RU121683U1 - CONVEYOR TYPE DRYING FURNACE - Google Patents

Abstract

Drying microwave oven of conveyor type, containing a working heating chamber, inside which a belt conveyor is installed for continuous movement of the processed product, individual chambers, to which an air duct for supplying cooling air is connected and groups of microwave generators are installed, a waveguide is connected to each of the generators and introduced into the heating chamber, and ending with a radiating antenna, made in the form of a horn or radiating slots, and in the sections of the waveguides directly adjacent to the microwave generators and located inside the individual chambers of each of the microwave generators, and the walls of the waveguides, non-radiating slots are cut through to pass hot air from the chambers of microwave generators through the waveguide into the heating chamber, characterized in that at least two electrodes made of non-magnetic metal are mounted in the working heating chamber, they are attached by means of dielectric insulators to the walls of the working chamber, and one electrode is a cathode and is made of metal grid with a fine cell and is located parallel to the wall of the waveguide, in which the emitting slits are cut, and the second electrode, which is the anode, is made of a metal perforated plate and is parallel to the punched tape of the conveyor, while the electrodes are located with an air gap from the walls of the working chamber and the waveguide, and in The housing of the microwave oven is equipped with a direct current source, the anode and cathode of which are electrically connected to the anode and cathode of the working chamber by means of non-magnetic metal conductors that pass through holes in dielectric insulators.

Description

The proposed utility model relates to installations for drying agricultural raw materials, in particular to dryers using microwave energy and the energy of an electric field of direct current. The invention is applicable for drying raw materials of plant origin with a capillary-porous structure: berries, juicy herbs and fruits, root crops, medicinal raw materials, mushrooms, can be used on farms, when preserving the grown crop, as well as harvested wild herbs and their roots.

A well-known means of increasing the efficiency of the heating and drying processes of various products and materials is the use of convection-microwave devices and installations in which the processed product is subjected to the simultaneous exposure to microwave (microwave) radiation and blowing with hot air. Such devices are known in patent documentation [1, 2, 3, 4].

Known microwave oven containing a working heating chamber, inside which there is a belt conveyor for continuous movement of the processed product, individual chambers to which an air duct for supplying cooling air is connected and groups of microwave generators are installed, and a waveguide connected to each of the generators is inserted into the heating chamber and ends with a radiating antenna, made in the form of a horn or radiating slots, and in areas of waveguides directly adjacent to microwave generators and inside the individual In each of the microwave chambers and in the walls of the waveguides, non-radiating slots are cut for the passage of hot air through them from the chambers of the microwave generators through the waveguide to the heating chamber [5].

The disadvantage of such a microwave oven is that only a small part of the supplied microwave energy to the drying object is spent on a positive temperature difference that accelerates the movement of moisture to the surface, and the remaining energy is used to heat the material and moisture in it, evaporate moisture, cover all heat losses . This is the reason for the lengthening of the drying process in such furnaces and reduces their productivity.

The proposed utility model is aimed at intensifying the drying process of capillary-porous raw materials of plant origin in microwave ovens due to electrokinetic phenomena that occur when a direct current electric field is applied to the drying object.

The problem is solved in that a microwave drying oven containing a working heating chamber, inside which there is a belt conveyor for continuous movement of the processed product, individual chambers to which an air duct for supplying cooling air is connected and groups of microwave generators are installed, a waveguide associated with each generators and introduced into the heating chamber and ending with a radiating antenna made in the form of a horn or radiating slits, and in sections of waveguides directly adjacent to the microwave At the generators and inside the individual chambers of each of the microwave generators, and the walls of the waveguides, non-emitting slots are cut for the passage of hot air from the chambers of the microwave generators through the waveguide into the heating chamber, according to a useful model, at least two non-magnetic electrodes are mounted in the working heating chamber metal, they are attached by means of dielectric insulators to the walls of the working chamber. One electrode is a cathode made of a metal mesh with a small cell and is parallel to the waveguide wall, in which emitting slits are cut, and the second electrode, which is the anode, is made of a metal perforated plate and parallel to the conveyor punch tape. The electrodes are located with an air gap from the walls of the working chamber and the waveguide. A direct current source is installed in the microwave oven housing to create a potential difference between the anode and cathode of the working chamber, as a result of which a direct current electric field is formed, and it is also equipped with an individual switch. The anode and cathode of the direct current source are electrically connected to the anode and cathode of the working chamber by means of conductors of non-magnetic metals that pass through holes in dielectric insulators.

