and a few hours. Therefore, it is suitable for both easy to dry and difficult to dry materials. The moisture content is only 0.1%. In addition, although there are many agitating blades in the dryer, and the materials are evenly mixed, the flow of materials from the feeding port to the discharge port in the dryer is basically piston flow, the residence time distribution is narrow, and the product is dried evenly.

6. Suitable for various drying operations. As mentioned above, the wedge-shaped paddle drying can adjust the drying process conditions by various methods, and its operation is easier to control than that of fluidized bed drying and air flow drying, so it is suitable for a variety of operations.

The main structure of hollow paddle dryer is composed of W-shaped groove and two rotating hollow shafts installed in the slot, on which are arranged hollow blades. The heat required for drying moisture is transmitted to the material by the inner wall of W-shaped groove with jacket and the wall of hollow blade. In the drying process, the hollow shaft with hollow blade heats the material and stirs the material to update the heating surface. It is a continuous conduction heating dryer.



characteristic

Compact structure, small floor area.

The heat utilization rate is high.

The blades have self-cleaning ability.

With less gas consumption, some auxiliary equipment can be reduced or omitted accordingly.

Wide adaptability of materials and even drying of products.

It is suitable for various drying operations.

Scope of application:

This machine is suitable for processing paste, granular and powder materials with good thermal stability. It can also dry heat sensitive materials and recover solvents during drying under special conditions.

Typical drying materials include carbon black, light calcium carbonate, nitrile uric acid, gypsum, clay, manganese dioxide, nylon and polyester chips, polyethylene, polypropylene (recovery solvent), etc.