CN210135766U - Drying machine - Google Patents

Abstract

The utility model discloses a drying machine, include: the drying cabinet, be used for providing a plurality of hot-blast district of providing hot-blast, be used for retrieving cold wind recovery area and adjusting device of cold wind, the drying cabinet is its inside from top to bottom inject communicating a plurality of drying district, every hot-blast district and at least one of providing the drying district reaches cold wind recovery area forms the wind path that is used for dry cereal, adjusting device sets up adjacent two between the hot-blast district that provides, its activity sets up, has at least on its activity route and makes adjacent two communicating position in hot-blast district and make adjacent two the position that separates in hot-blast district that provides, the desiccator can effectively practice thrift the drying cost and the dry time of desiccator.

Description

Drying machine

Technical Field

The utility model belongs to the technical field of dry processing equipment technique and specifically relates to a desiccator is related to.

Background

The drying machine is mainly used for drying grains of granular materials such as rice, wheat, corn, soybean, rapeseed, tea seeds, tung seeds and the like, the yield of the grains dried by the existing drying equipment is small, the demand of the grains dried by the existing drying equipment is multiplied, so that the market competition is more and more intense, and how to realize that grains with higher quality are dried by using less drying cost is the technical bottleneck of the development of the grain drying machine.

The prior art discloses a dryer with a static counter-flow structure, which mainly comprises a material box for accommodating grains, a hot air box positioned below the material box, a sieve plate arranged between the material box and the hot air box and fully distributed with through holes, a hot air source positioned on one side of the hot air box and used for providing hot air, and a hot air pipe for connecting the hot air source and the hot air box into a whole and transmitting the hot air.

When the hot air source is started, hot air is fed into the hot air box in a positive pressure mode through the hot air pipe, then the hot air passes through the sieve plate from bottom to top to enter the bottom of the material box, heat is transferred to grains, water vapor and dust of the grains are taken away, and the grains are discharged into the atmosphere. When the cereal of acceping in the material case is more, in drying process, all cereals of material incasement are in the dry state of being heated all the time, and the hot-blast temperature of material bottom layer cereal contact is higher, does a little fast, and the hot-blast temperature of the cereal contact at top is low, does a little slowly for a batch of cereal is different because of the position of acceping, and the degree that leads to the drying is different. Moreover, the static counterflow dryer is only suitable for drying small batches of materials, and cannot dry a large number of grains.

The prior art has also disclosed a drier of batch circulation mixed flow structure, including the material case that is located the drier bottom and is used for acceping cereal, the multiunit angle form pipe that is located material case top and be located the tempering layer of multiunit angle form pipe top. The ratio of the tempering time of the grains in the tempering layer to the drying time in the drying layer is more than 3, and is generally about 3-5. If the average drying rate needs to be increased again, the hot air temperature needs to be increased, the hot air speed needs to be increased, the drying cost is increased, the drying quality is reduced, in addition, the mixed-flow type drying machine can only dry grains inside a drying layer, no matter how many grains are loaded in a tempering layer, the uniform drying time is adopted in each drying tempering circulation, and the problems that the increasing value of the popping rate is higher, the germination rate is reduced and the like easily occur during grain drying are easily caused.

Accordingly, there is a need for an improved dryer.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a dryer which can effectively save drying cost and drying time and ensure drying quality.

The purpose of the utility model is realized through the following technical scheme:

a dryer, comprising: the drying oven comprises a drying oven, a plurality of hot air supply areas for supplying hot air, a cold air recovery area for recovering cold air and an adjusting device, wherein the drying oven is internally provided with a plurality of communicated drying areas from top to bottom, each hot air supply area, at least one drying area and the cold air recovery area form an air path for drying grains, and the adjusting device is arranged between two adjacent hot air supply areas and is movably arranged, and at least provided with a separation position for separating the two adjacent hot air supply areas from each other and a communication position for communicating the two adjacent hot air supply areas.

As a further improvement of the above technical solution, the plurality of drying zones include an upper drying zone located above the drying box, a middle drying zone located below the upper drying zone, and a lower drying zone located below the drying box.

As a further improvement of the technical proposal, a tempering layer is arranged between the middle drying area and the lower drying area.

As a further improvement of the above technical solution, the hot air supply area includes an upper hot air supply area installed on one side of the middle drying area, and a lower hot air supply area located on one side of the tempering layer and the lower drying area.

