CN100543392C - Microwave drying equipment - Google Patents

Abstract

The invention discloses a microwave drying equipment, which is provided with a ring-shaped box body on a frame, and a fixed plate is arranged in a cavity with a large half fan ring inside, and at least 9 sets of microwave waveguide devices and microwave ovens are arranged on the fixed plate. The generator assembly and the microwave waveguide device are evenly distributed and arranged on the fixed plate in a staggered manner. Below the fixed plate is a microwave drying chamber. Below the microwave drying chamber is a heating and rotating device, which is composed of a frequency conversion motor and a heating turntable. The middle part of the shaped box is provided with a dehumidification mechanism, and the left and right microwave suppressors and material loading and unloading areas are arranged in the cavity of a small half fan in the circular box. This equipment can make microwave radiation uniform, can effectively improve the uniformity of heating, and has strong versatility. Moreover, it has a compact structure, a small footprint, and convenient material loading and unloading, which is convenient for continuous production.

Description

Microwave drying equipment

technical field

The invention relates to a material drying equipment, in particular to a microwave drying equipment. It is suitable for heating and drying materials in food, daily chemical, pharmaceutical, agricultural and agricultural product processing industries.

Background technique

Microwave heating and drying uses microwaves to interact with material molecules in a rapidly changing high-frequency electromagnetic field, and is absorbed to produce thermal effects. Heat is generated inside the material, and heating and drying are rapid. Therefore, more and more people pay more and more attention to it, and develop microwave drying equipment to meet different drying materials.

As early as 1947, American Marvin Baker made the world's first microwave oven for heating food according to the heating effect of microwaves. After more than ten years of exploration, the world's first 915MHz/50Kw tunnel microwave heating equipment was successfully developed in 1965 by the American CryodeyComporatio company. Subsequently, developed countries such as the United States, Japan, Canada, and Europe all used microwave energy technology to solve problems in heating, baking, sterilization, and aging in the food industry, and achieved success one after another.

my country began to develop and promote microwave technology and equipment in the 1970s. In recent years, the application of microwave energy has developed rapidly in the food industry, chemical industry and agricultural product processing. Microwave heating and sterilization technology and equipment are becoming more and more perfect, and microwave heating and sterilization equipment of various uses and specifications with power ranging from a few Kw to hundreds of Kw emerge in endlessly. With the promotion and application of microwave drying equipment, people have higher and higher requirements for the performance of the equipment, especially the heating uniformity and versatility are the issues that users generally pay attention to.

Contents of the invention

The purpose of the present invention is to provide a microwave drying equipment, which can effectively ensure the uniformity of heating and has strong versatility; meanwhile, it has a compact structure, a small footprint, and convenient material loading and unloading, which is convenient for continuous production.

The invention is designed according to the principle of microwave heating combined with the principle of optical reflection. The solution is: a microwave drying equipment, which is provided with a ring-shaped box on the frame, and a fixed plate is arranged in a cavity with a large half fan ring, and at least 9 sets of microwave waveguide devices and microwave ovens are arranged on the fixed plate. The generator assembly and the microwave waveguide device are evenly distributed and arranged on the fixed plate in a staggered manner. Below the fixed plate is a microwave drying chamber. Below the microwave drying chamber is a heating and rotating device, which is composed of a frequency conversion motor and a heating turntable. The middle part of the shaped box is provided with a dehumidification mechanism, and the left microwave suppressor, the right microwave suppressor and the loading and unloading area are arranged in the small half-fan ring cavity in the circular box.

The microwave waveguide device is parabolic, and is composed of a parabolic reflector and a metal ball inside it, and at least one conical tube. The centerlines of all the conical tubes coincide with the centerline of the parabolic reflector. On the center line of the reflector, the microwave generator in the microwave generator assembly is located at the focus of the parabolic reflector.

There are two tapered tubes of different sizes inside the parabolic reflector.

In the present invention, a ring-shaped box is provided on the frame, and a microwave generator assembly and a microwave waveguide device are arranged in the box, which are arranged in the shape of a fan ring, and are evenly distributed and arranged on the fixed plate in a staggered manner. The heating and rotating device is arranged under the microwave drying chamber, and left and right microwave suppressors and material loading and unloading areas are also arranged in the circular box. Since the overall structure of the equipment is circular, it not only has a compact structure and a small footprint, but also facilitates loading and unloading of materials and continuous production. Since the heating rotating device is driven by a frequency conversion motor, its speed can be adjusted arbitrarily to meet the drying needs of different materials. Since the coupling ports of the microwave waveguide device are evenly distributed and arranged in a staggered manner on the fixed plate, and the coupling in the microwave drying chamber is in the strong field region of the mode to be excited and the weak field region of the possible parasitic mode, a circular complementary mode is formed , so that the value of the standing wave ratio is small, it can ensure the stable operation of the microwave generator, and can make the microwave drying chamber have more modes, which is conducive to the uniform distribution of the coupling port and the electromagnetic field of the mode in the microwave drying chamber, so as to ensure the uniformity of the microwave. Furthermore, because the design of the parabolic reflector of the parabolic microwave waveguide device is not only based on the principle of optical reflection, but also gathers the luminous flux radiated by the point light source in a limited solid angle through the function of the reflector, resulting in a very high Luminous intensity, and then reflect the point light source into a light shape with a certain shape and intensity through the rotating paraboloid of the reflector. The compound parabolic concentrator (CPC) is used. The CPC is a non-imaging solar concentrator. It is a concentrator designed based on the principle of edge optics. It can also reflect obliquely incident waves in parallel. Winston, Rabl et al. studied the optical properties of CPC with ideal specular reflective surfaces, and Bassett, Derrick, and Georlette et al. analyzed the collectors composed of ideal diffuse reflective surfaces of different shapes and ideal reflective absorbers from the perspective of probability statistics. . Therefore, the parabolic microwave waveguide device can not only reflect directly incident microwaves, but also reflect obliquely incident microwaves in parallel, so that the microwaves can be distributed as evenly as possible, and the uniformity of heating can be effectively improved. Since the conical cylinder and the metal ball are arranged in the parabolic reflector, the microwave reaching it can be diffusely reflected, so that the distribution of the microwave is more uniform, and it can prevent the microwave reflection from causing damage to the microwave source, thereby ensuring the occurrence of the microwave. The service life of the device, and strong versatility.

