With the improvement of people’s living standards, China is ushering in a new wave of consumption upgrades, including the milk powder market. Some people in the industry believe that if you want to seize opportunities in the consumer market, quality is the key to success. For dairy companies, milk sources are an important barrier to maintaining quality. In addition, the advanced milk powder processing technology and dairy processing equipment – high speed centrifugal mini spray dryer machine, is also a vital link to promote the upgrading of milk powder and ensure the quality of milk powder.
As we all know, milk powder production process mainly has two kinds of dry method and wet method. Compared with the dry process, the wet process is more complicated. Milk powder needs to be processed through multiple processes such as raw milk testing, filtration, purification, blending, homogenization, sterilization, concentration, spray drying, and packaging. Due to the relatively poor uniformity and quality of the product produced by the dry process, the taste and flavor are not as good as the wet process milk powder. At present, many dairy companies use wet process to ensure the taste and quality of milk powder.
The Key To The Wet Process
Wet process milk can be dried into powder at one time, and it also benefits from the development of spray drying technology and equipment. It is understood that the traditional milk powder drying process uses a vacuum evaporation tank to concentrate the milk to a cake state, and then dry it to make powder. After the milk is concentrated, the milk is “spread” on the heated drum, and then the thin milk film is baked into powder by drying and so on.
Although some drying processes can also dry milk into milk powder, due to high temperature heating, if the temperature and time are not controlled correctly, the nutritional content of milk powder will be damaged to varying degrees.
It is true that the emergence of high speed centrifugal spray dryer not only ensures that the milk can be spray-dried into powder at one time, but also controls the drying time and temperature to avoid the impact of excessive temperature and long time on the freshness and nutritional value of milk.
Process Flow Of Spray Dryer
High speed centrifugal spray dryer is a method of systematic technology applied to material drying.
Through mechanical action, the material to be dried is dispersed into very fine mist-like particles. In contact with hot air, the evaporation area of water is increased, the drying process is accelerated, and the water is quickly vaporized, and most of the water is removed instantly. By separation in a cyclone, a dry product is obtained.
By controlling the concentration of material liquid, feed amount, inlet air temperature, outlet air temperature, and air supply volume, the product quality can be well controlled, the process has strong continuity, high thermal efficiency, less waste gas and waste water, and the drying room has a certain load. Pressure, less dust in the workshop, high production efficiency, and fewer operators. This method can directly dry the solution and emulsion into powder or granular products, which can save the evaporation, crushing and other processes, and the product has high purity and concentrated particle size distribution.
Advantages Of Spray Dryers
(1) The drying speed is fast and the time is short.
The high speed centrifugal spray dryer is equipped with a high-efficiency cyclone separation device, which can improve the drying efficiency of milk, the drying speed is fast, the drying time is short, and it avoids damage to the nutrients in the milk, so that the protein denaturation is less, and the whey protein still maintains good solubility.
After the feed liquid is atomized, the surface area increases to more than 10,000 times. For example, if 1l of material liquid is atomized into droplets with a diameter of 50μm, its surface area can be increased to 120 square meters, and 95%~98% of the water can be evaporated instantaneously (0.01~0.04s) in the hot air flow, and the drying time is generally it only takes 5~40s.
(2) The product quality is good.
At the same time, the high speed centrifugal spray dryer is equipped with a temperature control system, and users can adjust the drying temperature according to the needs of milk powder processing technology to ensure the drying quality of milk powder.
The high speed centrifugal spray dryer uses a wide temperature range (80~300°c). Even if high temperature hot air is used, the outlet temperature will not be high because the heat exchange is mainly used to evaporate the moisture of the material, and the quality of the dried product is good, and protein is not easy to occur defects such as denaturation, vitamin loss, oxidation, etc. Therefore, it is especially suitable for heat-sensitive food processing that is easy to decompose and denature. At the same time, since the drying process is completed in hot air, the product can basically maintain hollow particles or loose aggregates similar to mist droplets, and has good dispersion, fluidity and melting properties.
(3) The process is simple and the control is convenient.
The mass fraction of water in the feed liquid is usually 40%~60%, and the mass fraction of water in some special feed liquids is as high as 90%. It can also be dried directly to obtain powder or fine granular products without concentration, which can save some evaporation, the process of crystallization, separation, crushing and screening simplifies the production process. By changing the concentration of raw materials, hot air temperature, spraying conditions, etc., products with different moisture and particle sizes can be obtained, which is easy to operate and control. Since the high speed centrifugal spray dryer is carried out in a fully enclosed drying tower, the drying room has a certain negative pressure, which not only ensures hygienic conditions but also avoids flying dust.
(4) High productivity.
The high speed centrifugal spray dryer can be adapted to large-scale production. Materials can be continuously fed and discharged, combined with coolers and wind conveying to form a continuous production line with fewer operators and low labor intensity.
Milk powder processing enterprises can adjust the pressure, flow rate and nozzle hole size of the high speed centrifugal spray dryer’s material liquid pump according to the process requirements, and can obtain the required powdery and spherical particles in a certain size ratio. For example, compared with ordinary milk powder, instant milk powder has large and loose particles and good solubility.