As a further improvement of the above technical solution, the cold air recovery area includes an upper cold air recovery area located on one side of the drying area and corresponding to the upper hot air supply area, and a lower cold air recovery area corresponding to the lower hot air supply area.

As a further improvement of the above technical solution, when the loading amount of the grains reaches the middle upper part of the upper drying zone, the adjusting device switches from the separation position to the communication position, so that the grains are dried in a plurality of drying zones in the dryer.

As a further improvement of the above technical solution, when the loading amount of the grains reaches above the tempering layer but below the lower portion of the upper drying zone, the adjusting device switches from the communicating position to the separating position, and the grains are dried in the lower drying zone in the dryer.

As the further improvement of the technical proposal, at least one layer of upper layer cooling air collection angle-shaped pipe is distributed in the upper drying area, at least a plurality of layers of middle layer angle-shaped pipes are distributed in the middle drying area, the middle layer angle-shaped pipe comprises a middle layer hot air output angle-shaped pipe and a middle layer cooling air collection angle-shaped pipe, at least a plurality of layers of lower layer angle-shaped pipes are distributed in the lower drying area, and the lower layer angle-shaped pipe comprises a lower layer hot air output angle-shaped pipe and a lower layer cooling air collection angle-.

As the further improvement of the technical proposal, the middle layer hot air output horn-shaped pipe and the middle layer cooling air collection horn-shaped pipe are horizontally arranged and are arranged adjacently and vertically in a staggered way, and the lower layer hot air output horn-shaped pipe and the lower layer cooling air collection horn-shaped pipe are horizontally arranged and are arranged adjacently and vertically in a staggered way.

As a further improvement of the above technical solution, the dryer further includes a distribution device located at the top of the drying box, a distribution device located below the plurality of drying zones, a discharge device located below the distribution device, and a material collection portion located below the discharge device.

The utility model has the advantages that:

the drying box of the drying machine is internally provided with a plurality of communicated drying areas from top to bottom, each hot air supply area, at least one drying area and a cold air recovery area form an air path for drying grains, and the adjusting device is arranged between two adjacent hot air supply areas and is movably arranged, and at least provided with a communicating position for communicating the two adjacent hot air supply areas and a separating position for separating the two adjacent hot air supply areas on the moving path.

This application is through the quantity and the positional relation of reasonable configuration drying area, hot-blast district of providing and cold wind recovery district, combines adjusting device reasonable selection again to be dried the wind path by the drying area, hot-blast district of providing and the formation of cold wind recovery district for the desiccator can realize drying according to the volume of its cereal of loading, reaches the balance between cereal volume, the hot-blast volume, thereby effective control cost and save time.

The desiccator compromise static counterflow dryer can be in succession low temperature dry with batch circulation grain drier can mechanize the advantage of drying in batches, long-time drying, short time are slowly soviet. The low-temperature drying is carried out at low wind speed in a large wind quantity, so that the speed of evaporating water on the surface of the grains is reduced, the speed of transferring water in the grains to the surface is close, the gradient and the pressure difference of water in and out of the grains are reduced, the internal stress of the grains is reduced, the increment value of the waist bursting rate and the crack rate are reduced, the germination rate is not reduced, the quality parameters such as taste value, appearance and processability are better, and the drying efficiency is higher.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is an assembled side view of the dryer of the present invention;

fig. 2 is an assembled front view of the dryer of the present invention;

fig. 3 is a hot air flow diagram of the adjusting device of the drying machine according to the present invention at the spaced position.

Description of the main element symbols:

1-a lifting device; 2-drying oven; 20-a dispensing device; 210-upper drying zone; 2101-upper cooling air collection horn; 211-middle drying zone; 2112-middle cooling wind collecting horn; 2111-horn-shaped tube for outputting hot air from middle layer; 212-lower drying zone; 2121-horn-shaped lower hot air outlet pipe; 2122-collecting horn-shaped tube for lower layer cooling air; 22-a tempering layer; 23-a flow splitting device; 24-a discharge device; 25-a material collecting part; 3-a hot air source; 30-an adjustment device; 301-hot air pipes; 31-upper hot air supply zone; 32-lower hot air supply zone; 33-a blower; 4-a grain expansion buffer zone; 5-a cold air recovery zone; 50-an upper cold air recovery area; 51-lower cold air recovery zone; 6-an exhaust fan; 7-a material conveying device.

