Shaft modular grain dryer of loud type with microwave energy supply

Abstract

FIELD: drying equipment for agricultural products.SUBSTANCE: modular shaft grain dryer of the louver type with microwave energy supply consists of a heated air chamber, a humid air chamber, a drying and cooling vertical chamber made of modules installed on a support frame, installed one above the other to form a shaft; in each module there are several narrow shafts with louvers located on them from top to bottom in several rows, separated from each other and from the walls of the module by supply and discharge channels. The dryer contains one microwave module installed in series with the drying modules and containing its own vertical grain columns on which microwave emitters are installed. The grain columns of the microwave module form single continuous vertical channels with the grain columns of the adjacent drying module; the microwave module is installed directly under the loading bin and above the drying modules. The grain columns of the microwave module are coaxial and are a direct continuation of the grain columns of the adjacent drying module. According to the invention, microwave emitters are built into the inclined parts of the louvered walls of the grain columns of the microwave module along their entire length via waveguides.EFFECT: ensuring uniform drying and simultaneous disinfection of grain through the combined action of microwave radiation and heated air, which improves the quality of the finished product and expands the functionality of the grain dryer.3 cl, 4 dwg

Description

[0001] The invention relates to drying equipment for agricultural products, in particular to modular shaft grain dryers and grain dryers with a gravity moving bed, for example, louvered and columnar, and can be used at grain drying points and elevators to combine the operations of drying and disinfecting grain crops.

[0002] A modular shaft grain dryer of the louver type is known (Patent RU 97499 U1, IPC F26B 17 / 22, published 10.09.2010), comprising a burner, fans, a loading hopper, an unloading table, a discharge device, a heating chamber, a vacuum chamber, and a vertical drying and cooling chamber of rectangular cross-section, consisting of modules installed one above the other. Each module contains several narrow shafts, separated from each other and from the module walls by an inter-shaft space. The shafts are formed by a pair of vertical guides with the ability to create narrow grain flows within the module.

[0003] A drawback of the existing grain dryer is its limited drying efficiency due to its exclusive use of convective heat input. The design does not incorporate physical energy input methods, such as high and ultra-high frequencies, which precludes volumetric heating of the grain and its disinfection from pathogenic microflora. The intensity of the drying process is limited by the rate of convective heat transfer. As a result, uneven heating persists across the grain column, negatively impacting the quality of the final product. The lack of combined energy input prevents the combination of drying and disinfection operations in a single process cycle, reducing the overall efficiency of grain processing.

[0004] The closest in technical essence and achieved effect is a louver-type modular shaft grain dryer (Patent RU 2792803 C1, IPC F26B 17 / 12, published 24.03.2023), which includes a heated air chamber, a humid air chamber, a drying and cooling vertical chamber made of modules installed on a support frame, installed one above the other to form a shaft, in each module there are several narrow shafts with blinds located on them from top to bottom in several rows, separated from each other and from the walls of the module by supply and discharge channels, wherein the supply and discharge channels of each module are separated by partitions from the supply and discharge channels of the module adjacent to it and are located in a checkerboard pattern relative to the boundary of the connection of the modules, and the plugs installed on the side of the inlet of the drying agent and the outlet of the mixture of the drying agent and moisture are also located in a checkerboard pattern in accordance with the location of the supply and discharge channels of each module.

[0005] A disadvantage of the well-known modular louver-type shaft grain dryer is the limited efficiency of heat and mass transfer, due to its exclusive reliance on convective drying. This prevents uniform heating across the grain column, as the high aerodynamic resistance of the bed hinders the penetration of the drying agent into its central zone. As a result, heating occurs primarily from the surface through the louvered slots, leading to significant temperature gradients across the cross-section. The intensity of the drying process is limited, as the rate of moisture removal is limited solely by convective heat transfer.

[0006] There is also no bactericidal effect on pathogenic microflora and pests contained in the grain mass. It is impossible to combine drying and disinfection operations in a single technological process.

[0007] The existing design of the grain dryer requires the use of complex technical solutions to compensate for the uneven distribution of the drying agent along the height of the grain column, such as the implementation of variable cross-section sub-louver slots, increasing their number, etc.

