CN109883183B

CN109883183B - Drying machine

Info

Publication number: CN109883183B
Application number: CN201910239126.7A
Authority: CN
Inventors: 吴杰俊
Original assignee: Changsha Wanhua Machine Co ltd; Hunan Chenzhou Grain & Oil Machinery Co ltd
Current assignee: Changsha Wanhua Machine Co ltd; Hunan Chenzhou Grain & Oil Machinery Co ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2024-01-23
Anticipated expiration: 2039-03-27
Also published as: CN109883183A

Abstract

The application provides a desiccator relates to the drying equipment field. A dryer, comprising: the tempering drying layer comprises a circulating fan, and a hot air output angular pipe and a hot air input angular pipe which are arranged in the tempering drying layer, wherein the hot air output angular pipe is communicated with an air outlet of the circulating fan, and the hot air input angular pipe is communicated with an air inlet of the circulating fan; the drying layer is provided with an air inlet pipe for supplying air to the drying layer and an exhaust fan for exhausting air from the drying layer; the tempering drying layer is arranged above the drying layer and is communicated with the drying layer. In the dryer provided by the application, in each drying tempering cycle, heat preservation, moisture preservation and tempering are adopted, the temperature rise of the interior of grains is faster, the tempering efficiency is improved, and the tempering time is reduced to about three-quarters to one-half of the whole period.

Description

Drying machine

Technical Field

The invention relates to the field of drying equipment, in particular to a dryer.

Background

The batch grain drier is one kind of mature grain drier and consists of drying tower and matched elevator. The drying layer of the batch type circulating grain dryer has two main types, namely a cross flow type structure and a mixed flow type structure.

The grain drying process is actually a process in which moisture migrates from the inside to the outside, and this migration process is actually mainly achieved by capillary channels inside the grain. The high temperature damages the channels, so that the waist bursting rate of the grains exceeds the industry standard, the quality of the grains is greatly reduced, the taste and appearance of the grains are seriously deteriorated, the flavor is reduced, the grinding rate is improved, and the market value is greatly reduced, so that the temperature and the speed of hot air for drying are required to be controlled during drying, and the grains are required to be subjected to moisture migration in a low-temperature environment through a large-stage tempering layer.

The tempering layer is arranged, so that the problem is avoided, but the ratio of tempering time of grains in the tempering layer to drying time in the drying layer is more than 5 and is generally between 10 and 15, so that the time of using hot air for drying in the drying layer actually occupies only a small part of the whole drying process, most of the time is used for tempering in the tempering layer, and the drying efficiency is low; in the harvesting season of grains, the grains are often mildewed and rotten due to insufficient operation capacity of the drying equipment, equipment investment is increased, and productivity waste is caused in off-season. There is a need in the market for a drying apparatus with high drying efficiency and good drying effect.

In view of this, the present invention has been made.

Disclosure of Invention

A first object of the present invention is to provide a dryer that employs insulation, moisture retention and tempering during each drying tempering cycle, whereby the grain continuously increases its internal temperature in the hot and humid air stream, causing the internal moisture to migrate more rapidly to the surface while the surface moisture is controllably discharged, the grain surface moisture content increasing to a level significantly higher than that obtainable in prior art tempering layers. The moisture gradient and pressure difference between the inside and the outside of the grain and the internal stress are further reduced, so that the temperature in the grain is increased faster, the tempering efficiency is improved, and the tempering time is reduced to about three-quarters to one-half of the whole period.

In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

a dryer, comprising:

the tempering drying layer comprises a circulating fan, and a hot air output angular pipe and a hot air input angular pipe which are arranged in the tempering drying layer, wherein the hot air output angular pipe is communicated with an air outlet of the circulating fan, and the hot air input angular pipe is communicated with an air inlet of the circulating fan;

the drying layer is provided with an air inlet pipe for supplying air to the drying layer and an exhaust fan for exhausting air from the drying layer;

the tempering drying layer is arranged above the drying layer and is communicated with the drying layer.

Preferably, an air inlet angular pipe and an air outlet angular pipe are arranged in the drying layer, the air inlet angular pipe is communicated with the air inlet pipe through an air inlet box, and the air outlet angular pipe is communicated with the exhaust fan through an air outlet box; or,

the drying device is characterized in that a screen plate is arranged in the drying layer, the screen plate forms a hot air channel, a cold air channel and a grain channel which are alternately arranged in sequence, the hot air channel is communicated with the air inlet box, and the cold air channel is communicated with the air outlet box.

More preferably, the hot air output angular pipe is arranged above the hot air input angular pipe, the hot air output angular pipe is communicated with the air outlet of the circulating fan through a first circulating hot air input bellows, and the hot air input angular pipe is communicated with the air inlet of the circulating fan through a first circulating hot air output bellows.

Further preferably, the first circulating hot air output air box is communicated with the air inlet box or the air outlet box through a first hot air branch pipe, and a first electric air damper for controlling hot air quantity is arranged at the joint of the air inlet box or the air outlet box and the first hot air branch pipe.

Preferably, an end of the hot air input angular pipe, which is far away from the first circulating hot air output bellows, is communicated with a heat exchanger or an external heat source through an auxiliary hot air input bellows.

