Flat plate type vacuum pulsation drying machine

Abstract

The invention belongs to the technical field of agriculture product processing, and particularly relates to a flat plate type vacuum pulsation drying machine. The flat plate type vacuum pulsation drying machine comprises a machine body, a control unit, a material drying unit and a pulsation vacuum unit, wherein the material drying unit is provided with multiple layers of material shelves. According to the flat plate type vacuum pulsation drying machine disclosed by the invention, a heating part adopts special electric heating plates, so that the processing is simple and convenient, the cost is low, the heating temperature is uniform, and the manufacturing cost, the using cost and the maintaining cost of the drying machine are greatly reduced; through a hierarchical control mode, corresponding heating plates can be opened according to actual processing amount, so that the energy consumption is reduced; meanwhile, soft material trays are adopted, so that the contact conditions between the material trays and the heating plates are remarkably improved, the quality of dried products can be effectively ensured, and the problem that the soft material trays are inconvenient to move is overcome by using a dedicated material tray shovel to assemble and disassemble the material trays; in addition, the flat plate type vacuum pulsation drying machine belongs to static drying, the breakage of materials cannot be caused; the processing and loading capacity of equipment can be effectively increased by virtue of a multi-layer structure.

Description

technical field [0001] The invention belongs to the technical field of agricultural product processing, and in particular relates to a flat-plate vacuum pulsation dryer. Background technique [0002] Drying is an important part of agricultural product processing. Different from vacuum drying technology, vacuum pulsation drying is a drying technology in which the pressure in the drying chamber fluctuates periodically according to certain rules. Comparative experiments show that vacuum pulsation drying has higher drying efficiency, shorter drying time and better rehydration than vacuum drying. This is because: First, the reason why the material is dry is because the partial pressure of water vapor on the evaporation surface It is greater than the partial pressure of water vapor in the dry environment, that is, there is a pressure gradient between the two, and the drying rate is proportional to the size of this pressure gradient. However, the current vacuum drying technology ...

AI Technical Summary

Problems solved by technology

[0005] First, complex pipelines need to be welded, and the equipment manufacturing cost is high

In order to improve the heat transfer efficiency, the heating part often adopts a labyrinth of water (oil), and there are many welds, which are easy to leak. Moreover, because it is used in a vacuum environment, the welding is easy to leak vacuum, which significantly increases the processing difficulty and processing cost of the equipment. ; At the same time, the equipment also needs to be equipped with accessories such as hot water tanks and hot water pumps, which increases the additional cost of drying equipment

[0006] Second, high energy consumption

To complete the heating medium circulation, the heating medium often needs to reach a certain amount, and it takes a lot of energy to heat it; the heating medium circulates in complex pipelines, and there is a large amount of head loss; and for uniform heating, sufficient heating, and heat The water circulation pump needs to run continuously, which increases the energy consumption of the equipment; at the same time, when a batch of materials is dried and the next batch of materials is not continuously dried, a large amount of heat contained in the heating medium will be lost and wasted

[0007] Third, the heating medium circulation pipeline system is prone to fouling and blockage, and is difficult to clean. Once a failure occurs, the heating medium in the complex pipeline needs to be poured out and replaced for maintenance, which is very inconvenient to maintain

[0008] Fourth, it is not conducive to the dynamic regulation of heating temperature

At present, the drying heat transfer of vacuum pulsation drying technology is mainly based on heat conduction, and the heat transfer effect will greatly affect the efficiency of vacuum pulsation drying and the quality of products

At present, the drying trays are mostly made of metal materials, with a thickness ranging from 1 to 1.5 mm. However, due to their large area and thin-walled structure, it is difficult to make the trays completely flat, resulting in poor bonding between the trays and the heating surface. Tight, large thermal resistance; at the same time, the large temperature range during the drying process (temperature rise ranges from 20 to 60°C), and the inevitable collision during use will also warp the hard metal tray. Concave and convex conditions, such as poor contact in the area, point-like heat conduction, etc., lead to insufficient and uneven heat supply for drying, affecting drying efficiency, and causing uneven drying of materials

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