The figure 1 shows a drying microwave oven conveyor type with a longitudinal section; figure 2 - drying microwave oven conveyor type with a cross section.

The conveyor-type drying microwave oven consists of the following main parts: a heating working chamber 1 with protective shutters 2, a conveyor belt 3, individual chambers of microwave generators 4, an air duct 5 with a fan 6, a waveguide 7 connected to each of the generators 8 and introduced into a heating chamber and ending with radiating slots 9, a direct current source 10 with an individual switch 11, an anode 12, a cathode 13, dielectric insulators 14.

The conveyor type microwave drying oven operates in a continuous mode of supply and extraction of the processed product and, accordingly, in the continuous operation of the microwave generators 8, fan 6 and DC source 10. The processed product is placed on a perforated conveyor belt 3 at the inlet of the furnace and moves inside the cavity of the working heating chamber 1 to the exit of the furnace, opening the protective curtains. During the entire time the product is moving, it is subjected to microwave irradiation from the emitting slots 9 located above the conveyor belt 3 and connected with the microwave generators 8 installed in the individual chambers of the ventilated duct 5, and it is also blown with hot air from the chambers of the microwave generators 4 through slotted holes cut through the walls of the waveguides, and then hot air enters the working heating chamber 1, at the same time it is exposed to an electric field yannogo current that arises between the anode 12 and cathode 13. As a result, in the working chamber heat treated product is heated released therein microwave energy, the energy of its blowing hot air, while the energy of the DC electric field intensifies the transfer of moisture to the processed surface of the product. The speed of the conveyor belt is selected so that during the movement of the product in the cavity of the working chamber, the drying process is completed.

This design of a conveyor type microwave drying oven provides an increase in the intensity of the drying process of capillary-porous raw materials of plant origin, and also increases their productivity.

References

1. Ac. USSR, class HB05 6/64 No. 1 608 833.

2. RF patent, cl. H05B 6/64 No. 2 050 704.

3. Application of Japan, cl. F26B 17/20 No. 61-14426.

4. Application of the Russian Federation, cl. Н05В 6/64, А21В 2/00 No. 2 000102405

5. Application of Germany, CL, А21В 2/00 No. 19 626512 (prototype)

Claims (1)

A conveyor-type drying oven containing a working heating chamber, inside which there is a belt conveyor for continuous movement of the processed product, individual chambers to which an air duct for supplying cooling air is connected and groups of microwave generators are installed, a waveguide connected to each of the generators and introduced into the heating chamber, and ending with a radiating antenna made in the form of a horn or radiating slits, and in sections of waveguides directly adjacent to microwave generators and non-radiating slots are cut inside the individual chambers of each of the microwave generators and the walls of the waveguides to pass hot air through them from the chambers of the microwave generators through the waveguide into the heating chamber, characterized in that at least two non-magnetic metal electrodes are mounted in the working heating chamber, they are attached by means of dielectric insulators to the walls of the working chamber, and one electrode is a cathode and is made of a metal mesh with a small cell and is parallel to the waveguide wall, in which radiating slots are cut into the swarm, and the second electrode, which is the anode, is made of a metal perforated plate and parallel to the conveyor puncture tape, while the electrodes are located with an air gap from the walls of the working chamber and the waveguide, and a direct current source, anode, and cathode are installed in the microwave oven casing which is electrically connected to the anode and cathode of the working chamber by means of conductors of non-magnetic metals that pass through holes in dielectric insulators.