The dryer uses steam, hot water or heat transfer oil as the heating medium, and the shaft end of the hollow blade shaft is provided with a rotary joint for the introduction and export of the heat medium. The heating medium is divided into two paths, which respectively enter the dryer casing jacket and the blade shaft inner cavity, and simultaneously heat the body body and the blade shaft, and the blade on the blade shaft is hollow and connected with the blade shaft number. Pass; heat and dry the material by conduction heating. The dried wet material is continuously and continuously fed into the feeding port of the dryer by the star-feeding valve. After the material enters the body, the material is turned and stirred by the rotation of the blade, and fully contacted with the heated body and the blade. It is heated sufficiently to evaporate the moisture on the surface of the material. At the same time, the material is conveyed in the direction of the discharge port with the rotation of the blade shaft, and the stirring is continued during the transportation, so that the water oozing out from the material continues to evaporate. Finally, a dry, uniform, acceptable product is discharged from the discharge port. The volatile gas is discharged from the exhaust port in the middle of the upper casing.
The hollow blade dryer is a conduction heating dryer. It has obvious advantages in energy saving and environmental protection compared with other types of dryers, but there are also limitations on the heat transfer area. The maximum heat transfer area of the prior art does not exceed 180 m2, and multiple configurations are required when handling a large amount of materials, the floor space is large, and the manufacturing cost is high. The prior art of single large-scale manufacturing is to increase the diameter of the blade shaft or horizontally arrange four blade shafts in the same casing. Both methods have many difficulties in processing, lifting, installation and maintenance.
In response to the above problems and the needs of the development of the industry, the company is currently working on the research of technical solutions related to multi-layer multi-stage large-scale mixing and drying systems.
Project achievement
1. Successfully developed a multi-layer multi-stage large-scale drying system with modular and standardized design, which can be controlled at the level according to needs;
2. The system integrates the dual-flow high-level material mixing technology, heat pump heat recovery technology and multi-effect evaporation energy-saving technology. The three technologies are combined by a multi-layer structure to realize large-scale manufacture of a hollow blade dryer, which is a drying device capable of processing materials in large quantities;
3. The entire device is a superposition of several working units in the vertical direction. Each work unit bears the process load in a specific process environment position and works independently, and the entire device is combined organically and continuously to complete the process task;
4. Each layer structure consists of a jacketed W-shaped housing and two hollow blade shafts and transmissions. Hollow blades are arranged on the shaft, and the rotary end of the heat medium is introduced at the shaft end. The heat required to dry the moisture is conducted to the material by the inner wall of the jacketed W-shaped groove and the hollow blade wall. During the drying process, the hollow shaft with hollow blades is used to stir the sludge while heating the sludge, thereby updating the heating surface;
5. The heating medium is steam, hot water or heat transfer oil. The heating medium is introduced into the casing jacket and the two hollow blade shafts, and the sludge is heated and dried by conduction heating. The hollow blade shaft structure of different materials is different; the material is evenly added by the feeding spiral, Under the stirring action of the two hollow blade shafts, the interface is updated, and the sludge is pushed to the discharge port, and the next layer of drying unit is further dried, and then added to the new sludge, and so on, and finally dried. The mud is discharged from the discharge port;
6. It is equipped with heat pump heat recovery facilities, multi-effect evaporation energy-saving facilities, material addition facilities, dust recovery facilities and finished product delivery facilities.
7. The basic structure of the feeding system includes a cloth conveyor, a V-shaped multi-layer silo and a feeding screw device; the three silo outlets of the V-shaped multi-layer silo are respectively inserted into the mixing by the upper, middle and lower cloth conveyors. The upper mixing drying unit, the middle mixing drying unit and the lower mixing drying unit corresponding to the drying device; three feeding screw devices of upper, middle and lower are respectively arranged above the outlets of the three silos;
8. The feeding system can be composed of one or more cloth conveyors according to the number of unit layers of the hot shaft mixing and drying device, corresponding to each unit layer of the hot shaft mixing and drying device, the feeding port of each cloth conveyor and The corresponding discharge ports of the V-shaped multi-layer silos are connected, and the discharge ports of the cloth conveyors are multi-layer and multi-port discharge;
9. The system is suitable for the drying of water-containing powdery materials, paste materials and block cake materials in the coal industry, metallurgical industry, environmental protection industry and chemical industry; its structure is multi-layer structure, and each layer needs to be added. The material to be dried, and can be distributed in the drying device in a relatively uniform axial direction of the material to be dried. A silo is used to add the materials to be dried to each unit layer of the multi-layer drying device through a plurality of conveyors, and the silo has a material flow storage function.