Preferably, the hot air output angular pipe is arranged below the hot air input angular pipe, the hot air output angular pipe is communicated with an air outlet of the circulating fan through a second circulating hot air input bellows, and the hot air input angular pipe is communicated with an air inlet of the circulating fan through a second circulating hot air output bellows.

Further preferably, the dryer further comprises a heat exchanger or an external heat source, and one end of the hot air input angular pipe far away from the second circulating hot air output bellows is communicated with the air inlet bellows or the heat exchanger or the external heat source or the air outlet bellows through a second auxiliary hot air input bellows; the second circulating hot air output air box is communicated with the air inlet box or the air outlet box through a second hot air branch pipe, and a second electric air damper for controlling hot air quantity is arranged at the joint of the air inlet box or the air outlet box and the second hot air branch pipe.

Preferably, the dryer further comprises a heat exchanger or an external heat source, and a grain expansion buffer area is further arranged above the tempering drying layer and is communicated with the air inlet box or the heat exchanger or the external heat source or the air outlet box through a third hot air branch pipe.

More preferably, the drying layer is sequentially divided into a middle drying layer, a middle tempering layer and a lower drying layer from top to bottom, and the air inlet horn pipe and the air outlet horn pipe are positioned in the middle drying layer and the lower drying layer.

Optionally, the dryer also comprises a grain collecting hopper, a lower grain chute, a grain lifting machine, an upper grain chute and a grain homogenizing tray; the grain collecting hopper is arranged below the drying layer and is communicated with the lower end of the grain lifting machine through the lower grain chute; the feeding end of the upper cereal chute is communicated with the upper end of the cereal lifting machine; the grain homogenizing tray is arranged at the discharge end of the upper grain chute and is used for uniformly distributing grains in the tempering drying layer.

Compared with the prior art, the invention has the beneficial effects that:

(1) The original mode of low-temperature cooling and drying of the tempering layer is changed, and tempering is carried out in a heat-preservation and moisture-preservation state, so that the problem of improvement of the high-temperature waist burst rate is solved, and the problem of low tempering efficiency in a low-temperature cooling state is also solved;

(2) The drying process is optimized, and the drying efficiency is obviously improved; the contradiction between the high speed of mechanical harvesting of grains in large batches and the low drying speed of a grain dryer is improved;

(3) The quality of grain materials such as the dry grains, tea seeds, tung seeds and the like of the dryer is improved, and the quality of heat-sensitive grains such as rice is particularly improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

Fig. 1 is a schematic view showing the internal structure of a dryer provided in embodiment 1;

fig. 2 is a schematic view showing the external structure of the dryer provided in embodiment 1;

FIG. 3 is a schematic view of a dryer with an electrically powered damper on the inlet box provided in example 2;

FIG. 4 is a schematic diagram of a dryer with an electrically powered damper on the outlet box according to example 2;

fig. 5 is a schematic view of a dryer provided with a heat exchanger according to embodiment 3;

fig. 6 is a schematic view of a dryer provided with an external heat source according to example 3;

fig. 7 is an internal schematic view of the dryer provided in example 4;

FIG. 8 is a schematic diagram of a dryer with an electrically powered damper on the inlet box provided in example 4;

FIG. 9 is a schematic diagram of a dryer with an electrically powered damper on the outlet box provided in example 4;

fig. 10 is a schematic view of a dryer provided with a heat exchanger according to embodiment 4;

fig. 11 is a schematic view of a dryer provided with an external heat source according to example 4;

fig. 12 is an internal schematic view of the dryer provided in example 5;

FIG. 13 is a schematic view of a dryer with an electrically powered damper on the inlet box provided in example 5;

FIG. 14 is a schematic view of a dryer with an electrically powered damper on the outlet box provided in example 5;

fig. 15 is a schematic view of a dryer provided with a heat exchanger according to embodiment 5;

fig. 16 is a schematic view of a dryer provided with an external heat source according to example 5;

FIG. 17 is a schematic diagram of a dryer provided in example 6;

fig. 18 is a schematic diagram of a dryer provided in example 7.

Reference numerals: 1-a hot air output horn pipe; 2-hot air is input into the horn-shaped pipe; 3-a circulating fan; 4-circulating air pipes; 5-an air inlet pipe; 6-exhaust fan; 7-air inlet angle-shaped pipes; 8-an air outlet angle pipe; 9-an air inlet box; 10-an air supply pipe; 11-a wind outlet box; 12-an automatic control box; 13-transitional air pipes; 14-a first circulating hot air input bellows; 15-a first circulating hot air output bellows; 16-a grain collection hopper; 17-lower cereal chute; 18-grain elevator; 19-upper cereal slide pipe; 20-a grain refining disc; 21-a thermal insulation tempering layer with moisture; 22-a low-temperature wet hot air output layer; 23-insulating and moisturizing dry layers; 24-an air flow mixing input layer; 25-drying the layer; 26-a main drying layer; 27-a backflow air pipe; 28-a first hot air branch pipe; 29-a first electrically powered damper; 30-a first auxiliary hot air input windbox; 31-a heat exchanger; 32-an external heat source; 33-a first line; 34-a second circulating hot air input bellows; 35-a second circulating hot air output bellows; 36-a second auxiliary hot air input bellows; 37-a second hot air branch pipe; 38-a second electrically powered damper; 39-a second line; 40-tempering layer; 41-wet hot air drying the layer; 42-cereal expansion buffer; 43-a third hot air branch pipe; 44-a third electrically powered damper; 45-air supply fans; 46-an intermediate dry layer; 47-middle tempering layer; 48-lower drying layer; 49-upper dry layer; 50-sieve plates; 51-a hot air channel; 52-a cold air channel; 53-cereal channel; 54-edge guide slide carriage; 55-middle guide angle slide carriage; 56-a conveying device.