Detailed Description

To facilitate an understanding of the present invention, the dryer will be described more fully below with reference to the accompanying drawings. A preferred embodiment of the dryer is shown in the drawings. However, the dryer may also be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the dryer is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 3, the present invention provides a drying machine, which is mainly used for drying grain such as rice, wheat, corn, soybean, rapeseed, tea seed, and tung seed.

The drying machine comprises a lifting device 1 for lifting grains and a drying box 2 which is positioned on the side edge of the lifting device 1 and used for drying the grains. The lifted grain is then transported by a conveyor 7 to a grain expansion buffer 4 at the top of the drying box 2.

The drying box 2 mainly includes a scattering device 20 located at the top of the drying box 2, a plurality of drying zones (not numbered) and tempering layers 22 located below the scattering device 20, a plurality of flow dividing devices 23 located below the drying zones (not numbered), a discharging device 24 located below the flow dividing devices 23, and a material collecting portion 25 located below the discharging device 24. When in the working state, the material collecting part 25 is in a positive pressure state, and the pressure is basically the same as that of the grain expansion buffer zone 4. The distributing device 20 distributes the grains conveyed by the conveying device 7 uniformly into the space at the top of the drying box 2. The distribution device 23 can uniformly distribute the dried grains to prevent the grains from being stacked together. The discharging device 24 discharges the grains in the diversion device 23 to the material collection portion 25 through a material poking roller (not numbered). The material collecting portion 25 transfers the collected grains to the bottom of the lifting device 1 and then circularly lifts the grains to the top of the drying box 2.

Referring to fig. 2, the drying box 2 defines a plurality of drying zones (not numbered) therein from top to bottom, the drying zones include an upper drying zone 210 located below the scattering device 20, a middle drying zone 211 located below the upper drying zone 210, and a lower drying zone 212 located above the flow dividing device 23, and a tempering layer 22 is disposed between the middle drying zone 211 and the lower drying zone 212.

Wherein, the lower part of the upper drying area 210 is evenly distributed with at least one layer of upper layer cooling wind collecting angular pipes 2101. Multiple layers of middle layer horn-shaped tubes (not numbered) are uniformly distributed in the middle drying zone 211.

The middle-layer angular pipe (not numbered) comprises a middle-layer hot air output angular pipe 2111 and a middle-layer cooling air collection angular pipe 2112. The middle-layer hot air output horn-shaped pipe 2111 and the middle-layer cooling air collection horn-shaped pipe 2112 are horizontally installed, and the adjacent upper and lower layers are uniformly installed in a staggered manner.

The lower drying zone 212 is uniformly distributed with a plurality of layers of lower layer angular tubes (not numbered) which comprise lower layer hot air output angular tubes 2121 and lower layer cooling air collection angular tubes 2122. The lower hot air output horn-shaped tube 2121 and the lower cooling air collection horn-shaped tube 2122 are horizontally arranged, and the adjacent upper and lower layers are uniformly arranged in a staggered manner. The horn-shaped pipe is pentagonal or triangular, the horn-shaped pipe can be the same cross section size in the length direction, and can also be gradually deformed with one end being large and the other end being small, one end of the horn-shaped pipe is opened, and the other end is closed. The number of layers of the multi-layer angular pipe is determined according to the drying capacity of the dryer.

Wherein, a hot air source 3 and a blower 33 are arranged on one side of the drying box 2, a regulating device 30 is arranged between an upper hot air supply area 31 and a lower hot air supply area 32, the regulating device is movably arranged, and at least comprises a communicating position for communicating two adjacent hot air supply areas and a separating position for separating the two adjacent hot air supply areas on the moving path, and the direction of the hot air can be regulated according to the quantity of the grains.

The hot air source 3 of the dryer supplies heat energy to a plurality of hot air supply regions (not numbered) for supplying hot air, respectively, the hot air supply regions including an upper hot air supply region 31 installed at one side of the middle drying region 211, and a lower hot air supply region 32 located at one side of the tempering layer 22 and the lower drying region 212. The hot air pipe 301 is installed on the upper portion of the upper hot air supply area 31, the hot air pipe 301 is communicated with the grain expansion buffer area 4 on the top of the drying box 2, and the grain expansion buffer area 4 is in a positive pressure state. The hot air sources can be installed in a plurality according to requirements, each hot air source corresponds to a corresponding hot air supply area one by one, namely the upper hot air source corresponds to the upper hot air supply area 31, the lower hot air source corresponds to the lower hot air supply area 32, the hot air sources are arranged at different positions so as to provide corresponding hot air volume, and different hot air supply areas can be opened according to the number of grains.

