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The principle of industrial microwave application in food (2)

Time: 2012-4-12 10:19:59 Browse: 55

Hot air heating
microwave
microwave
Far infrared

a, using microwave energy for final drying, sterilization                           b, preheating and sterilization with microwave energy
        (microwave hot air equipment)                                    (microwave infrared equipment)
Ultraviolet light
Microwave heating
Light wave
Forced air cooling

C, using microwave and ultraviolet light, light wave combined (violet light equipment) drying, sterilization equipment

【Picture 1-1   Hybrid microwave application equipment

Figure (a) is mainly suitable for the drying of high water content products. Since the heat of vaporization of water is very high, considerable energy is required to effectively dry it. Therefore, microwave energy is more economical and reasonable only in the less effective section of conventional drying. In materials with large water content, the water should be removed by mechanical means (such as water absorption, extrusion or centrifugation) as much as possible, and then the hot air is blown through the surface of the material to provide the desired heat of vaporization using a conventional hot air drying oven. The efficiency of this drying technique decreases as drying progresses. Mainly because the rate of surface evaporation exceeds the rate of migration of moisture from the interior of the material to the surface. Then there was a phenomenon of external dryness. In addition, the general dry material has low heat conductivity, so the drying process becomes very slow. As a result, the effective length of the drying furnace is increased, the area is increased, and energy is wasted due to heat loss of the drying furnace body.

In the low-water-drying section where the drying rate begins to decrease, the osmotic heating characteristics of the microwave energy can cause the residual moisture inside the material to migrate to the surface quickly. In addition, hot air is often also blown into the microwave dryer to more efficiently discharge the water vapor' to obtain better economic benefits.
Figure (b) is mainly used for continuous vulcanization of rubber products. Due to the poor thermal conductivity of rubber, it takes a long time to vulcanize with conventional heating to achieve the desired vulcanization temperature for the entire section of the product. Moreover, defects such as surface over-vulcanization or central under-vulcanization often occur. Due to the volumetric heating characteristics of the microwave energy, the entire section of the rubber product can be heated to a desired temperature in a short time, and then enters a conventionally heated insulated passage, the main purpose of which is to prevent the rubber from cooling before the vulcanization reaction occurs. No heat is transferred to the rubber in the channel, and its efficiency can be controlled by the heat loss of the surface. Ideally, all the heat required for the product in the system can be supplied by microwave energy, but in actual continuous production, the type of rubber and the cross-sectional area vary greatly due to the extrusion speed, so in some cases Only most of the energy is provided by the microwave, and the thermal balance is still in the conventional way.

Figure (c) is actually in the conventional drying box in front of the microwave equipment, a part of the microwave equipment is recycled and heated by ultraviolet rays to pre-sterilize the surface of the incoming material, so that the drying box can work more effectively; Due to the fact that the surface bacteria cannot be uniformly killed by microwave sterilization, the reason is that the thermal effect of the microwave and the mechanism of the biological effect and the characteristics of the microwave drying/sterilization have a good effect on the sterilization of the material, but the microwave equipment must be put into operation. The moisture released by the material and the heat of the electric heater itself are discharged from the pipeline through the dehumidification system, so that the temperature of the surface of the material is reduced when the material passes through the microwave heating box, and the material does not reach the microwave heating requirement. At the temperature, there is a slight decrease in the sterilization efficiency.

Now our company exclusively introduces violet low-light technology (ultraviolet light, microwave, light wave) and forced air cooling technology, using microwave, ultraviolet light and light wave as heat source, using microwave electromagnetic field thermal effect and biological effect mechanism, ultraviolet sterilizable characteristics, light wave can make Material molecules and atomic vibrations change the potential distribution of cell sections, affect the concentration of electrons and ions around the cell membrane, and thus change the permeability of cell membranes. Therefore, bacteria are malnourished and cannot be metabolized. Their structural dysfunction, growth and development are inhibited by surface death, enough Strong optical wave field can lead to hydrogen bond relaxation, rupture and recombination, which can induce genetic mutation or chromosomal aberration or even rupture. Light wave sterilizing utilizes the effect of this magnetic field to destroy the organism, and then uses the force at the exit. Air-cooling technology lowers the temperature of the material for the packaging process and automated production. The combination of the four, the sterilization rate will be more than three times that of microwave sterilization, the drying rate is more than 10 hot air drying, and the rate of curing materials is more than 6 times faster than other heat sources. Through continuous experimentation, improvement and innovation, microwave equipment has been well received by users from the aspects of drying, sterilization, equipment performance and appearance. This scientific and practical combination has no environmental pollution and greatly prolongs the shelf life of the product. This technology will bring good news and challenges to manufacturers such as cakes, meat, fish fillets, moon cakes, bread, pickles, condiments, snack foods, and pharmaceuticals!

Fourth, the economic effect analysis of microwave energy application technology
The adoption of new technologies must be aimed at achieving significant economic and social benefits, although microwave energy technology has been widely used in various fields of industry, science and medicine, and in these applications, it is more than equivalent conventional technology. Has a unique advantage. However, due to the large investment in microwave energy equipment, it is necessary to consider the economic problems of application before and after adopting this new technology in the industry. The analysis and research of economic problems must be comprehensively compared and comprehensively analyzed with traditional conventional technologies in terms of energy consumption rate, productivity, labor, product quality, land size, labor conditions, operating costs and technical level. The correct conclusion.

The development of microwave equipment must be closely integrated with the product process, because the basic principle of microwave heating is completely different from conventional heating, so the conventional heating process cannot be directly transplanted to the microwave Heating System. Equipment designers must fully understand the characteristics of the product process, so that the equipment functions to meet the process requirements to the maximum extent, and users should also understand the difference between microwave heating and conventional heating. Improve and adjust the original process to meet the requirements of microwave heating.

Microwave energy technology, like other new technologies, is not a "universal" and has a certain range of use. For some products it has the advantage that conventional technology can't match, but for others it may not be more efficient and economical than conventional technology. If you ignore the nature of the product and lack comprehensive consideration of technical conditions and economic issues, blind adoption will bring investment losses. In particular, heat drying in industrial production is a very complicated process, and the drying speed is greatly reduced as the water content is reduced. This is an important reason for the high energy consumption rate and low product rate of traditional drying equipment. If in the drying process, the best combination of conventional, hot air, steam, ultraviolet light, light wave, far-infrared drying and microwave heating in different moisture content sections, the technical and economic advantages can be achieved very much. Significant economic benefits. The use of high-tech to transform traditional food technology will open up a new path for domestic and overseas enterprises. The application of microwave energy in food and other industries is the demand of the majority of businesses and consumers, and also the need for scientific development and human social progress.

We firmly believe that as long as we work closely with scientists in the field of microwave and electronic technology and food technology, we will surely bring our food industry to the international advanced level!

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