Infrared drying
Radiation drying is a method of processing products using radiation lamps as an emitter. It consists in the use of radiation of a certain length, which is converted into heat and supplied to the product for the drying purpose.
The advantages of the method
— A low incandescent temperature while maintaining high energy conversion rates. An infrared lamp heats up to 2500K, while a conventional lamp heats up to 2920 K. At the same time, the efficiency of food processing does not decrease.
— Infrared drying is superior to convective and conductive food processing. This method significantly reduces the processing time of the product, due to which moisture is removed much faster. After thermal energy penetrates the capillary-porous structure of the product, it sinks to a certain depth, usually 0.1-2 mm. Due to the action on the capillaries, the thermal energy released by radiation rays is quickly absorbed. There is an intensive heat exchange, and as a result a large percentage of moisture is removed.
Scope of use
Drying with infrared rays is used in the textile industry for fine fabrics. Painted metal products, as well as painted wood, cardboard and plastic products often can be processed with this equipment.
The types of chambers
There are two types of infrared dehydration equipment: lamp and gas.
Lamp equipment is the most energy-consuming. The heating process consumes a large amount of energy, the cost of which is offset by the reduction in dehydration time.
Gas equipment is featured with a more simple and convenient design and lower energy consumption. When such equipment is turned on, infrared radiation begins to act by heating the gas, which is burned under the action of radiant rays. When flue gases are used, they are not burned, but pass inside the emitters. The product is intensively heated, maintaining a high temperature threshold, causing a high degree of moisture concentration. The moisture separation is inhibited with the inner layers of the product. To exclude this phenomenon, drying is programmed for non-continuous mode — the process is divided into several periods. The beginning periods are 2-4 seconds, the next are 20-80 seconds. During short periods, intensive heat exchange occurs, and then moisture separation is fulfilled.
Non-continuous / intermittent dehydration
Using the intermittent drying method, you save energy, retain most of the vitamins and beneficial properties of the product. The dehydration time is noticeably reduced.
An ideal option
The best indicators of product drying are obtained by combining the processes of radiation and convective drying, which reduces the processing time of the product and contributes to an uniform distribution of heat in the chamber.