[0008] The quality of the finished product depends significantly on the uniform distribution of air flows in the system of supply and discharge channels and directly in the grain columns themselves.

[0009] The above mentioned disadvantages limit the technological capabilities of the grain dryer and do not allow for a comprehensive improvement in the quality of finished products while simultaneously disinfecting the grain material.

[0010] The technical objective of the invention is to create a modular shaft grain dryer of a louver type, which ensures an increase in the uniformity of drying and the quality of the finished product due to the combined effect of microwave energy and a drying agent, as well as the disinfection of grain from pathogenic microflora and pests.

[0011] The stated technical problem of the invention is achieved in that in a louver-type modular shaft grain dryer with a microwave energy supply, consisting of a heated air chamber, a humid air chamber, a drying and cooling vertical chamber made of modules installed on a support frame, installed one above the other to form a shaft, in each module there are several narrow shafts with louvers located on them from top to bottom in several rows, separated from each other and from the walls of the module by supply and discharge channels, containing at least one microwave module installed in series with the drying modules and containing its own vertical grain columns on which microwave emitters are installed, wherein the grain columns of the microwave module form single continuous vertical channels with the grain columns of the adjacent drying module, what is new is that,that microwave emitters are built into the inclined parts of the louvered walls of the grain columns of the microwave module along their entire length using waveguides.

[0012] The technical result consists in ensuring uniform drying and simultaneous disinfection of grain due to the combined effect of microwave radiation and heated air, which improves the quality of the finished product and expands the functionality of the grain dryer.

[0013] Fig. 1 shows a sectional view of a modular louver-type shaft grain dryer with microwave energy supply; Fig. 2 is a frontal view of the microwave module; Fig. 3 is a section A-A; Fig. 4 is a grain column of the microwave module.

[0014] The dryer comprises a support frame 5 with an unloading device, a loading hopper 1, drying modules 3, and a cooling module 4, each consisting of a frame clad with side walls. The modules are installed one above the other and are equipped with service platforms 12 and ladders. The upper element of the drying tower is a microwave module 2, located directly beneath the loading hopper 1.

[0015] Vertical wall 11, located in the heating chamber between burner 9 and the shaft, divides the chamber into a zone for direct air heating and a zone for airflow stabilization. It also serves to prevent unevenly heated air and sparks from the burner flame from entering the grain columns. The interior of the heating chamber is lined with thermal insulation.

[0016] Fans 6, mounted on supports 8 and connected to the dust collection system 7, are used to create a vacuum in the humid air chamber. Heating of the drying agent is carried out using a burner 9. Partition 10 serves to transfer the lower cooling section to the drying section.

[0017] The microwave module 2 contains its own vertical grain columns 13 with louvered walls 16, in the inclined parts of which microwave emitters 14 are built in along their entire length by means of waveguides 15. The grain columns 13 of the microwave module are made coaxial and are a direct continuation of the grain columns 18 of the adjacent drying module, ensuring the continuity of the grain flow.

[0018] Drying modules 3 contain grain columns 18, separated from each other and from the module walls by inlet and outlet channels. The inlet and outlet channels of each module are separated by partitions from the inlet and outlet channels of the adjacent module. The columns are connected by crossbeams. The grain dryer shaft is formed by grain columns, which create several narrow grain streams.

[0019] On both sides of the shaft between the grain columns, in accordance with the location of the inlet and outlet channels of each module, plugs are installed that separate the heating chamber from the humid air chamber, preventing the drying agent from passing through the inter-shaft space and thereby ensuring the passage of the drying agent through the grain layer in the columns.

[0020] The grain dryer works as follows.