Description of drawings

Figure 1 is a top view of the structure of the microwave drying equipment

Fig. 2 is a schematic cross-sectional view of A-A in Fig. 1 .

Fig. 3 is a distribution diagram of coupling ports of the microwave waveguide device.

FIG. 4 is a cross-sectional view of the microwave waveguide device in FIG. 2 .

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Fig. 1 and Fig. 2, an annular box body 16 is connected on the frame 5, and the large half fan annular cavity in it is the microwave drying area 1, and the small half fan annular cavity corresponding to the microwave drying area 1 is provided with There is a left microwave suppressor 2 and a right microwave suppressor 4 adjacent to the microwave drying area 1, and the loading and unloading material area 3 is set between the left and right microwave suppressors 2 and 4, and passes through the left and right microwave suppressors 2 and 4. 4 can shield microwave radiation. The annular box body 16 is closed by a cover plate 13 .

There is a fixed plate 9 in the large half-fan annular cavity 12 on the upper part of the microwave drying area 1 in the annular box 16, and a plurality of sets of microwave waveguide devices 10 and microwave generator assemblies 11 are arranged on the fixed plate 9, and the microwave waveguide devices are all staggered and arranged on the fixed plate 9, according to the different diameters of the box, there are at least 9 microwave waveguide devices, as shown in Figure 3 for the situation of 19 microwave waveguide devices, the coupling ports 17 of all microwave waveguide devices The centers are evenly distributed on the two arcs. Below the fixed plate 9 is a microwave drying cavity 8 . The heating rotating device composed of the frequency conversion motor 6 and the heating turntable 7 connected thereto is installed under the microwave drying cavity 8 . In the middle part of the annular box 16, there is a dehumidification fan interface 14 connected with the box, which is connected with the dehumidification fan, and on the inner wall of the annular box 16, heat dissipation windows 15 are distributed to form a dehumidifier. wet body.

In Fig. 4, the microwave waveguide device is parabolic, and a large conical cylinder 19 is arranged in the parabolic reflector 18, and a small conical cylinder 20 and a metal ball 21 are set inside it. On the polytetrafluoro plate 22 below the body 18, the centerlines of all conical tubes coincide with the centerlines of the parabolic reflector, and the metal ball is located on the centerline of the parabolic reflector, and the microwave in the microwave generator assembly generates The reflector is located at the focus of the parabolic reflector.

Load the material from the loading and unloading area onto the heating turntable 7, connect the power supply of the microwave generator assembly and the heating rotating device, and make the equipment in working condition. The rotating speed of the heating turntable 7 can be adjusted arbitrarily through the frequency conversion motor 6 to meet Drying needs of different materials. The microwave generated by the microwave generator interacts with the material material molecules in the rapidly changing high-frequency electromagnetic field in the microwave drying chamber 8, and is absorbed to produce a thermal effect, and heat is generated inside the material to make it rapidly heated and dried. After meeting the drying requirements, cut off the power supply, and then take out the processed materials from the loading and unloading area 3.

Claims (3)

1, a kind of microwave drying equipment, it is characterized in that, on the frame (5), be provided with annular casing (16), in it, there is fixed plate (9) in the cavity of big half fan ring, fixed plate ( 9) There are at least 9 sets of microwave waveguide devices (10) and microwave generator assemblies (11), the microwave waveguide devices are evenly distributed and arranged on the fixed plate (9), and the bottom of the fixed plate (9) is microwave drying Chamber (8), microwave drying chamber (8) is provided with a heating rotating device below, which is composed of a frequency conversion motor (6) and a heating turntable (7), and a dehumidification mechanism is arranged in the middle of the circular box (16) , and be provided with left microwave suppressor (2), right microwave suppressor (4) and loading and unloading material area (3) in the cavity that is the small half-fan ring in the annular casing (16). 2. The microwave drying equipment according to claim 1, characterized in that: the microwave waveguide is in the shape of a parabola, consisting of a parabolic reflector (18) and a metal ball (21) arranged inside it, and at least one conical cylinder, The centerlines of all the tapered tubes coincide with the centerlines of the parabolic reflectors, the metal balls are located on the centerlines of the parabolic reflectors, and the microwave generator in the microwave generator assembly is located at the focal point of the parabolic reflectors. 3. The microwave drying equipment according to claim 2, characterized in that there are two tapered cylinders with different sizes inside the parabolic reflector.

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