Detailed Description

The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings and detailed description, but it will be understood by those skilled in the art that the examples described below are some, but not all, examples of the present application, and are only for illustrating the present application and should not be construed as limiting the scope of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

Example 1

As shown in fig. 1 and 2, a dryer comprises a tempering drying layer and a drying layer which are arranged in a penetrating manner from top to bottom in the height direction; the tempering drying layer comprises a circulating fan 3, a hot air output angular pipe 1 and a hot air input angular pipe 2 which are arranged in the tempering drying layer, wherein the hot air output angular pipe 1 is communicated with an air outlet of the circulating fan 3, the hot air input angular pipe 2 is communicated with an air inlet of the circulating fan 3, and the hot air output angular pipe 1 is communicated with the circulating fan 3 through a circulating air pipe 4. The drying layer is provided with an air inlet pipe 5 for supplying air to the drying layer and an exhaust fan 6 for exhausting air from the drying layer.

In an alternative embodiment, in order to better optimize the distribution of hot air in the drying layer, an air inlet horn-shaped pipe 7 and an air outlet horn-shaped pipe 8 are arranged in the drying layer, the air inlet horn-shaped pipe 7 is communicated with the air inlet pipe 5 through an air inlet box 9 and an air supply air pipe 10, and the air outlet horn-shaped pipe 8 is communicated with the exhaust fan 6 through an air outlet box 11. A transition air pipe 13 can be arranged between the exhaust fan 6 and the air outlet box 11.

The hot air output horn-shaped pipe 1 is arranged above the hot air input horn-shaped pipe 2 along the height direction; in order to improve the tightness of hot air in the circulation process and the integration level of equipment, the hot air output angular pipe 1 is communicated with the air outlet of the circulating fan 3 through a first circulating hot air input air box 14, and the hot air input angular pipe 2 is communicated with the air inlet of the circulating fan 3 through a first circulating hot air output air box 15.

Referring to fig. 1, the angular tube cross section is preferably pentagonal. The opposite end of the hot air output horn-shaped pipe 1 connected with the first circulating hot air input bellows 14 and the opposite end of the hot air input horn-shaped pipe 2 connected with the first circulating hot air output bellows 15 are connected with the inner wall of the dryer.

In a preferred embodiment, the conveyor comprises a grain collection hopper 16, a lower grain chute 17, a grain elevator 18, an upper grain chute 19 and a grain refining tray 20; the grain collecting hopper 16 is arranged below the drying layer and is communicated with the lower end of the grain elevator 18 through the lower grain chute 17; the feeding end of the upper grain chute 19 is communicated with the upper end of the grain lifting machine 18, and the discharging end of the upper grain chute 19 is provided with a grain refining disc 20 for evenly distributing grains on the tempering drying layer.

According to the different functions of each drying section, the dryer can be divided into a heat preservation belt moisture tempering layer 21, a low-temperature wet hot air output layer 22, a heat preservation and moisture preservation drying layer 23, an air flow mixing input layer 24, a secondary drying layer 25 and a main drying layer 26 from top to bottom.

The direction of flow of the wind within the apparatus (see arrow in particular) is generally as follows: the hot air from the air inlet pipe 5 is distributed through the air inlet box 9 and then is sent to the air inlet horn-shaped pipe 7 in the main trunk layer, the hot air passes through grains in various movement directions, the heat is transferred to the grains, water vapor and dust are taken away at a medium speed, the grains enter the air outlet horn-shaped pipe 8, are collected through the air outlet box 11, are discharged into tail air treatment equipment through the air passing pipe 13 and the exhaust fan 6, and are discharged into the atmosphere; in the longitudinal direction, under the action of the circulating fan 3, a negative pressure area is formed near the hot air input angular pipe 2 arranged on the air flow mixing input layer 24, air is sucked from the heat preservation and moisture preservation drying layer 23 and the secondary drying layer 25, and after being collected through the first circulating hot air output bellows 15, the collected air is sent into the hot air output angular pipe 1 arranged on the low-temperature wet hot air output layer 22 through the circulating fan 3, the circulating air pipe 4 and the first circulating hot air input bellows 14, the hot air output angular pipe 1 sends wind upwards into the heat preservation and moisture preservation layer 21 and downwards into the heat preservation and moisture preservation drying layer 23, and part of the wind has a certain temperature and humidity due to the fact that the main drying layer 26, the secondary drying layer 25 and the heat preservation and moisture preservation drying layer 23, so that the grain can reach the balance among the temperature, the humidity and the moisture migration speed of the heat preservation and moisture preservation drying layer 21. The hot air enters the grain elevator 18 through the upper grain chute 19 at the top of the dryer after heat exchange between the heat-preserving and moisture-bearing tempering layer 21 and grains, then enters the grain collecting hopper 16 and the air outlet angle-shaped pipe 8 of the main drying layer 26 through the backflow air pipe 27, is collected through the air outlet box 11, is discharged into tail air treatment equipment through the transition air pipe 13 and the exhaust fan 6, and is discharged into the atmosphere.