[0021] Pre-cleaned wet grain is fed into loading hopper 1. Under the action of gravity, the grain enters microwave module 2. In vertical grain columns 13 of the microwave module, a combined energy effect on the grain mass is realized. This includes volumetric heating of the grain by an ultra-high-frequency electromagnetic field from emitters 14, located in the inclined walls of the blinds 16 via waveguides 15, and convective drying due to the passage of a drying agent through sub-louvered slots 17. This combination of microwave radiation and convection provides a synergistic effect, expressed in the simultaneous achievement of two technological results - intensive moisture removal due to volumetric heating of the grain layer and bactericidal treatment due to denaturation of the protein structures of pathogenic microflora and inactivation of the enzymes of mold fungi and bacteria.Volumetric heating of the grain in the microwave module intensifies the diffusion of moisture from the inner layers of the grain to the surface, where it is effectively removed by a flow of drying agent supplied through the louvered slots. Uniform microwave exposure across the entire grain flow is ensured by the spatial distribution of microwave emitters along the entire length of the columns.

[0022] After microwave module 2, the grain passes sequentially through drying modules 3, where the convective drying process continues. The grain flows by gravity down the louvered grain columns 18 of the drying tower, uniformly filling all columns of drying modules 3 and cooling module 4.

[0023] After loading the dryer with wet grain, the process line switches to cyclic operation. Fans 6 are turned on, burner 9 is ignited, and the drying agent temperature is set to the required value. Simultaneously, the unloading device, mounted on support frame 5, is activated. By adjusting the unloading device, the required capacity is established, after which the main grain drying process begins.

[0024] The drying process in drying modules 3 is carried out as follows. Bulk material moves downwards under the force of gravity and is mixed in the grain columns by louvers. The geometry of the grain layer creates the necessary pressure, ensuring its passage without the formation of stagnant zones. Due to the vacuum created by fans 6, the air flow (drying agent), heated by burner 9, enters the inter-shaft space (supply channels) from the hot air chamber, resting against plugs (not shown).

[0025] The drying agent passes through a layer of bulk material, heating it, transferring thermal energy and removing moisture and dust. The exhaust moist airflow is directed through exhaust ducts into a moist air chamber, from where it is transported by fans 6 to the dust collection system 7 for purification before being released into the atmosphere.

[0026] In cooling module 4, the material is cooled by atmospheric air, which passes through the grain layer and is discharged through a system of exhaust ducts. If drying without cooling is required, the adjustment partition 10 moves to the bottom of the cooling module, converting it into an additional drying section.

[0027] The bulk material from the grain columns of cooling module 4 is directed through the unloading device onto the conveyors of the process line. This process continues until the material moisture content reaches the required level. After this, the process line switches to in-line drying of the bulk material. During in-line drying, the dried material, after drying and cooling in the dryer, is transported by the process line's transport vehicles for further processing.

[0028] Thus, the proposed modular louver-type grain dryer with microwave energy supply provides a combined energy impact on the grain material. Uniform microwave energy impact on the grain mass throughout the grain column is achieved by installing microwave emitters in the inclined sections of the louvered walls along the entire length of the microwave module's columns using waveguides, as well as by coaxially arranging these columns with a direct extension into the adjacent drying module. The combined use of volumetric microwave heating and convective drying ensures uniform drying and simultaneous disinfection of the grain, improves the quality of the finished product, and expands the functionality of the grain dryer by combining drying and disinfection in a single process.

Claims

1. A modular shaft grain dryer of a louvered type with a microwave energy supply, consisting of a heated air chamber, a humid air chamber, a drying and cooling vertical chamber made of modules installed on a support frame, installed one above the other to form a shaft, in each module there are several narrow shafts with louvers arranged on them from top to bottom in several rows, separated from each other and from the walls of the module by supply and discharge channels, containing at least one microwave module installed in series with the drying modules and containing its own vertical grain columns on which microwave emitters are installed, wherein the grain columns of the microwave module form single continuous vertical channels with the grain columns of the adjacent drying module, characterized in that the microwave emitters are built into the inclined parts of the louvered walls of the grain columns by means of waveguides Microwave modules along their entire length.

2. A grain dryer according to paragraph 1, characterized in that the microwave module is installed directly under the loading hopper and above the drying modules.

3. A grain dryer according to paragraph 1, characterized in that the grain columns of the microwave module are coaxial and are a direct continuation of the grain columns of the adjacent drying module.

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