The drying machine is provided with a cold air recovery area 5 for recovering cold air on the other side of the drying box 2, the cold air recovery area 5 is communicated with an air outlet (not numbered), and each hot air supply area, at least one drying area and the cold air recovery area form an air path for drying grains. The cold air recovering section 5 includes an upper cold air recovering section 50 located at the other side of the drying section and corresponding to the upper hot air supplying section 31, and a lower cold air recovering section 51 corresponding to the lower hot air supplying section 32. The cooling air is discharged into the atmosphere through an exhaust fan 6 from an air outlet (not numbered) thereof.

The utility model discloses a working process of desiccator when carrying out the drying to cereal is:

wherein, the cereal that is located the bottom promotes through hoisting device 1, delivers to the top of drying cabinet 2 through feeding device 7, scatters the cereal through scattering device 20 and gets into upper drying district 210, contacts with the hot-blast of downward flow, and hot-blast heat passes to cereal, and the moisture absorption heat rising temperature on cereal granule surface becomes steam, and cereal granule surface absorption heat also rises the temperature. After the hot air releases heat, it carries water vapor and dust at a low wind speed, enters the upper cooling air collecting angular pipe 2101 of the upper drying zone 210, sequentially passes through the upper cold air recovery zone 50 and the lower cold air recovery zone 51, and then enters the tail air treatment equipment (not shown) through the exhaust fan 6 to be discharged into the atmosphere. The moisture loss rate of the grain in the upper drying zone 210 is low, mainly to increase the internal and external temperature of the grain.

Then, the grains continue to descend into the middle drying zone 211, and the hot air blown out from the middle hot air output horn 2111 of the middle drying zone 211 passes through the grain layer in various moving directions to transfer heat to the grains. The moisture on the surface of the grain absorbs heat to raise the temperature, and the moisture turns into water vapor, and the heat absorbed on the surface of the grain continues to raise the temperature. The hot air, after releasing heat, takes away water vapor and dust at a medium speed, enters the middle layer cooling air collecting angular pipe 2112, sequentially passes through the upper cold air recovery area 50 and the lower cold air recovery area 51, and then enters the tail air treatment equipment (not shown) through the exhaust fan 6 to be discharged into the atmosphere. The temperature of the grain in the intermediate drying zone 211 continues to rise, with moderate rate of reduced drying.

The grain then continues to descend into the middle tempering layer 22, transferring heat from the grain surface inwardly and transferring moisture from the interior outwardly to provide a cushion for the grain to better dry in the lower drying zone 212.

The grain then continues to descend into the lower drying zone 212, and the hot air blown from the lower hot air output horn 2121 of the lower drying zone 212 passes through the grain layer in multiple directions of motion, transferring heat to the grain. The moisture on the surface of the grain absorbs heat to raise the temperature, and the moisture turns into water vapor, and the heat absorbed on the surface of the grain continues to raise the temperature. After the hot air emits heat, the hot air takes away water vapor and dust at a medium speed, enters the lower cooling air collecting horn-shaped pipe 2122, passes through the lower cold air recovery area 51, enters tail air treatment equipment (not shown) through the exhaust fan 6, is discharged into the atmosphere, and the temperature of the grains continues to rise in the lower drying area 212, and the drying rate is medium.

And then, cereal continues to descend and gets into material collection portion 25, discharges downwards through discharge device 24, gets into material collection portion 25, and conveyor feeds into hoisting device 1, accomplishes a drying process, and the moisture of cereal reduces certain numerical value. And (5) after multiple times of circulating drying, reducing the water content of the grains to a set value, and finishing drying.