Example 2

As shown in fig. 3 and 4, on the basis of embodiment 1, the air inlet box 9 (see fig. 3) or the air outlet box 11 (see fig. 4) is communicated with the first circulating hot air output box 15 through a first hot air branch pipe 28, and a first electric air damper 29 for controlling the hot air quantity is arranged at the joint of the first hot air branch pipe 28 and the air inlet box 9 or the air outlet box 11.

The main purpose of the electric damper is to directly supplement a part of hot air with higher temperature (without heat exchange through the drying layer) from the air inlet pipe 5 to the tempering drying layer from the air inlet box 9 to regulate the temperature of the tempering drying layer.

The main purpose of providing the electric damper on the air outlet box 11 is to directly supplement a part of warm and humid air with relatively low temperature from the drying layer (heat exchange is performed through the drying layer) from the air outlet box 11 to the tempering drying layer so as to regulate the temperature and humidity of the tempering drying layer.

In an alternative embodiment, the air inlet box 9 and the air outlet box 11 can be provided with electric air regulating doors at the same time, and are communicated with the first circulating hot air output box 15 through branch pipes, so as to realize more accurate temperature and humidity regulation.

Example 3

As shown in fig. 5, on the basis of example 1, the other end of the hot air input angular pipe 2 opposite to the one end of the first circulating hot air output blower 15 is communicated with the heat exchanger 31 through the first auxiliary hot air input blower 30. The normal temperature air in the atmosphere is heated by the heat exchanger 31, then enters the first auxiliary hot air input bellows 30 and the hot air input angular pipe 2, is mixed with the hot air from the drying layer and the air of the heat-preserving and moisture-preserving drying layer 23, and then enters the heat-preserving and moisture-preserving drying layer 23 and the heat-preserving and moisture-preserving tempering layer 21 through the first circulating hot air output bellows 15, the circulating fan 3, the circulating air pipe 4, the first circulating hot air input bellows 14 and the hot air output angular pipe 1 to form a circulation.

In an alternative embodiment, as shown in fig. 6, the heat exchanger 31 may be replaced by an external heat source 32, the external heat source 32 being in communication with the first circulating hot air output windbox 15 via a first conduit 33.

In examples 1 to 4, the amount of hot air entering the hot air input horn-shaped pipe 2 from the main drying layer 26 through the sub drying layer 25 into the air flow mixing input layer 24 depends on the negative pressure difference between the hot air input horn-shaped pipe 2 and the main drying layer 26 in the air flow mixing input layer 24, and the rotation speed of the circulating fan 3 is adjusted according to the temperature and humidity sensors provided in the circulating air pipe 4, compared with the values provided in the electronic control system, and the negative pressure difference can be adjusted, thereby adjusting the amount of hot air and heat energy entering the hot air input horn-shaped pipe 2 in the air flow mixing input layer 24, and adjusting the temperature rise amplitude of the wet hot air flow; the opening degree of the first electric damper 29, the flow rate of steam, heat transfer oil and flue gas entering the heat exchanger 31, or the fuel amount of the external heat source 32 may be adjusted to control the temperature and humidity of the hot and humid air flow within a set range, for example, 30-50 ℃ and 20% or more. After the grains are dried by the main drying layer 26, the moisture on the surface is taken away by hot air, and the grain surfaces absorb part of heat at the same time, so that the temperature is increased. An automatic control box 12 is arranged, and the temperature of the surface of the grains is controlled within a safe temperature range through detection, display and control of an on-line grain thermometer, so that high-air-quantity medium-low-temperature drying is implemented. After leaving the main drying layer 26, the grains are discharged downwards into the grain collecting hopper 16 through a stirring roller, are sent to the base of the grain lifting machine 18 through the lower grain chute 17, lifted and discharged through the lifting machine, enter the upper grain chute 19, enter the grain refining disc 20 at the top of the tower for dispersion, and enter the heat-preserving and moisture-relieving layer 21. The grains slowly flow downwards in the heat-preserving moisture tempering layer 21, and the hot air flow from the hot air output horn pipe 1 in the low-temperature wet hot air output layer 22 enters the heat-preserving moisture tempering layer 21 upwards under the combined action of the positive pressure of the circulating fan 3 and the negative pressure of the exhaust fan 6 to continuously supplement heat to the grains in the tempering layer. Because the humidity in the hot and humid air flow is higher than that of the surface of the grains in the heat preservation and moisture tempering layer 21, the surface of the grains in the tempering layer is basically not discharged, only absorbs heat and continuously transmits the heat to the inside of the grains, that is, the grains are heat preservation and tempering in the tempering layer, the inside of the grains continuously acquire heat, the internal water molecules acquire kinetic energy to increase, the migration speed to the surface of the grains increases, the water gradient and the pressure difference inside and outside the grains are reduced, the internal stress is reduced, the biochemical reaction in the grains is more normal, and the waist bursting rate, the taste value and other quality parameters are better. After passing through the heat-insulating and moisture-retaining tempering layer 21, the hot and humid air flows through the upper grain conveying device, the middle lifting seat, the lifting cylinder body, the return air pipe 27, the grain collecting hopper 16, the cooling air channel of the main drying layer 26, the air outlet box 11, the transition air pipe 13, the exhaust fan 6, the tail air sedimentation device and are discharged into the atmosphere. The grains continue to slowly descend, enter the heat-preserving and moisture-preserving drying layer 23 through the low-temperature wet hot air output layer 22, the internal and external temperatures of the grains continue to ascend within a safe setting range, and the moisture in the grains continuously migrates to the surface outwards. Because the grain particle outer surfaces are in contact with the hot and humid air stream, the rate of water removal from the grain surface is relatively slow and controlled. When the grain descends to the vicinity of the hot air inlet horn of the air flow mixing inlet layer 24, the moisture content of the grain surface rises to be significantly higher than that just entering the thermal insulation belt moisture tempering layer 21, and reaches dynamic balance with the temperature and humidity in the circulating hot and humid air flow. This stage mainly promotes the rise of the internal temperature of the grains, discharging the internal moisture. The grain continues to descend through the air flow mixing input layer 24 and into the secondary drying layer 25, which corresponds to a low air velocity counter current drying layer, drying at a low speed. The grain continues to descend into the primary drying layer 26, which has a higher hot air temperature than the five layers above (secondary drying layer 25, air mix input layer 24, insulating moisture drying layer 23, low temperature wet hot air output layer 22, insulating moisture tempering layer 21), but still in a controlled range, and which has a much higher hot air volume and a much higher air velocity than the five layers above. Because the difference value and the pressure difference between the internal and external water contents of the grains become smaller after the grains pass through the heat-preserving moisture-retaining tempering layer 21 and the heat-preserving moisture-retaining drying layer 23, the problems of overlarge moisture pressure difference and thermal stress in the process of quickly drying the grains in the main drying layer 26 are difficult to occur, and the grain has low bursting-out rate, high taste value and other quality parameters.

