Centralized drying system of high-humidity grain and drying method thereof

Abstract

The invention relates to a centralized drying system of high-humidity grain and a drying method thereof. According to the grain deliver direction, the centralized drying system comprises a preliminary cleaning machine, a wet grain hoister, a wet grain dryer, a conveyor, a middle hoister, a main drying tower, a dry grain conveyor, a dry grain hoister and a dry grain storage silo which are successively connected, wherein the main drying tower successively comprises a high-temperature drying section, a low-temperature drying section and a cooling section; the system also comprises a hot-blast stove, a heat exchanger, a dust remover and a smoke draught fan which are successively connected, wherein the smoke draught fan is connected with the wet grain drier; the heat exchanger is connected to the main high-temperature drying section by an air heater, and the air heater is connected to the low-temperature drying section by a thermosistor; the heat exchanger is connected with the wet grain drier by a wind stopping device and an air cooler; and ambient air is communicated with the air cooler by the cooling section. The drying system can fully utilize natural air and recycle the waste heat and waste gas of the drying system to efficiently dry in an energy saving mode and reduce drying waste gas, waste liquid and dust emission; the drying system has favourable drying effect and is especially suitable for drying a great quantity of high-wet grain in a centralized mode.

Description

technical field [0001] The invention relates to the technical field of high-humidity grain drying, in particular to a high-humidity grain centralized drying system and a drying method thereof. Background technique [0002] High-humidity grain drying has obvious two-stage nature. When the moisture content of the grain is in the first deceleration drying section and above, the natural air at normal temperature has a considerable drying capacity for it. This is because there is more free water on the surface of high-humidity grains, and the evaporation of these free water on the surface is not limited by the material, so it is easy to dry. Therefore, under the same conditions, the drying rate at the first deceleration drying stage and above is also the same. Larger, but the existing grain drying process system does not make full use of the high drying potential in this section. In terms of design concept, the air is heated first and then sent to the drying room, and the hot ai...

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Problems solved by technology

This is because there is more free water on the surface of high-humidity grains, and the evaporation of these free water on the surface is not limited by the material, so it is easy to dry. Therefore, under the same conditions, the drying rate at the first deceleration drying stage and above is also the same. Larger, but the existing grain drying process system does not make full use of the high drying potential in this section. In terms of design concept, the air is heated first and then sent to the drying room, and the hot air supplies the material with heating and water evaporation. heat and absorb moisture evaporated from the grain

For high-humidity grain drying, the obvious disadvantages of this method are: ①During the drying process, the hot air provides heat energy to the grain, and the direction of heat transfer is opposite to the direction of water evaporation, and the reverse heat transfer weakens the drying process; The temperature difference of the hot air in the grain layer is large, the temperature and humidity of the hot air in the grain layer change greatly, and the phenomenon that the lower layer is dry and the upper layer absorbs moisture often occurs, that is, the moisture absorbed by the high-temperature hot air in the lower layer will continue to decrease due to the temperature during the migration process in the dry layer. , so that part of the water carried is condensed on the upper layer; ③ the unit energy consumption is high, and the processing efficiency of the equipment is low; ④ there are defects such as large heat absorption and low drying efficiency of grain heating, and it is difficult to meet the needs of centralized drying of a large amount of wet grain

Lack of a drying process system that specifically removes moisture in the high-humidity section for the high-humidity characteristics of grain, not only the drying energy consumption is high, but also the drying efficiency and equipment processing efficiency are very low

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