When the loading of the grains in the dryer reaches the middle upper part of the upper drying zone, the drying process of the dryer is as follows:

the hot air is conveyed into the hot air supply area through the hot air source 3, the adjusting device 30 is switched from a separated position to a communicated position, the hot air moves upwards and downwards respectively according to the loading capacity of grains, one path of hot air moves downwards, the hot air horizontally enters the lower hot air output horn-shaped pipe 2121 of the lower drying area 212, passes through a grain layer in multiple moving directions, transfers heat to the grains, takes away water vapor and dust at medium wind speed, enters the lower cooling air collection horn-shaped pipe 2122 of the lower drying area 212, passes through the lower cold air recovery area 51, then enters tail air treatment equipment (not shown) through the exhaust fan 6, and is exhausted into the atmosphere. The other path of hot air moves upwards, enters the upper hot air supply area 31 through the adjusting device 30, then horizontally enters the middle-layer hot air output angle-shaped pipe 2111 of the middle drying area 211, passes through a grain layer in various moving directions, transfers heat to grains, takes away water vapor and dust at a middle air speed, enters the middle-layer cooling air collection angle-shaped pipe 2112, sequentially passes through the upper cold air recovery area 50 and the lower cold air recovery area 51, and then enters tail air treatment equipment (not shown) through the exhaust fan 6 to be discharged into the atmosphere. A small amount of hot air continuously goes upward, enters the grain expansion buffer zone 4 through the hot air pipe 301, moves downward, passes through the grains in the upper drying zone 210, transfers heat to the grains, takes away water vapor and dust at a lower wind speed, enters the upper cooling air collecting horn-shaped pipe 2101, sequentially passes through the upper cold air recovery zone 50 and the lower cold air recovery zone 51, then enters tail air treatment equipment (not shown) through the exhaust fan 6, and is discharged into the atmosphere.

Referring specifically to fig. 3, when the loading of the grain in the dryer is low, such as at the beginning and end of grain harvesting, and the harvested grain is not enough to fill the dryer, the operation of the dryer is as follows:

as long as the grain loading exceeds the upper part of the tempering layer but is lower than the lower part of the upper drying area, namely the lower drying area 212 is covered and a certain margin is provided for compensating the shrinkage after the grain is dried, the adjusting device 30 is switched from the communicating position to the separating position to carry out the communicating hot air drying. The hot air passes through the hot air source 3, enters the lower hot air supply area 32, then horizontally enters the lower hot air output angular pipe 2121 of the lower drying area 212, passes through the grain layer in various moving directions, transfers heat to grains, takes away water vapor and dust, enters the lower cooling air collection angular pipe 2122, passes through the lower cold air recovery area 51, then enters the tail air treatment equipment (not shown) through the exhaust fan 6, and is discharged into the atmosphere. Cereal gets into material collection portion 25, discharges downwards through discharge device 24, gets into material collection portion 25, sends hoisting device 1 into through conveyor, accomplishes a drying process, and the moisture of cereal reduces certain numerical value. And (5) after multiple times of circulating drying, reducing the water content of the grains to a set value, and finishing drying.

Therefore, the drying machine can dry grains according to the amount of the grains loaded by the drying machine by reasonably configuring the quantity and the position relation of the drying area 212, the hot air supply area and the cold air recovery area and reasonably selecting the drying air path formed by the drying area 212, the hot air supply area and the cold air recovery area by combining the adjusting device 30, so that the balance between the grain amount and the hot air amount is achieved, and the cost and the time are effectively controlled.

The utility model discloses an in-process that the desiccator carries out the drying to various cereal, its hot-blast temperature and cereal temperature are all inequality to different cereal, the regulation and control of the hot-blast temperature and the cereal temperature of following various different cereal:

1) when drying the rice commodity, the temperature of the hot air is controlled to be 45-55 ℃, and the temperature of the rice is controlled to be below 42 ℃. When drying the rice seeds, the temperature of the hot air is controlled to be 35-45 ℃, and the temperature of the rice is controlled to be below 37 ℃.

2) When drying wheat commercial grains, the temperature of hot air is controlled at 50-60 ℃, and the temperature of wheat is controlled below 47 ℃. When drying wheat seeds, the hot air is controlled at 40-50 ℃ and the wheat temperature is controlled below 42 ℃.

3) When the corn feed grain is dried, the temperature of hot air is controlled to be 80-100 ℃, and the temperature of corn is controlled to be below 80 ℃. When the commercial corn is dried, the temperature of hot air is controlled to be 60-80 ℃, and the temperature of corn is controlled to be below 53 ℃. When the corn seeds are dried, the hot air is controlled to be 40-50 ℃, and the wheat temperature is controlled to be below 42 ℃.

