Rotary continuous microwave drier

Abstract

The rotary continuous microwave drier includes one microwave drying oven with inner cavity with wall painted with one layer of PTFE, right and left parallel vertical baffles of metal plates surface painted with PTFE on the two sides of the oven, one 4-20 deg inclined rotary container with material feeding pipe and air exhaust pipe extending beyond the side oven all at the high end and material discharge pipe and air intake pipe extending beyond the side oven wall at the lower end, microwave suppressors set at the joints between each of the said pipes and the side oven wall. The apparatus dries material inside the container continuously and automatically, and the evaporated water vapor is limited inside the container and thus has no influence on the circuit, resulting in long service life and high operation safety of the equipment.

Description

field of invention [0001] The invention belongs to a microwave continuous drying device, in particular to a rotary continuous microwave drying device suitable for drying granular and powdery materials with high water content and materials that are easily oxidized and decomposed when heated. Background technique [0002] The drying of materials is a very important link in many production processes. The selection of drying methods and drying equipment will have a great impact on the output and quality of the target product, as well as the consumption of manpower, material resources and energy in the drying process. As a new type of drying method, microwave drying uses the principle of selective absorption of microwave by materials to rapidly heat the water in it, and finally achieves the purpose of evaporation and removal. Because microwaves can penetrate into the material and heat the material in volume, microwave drying has the advantages of unifo...

AI Technical Summary

Problems solved by technology

In order to prevent microwave leakage, the opening height at both ends of the equipment is relatively small, generally about 5 cm, and the ventilation capacity of microwave equipment is poor, so it is only suitable for drying materials with low moisture content, small thickness and stable properties.

However, for the drying of granular or powdery heat-sensitive materials, the equipment has defects such as low water vapor diffusion rate and easy local overheating and denaturation of materials.

Although some equipment is equipped with a blower device to increase the diffusion rate of water vapor and bring out the excess heat generated during the drying process, due to the defects of the conveyor belt continuous microwave drying equipment itself, there are still many problems in the drying process of materials.

The main performance is as follows: (1) Due to the small size of powdery and granular materials, non-porous conveyor belts are used for material transportation, and the airflow can only pass through the sides of the conveyor belt or the upper surface of the materials to cool the materials and take away the evaporated water vapor, although the materials The surface layer has been well dried, but the water vapor and excess heat inside the bottom material on the conveyor belt are difficult to be carried out by the air flow in time, and it is easy to overheat and cause material denaturation; (2) due to the poor exhaust capacity of the equipment, water vapor (drying process (produced in the process) when encountering the inner wall of the equipment with a relatively low temperature, it is easy to condense and drip back, causing the material to be overheated and denatured, which affects the quality of the product; (3) The material is easily affected by environmental impurities when transported on the conveyor belt Materials with high water content are likely to cause moisture inside the equipment, resulting in short circuits, affecting product quality and equipment life, and reducing the safety of equipment operation; (4) For materials with high water content, due to equipment The internal ventilation and cooling capacity is poor, and the water vapor diffusion rate is slow, which affects the drying speed of the material. Therefore, water vapor and heat are easy to accumulate inside the material, causing local overheating of the material; (5) The thickness of the material is affected by the material properties, water content and other conditions Therefore, it is difficult to increase the production capacity of conveyor belt microwave drying equipment; (6) because the gas cannot be effectively contacted with the material, the gas utilization rate is low; at the same time, because the material drying is carried out on the open conveyor belt, it is difficult to recover the gas. easy to cause environmental pollution

At present, there is no better solution for microwave drying of granular or powdery heat-sensitive materials

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