Dryers for the food industry
Drying is a thermophysical and at the same time a technological process that takes into account heat, moisture and mass transfer, these indicators determine the required drying time and the type of equipment for drying vegetables, fruits, berries, meat and fish, taking into account the technological process.
≫ Vacuum drying
≫ Freeze-drying (freeze-drying)
≫ Ultrasonic drying (Acoustic drying)
≫ Dehydrators for drying
≫ Infrared drying
≫ Microwave drying
≫ Belt dryers
Equipment for drying food products
During the drying process, heat and moisture change, and the biochemical properties of the product are transformed, which in turn affects the preservation of nutrients and vitamins. Therefore, the drying process cannot be viewed only from the perspective of thermophysical processes, but is also a physical and chemical process that relies on knowledge of technology and biochemistry. Depending on the type of product, its structure and moisture exchange rate, there are a number of drying methods. These include infrared, microwave, convection and condensation (dehydrators), freeze-drying, vacuum and acoustic drying for food products.
The freeze drying chamber is applied to freshly frozen products, the process of moisture elimination takes place in a vacuum environment. The advantage of freeze drying is that by using a pressure temperature lower than the temperature of ice, the frozen product can be converted to a gaseous state without a liquid phase. This reduces the number of drying steps, which has a significant impact on the duration of the drying process. In freeze drying, the freezing stage is not the most important, but rather the freezing stage, as it affects the rate of evaporation of ice crystals and, consequently, the quality of processing.
An acoustic drying chamber is an ultrasonic system. The ultrasonic impact on the product helps to remove moisture on its surface, and part of it is evenly distributed through the capillaries. Acoustic waves are applied until the moisture content reaches the required level. It is important not to overdry the product, otherwise it will lose all its useful properties. The acoustic drying method is used for cereals, vegetables, fruits, and other food products.
Dehydrator is a unique equipment designed for drying meat, fruits, vegetables, etc. With the help of a dehydrator, moisture is removed from the food and then placed in a freezer to preserve it for a long period of time. These dryers are divided into two types – convection drying (from +35C to +120C), and condensation drying, which, unlike convection drying, takes place at a temperature of +30C to +40C.
Infrared drying chambers are widely used in food processing. Its essence lies in the fact that under the influence of infrared rays, the molecules of a substance are set in motion, which causes the product to heat up. The heating is more efficient than the convective drying method. This is due to the fact that the infrared beam penetrates to a depth of 6 to 12 millimeters. However, despite this, the radiant energy does not penetrate to the full depth of the product layer, but promotes active heat exchange at a depth of 6-7 millimeters, which accelerates drying.
is an advanced technology that can be used to dry fish, meat, grain, fruits and vegetables, as well as herbs. During heating, the raw material loses its initial moisture, but this does not affect the speed and quality of the drying process. The drying of the product does not slow down, because thermal conductivity does not play a significant role. The least amount of time is spent on microwave drying mushrooms, fruits, vegetables, fish and meat. At the lowest temperatures, the product receives more intensive processing, which preserves all the nutrients.
They are usually made in the form of a multi-tiered belt conveyor, which continuously moves the product in a chamber operating at atmospheric pressure, gradually pouring from the upper belt to the lower one. These dryers are more compact than chamber and tunnel dryers and are characterized by a higher drying intensity. They are used for drying vegetables and fruits, bakery products, starch, and small pasta.