The whole process of the grains in the dryer is contacted with hot air, and the temperature, humidity and speed of the hot air are different in different layers and are set by people and automatically controlled, so that the drying speed of the grains is obviously improved compared with that of the prior art dryer, and the quality of the grains after drying is better.

Example 4

As shown in fig. 7, the difference from embodiment 1 is that the hot air output angular pipe 1 is provided below the hot air input angular pipe 2 in the height direction, the hot air output angular pipe 1 communicates with the air outlet of the circulation blower 3 through the second circulation hot air input bellows 34, and the hot air input angular pipe 2 communicates with the air inlet of the circulation blower 3 through the second circulation hot air output bellows 35.

In an alternative embodiment, the hot air input angular tube 2 communicates with the second circulating hot air output plenum 35 at the opposite end to one end, and communicates with the inlet plenum 9 (see FIG. 8) or the outlet plenum 11 (see FIG. 9) through a second auxiliary hot air input plenum 36. The second auxiliary hot air input air box 36 is communicated with the air inlet box 9 or the air outlet box 11 through a second hot air branch pipe 37, and a second electric air damper 38 for controlling the hot air quantity is arranged at the joint of the air inlet box 9 or the air outlet box 11 and the second hot air branch pipe 37.

In another alternative embodiment, as shown in fig. 10 and 11, the hot air input angular pipe 2 communicates with one end of the second circulating hot air output windbox 35 and the other end thereof communicates with the heat exchanger 31 (see fig. 10) or the external heat source 32 (see fig. 11) through the second auxiliary hot air input windbox 36. The second auxiliary hot air inlet bellows 36 communicates with the external heat source 32 via a second conduit 39.

Depending on the function of each drying section, the dryer may be divided into a tempering layer 40, an air flow mixing input layer 24, a heat-preserving moisture-preserving drying layer 23, a low-temperature wet hot air output layer 22, a wet hot air drying layer 41 and a main drying layer 26 from top to bottom.

The grains slowly flow down in the tempering layer 40, heat at the surface of the grains is transferred to the inside, moisture in the inside migrates to the outside, and the temperature of the surface of the grains is lowered. The grains continue to descend, enter the heat preservation and moisture preservation drying layer 23 and the low-temperature wet hot air output layer 22 through the air flow mixing input layer 24, the internal and external temperatures of the grains continuously rise within a safe setting range, and moisture in the grains continuously migrates to the surface outwards. Because the grain particle outer surfaces are in contact with the hot and humid air stream, the rate of water removal from the grain surface is relatively slow and controlled. The moisture content of the surface of the grains is increased to be obviously higher than that of the grains just entering the heat preservation and moisture preservation drying layer, and the grains reach dynamic balance with the temperature and the humidity in the circulating hot and humid air flow. This stage mainly promotes the rise in internal temperature of the grain and the migration of internal moisture outwards. The grains continue to descend and enter the wet hot air drying layer 41 along with the hot and humid air flow, and the air speed is low and the drying speed is low. The grain continues to descend into the main drying layer 26, which has a higher hot air temperature than the upper four layers (air mix input layer 24, insulation and moisture-retention drying layer 23, low temperature wet hot air output layer 22, wet hot air drying layer 41), but still within a controlled range, which has a much greater hot air volume and a much higher air velocity than the upper four layers. Because the gradient and the pressure difference of the moisture content inside and outside the grains become smaller after the grains pass through the tempering layer 40, the air flow mixing input layer 24, the heat preservation and moisture preservation drying layer 23, the low-temperature wet hot air output layer 22 and the wet hot air drying layer 41, the problems of overlarge moisture pressure difference and thermal stress in the process of quickly drying the grains in the main drying layer 26 are not easy to occur, the grain waist bursting rate is low, and the taste value and other quality parameters are high. After the grains are dried by the main drying layer 26, the moisture on the surface is taken away by hot air, and the grain surfaces absorb part of heat at the same time, so that the temperature is increased. The temperature of the grain surface can be controlled within a safe temperature range due to the detection and display of an online grain thermometer and the control of an electric control system, and the medium-low temperature drying with large air quantity is implemented. After leaving the main drying layer 26, the grains are discharged downwards into the grain collecting hopper 16 through a stirring roller, are sent to the base of the grain lifter 18 through a lower conveying device, lifted and discharged through the lifter, enter an upper conveying device, enter a grain refining disc 20 at the top of the tower for dispersion, and enter a tempering layer 40 to form a drying cycle.

