A spray drying system for easy-to-stick materials

Abstract

The invention relates to a spray drying system for wall-attaching materials, and relates to the technical field of material drying. According to the invention, a layer of air wall wind with adjustable temperature, humidity and air volume is directly formed at the power-attaching part in a tower, the temperature and the humidity of the air wall wind are lower than the thermal boning temperature and the moisture absorption humidity of powder and particle materials, the air wall wind and the wind in the tower are finally mixed to form mixed wind, the temperature and humidity of the mixed wind are lower than the thermal boning temperature and the moisture absorption humidity of the powder and particle materials, and the temperature of the particle materials under the action of air wall wind before contacting the tower wall is lower than the thermal boning temperature. With the adoption of the system provided by the invention, three wall-attaching conditions of materials can be solved or reduced, and the effects of improving the production efficiency, improving the per unit yield, reducing energy consumption, prolonging the continuous production time, improving the production safety and the improving the quality of a product are achieved through high air inlet temperature.

Description

technical field [0001] The invention relates to the drying technology of materials, in particular to the technical field of spray drying of materials which are easy to stick to walls. Background technique [0002] The spray dryer has a wide range of applications. According to the characteristics of the material, it can be dried by hot air or shaped by cold air. A large number of products with very different characteristics can be produced by this method. The commonly used ones are: polymers and resins, dyes, pigments, Ceramics, glass, rust removers, insecticides, carbohydrates, dairy and egg products, tannins, by-products of slaughterhouses, blood and blood products, detergents and surfactants, fertilizers, organic compounds, inorganic compounds , instant food, medicine, etc. [0003] The advantages of spray drying: the materials of solution, emulsion, suspension and paste can be spray dried into dry powder, fine and medium particle products, 0.08 ~ 0.2mm, fast speed, high ...

AI Technical Summary

Problems solved by technology

[0007] 1. Wet and sticky walls with non-drying materials: Because the air intake is normally at 120-140°C, the evaporation strength of atomized droplets and hot air is relatively low, and solid dust is easy to dry out. To solve the situation, it is often necessary to enlarge the tower diameter and tower height, resulting in production Disadvantages of increased difficulty and high production cost; after adopting cold air or water jacket, after sticking the material on the wall of the tower, it has the function of alleviating high temperature denaturation, but the material will still be denatured at high temperature after sticking to the wall; and due to the heat dissipation effect of the cold jacket, heat The loss is particularly large; it is not suitable for materials with thermal viscosity and strong water absorption at the same time; the tower diameter design is often wrong, and the tower height design is wrong; especially when the solid suspension spray dryer and spray granulator produce small particle materials. This situation occurs; after the heat and mass exchange between the hot air and the liquid droplets, the absolute humidity of the wind is relatively high, and it is very easy for the dust to absorb moisture when it hits the cold wall

[0008] 2. Electrostatic sticking of materials: Due to the normal production of particle diameters of 200-600 mesh by the comparison method, it often occurs that the dust diameter is too small to cause electrostatic sticking to the wall, and the airflow spray dryer is more prone to this situation; When static electricity sticks to the wall, it is difficult to solve it. It is necessary to increase the particle diameter of the material and find a solution from the material of the tower, and it is difficult to solve. The comparison document adopts the wind sweeping method to prevent dust from contacting the tower wall, and there is also a mechanical arm sweeping method It is only a relief. For example, the spray drying of soybean milk powder requires 1-2 hours to clean the drying tower, resulting in no guarantee of production cost and production safety; There is a large amount of sticky material, which is difficult to clean; at the same time, because the dust is too fine, the finished product is too absorbent; if the air sweep arm or mechanical wall is used, the tower diameter and height cannot be large, and the air inlet temperature is limited. very low yield

[0009] 3. Heat-soluble melting wall when reaching the melting point and sticking point temperature: it often appears in materials with low melting point, such as corn steep liquor, polysaccharides, traditional Chinese medicine extracts, bananas, tomatoes and other materials, which are accompanied by strong water absorption at the same time It has the characteristics of low heat resistance and low temperature resistance. When the hot air temperature is not high, the drying degree is not enough. When the temperature is above 50-80°C, it also shows thermal viscosity and high temperature deterioration. It is difficult to use ordinary drying methods. Processing, or even processing; These materials are basically produced by adding a large amount of auxiliary materials at present, resulting in various adverse phenomena such as low content and environmental pollution.

[0010] Therefore, the invention patent technology with the application number 201010120276.5 adopts the low-temperature and low-humidity process air drying method, and the tower diameter and tower height are limited by the air sweep arm, so the production efficiency is extremely low, the energy consumption is particularly high, the continuous production time is short, and there is still a sticking phenomenon. Cleaning is particularly difficult, safety and productivity are low, and product quality is not very good

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