RU214723U1 - Device for combined microwave-IR drying of cereals - Google Patents

Abstract

The utility model relates to agricultural engineering and the food industry, in particular to the technique of drying and heat treatment of bulk materials, and can be used for combined drying of cereals. The device is a working chamber, inside of which there is a conveyor belt, above which microwave modules are placed, above the conveyor belt there are additionally IR modules and fans for removing the vapor-air mixture. The device provides combined microwave-IR drying of grain products. 1 ill.

Description

The utility model relates to agricultural engineering and the food industry, in particular to the technique of drying and heat treatment of bulk materials, and can be used for drying cereals. The most appropriate is the use of the utility model in the technological lines of drying grain, for example, in seed companies or small farms. In all these examples, it is important to implement the principles of a gentle, uniform thermal effect on grain, ensuring low energy costs and compact equipment.

There is a known method of infrared drying of seeds (RU 2433364 C1 F26B 3/30 (2006.01)), which are placed in layers on a substrate, where thermal energy with different flux density of infrared radiation is gradually introduced on the tiers, combined with forced ventilation of the steam-air medium, which is removed.

What is new is that the drying of sunflower seeds with a layer 2-3 cm high, placed on a Teflon tape of an endless conveyor, is carried out by infrared radiation with a wavelength of 1.5-3.0 μm at a constant moisture removal rate, setting the density of the thermal energy flux of infrared radiation for each stage.

The advantage of this method is the constant removal of the steam-air medium from the drying zone, as well as the effective heating of the surface layer of the grain during drying. Disadvantage - the use of infrared emitters does not allow you to quickly and evenly heat the product in the entire volume.

A combined microwave-convective dryer is known (RU 2493515 C1, F26B 15/26 (2006.01), F26B 3/347 (2006.01). New in the design is that the body of the dryer has the form of a spiral box made along a helical line. Inside the box there are communicating between the chambers: loading chamber, sequentially alternating microwave chambers and cooling chambers, unloading chamber.A magnetron is installed on the inner side wall of each microwave chamber, the lower part of the cooling chambers is connected by means of an air duct to a fan, and their upper parts are connected to an exhaust diffuser for Two parallel chain conveyors pass through all chambers, on which perforated trays are hinged.

The device improves the quality of the products obtained by removing evaporated moisture, maintaining a rational temperature effect on the product. The disadvantage of the dryer is the presence of an additional coolant - heated air, as well as the low efficiency of heating the outer layers of the product in the first drying period.

The closest in technical essence is the design of a microwave installation for drying bulk materials (RU 185878 U1, F26B 3/347 (2006.01)). The installation has a metal frame, on which a stator is placed, which drives the conveyor metal belt - the rotor. The rotor is located on roller pulleys and is tensioned using a tension mechanism. These nodes are outside the working chamber. In the working chamber, a shutter-metering device with a linear motor and magnetron emitters are mounted, alternately alternating with microwave power sensors. All functional elements of the structure are located in a common screen housing, to which the loading and receiving hoppers are attached. The use of the utility model makes it possible to improve the quality and speed of drying at reduced energy costs.

The disadvantages of the prototype are the lack of fans to remove the vapor mixture from the surface of the product; the use of a microwave emitter is not effective enough to heat the surface layer of the product.

The purpose of the utility model is to create an energy-efficient installation for drying grain products.

The technical result of the proposed utility model is:

ensuring the maintenance of a rational thermal effect on the processed product due to a combination of microwave and infrared emitters;

reduction of energy consumption for drying;

increase in productivity and quality of processing due to the combination of microwave and IR drying with the transportation of the grain layer along the emitters distributed from above.

In FIG. 1 shows a schematic diagram of the proposed device, where

1 - working chamber;

2 - loading hopper;

3 - receiving hopper;

4 - radio transparent conveyor belt;

5 - microwave module;

6 - IR module;

7 - magnetron;

8 - fan;

9 - waveguide;

10 - quartz IR emitter;

11 - slide gate.

The device is a working chamber (1), to which the loading (2) and receiving hoppers (3) are attached. A slide gate (11) is fixed in the hopper (2). Inside the chamber (1) there is a radio-transparent conveyor belt (4), above which two microwave (5) and two IR (6) modules are alternately placed. The microwave module (5) consists of a magnetron emitter (7), a fan (8), and a waveguide (9). The IR module (6) contains two quartz IR emitters (10) located above the conveyor belt 4 at a height H, which ensures the uniform distribution of the heat flux, the required temperature on the surface of the product (for wheat, the height H=13 cm is experimentally determined).

Distinctive essential features characterizing the utility model are:

fans for removing the steam-air mixture;

additional IR emitters.

The presented set of distinctive essential features leads to the achievement of the purpose of the utility model.

The device works as follows.

The grain is poured into the hopper 2. The performance is adjusted by changing the flow area of the valve 11. The grain from the hopper is captured by the conveyor belt 4. In the direction of travel, the grain enters the microwave module 5. The microwave module 5 performs the functions of transferring energy to the product and removing the steam-air mixture from the working chamber 1. The emitter of the magnetron 7 generates microwaves, which are fed through the waveguide 9 to the grain. The supply of microwave energy contributes to the equalization of the temperature in the bulk of the grain. This intensifies the internal transfer of moisture. Moisture is "pumped" from the central zones to the surface and moistens it and evaporates. The resulting steam-air mixture is removed using a fan 8.

Next, the grain enters the IR module 6, in which the wet grain surface is heated by the action of two quartz IR emitters 10. The use of IR emitters as low-inertia distributed heat sources makes it possible to control the supply of thermal energy to the grain surface along the length of the conveyor belt and by drying time.

Next, the grain is alternately exposed to the subsequent microwave and IR module.

Grain is unloaded into the receiving hopper 3.

A comparative analysis of the efficiency showed that the use of microwave and IR methods of heat supply can significantly intensify the drying process.

Claims (1)

A device for combined microwave-IR drying of grain, including a working chamber, inside of which there is a conveyor belt, above which microwave modules are placed, characterized in that two IR modules and fans are additionally located above the conveyor belt to remove the vapor-air mixture.

Images