Example 5

As shown in fig. 12 and 13, a dryer includes a tempering drying layer and a drying layer which are arranged in a penetrating manner from top to bottom in the height direction; the tempering drying layer is internally provided with a hot air output angular pipe 1 and a hot air input angular pipe 2, the hot air output angular pipe 1 is arranged below the hot air input angular pipe 2 along the height direction, the hot air output angular pipe 1 is communicated with the air outlet of the circulating fan 3 through a second circulating hot air input air box 34, and the hot air input angular pipe 2 is communicated with the air inlet of the circulating fan 3 through a second circulating hot air output air box 35. The grain expansion buffer area 42 is further arranged above the tempering drying layer along the height direction, and the grain expansion buffer area 42 is communicated with the air inlet box 9 (see fig. 13) or the heat exchanger 31 (see fig. 15, when the heat exchanger is connected, the third hot air branch pipe 43 can be omitted), or the external heat source 32 (see fig. 16) or the air outlet box 11 (see fig. 14) through the third hot air branch pipe 43. When the grain expansion buffer area 42 is communicated with the air inlet box 9 or the air outlet box 11 through the third hot air branch pipe 43, a third electric air damper 44 is arranged at the joint. The drying layer is provided with an air inlet pipe 5 and an air supply fan 45 for supplying air to the drying layer and an exhaust fan 6 for exhausting air from the drying layer. The drying layer is sequentially divided into a middle drying layer 46, a middle tempering layer 47 and a lower drying layer 48 from top to bottom along the height direction, an air inlet horn-shaped pipe 7 and an air outlet horn-shaped pipe 8 are arranged in the middle drying layer 46 and the lower drying layer 48, the air inlet horn-shaped pipe 7 is communicated with the air inlet pipe 5 through an air inlet box 9, and the air outlet horn-shaped pipe 8 is communicated with the exhaust fan 6 through an air outlet box 11.

Depending on the function of each drying section, the dryer may be divided from top to bottom into a grain expansion buffer zone 42, an upper drying layer 49, an air flow mixing input layer 24, a heat-retaining moisture-retaining drying layer 23, a low-temperature wet hot air output layer 22, a wet hot air drying layer 41, an intermediate drying layer 46, an intermediate tempering layer 47, and a lower drying layer 48.