The utility model discloses a drying cabinet of desiccator prescribes a limit to communicating a plurality of drying district from top to bottom in its inside, goes up drying district 210, well drying district 211 and drying district 212 under promptly, every hot-blast district and at least one of providing the drying district reaches cold wind recovery area forms the wind path that is used for dry cereal, adjusting device 30 sets up adjacent two between the hot-blast district that provides, adjusting device 30 activity sets up, has at least on adjusting device 30's activity route and makes adjacent two the communicating position of hot-blast district that provides communicates with each other and makes adjacent two the position that separates is provided to hot-blast district. The moving path of the adjusting device 30 is determined according to the grain loading, when the grain loading reaches the middle upper part of the upper drying area, the adjusting device 30 is opened, the grains are contacted with the hot air of the hot air supply area in the three drying areas in the drying machine, the total drying reduction rate of the three drying layers is not low, the drying speed of the grains is obviously improved compared with that of the drying machine in the prior art, and the quality of the grains after drying is good. When the grain load is less, the grain load reaches the upper part of the tempering layer but is lower than the lower part of the upper drying area, namely, the lower drying area 212 is covered and has a certain margin for compensating the shrinkage after the grain is dried, the adjusting device 30 is closed, and at least one drying area is contacted with the hot air of the hot air supply area, so that the drying cost and the drying time of the dryer can be effectively saved.

Furthermore, the utility model discloses a desiccator has following advantage: in a long drying time, low-temperature drying with large air volume and low air speed is adopted, so that the evaporation speed of water on the surface of the grains is reduced, the speed of water in the grains migrating to the surface is close, the gradient and pressure difference of water inside and outside the grains are reduced, the internal stress of the grains is reduced, the increment value of the waist bursting rate and the crack rate are reduced, the germination rate is not reduced, and the quality parameters such as taste value, appearance, processability and the like are better.

The above-described embodiments are merely illustrative of several embodiments of the present invention, which are described in detail and specific, but not intended to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A dryer, comprising:

the drying box is internally provided with a plurality of communicated drying areas which are limited from top to bottom;

a plurality of hot wind supply areas for supplying hot wind;

the cold air recovery area is used for recovering cold air, and each hot air supply area, at least one drying area and the cold air recovery area form an air path for drying grains; and

the adjusting device is arranged between the two adjacent hot air supply areas, is movably arranged, and at least comprises a communicating position for communicating the two adjacent hot air supply areas and a separating position for separating the two adjacent hot air supply areas on the moving path.

2. The dryer of claim 1 wherein said plurality of drying zones includes an upper drying zone located above the cabinet, a middle drying zone located below the upper drying zone, and a lower drying zone located below the cabinet.

3. The dryer of claim 2, wherein a tempering layer is further disposed between the middle drying zone and the lower drying zone.

4. The drying machine as claimed in claim 3, wherein the hot air supply zone comprises an upper hot air supply zone installed at one side of the middle drying zone, and a lower hot air supply zone located at one side of the tempering layer and the lower drying zone.

5. The drying machine as claimed in claim 4, wherein the cool air recovery area includes an upper cool air recovery area at a side of the drying area corresponding to the upper hot air supply area, and a lower cool air recovery area corresponding to the lower hot air supply area.

6. The dryer of claim 4 wherein said adjustment means switches from said isolated position to said open position when said grain load reaches an upper-middle drying zone to allow grain to be dried in multiple drying zones within the dryer.

7. The dryer of claim 4 wherein said adjustment means switches from said open position to said closed position when the grain load reaches above the tempering layer but below the lower portion of the upper drying zone, and grain is dried in the lower drying zone of the dryer.

8. The dryer as claimed in claim 6, wherein at least one layer of upper cooling wind collecting angular tubes is distributed in the upper drying zone, at least a plurality of layers of middle angular tubes are distributed in the middle drying zone, the middle angular tubes comprise a middle layer hot wind output angular tube and a middle layer cooling wind collecting angular tube, at least a plurality of layers of lower layer angular tubes are distributed in the lower drying zone, and the lower layer angular tubes comprise a lower layer hot wind output angular tube and a lower layer cooling wind collecting angular tube.

9. The dryer as claimed in claim 8, wherein the horn-shaped middle air outlet duct and the horn-shaped middle cooling air collecting duct are horizontally installed and are installed in a staggered manner adjacent to each other in the upper and lower stages, and the horn-shaped lower air outlet duct and the horn-shaped lower cooling air collecting duct are horizontally installed and are installed in a staggered manner adjacent to each other in the upper and lower stages.

10. The dryer of claim 8 further comprising a distribution device at the top of the cabinet, a distribution device below the plurality of drying zones, a discharge device below the distribution device, and a material collection portion below the discharge device.

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