Excellent product performance of spray dryer

Spray dryer has fast drying speed and good product performance
After the material liquid is sprayed, it is atomized into dispersed particles, and the surface area is greatly increased. After contact with hot air, the drying process can be completed in a very short time. Under normal circumstances, 95% to 98% of the water can evaporate within 1 to 3 seconds at 100 to 150°C. Since the drying process is completed in an instant, the particles of the finished product can basically maintain a spherical shape similar to the liquid droplets, thus having good dispersion, excellent brewability and high solubility.
The temperature of the droplets during the drying process of the spray dryer is not high, and the product quality is better.
The temperature range used by the spray dryer is very wide (80-800 degrees). Even if high-temperature hot air is used, the exhaust air temperature will still not be very high. In the early stage of drying, the temperature of the material does not exceed the wet bulb humidity of the surrounding hot air, which affects the quality of the dried product. better. For example, defects such as protein changes, vitamin loss, and oxidation are less prone to occur. The quality spray drying tower for heat-sensitive materials, organisms and drugs can basically approach the standard of drying under vacuum.
Spray dryer products have good dispersion, fluidity and solubility
Since the drying process is completed in the air, the product can basically maintain a spherical shape similar to liquid droplets, with good dispersion, fluidity and solubility.
Reduce wall sticking and burnt powder and improve finished product quality
Spray dryers, centrifugal spray dryers and multi-nozzle spray dryers are three typical spray equipment. The spray direction of centrifugal spray and multi-nozzle spray is horizontal or vertical (axis direction). In the horizontal direction, in order to make the hot air and liquid droplets come into good contact and improve the drying efficiency, the hot air is allowed to form a vortex, which is prone to adhesion. The adhered and deposited materials will cause problems such as thermal degeneration and difficulty in cleaning. When the speed of the hot air is along the axis of the drying tower, the hot air streamlines often deviate as a whole. The hot air cannot mix well with the material liquid, resulting in low efficiency and partial adhesion.
Integration of spray dryer drying tower, separation chamber and cooling chamber
In order to meet market needs, improve product solubility, brewability and packaging performance. Some spray drying equipment adds granulation equipment, but it will increase the thermal denaturation of the product and the loss of aromatic substances. The MD spray dryer effectively solves the integration problem of the drying tower, separation chamber and cooling chamber. During the reduced-speed drying stage of spray drying, the temperature of the powder increases as the moisture content decreases. Taking dairy products as an example, when the drying air temperature in the lower part of the drying tower is 90 to 100°C, the temperature of the powder is about 60°C. In order to prevent thermal denaturation, it is desired to cool down quickly after drying. In this regard, the MD-type spray dryer is equipped with a flow cooling chamber at the lower part of the drying tower. This system has cyclone separated fine powder, which is transported to the flow cooling chamber at the lower part of the separation chamber by air, together with the powder separated by gravity in the separation chamber. Cool to about 30°C and then discharge. The result is good control over thermal denaturation.
The spray dryer production process is decomposed and the operation is easy to control.
Spray dryers are usually used to process solutions with a moisture content of 40%-60%. Even if the moisture content of the material is as high as 90%, it can be dried into powdery products at one time without concentration. Most products do not need to be crushed and screened after drying, thus reducing production procedures and simplifying the production process. The particle size, bulk density and moisture of the product can be adjusted within a certain range by changing the operating conditions, and the control and management are very convenient.
Utilization of secondary hot air in spray dryer
When hot air blows into the drying tower, the temperature at the blowing point is very high. If there is a trace amount of product attached to this part, it will all turn brown, and it will continue to fall, which will cause the product quality to decline. In this regard, the MD-type spray dryer is equipped with two concentric cylinders at the mouth of the drying tower where hot air blows. From the middle of these two cylinders, low-temperature secondary hot air (70~100℃) can be refluxed, effectively solving the problem. The above-mentioned quality degradation problem caused by adhesion. Moreover, the ratio of secondary hot air volume (G) to hot air volume (G) G′?G=0.05, or larger (can be increased to 0.3~0.4), which is beneficial to improving product solubility.
Spray dryers prevent pollution and improve the production environment
Since spray drying is carried out in a closed drying tower, this avoids the dry product from flying in the workshop. For toxic and odorous materials, a closed cycle system production process can be used to burn the toxic and odorous materials to prevent air pollution and improve the production environment.
Spray dryer is suitable for continuous large-scale production
Spray drying can adapt to the requirements of industrial large-scale production. The dried products are continuously discharged and can be combined with coolers and wind conveyors for post-processing to form a continuous production line.