The grains are lifted by a lifting machine, sent to the top of the tower by an upper grain conveying device, scattered into an upper drying layer 49 by a refining device, contacted with downward flowing low-speed hot air, the heat of the hot air is transferred to the grains, and the moisture on the surfaces of grains absorbs the heat to raise the temperature and become water vapor; the heat on the surface of the cereal grains is transferred to the inside, and the moisture in the inside migrates to the outside. The grains continue to descend, enter the heat preservation and moisture preservation drying layer 23 and the low-temperature and humidity hot air output layer 22 in sequence through the air flow mixing input layer 24, the internal and external temperatures of the grains continuously rise within a safe setting range, and the moisture in the grains continuously migrates to the surface outwards. Because the grain particle outer surfaces are in contact with the hot and humid air stream, the rate of water removal from the grain surface is relatively slow and controlled. The moisture content of the surface of the grains rises to be obviously higher than that of the grains just entering the heat preservation and moisture preservation drying layer 23, and reaches dynamic balance with the temperature and the humidity in the circulating hot and humid air flow. This stage mainly promotes the rise in internal temperature of the grain and the migration of internal moisture outwards. The grains continue to descend and enter the wet hot air drying layer 41 along with the hot and humid air flow, and the air speed is low and the drying speed is low. The grain continues to descend into the intermediate drying layer 46 and the hot air blown from the inlet angled tube 7 of the intermediate drying layer 46 passes through the grain layer in a variety of directions of movement, transferring heat to the grain. The moisture on the surface of the grain particles absorbs heat to raise the temperature and become water vapor, and the surface of the grain particles absorbs heat to continuously raise the temperature. After the hot air gives off heat, water vapor and dust are taken away at a medium speed, enter the air outlet horn pipe 8 of the intermediate drying layer 46, enter the air outlet box 11 from the air outlet, enter tail air treatment equipment through the exhaust fan 6 and the air outlet pipe, and are discharged into the atmosphere. The hot air temperature of the layer is higher than that of the upper four layers (the air flow mixing input layer 24, the heat preservation and moisture preservation drying layer 23, the low-temperature wet hot air output layer 22 and the wet hot air drying layer 41), but the hot air quantity of the layer is still in a controlled range, and the hot air quantity of the layer is much larger than that of the upper four layers, and the air speed is much higher. In the intermediate drying layer 46, the grain temperature continues to rise with moderate drying rates. Because the gradient and pressure difference of the moisture content inside and outside the grains become smaller after the grains pass through the air flow mixing input layer 24, the heat preservation and moisture preservation drying layer 23, the low-temperature wet hot air output layer 22 and the wet hot air drying layer 41, the problems of excessive moisture pressure difference and thermal stress are not easy to occur in the process of faster drying the grains in the middle drying layer 46. The grains continue to descend into the intermediate tempering layer 47, the heat from the grain surface is transferred to the inside, and the moisture from the inside migrates to the outside, making a mat for the grains to dry better in the lower drying layer. The grains continue to descend into the lower drying layer 48 and the hot air blown from the inlet angled tube 7 of the lower drying layer 48 passes through the grain layer in various directions of movement, transferring heat to the grains. The moisture on the surface of the grain particles absorbs heat to raise the temperature and become water vapor, and the surface of the grain particles absorbs heat to continuously raise the temperature. After the hot air gives off heat, water vapor and dust are taken away at a medium speed, enter the air outlet horn pipe 8 of the intermediate drying layer 46, enter the air outlet box 11 from the air outlet, enter tail air treatment equipment through the exhaust fan 6 and the air outlet pipe, and are discharged into the atmosphere. In the lower drying layer 48, the grain temperature continues to rise with moderate drying rates. The grains continue to descend into the material splitting hopper, are discharged downwards through the material stirring roller discharging device, enter the grain collecting hopper 16, are fed into the grain lifting machine 18 through the lower conveying device, finish the primary drying process, and reduce the moisture of the grains by a certain value. And (3) after repeated cyclic drying, the water content of the grains is reduced to a set value, and drying is finished.

At the beginning and end of grain harvesting, there may be instances where the harvested grain is not sufficiently filled with the dryer. In view of this, the present application is structured to close the electric damper (or to close the heat source valve of the heat exchanger, or to close the external hot air source) for on-air drying as long as the grain load reaches the top of the wet hot air drying layer 41, i.e., covers the intermediate drying layer 46 with some margin to compensate for the shrinkage after grain drying. The temperature of hot air is reduced to a temperature value for drying seeds, the hot air enters an air inlet box 9 through an air inlet pipe 5 and an air supply fan 45, then horizontally enters an air inlet horn-shaped pipe 7 of an intermediate drying layer 46 and a lower drying layer 48, passes through a grain layer in various movement directions, transfers heat to grains, takes away water vapor and dust, enters an air outlet horn-shaped pipe 8 of the intermediate drying layer 46 and the lower drying layer 48, enters an air outlet box 11 from an air outlet of the air outlet, enters tail air treatment equipment through an exhaust fan 6 and an air outlet pipe, and is discharged into the atmosphere. The grains descend into the material splitting hopper, are discharged downwards through the stirring roller discharging device, enter the grain collecting hopper 16, are fed into the grain lifting machine 18 through the lower conveying device, finish the primary drying process, and reduce the moisture of the grains by a certain value. And (3) after repeated cyclic drying, the water content of the grains is reduced to a set value, and drying is finished.

Example 6

As shown in fig. 17, the difference from embodiment 1 is that a screen plate 50 is provided in the drying layer, the screen plate 50 constitutes a hot air passage 51, a cold air passage 52 and a grain passage 53 alternately provided in this order, the hot air passage 51 communicates with the air inlet box 9, and the cold air passage 52 communicates with the air outlet box 11.

It should be noted that, in embodiments 2 to 5, the same screen plate may be disposed in the drying layer to form a hot air channel, a cold air channel and a grain channel, so as to replace the air inlet angular tube and the air outlet angular tube.

When the dryer is used, hot air is fed into the hot air channel 51 through the air inlet box 9, then enters the grain channel 53 through the sieve holes on the sieve plate 50, grains enter the grain channel 53 from top to bottom through the tempering drying layer, heat exchange occurs between the grains and the hot air, the grains enter the grain collecting hopper 16, the temperature of the hot air is reduced, the hot air enters the cold air channel 52 through the sieve holes of the sieve plate 50, and then is collected through the air outlet box 11, and the hot air is discharged out of the dryer under the action of the exhaust fan 6. The gas flows in a cross-flow manner in the drying layer and exchanges heat.

In a preferred embodiment, to avoid accumulation of grain on top of the screen 50 as it enters the grain channel 53, the top end of the screen 50 is provided with a rim guide slide 54 and a middle guide angle slide 55, and the rim guide slide 54 and the middle guide angle slide 55 are each provided with an air outlet. This arrangement also contributes to an increase in heat exchange area. In an alternative embodiment, the lower cereal chute 17 may be replaced with other conveying means 56, such as a feeding auger.

