Vacuum belt type drying units

Abstract

The invention provides a unit which can continuously coat the viscous liquid material on a conveyor belt and achieve low-temperature drying in a vacuum state. The unit comprises a vacuum cavity body; a material conveying belt delivery mechanism is arranged in the vacuum cavity body which is connected with an adjustable vacuum system; a feeding mechanism and a distributing mechanism are arranged at the front end of the unit; and a cutting mechanism, a powder shoveling mechanism, a crushing mechanism and a material collector are arranged in sequence at the rear end of the unit. The entire unit can adopt a DCS distributed control system and a touch-screen human-machine interface operating system to effectively control the complex relationships among the heating temperature, the vacuum degree, the cooling temperature, the delivery speed of the unit and the dried extract powder quality, so that the drying quality of batch products can be more stable and reliable.

Description

technical field [0001] The invention relates to a vacuum belt drying unit, which is a device for continuously coating viscous liquid raw materials on a conveyor belt and drying them at low temperature in a vacuum state. Background technique [0002] At present, the drying of most plant extracts mainly relies on hot air circulation oven drying, and some of them use decompression drying and spray drying. Hot air circulation oven drying mainly has problems such as uneven heating, long time, high temperature, easy bonding, easy coking, difficulty in collecting paste, large material loss, and high energy consumption; although decompression drying is more advanced than hot air circulation oven drying It is a big step forward, but the equipment currently used is still relatively simple, and cannot effectively solve key problems such as low thermal conductivity, lack of effective control of vacuum and temperature, the drying time is still long, the efficiency is still not high, and ...

AI Technical Summary

Problems solved by technology

Its advantage is to directly turn thin liquid into dry powder, which is fast drying and continuous operation; its disadvantage is that the powder is too fine rather than granular, the powder is dense and poor in water solubility; it is difficult to handle the viscous extract; the volume heat transfer coefficient is small, drying Low strength; complex equipment structure, large footprint and high cost

What's more serious is that the temperature of the hot air flow can be as high as 300°C during spray drying, which affects the color of the dry powder, easily produces scorch, and destroys some heat-sensitive active substances.

In addition, if spray drying is used for some materials containing polysaccharides, materials with high polysaccharide content will stick to the wall of the spray drying collector, resulting in difficulty in powder collection and drying failure

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