Example 7

In another alternative embodiment, as shown in fig. 18, the difference from example 6 is the arrangement of the hot air passage 51, the cold air passage 52 and the grain passage 53, and the number of layers of the inlet horn 7 and the outlet horn 8. In the drying layer, a hot air passage 51 is provided at the outermost side, and a grain passage 53, a cold air passage 52 and a hot air passage 51 are alternately provided in this order at the intermediate position.

The tempering layer is improved, and the original low-temperature cooling tempering process is changed into a heat-preserving and moisture-preserving tempering process. At relatively higher temperature, the speed of the migration of the moisture in the grains to the surface is improved, tempering efficiency is improved, tempering time is shortened, drying efficiency is improved, the moisture migration channel in the grains is not damaged, and the rise of the bursting waist rate is avoided. In each drying tempering cycle, heat preservation, moisture preservation and tempering are adopted, the internal temperature of the grains rises faster, tempering efficiency is improved, and tempering time is reduced to about one fourth to one half of the whole period. With multi-layer drying, the drying time is lengthened to about one-half to three-quarters of the total cycle. In longer drying time, the low-temperature drying with larger air quantity and medium low air speed is adopted, so that the evaporation speed of the moisture on the surface of the grain is reduced, the migration speed of the moisture in the grain to the surface is close, the internal and external moisture gradient and pressure difference of the grain are reduced, the internal stress of the grain is reduced, the value and the crack rate of the burst waist rate are increased, the germination rate is not reduced, and the quality parameters such as the taste value, the appearance and the processing performance are better. The dryer provided by the application can also be used for drying seeds, the germination rate is not reduced, and the drying rate reaches 0.9% -1.3%.

While particular embodiments of the present invention have been illustrated and described, it will be appreciated that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

1. A dryer, comprising:

the tempering drying layer is arranged above the drying layer and is communicated with the drying layer;

an air inlet horn-shaped pipe and an air outlet horn-shaped pipe are arranged in the drying layer, the air inlet horn-shaped pipe is communicated with the air inlet pipe through an air inlet box, and the air outlet horn-shaped pipe is communicated with the exhaust fan through an air outlet box; or,

a sieve plate is arranged in the drying layer, the sieve plate forms a hot air channel, a cold air channel and a grain channel which are alternately arranged in sequence, the hot air channel is communicated with the air inlet box, and the cold air channel is communicated with the air outlet box;

the hot air output angular pipe is arranged above the hot air input angular pipe, the hot air output angular pipe is communicated with an air outlet of the circulating fan through a first circulating hot air input bellows, and the hot air input angular pipe is communicated with an air inlet of the circulating fan through a first circulating hot air output bellows;

the first circulating hot air output air box is communicated with the air inlet box or the air outlet box through a first hot air branch pipe, and a first electric air regulating door for controlling hot air quantity is arranged at the joint of the air inlet box or the air outlet box and the first hot air branch pipe;

one end of the hot air input angular pipe, which is far away from the first circulating hot air output air box, is communicated with a heat exchanger or an external heat source through an auxiliary hot air input air box.

2. The dryer of claim 1, further comprising a grain collection hopper, a lower grain chute, a grain elevator, an upper grain chute, and a grain refining tray; the grain collecting hopper is arranged below the drying layer and is communicated with the lower end of the grain lifting machine through the lower grain chute; the feeding end of the upper cereal chute is communicated with the upper end of the cereal lifting machine; the grain homogenizing tray is arranged at the discharge end of the upper grain chute and is used for uniformly distributing grains in the tempering drying layer.

3. A dryer, comprising:

the hot air output angular pipe is arranged below the hot air input angular pipe, the hot air output angular pipe is communicated with an air outlet of the circulating fan through a second circulating hot air input bellows, and the hot air input angular pipe is communicated with an air inlet of the circulating fan through a second circulating hot air output bellows;

the dryer also comprises a heat exchanger or an external heat source, and one end of the hot air input angular pipe far away from the second circulating hot air output air box is communicated with the air inlet box, the heat exchanger, the external heat source or the air outlet box through a second auxiliary hot air input air box; the second circulating hot air output air box is communicated with the air inlet box or the air outlet box through a second hot air branch pipe, and a second electric air damper for controlling hot air quantity is arranged at the joint of the air inlet box or the air outlet box and the second hot air branch pipe;

the dryer also comprises a heat exchanger or an external heat source, a grain expansion buffer area is further arranged above the tempering drying layer, and the grain expansion buffer area is communicated with the air inlet box, the heat exchanger, the external heat source or the air outlet box through a third hot air branch pipe.

4. A dryer according to claim 3, wherein the drying layer is divided into a middle drying layer, a middle tempering layer and a lower drying layer in sequence from top to bottom, and the inlet and outlet horns are located in the middle and lower drying layers.

5. The dryer of claim 3 or 4, further comprising a grain collection hopper, a lower grain chute, a grain elevator, an upper grain chute, and a grain refining tray; the grain collecting hopper is arranged below the drying layer and is communicated with the lower end of the grain lifting machine through the lower grain chute; the feeding end of the upper cereal chute is communicated with the upper end of the cereal lifting machine; the grain homogenizing tray is arranged at the discharge end of the upper grain chute and is used for uniformly distributing grains in the tempering drying layer.